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Sample records for anopheles funestus species

  1. Thermal limits of wild and laboratory strains of two African malaria vector species, Anopheles arabiensis and Anopheles funestus

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    Lyons Candice L

    2012-07-01

    Full Text Available Abstract Background Malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. As climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. Despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves. Methods Using a ramping protocol (to assess critical thermal limits - CT and plunge protocol (to assess lethal temperature limits - LT information on the thermal tolerance of two of Africa’s important malaria vectors, Anopheles arabiensis and Anopheles funestus was collected. The effects of age, thermal acclimation treatment, sex and strain (laboratory versus wild adults were investigated for CT determinations for each species. The effects of age and sex for adults and life stage (larvae, pupae, adults were investigated for LT determinations. Results In both species, females are more tolerant to low and high temperatures than males; larvae and pupae have higher upper lethal limits than do adults. Thermal acclimation of adults has large effects in some instances but small effects in others. Younger adults tend to be more tolerant of low or high temperatures than older age groups. Long-standing laboratory colonies are sufficiently similar in thermal tolerance to field-collected animals to provide reasonable surrogates when making inferences about wild population responses. Differences between these two vectors in their thermal tolerances, especially in larvae and pupae, are plausibly a consequence of different habitat utilization. Conclusions Limited plasticity is characteristic of the adults of these vector species relative to others examined to date, suggesting limited scope for within-generation change in thermal tolerance. These findings and the greater tolerance

  2. Sibling species of the Anopheles funestus group, and their infection with malaria and lymphatic filarial parasites, in archived and newly collected specimens from northeastern Tanzania

    DEFF Research Database (Denmark)

    Derua, Yahya A; Alifrangis, Michael; Magesa, Stephen M;

    2015-01-01

    vectors of both malaria and lymphatic filariasis. METHODS: Archived (from 2005-2012) and newly collected (from 2014) specimens of the An. funestus group collected indoors using CDC light traps in villages in northeastern Tanzania were analysed. They were identified to sibling species by PCR based......, and Anopheles leesoni, with the first being by far the most common (overall 94.4%). When comparing archived specimens from 2005-2007 to those from 2008-2012, a small but statistically significant decrease in proportion of An. funestus s.s. was noted, but otherwise observed temporal changes in sibling species...... composition were minor. No P. falciparum was detected in archived specimens, while 8.3% of the newly collected An. funestus s.s. were positive for this parasite. The overall W. bancrofti infection rate decreased from 14.8% in the 2005-2007 archived specimens to only 0.5% in the newly collected specimens...

  3. [Anopheles funestus and rice agriculture in the Madagascar highlands].

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    Marrama, L; Rajaonarivelo, E; Laventure, S; Rabarison, P

    1995-01-01

    An exhaustive study of the potential habitats of Anopheles funestus was led during 1992 in Ankazobe on the Plateau of Madagascar, 95 km northwest of the capital Tananarive. The rice fields provide more than 90% of the positive habitats versus less than 10% for the nonhuman biotopes. Larva are especially abundant on the surfaces of the rice during grain head formation and maturation. The dense vegetation coverage provides them with shade and protection against predators. After harvesting, the follows can be filled with water and wild vegetation, and then also provide an important share of the habitats. The rice fields are omnipresent on the Plateau where they supply the basis of local alimentation. A. funestus then constitutes a serious risk for all of the villages. The role of the rice fields as habitats for A. funestus has already been noted in Kenya but in West Africa the rice fields do not host this species, even if this species is very abundant in the other types of habitats.

  4. Pyrethroid resistance in an Anopheles funestus population from Uganda.

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    John C Morgan

    Full Text Available BACKGROUND: The susceptibility status of Anopheles funestus to insecticides remains largely unknown in most parts of Africa because of the difficulty in rearing field-caught mosquitoes of this malaria vector. Here we report the susceptibility status of the An. funestus population from Tororo district in Uganda and a preliminary characterisation of the putative resistance mechanisms involved. METHODOLOGY/PRINCIPAL FINDINGS: A new forced egg laying technique used in this study significantly increased the numbers of field-caught females laying eggs and generated more than 4000 F1 adults. WHO bioassays indicated that An. funestus in Tororo is resistant to pyrethroids (62% mortality after 1 h exposure to 0.75% permethrin and 28% mortality to 0.05% deltamethrin. Suspected DDT resistance was also observed with 82% mortality. However this population is fully susceptible to bendiocarb (carbamate, malathion (organophosphate and dieldrin with 100% mortality observed after exposure to each of these insecticides. Sequencing of a fragment of the sodium channel gene containing the 1014 codon conferring pyrethroid/DDT resistance in An. gambiae did not detect the L1014F kdr mutation but a correlation between haplotypes and resistance phenotype was observed indicating that mutations in other exons may be conferring the knockdown resistance in this species. Biochemical assays suggest that resistance in this population is mediated by metabolic resistance with elevated level of GSTs, P450s and pNPA compared to a susceptible strain of Anopheles gambiae. RT-PCR further confirmed the involvement of P450s with a 12-fold over-expression of CYP6P9b in the Tororo population compared to the fully susceptible laboratory colony FANG. CONCLUSION: This study represents the first report of pyrethroid/DDT resistance in An. funestus from East Africa. With resistance already reported in southern and West Africa, this indicates that resistance in An. funestus may be more widespread

  5. Vectorial status and insecticide resistance of Anopheles funestus from a sugar estate in southern Mozambique

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    Nhamahanga Eduardo

    2011-02-01

    Full Text Available Abstract Background The dual problems of rising insecticide resistance in the malaria vectors and increasing human malaria cases since 2001 in southern Mozambique are cause for serious concern. The selection of insecticides for use in indoor residual spraying (IRS programmes is highly dependent on the extent to which local mosquitoes are susceptible to the approved classes of insecticides. The insecticide resistance status and role in malaria transmission of Anopheles funestus was evaluated at the Maragra Sugar Estate in southern Mozambique where an IRS vector control programme has been in operation for seven years using the carbamate insecticide bendiocarb. Results No Anopheles species were captured inside the sugar estate control area. Anopheles funestus group captured outside of the estate represented 90% (n = 475 of the total collections. Of the specimens identified to species by PCR (n = 167, 95% were An. funestus s.s. One An. rivulorum was identified and seven specimens did not amplify. The Anopheles gambiae complex was less abundant (n = 53 and of those identified (n = 33 76% were An. arabiensis and 24% An. merus. Insecticide susceptibility tests showed that wild-caught and F-1 family An. funestus were resistant to deltamethrin (32.5% mortality and lambda-cyhalothrin (14.6% mortality, less so to bendiocarb (71.5% mortality and fully susceptible to both malathion and DDT (100%. Bendiocarb and pyrethroid resistance was nullified using 4% piperonyl butoxide (Pbo, strongly suggesting that both are mediated by P450 monooxygenase detoxification. ELISA tests of An. funestus for Plasmodium falciparum, gave a sporozoite rate of 6.02% (n = 166. One unidentified member of the An. gambiae complex tested positive for P. falciparum sporozoites. Conclusion Anopheles funestus was found to be the most abundant and principle vector of malaria in this area, with members of the An. gambiae complex being secondary vectors. Despite the continual use of

  6. Cuticle thickening associated with pyrethroid resistance in the major malaria vector Anopheles funestus

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    Coetzee M

    2010-08-01

    Full Text Available Abstract Background Malaria in South Africa is primarily transmitted by Anopheles funestus Giles. Resistance to pyrethroid insecticides in An. funestus in northern Kwazulu/Natal, South Africa, and in neighbouring areas of southern Mozambique enabled populations of this species to increase their ranges into areas where pyrethroids were being exclusively used for malaria control. Pyrethroid resistance in southern African An. funestus is primarily conferred by monooxygenase enzyme metabolism. However, selection for this resistance mechanism is likely to have occurred in conjunction with other factors that improve production of the resistance phenotype. A strong candidate is cuticle thickening. This is because thicker cuticles lead to slower rates of insecticide absorption, which is likely to increase the efficiency of metabolic detoxification. Results Measures of mean cuticle thickness in laboratory samples of female An. funestus were obtained using scanning electron microscopy (SEM. These females were drawn from a laboratory colony carrying the pyrethroid resistance phenotype at a stable rate, but not fixed. Prior to cuticle thickness measurements, these samples were characterised as either more or less tolerant to permethrin exposure in one experiment, and either permethrin resistant or susceptible in another experiment. There was a significant and positive correlation between mean cuticle thickness and time to knock down during exposure to permethrin. Mean cuticle thickness was significantly greater in those samples characterised either as more tolerant or resistant to permethrin exposure compared to those characterised as either less tolerant or permethrin susceptible. Further, insecticide susceptible female An. funestus have thicker cuticles than their male counterparts. Conclusion Pyrethroid tolerant or resistant An. funestus females are likely to have thicker cuticles than less tolerant or susceptible females, and females generally have

  7. Spatial distribution, blood feeding pattern, and role of Anopheles funestus complex in malaria transmission in central Kenya.

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    Muturi, Ephantus J; Kamau, Luna; Jacob, Benjamin G; Muriu, Simon; Mbogo, Charles M; Shililu, Josephat; Githure, John; Novak, Robert J

    2009-10-01

    Studies were conducted to determine the role of sibling species of Anopheles funestus complex in malaria transmission in three agro-ecosystems in central Kenya. Mosquitoes were sampled indoors and outdoors, and rDNA PCR was successfully used to identify 340 specimens. Anopheles parensis (91.8%), A. funestus (6.8%), and Anopheles leesoni (1.5%) were the three sibling species identified. A. parensis was the dominant species at all study sites, while 22 of 23 A. funestus were collected in the non-irrigated study site. None of the 362 specimens tested was positive for Plasmodium falciparum circumsporozoite proteins by enzyme-linked immunosorbent assay. The most common blood-meal sources (mixed blood meals included) for A. parensis were goat (54.0%), human (47.6%), and bovine (39.7%), while the few A. funestus s.s. samples had fed mostly on humans. The human blood index (HBI) for A. parensis (mixed blood meals included) in the non-irrigated agro-ecosystem was 0.93 and significantly higher than 0.33 in planned rice agro-ecosystem. The few samples of A. funestus s.s. and A. funestus s.l. also showed a trend of higher HBI in the non-irrigated agro-ecosystem. We conclude that agricultural practices have significant influence on distribution and blood feeding behavior of A. funestus complex. Although none of the species was implicated with malaria transmission, these results may partly explain why non-irrigated agro-ecosystems are associated with higher risk of malaria transmission by this species compared to irrigated agro-ecosystems.

  8. Comparative performance of the Mbita trap, CDC light trap and the human landing catch in the sampling of Anopheles arabiensis, An. funestus and culicine species in a rice irrigation in western Kenya

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    Ndegwa Paul N

    2005-01-01

    Full Text Available Abstract Background Mosquitoes sampling is an important component in malaria control. However, most of the methods used have several shortcomings and hence there is a need to develop and calibrate new methods. The Mbita trap for capturing host-seeking mosquitoes was recently developed and successfully tested in Kenya. However, the Mbita trap is less effective at catching outdoor-biting Anopheles funestus and Anopheles arabiensis in Madagascar and, thus, there is need to further evaluate this trap in diverse epidemiological settings. This study reports a field evaluation of the Mbita trap in a rice irrigation scheme in Kenya Methods The mosquito sampling efficiency of the Mbita trap was compared to that of the CDC light trap and the human landing catch in western Kenya. Data was analysed by Bayesian regression of linear and non-linear models. Results The Mbita trap caught about 17%, 60%, and 20% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in sampling proportionality between the Mbita trap and the human landing catch for both An. arabiensis and the culicine species. For An. funestus, the Mbita trap portrayed some density-dependent sampling efficiency that suggested lowered sampling efficiency of human landing catch at low densities. The CDC light trap caught about 60%, 120%, and 552% of the number of An. arabiensis, An. funestus, and culicine species caught in the human landing collections respectively. There was consistency in the sampling proportionality between the CDC light trap and the human landing catch for both An. arabiensis and An. funestus, whereas for the culicines, there was no simple relationship between the two methods. Conclusions The Mbita trap is less sensitive than either the human landing catch or the CDC light trap. However, for a given investment of time and money, it is likely to catch more mosquitoes over a longer (and hence

  9. Identification and analysis of Single Nucleotide Polymorphisms (SNPs in the mosquito Anopheles funestus, malaria vector

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    Hemingway Janet

    2007-01-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are the most common source of genetic variation in eukaryotic species and have become an important marker for genetic studies. The mosquito Anopheles funestus is one of the major malaria vectors in Africa and yet, prior to this study, no SNPs have been described for this species. Here we report a genome-wide set of SNP markers for use in genetic studies on this important human disease vector. Results DNA fragments from 50 genes were amplified and sequenced from 21 specimens of An. funestus. A third of specimens were field collected in Malawi, a third from a colony of Mozambican origin and a third form a colony of Angolan origin. A total of 494 SNPs including 303 within the coding regions of genes and 5 indels were identified. The physical positions of these SNPs in the genome are known. There were on average 7 SNPs per kilobase similar to that observed in An. gambiae and Drosophila melanogaster. Transitions outnumbered transversions, at a ratio of 2:1. The increased frequency of transition substitutions in coding regions is likely due to the structure of the genetic code and selective constraints. Synonymous sites within coding regions showed a higher polymorphism rate than non-coding introns or 3' and 5'flanking DNA with most of the substitutions in coding regions being observed at the 3rd codon position. A positive correlation in the level of polymorphism was observed between coding and non-coding regions within a gene. By genotyping a subset of 30 SNPs, we confirmed the validity of the SNPs identified during this study. Conclusion This set of SNP markers represents a useful tool for genetic studies in An. funestus, and will be useful in identifying candidate genes that affect diverse ranges of phenotypes that impact on vector control, such as resistance insecticide, mosquito behavior and vector competence.

  10. High level of pyrethroid resistance in an Anopheles funestus population of the Chokwe District in Mozambique.

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    Nelson Cuamba

    Full Text Available BACKGROUND: Although Anopheles funestus is difficult to rear, it is crucial to analyse field populations of this malaria vector in order to successfully characterise mechanisms of insecticide resistance observed in this species in Africa. In this study we carried out a large-scale field collection and rearing of An. funestus from Mozambique in order to analyse its susceptibility status to insecticides and to broadly characterise the main resistance mechanisms involved in natural populations. METHODOLOGY/PRINCIPAL FINDINGS: 3,000 F(1 adults were obtained through larval rearing. WHO susceptibility assays indicated a very high resistance to pyrethroids with no mortality recorded after 1 h 30 min exposure and less than 50% mortality at 3 h 30 min. Resistance to the carbamate, bendiocarb was also noted, with 70% mortality after 1h exposure. In contrast, no DDT resistance was observed, indicating that no kdr-type resistance was involved. The sequencing of the acetylcholinesterase gene indicated the absence of the G119S and F455W mutations associated with carbamate and organophosphate resistance. This could explain the absence of malathion resistance in this population. Both biochemical assays and quantitative PCR implicated up-regulated P450 genes in pyrethroid resistance, with GSTs playing a secondary role. The carbamate resistance observed in this population is probably conferred by the observed altered AChE with esterases also involved. CONCLUSION/SIGNIFICANCE: The high level of pyrethroid resistance in this population despite the cessation of pyrethroid use for IRS in 1999 is a serious concern for resistance management strategies such as rotational use of insecticides. As DDT has now been re-introduced for IRS, susceptibility to DDT needs to be closely monitored to prevent the appearance and spread of resistance to this insecticide.

  11. Pyrethroid resistance in southern African Anopheles funestus extends to Likoma Island in Lake Malawi

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    Edwardes M

    2010-12-01

    Full Text Available Abstract Background A mosquito survey was carried out on the island of Likoma in Lake Malawi with a view to collecting baseline data to determine the feasibility of implementing an integrated malaria vector control programme. No vector control interventions are currently being applied on the island apart from the sporadic use of treated and untreated bed nets. Results Large numbers of Anopheles funestus were found resting inside houses. WHO susceptibility tests were carried out on wild caught females and 1-5 day old F-1 female progeny. Wild caught females were tested on deltamethrin (77.8% mortality and bendiocarb (56.4% mortality. Female progeny were tested on deltamethrin (41.4% mortality, permethrin (40.4%, bendiocarb (52.5%, propoxur (7.4%, malathion, fenitrothion, DDT, dieldrin (all 100% and pirimiphos-methyl (98.9%. The malaria parasite rate was 4.9%. A small number of Anopheles arabiensis were also collected. Conclusion This locality is 1,500 km north of the currently known distribution of pyrethroid resistant An. funestus in southern Africa. The susceptibility results mirror those found in southern Mozambique and South African populations, but are markedly different to An. funestus populations in Uganda, indicating that the Malawi resistance has spread from the south.

  12. Studies on the bionomics of male Anopheles gambiae Giles and male Anopheles funestus Giles from southern Mozambique.

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    Charlwood, J D

    2011-12-01

    Little is known about the fitness of wild male mosquitoes, the females of which are vectors of malaria. The problem of studying male biology has been exacerbated by difficulties associated with catching them. In southern Mozambique, however, almost the entire adult population of An. funestus and An. gambiae s.l. rest inside houses. They leave in a dusk exodus, which makes them easy to collect. In 8,348 exit collections from a village from 2003 to 2009, 567,195 male An. funestus and 34,591 male An. gambiae s.l. were collected. During the study, numbers of An. funestus increased but numbers of An. gambiae s.l. declined to the point of extinction. Overall numbers of An. gambiae s.l. were positively correlated with temperature, whilst the relationship between temperature and numbers of An. funestus changed from an initially positive one in the first three years of the study to a negative one in the last three years. Marked males were recaptured up to 300 m from the release site, with most recaptures occurring within 150 m. Estimated mean daily survival of male An. funestus was 0.86 (95% C.I. 0.869-0.850). For the years 2003-2007, estimated mean daily survival of male An gambiae s.l. was 0.660 (95% C.I. 0.682-0.638). For either species, there was no relationship between mean weekly temperature and estimated daily survival. These results imply that males of An. funestus live as long as females but have a relatively short flight range. They are discussed in the light of possible release strategies of sterile or genetically modified mosquitoes.

  13. Recent reduction in the water level of Lake Victoria has created more habitats for Anopheles funestus

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    Futami Kyoko

    2008-07-01

    Full Text Available Abstract Background The water level of Lake Victoria has fallen more than 1.5 m since 1998, revealing a narrow strip of land along the shore. This study determined whether the recent drop in the water level has created additional breeding grounds for malaria vectors. Methods The recent and past shorelines were estimated using landmarks and a satellite image. The locations of breeding habitats were recorded using a GPS unit during the high and low lake water periods. GIS was used to determine whether the breeding habitats were located on newly emerged land between the new and old shorelines. Results Over half of the breeding habitats existed on newly emerged land. Fewer habitats for the Anopheles gambiae complex were found during the low water level period compared to the high water period. However, more habitats for Anopheles funestus were found during the high water level period, and they were all located on the newly emerged land. Conclusion The recent reduction in water level of Lake Victoria has increased the amount of available habitat for A. funestus. The results suggest that the water drop has substantially affected the population of this malaria vector in the Lake Victoria basin, particularly because the lake has a long shoreline that may harbour many new breeding habitats.

  14. The Role of Oxidative Stress in the Longevity and Insecticide Resistance Phenotype of the Major Malaria Vectors Anopheles arabiensis and Anopheles funestus.

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    Shüné V Oliver

    Full Text Available Oxidative stress plays numerous biological roles, both functional and pathological. The role of oxidative stress in various epidemiologically relevant biological traits in Anopheles mosquitoes is not well established. In this study, the effects of oxidative stress on the longevity and insecticide resistance phenotype in the major malaria vector species An. arabiensis and An. funestus were examined. Responses to dietary copper sulphate and hydrogen peroxide were used as proxies for the oxidative stress phenotype by determining the effect of copper on longevity and hydrogen peroxide lethal dose. Glutathione peroxidase and catalase activities were determined colorimetrically. Oxidative burden was quantified as protein carbonyl content. Changes in insecticide resistance phenotype were monitored by WHO bioassay. Insecticide resistant individuals showed an increased capacity for coping with oxidative stress, mediated by increased glutathione peroxidase and catalase activity. This effect was observed in both species, as well as in laboratory strains and F1 individuals derived from wild-caught An. funestus mothers. Phenotypic capacity for coping with oxidative stress was greatest in strains with elevated Cytochrome P450 activity. Synergism of oxidative stress defence enzymes by dietary supplementation with haematin, 3-Amino-1, 2, 4-triazole and Sodium diethyldithiocarbamate significantly increased pyrethroid-induced mortality in An. arabiensis and An. funestus. It is therefore concluded that defence against oxidative stress underlies the augmentation of the insecticide resistance phenotype associated with multiple blood-feeding. This is because multiple blood-feeding ultimately leads to a reduction of oxidative stress in insecticide resistant females, and also reduces the oxidative burden induced by DDT and pyrethroids, by inducing increased glutathione peroxidase activity. This study highlights the importance of oxidative stress in the longevity and

  15. African water storage pots for the delivery of the Entomopathogenic fungus Metarhizium anisopliae to the Malaria vectors Anopheles gambiae s.s. and Anopheles funestus

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    Farenhorst, M.; Farina, D.; Scholte, E.J.; Takken, W.; Hunt, R.H.; Coetzee, M.; Knols, B.G.J.

    2008-01-01

    We studied the use of African water storage pots for point source application of Metarhizium anisopliae against the malaria vectors Anopheles gambiae s.s. and An. funestus. Clay pots were shown to be attractive resting sites for male and female An. gambiae s.s. and were not repellent after impregnat

  16. Multiple Insecticide Resistance in the Malaria Vector Anopheles funestus from Northern Cameroon Is Mediated by Metabolic Resistance Alongside Potential Target Site Insensitivity Mutations

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    Menze, Benjamin D.; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Antonio-Nkondjio, Christophe; Awono-Ambene, Parfait H.; Wondji, Charles S.

    2016-01-01

    Background Despite the recent progress in establishing the patterns of insecticide resistance in the major malaria vector Anopheles funestus, Central African populations of this species remain largely uncharacterised. To bridge this important gap and facilitate the implementation of suitable control strategies against this vector, we characterised the resistance patterns of An. funestus population from northern Cameroon. Methods and Findings Collection of indoor-resting female mosquitoes in Gounougou (northern Cameroon) in 2012 and 2015 revealed a predominance of An. funestus during dry season. WHO bioassays performed using F1 An. funestus revealed that the population was multiple resistant to several insecticide classes including pyrethroids (permethrin, deltamethrin, lambda-cyhalothrin and etofenprox), carbamates (bendiocarb) and organochlorines (DDT and dieldrin). However, a full susceptibility was observed against the organophosphate malathion. Bioassays performed with 2015 collection revealed that resistance against pyrethroids and DDT is increasing. PBO synergist assays revealed a significant recovery of susceptibility for all pyrethroids but less for DDT. Analysis of the polymorphism of a portion of the voltage-gated sodium channel gene (VGSC) revealed the absence of the L1014F/S kdr mutation but identified 3 novel amino acid changes I877L, V881L and A1007S. However, no association was established between VGSC polymorphism and pyrethroid/DDT resistance. The DDT resistant 119F-GSTe2 allele (52%) and the dieldrin resistant 296S-RDL allele (45%) were detected in Gounougou. Temporal analysis between 2006, 2012 and 2015 collections revealed that the 119F-GSTe2 allele was relatively stable whereas a significant decrease is observed for 296S-RDL allele. Conclusion This multiple resistance coupled with the temporal increased in resistance intensity highlights the need to take urgent measures to prolong the efficacy of current insecticide-based interventions against

  17. Molecular tools for studying the major malaria vector Anopheles funestus: improving the utility of the genome using a comparative poly(A) and Ribo-Zero RNAseq analysis

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    WEEDALL, GARETH D.; Irving, Helen; Hughes, Margaret A.; Wondji, Charles S.

    2015-01-01

    Background Next-generation sequencing (NGS) offers great opportunities for studying the biology of insect vectors of disease. Prerequisites for successful analyses include high quality annotated genome assemblies and that techniques designed for use with model organisms be tested and optimised for use with these insects. We aimed to test and improve genomic tools for studying the major malaria vector Anopheles funestus. Results To guide future RNAseq transcriptomic studies of An. funestus, we...

  18. Wide cross-reactivity between Anopheles gambiae and Anopheles funestus SG6 salivary proteins supports exploitation of gSG6 as a marker of human exposure to major malaria vectors in tropical Africa

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    Petrarca Vincenzo

    2011-07-01

    Full Text Available Abstract Background The Anopheles gambiae gSG6 is an anopheline-specific salivary protein which helps female mosquitoes to efficiently feed on blood. Besides its role in haematophagy, gSG6 is immunogenic and elicits in exposed individuals an IgG response, which may be used as indicator of exposure to the main African malaria vector A. gambiae. However, malaria transmission in tropical Africa is sustained by three main vectors (A. gambiae, Anopheles arabiensis and Anopheles funestus and a general marker, reflecting exposure to at least these three species, would be especially valuable. The SG6 protein is highly conserved within the A. gambiae species complex whereas the A. funestus homologue, fSG6, is more divergent (80% identity with gSG6. The aim of this study was to evaluate cross-reactivity of human sera to gSG6 and fSG6. Methods The A. funestus SG6 protein was expressed/purified and the humoral response to gSG6, fSG6 and a combination of the two antigens was compared in a population from a malaria hyperendemic area of Burkina Faso where both vectors were present, although with a large A. gambiae prevalence (>75%. Sera collected at the beginning and at the end of the high transmission/rainy season, as well as during the following low transmission/dry season, were analysed. Results According to previous observations, both anti-SG6 IgG level and prevalence decreased during the low transmission/dry season and showed a typical age-dependent pattern. No significant difference in the response to the two antigens was found, although their combined use yielded in most cases higher IgG level. Conclusions Comparative analysis of gSG6 and fSG6 immunogenicity to humans suggests the occurrence of a wide cross-reactivity, even though the two proteins carry species-specific epitopes. This study supports the use of gSG6 as reliable indicator of exposure to the three main African malaria vectors, a marker which may be useful to monitor malaria transmission

  19. Assessment of Anopheles salivary antigens as individual exposure biomarkers to species-specific malaria vector bites

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    Ali Zakia M I

    2012-12-01

    Full Text Available Abstract Background Malaria transmission occurs during the blood feeding of infected anopheline mosquitoes concomitant with a saliva injection into the vertebrate host. In sub-Saharan Africa, most malaria transmission is due to Anopheles funestus s.s and to Anopheles gambiae s.l. (mainly Anopheles gambiae s.s. and Anopheles arabiensis. Several studies have demonstrated that the immune response against salivary antigens could be used to evaluate individual exposure to mosquito bites. The aim of this study was to assess the use of secreted salivary proteins as specific biomarkers of exposure to An. gambiae and/or An. funestus bites. Methods For this purpose, salivary gland proteins 6 (SG6 and 5′nucleotidases (5′nuc from An. gambiae (gSG6 and g-5′nuc and An. funestus (fSG6 and f-5′nuc were selected and produced in recombinant form. The specificity of the IgG response against these salivary proteins was tested using an ELISA with sera from individuals living in three Senegalese villages (NDiop, n = 50; Dielmo, n = 38; and Diama, n = 46 that had been exposed to distinct densities and proportions of the Anopheles species. Individuals who had not been exposed to these tropical mosquitoes were used as controls (Marseille, n = 45. Results The IgG responses against SG6 recombinant proteins from these two Anopheles species and against g-5′nucleotidase from An. gambiae, were significantly higher in Senegalese individuals compared with controls who were not exposed to specific Anopheles species. Conversely, an association was observed between the level of An. funestus exposure and the serological immune response levels against the f-5′nucleotidase protein. Conclusion This study revealed an Anopheles salivary antigenic protein that could be considered to be a promising antigenic marker to distinguish malaria vector exposure at the species level. The epidemiological interest of such species-specific antigenic markers is discussed.

  20. Studies on the bionomics of male Anopheles gambiae Giles and male Anopheles funestus Giles from southern Mozambique

    DEFF Research Database (Denmark)

    Charlwood, J D

    2011-01-01

    . gambiae s.l. rest inside houses. They leave in a dusk exodus, which makes them easy to collect. In 8,348 exit collections from a village from 2003 to 2009, 567,195 male An. funestus and 34,591 male An. gambiae s.l. were collected. During the study, numbers of An. funestus increased but numbers of An...

  1. Activity of Ocimum basilicum, Ocimum canum, and Cymbopogon citratus essential oils against Plasmodium falciparum and mature-stage larvae of Anopheles funestus s.s.

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    Akono Ntonga, Patrick; Baldovini, Nicolas; Mouray, Elisabeth; Mambu, Lengo; Belong, Philippe; Grellier, Philippe

    2014-01-01

    The biological activities of essential oils from three plants grown in Cameroon: Ocimum basilicum, Ocimum canum, and Cymbopogon citratus were tested against Plasmodium falciparum and mature-stage larvae of Anopheles funestus. Gas chromatography and gas chromatography - mass spectrometry analyses showed that the main compounds are geranial, 1,8-cineole and linalool in C. citratus, O. canum and O. basilicum, respectively. Larvicidal tests carried out according to the protocol recommended by the World Health Organization showed that the essential oil of leaves of C. citratus is the most active against larvae of An. funestus (LC50 values = 35.5 ppm and 34.6 ppm, respectively, for larval stages III and IV after 6 h of exposure). Besides, the in vitro anti-plasmodial activity evaluated by the radioisotopic method showed that the C. citratus oil is the most active against P. falciparum, with an IC50 value of 4.2 ± 0.5 μg/mL compared with O. canum (20.6 ± 3.4 μg/mL) and O. basilicum (21 ± 4.6 μg/mL). These essential oils can be recommended for the development of natural biocides for fighting the larvae of malaria vectors and for the isolation of natural products with anti-malarial activity.

  2. QSAR analyses of DDT analogues and their in silico validation using molecular docking study against voltage-gated sodium channel of Anopheles funestus.

    Science.gov (United States)

    Saini, V; Kumar, A

    2014-01-01

    DDT has enjoyed the reputation of a successful pesticide in disease control programme and agricultural practices along with the serious opposition and ban later on due to its biomagnification and toxic action against non-target organisms. The present work was carried out to develop QSAR models for analysing DDT analogues for their pesticidal activity and in silico validation of these models. A 2D-QSAR model was generated using stepwise with multiple regression, and the model with a value of r(2) = 0.7324; q(2) = 0.6215; pred r(2) = 0.7038, containing five descriptors, was selected for further study. The 3D QSAR with CoMFA analysis showed that steric contribution of 21% and electrostatic contribution of about 79% were required for larvicidal activity of DDT analogues. A set of 3430 molecules was generated using the basic DDT skeleton as template, and these were evaluated for their mosquito larvicidal activity using the generated QSAR models and DDT as standard. Eleven molecules were selected for in silico validation of these models. For this, a docking study of the selected molecules against the homology-modelled voltage-gated sodium channel of Anopheles funestus was conducted. The study showed that the activities of these analogues as predicted by 2D-QSAR, 3D-QSAR with CoMFA and dock score were observed to be well correlated.

  3. Unexpected diversity of Anopheles species in Eastern Zambia: implications for evaluating vector behavior and interventions using molecular tools.

    Science.gov (United States)

    Lobo, Neil F; St Laurent, Brandyce; Sikaala, Chadwick H; Hamainza, Busiku; Chanda, Javan; Chinula, Dingani; Krishnankutty, Sindhu M; Mueller, Jonathan D; Deason, Nicholas A; Hoang, Quynh T; Boldt, Heather L; Thumloup, Julie; Stevenson, Jennifer; Seyoum, Aklilu; Collins, Frank H

    2015-12-09

    The understanding of malaria vector species in association with their bionomic traits is vital for targeting malaria interventions and measuring effectiveness. Many entomological studies rely on morphological identification of mosquitoes, limiting recognition to visually distinct species/species groups. Anopheles species assignments based on ribosomal DNA ITS2 and mitochondrial DNA COI were compared to morphological identifications from Luangwa and Nyimba districts in Zambia. The comparison of morphological and molecular identifications determined that interpretations of species compositions, insecticide resistance assays, host preference studies, trap efficacy, and Plasmodium infections were incorrect when using morphological identification alone. Morphological identifications recognized eight Anopheles species while 18 distinct sequence groups or species were identified from molecular analyses. Of these 18, seven could not be identified through comparison to published sequences. Twelve of 18 molecularly identified species (including unidentifiable species and species not thought to be vectors) were found by PCR to carry Plasmodium sporozoites - compared to four of eight morphological species. Up to 15% of morphologically identified Anopheles funestus mosquitoes in insecticide resistance tests were found to be other species molecularly. The comprehension of primary and secondary malaria vectors and bionomic characteristics that impact malaria transmission and intervention effectiveness are fundamental in achieving malaria elimination.

  4. Widespread pyrethroid and DDT resistance in the major malaria vector Anopheles funestus in East Africa is driven by metabolic resistance mechanisms.

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    Charles Mulamba

    Full Text Available BACKGROUND: Establishing the extent, geographical distribution and mechanisms of insecticide resistance in malaria vectors is a prerequisite for resistance management. Here, we report a widespread distribution of insecticide resistance in the major malaria vector An. funestus across Uganda and western Kenya under the control of metabolic resistance mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Female An. funestus collected throughout Uganda and western Kenya exhibited a Plasmodium infection rate between 4.2 to 10.4%. Widespread resistance against both type I (permethrin and II (deltamethrin pyrethroids and DDT was observed across Uganda and western Kenya. All populations remain highly susceptible to carbamate, organophosphate and dieldrin insecticides. Knockdown resistance plays no role in the pyrethroid and DDT resistance as no kdr mutation associated with resistance was detected despite the presence of a F1021C replacement. Additionally, no signature of selection was observed on the sodium channel gene. Synergist assays and qRT-PCR indicated that metabolic resistance plays a major role notably through elevated expression of cytochrome P450s. DDT resistance mechanisms differ from West Africa as the L119F-GSTe2 mutation only explains a small proportion of the genetic variance to DDT resistance. CONCLUSION: The extensive distribution of pyrethroid and DDT resistance in East African An. funestus populations represents a challenge to the control of this vector. However, the observed carbamate and organophosphate susceptibility offers alternative solutions for resistance management.

  5. The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes

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    Ketseoglou Irene

    2012-10-01

    Full Text Available Abstract Background Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays. Findings There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus An. arabiensis An. gambiae An. quadriannulatus, where 50. The LC50 of PCC 7120#11 against the important malaria vectors An. gambiae and An. arabiensis was 12.3 × 105 cells/ml and 8.10 × 105 cells/ml, respectively. PCC 7120#11 was not effective against An. funestus, with less than 50% mortality obtained at concentrations as high as 3.20 × 107 cells/ml. Conclusions PCC 7120#11 exhibited good larvicidal activity against larvae of the An. gambiae complex, but relatively weak larvicidal activity against An. funestus. The study has highlighted the importance of evaluating a novel mosquitocidal agent against a range of malaria vectors so as to obtain a clear understanding of the agent’s spectrum of activity and potential as a vector control agent.

  6. Anopheles (Anopheles) petragnani Del Vecchio 1939-a new mosquito species for Germany.

    Science.gov (United States)

    Becker, Norbert; Pfitzner, Wolf Peter; Czajka, Christina; Kaiser, Achim; Weitzel, Thomas

    2016-07-01

    The so far known species of the Anopheles Claviger Complex, Anopheles claviger s.s. and Anopheles petragnani, can only be distinguished by partial overlapping characteristics of immature stages and by nucleotide sequence variation of the genomic ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS2) region. The known distribution of An. petragnani is so far restricted to the western Mediterranean region, whereas An. claviger s.s. occurs across most of Europe, up to the Middle East and North Africa. In our study, we investigated the larval mosquito fauna in rock pools of the Murg valley (Black Forest, Germany) once a month from April to December 2015.Among other species, larvae belonging to the Anopheles Claviger Complex were found. The fourth instar larvae were morphologically identified by chaetotaxy of the head and abdomen. The results were confirmed by a multiplex PCR and additional sequencing of the amplificates.Of the 1289 collected larvae from the rock pools, seven belonged to the Anopheles Claviger Complex. Five individuals were determined morphologically as An. petragnani and two as An. claviger s.s. The associated mosquito fauna comprised of Aedes japonicus japonicus (548 individuals), Culex pipiens s.l. and Culex torrentium (493 individuals) and Culex hortensis (241 individuals).This is the first record of An. petragnani north of the Alps. Further studies will reveal whether this is an isolated population of An. petragnani and if the investigated rock pool breeding sites represent typical habitats of this species in temperate regions in Central Europe.

  7. On the conspecificity of Anopheles fluviatilis species S with Anopheles minimus species C

    Indian Academy of Sciences (India)

    O P Singh; D Chandra; N Nanda; S K Sharma; Pe Than Htun; T Adak; S K Subbarao; A P Dash

    2006-12-01

    Anopheles fluviatilis and An. minimus complexes, each comprising of at least three sibling species, are closely related and important malaria vectors in Oriental Region. Recently An. fluviatilis species S, which is a highly efficient malaria vector in India, has been made conspecific with An. minimus species C (senior synonym) on the basis of homology in 335 base pair nucleotide sequence of D3 domain of 28S ribosomal DNA (rDNA). We examined the conspecificity of these two nominal species by obtaining and analysing the DNA sequences of nuclear ribosomal loci internal transcribed spacer 2 (ITS2) and D2-D3 domain of 28S rDNA (28S-D2/D3) from those of An. fluviatilis S and An. minimus C. We found that the sequences of An. fluviatilis S are appreciably different from those of An. minimus C with pair-wise distance (Kimura-2-parametre model) of 3.6 and 0.7% for loci ITS2 and 28S-D2/D3, respectively. Pair-wise distance and phylogenetic analyses using ITS2 sequences of members of Minimus and Fluviatilis Complexes revealed that An. fluviatilis S is distantly related to An. minimus C as compared to any other members of the Fluviatilis Complex. These findings suggest that the two nominal species, An. fluviatilis S and An. minimus C, do not merit synonymy. The study also confirms that the reported species An. fluviatilis X is synonym with species S.

  8. Dynamics of immature stages of Anopheles arabiensis and other mosquito species (Diptera: Culicidae) in relation to rice cropping in a rice agro-ecosystem in Kenya.

    Science.gov (United States)

    Mwangangi, Joseph; Shililu, Josephat; Muturi, Ephantus; Gu, Weidong; Mbogo, Charles; Kabiru, Ephantus; Jacob, Benjamin; Githure, John; Novak, Robert

    2006-12-01

    We determined changes in species composition and densities of immature stages of Anopheles arabiensis mosquitoes in relation to rice growth cycle in order to generate data for developing larval control strategies in rice ecosystems. Experimental rice paddies (6.3m x 3.15m) exposed to natural colonization of mosquitoes were sampled weekly for two rice growing cycles between February 2004 and March 2005. Overall, 21,325 Anopheles larvae were collected, of which 91.9% were 1st and 2nd instars and 8.1% were 3rd and 4th instars. An. arabiensis was the predominant species (84.1%) with other species, An. pharoensis (13.5%), An. funestus (2.1%), An. coustani (0.3%), and An. maculipalpis (0.1%) accounting for only a small proportion of the anophelines collected. Culex quinquefasciatus (65.7%) was the predominant species among the non-anopheline species. Others species collected included: C. annulioris (9.9%), C. poicilipes (7.3%), C. tigripes (7.2%), C. duttoni (0.6%), Aedes aegypti (5.3%), Ae. cumminsii (3.5%), and Ae. vittatus (0.7%). The densities of the major anopheline species were closely related to rice stage and condition of the rice field. An. arabiensis, the predominant species, was most abundant over a three-week period after transplanting. Low densities of larvae were collected during the late vegetative, reproductive, and ripening phases of rice. An increase in larval density ten days post-transplanting was found to correlate with the application of fertilizer (sulphate of ammonia). Culicine and aedine species densities were significantly higher during the post-harvesting period. Our results suggest that the transplanting stage is favorable for the growth of immature stages of An. arabiensis and provides a narrow window for targeted larval intervention in rice.

  9. Mosquito biosurveillance on Kyushu Island, Japan, with emphasis on Anopheles Hyrcanus Group and related species (Diptera: culicidae).

    Science.gov (United States)

    Rueda, Leopoldo M; Pagac, Benedict; Iwakami, Masashiro; Spring, Alexandra R; Motoki, Mayasa T; Pecor, James E; Higa, Yukiko; Futami, Kyoko; Imanishi, Nozomi; Long, Lewis S; Debboun, Mustapha

    2014-01-01

    This report includes the distribution records of the Anopheles (Anopheles) Hyrcanus Group and associated species in Kyushu Island, Japan, based on our field collections from various localities of 4 prefectures (Fukuoka, Kumamoto, Nagasaki, Saga), primarily from 2002-2013. The status of common and potential mosquito vectors, particularly Anopheles species, in Japan are noted.

  10. Mosquitoes of Anopheles hyrcanus (Diptera, Culicidae) Group: Species Diagnostic and Phylogenetic Relationships.

    Science.gov (United States)

    Khrabrova, Natalia V; Andreeva, Yulia V; Sibataev, Anuarbek K; Alekseeva, Svetlana S; Esenbekova, Perizat A

    2015-09-01

    Herein, we report the results of study of Anopheles species in Primorsk and Khabarovsk regions of Russia. Three species of the Anopheles hyrcanus group: An. kleini, An. pullus, and An. lesteri were identified by molecular taxonomic diagnostics for the first time in Russia. Surprisingly, An. sinensis, which earlier was considered the only species of Anopheles in Russian Far East, was not observed. We analyzed nucleotide variation in the 610-bp fragment of the 5' end of the cytochrome c oxidase subunit I (COI) region. All species possessed a distinctive set of COI sequences. A maximum likelihood phylogenetic tree was constructed for members of the hyrcanus group. The examined Anopheles hyrcanus group members could be divided into two major subgroups: subgroup 1 (An. hyrcanus and An. pullus) and subgroup 2 (An. sinensis, An. kleini, and An. lesteri), which were found to be monophyletic.

  11. Reconsideration of Anopheles rivulorum as a vector of Plasmodium falciparum in western Kenya: some evidence from biting time, blood preference, sporozoite positive rate, and pyrethroid resistance

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    Kawada Hitoshi

    2012-10-01

    Full Text Available Abstract Background Anopheles gambiae, An. arabiensis, and An. funestus are widespread malaria vectors in Africa. Anopheles rivulorum is the next most widespread species in the An. funestus group. The role of An. rivulorum as a malaria vector has not been fully studied, although it has been found to be a minor or opportunistic transmitter of Plasmodium falciparum. Methods Mosquitoes were collected indoors over a 12-hour period using a light source attached to a rotating bottle collector in order to determine peak activity times and to provide DNA for meal source identification. Gravid female mosquitoes were collected indoors via an aspirator to generate F1 progeny for testing insecticidal susceptibility. Blood meal sources were identified using a multiplexed PCR assay for human and bovine cytochrome-B, and by matching sequences generated with primers targeting vertebrate and mammalian cytochrome-B segments to the Genbank database. Results Anopheles rivulorum fed on human blood in the early evening between 18:00 and 20:00, when insecticide-treated bed nets are not in use, and the presence of Plasmodium falciparum sporozoites in 0.70% of the An. rivulorum individuals tested was demonstrated. Susceptibility to permethrin, deltamethrin, and DDT is higher in An. rivulorum (84.8%, 91.4%, and 100%, respectively than in An. funestus s.s. (36.8%, 36.4%, and 70%, respectively, whereas mortality rates for propoxur and fenitrothion were 100% for both species. Resistance to pyrethroids was very high in An. funestus s.s. and the potential of the development of high resistance was suspected in An. rivulorum. Conclusion Given the tendency for An. rivulorum to be active early in the evening, the presence of P. falciparum in the species, and the potential for the development of pyrethroid resistance, we strongly advocate reconsideration of the latent ability of this species as an epidemiologically important malaria vector.

  12. Isoenzymatic variability among five Anopheles species belonging to the Nyssorhynchus and Anopheles subgenera of the Amazon region, Brazil

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    Joselita Maria Mendes dos Santos

    2003-03-01

    Full Text Available An isoenzymatic comparative analysis of the variability and genetics differentiation among Anopheles species was done in populations of An. (Nys. intermedius and An. (Ano. mattogrossensis of the Anopheles subgenus, and of An. darlingi, An. albitarsis and An. triannulatus of the Nyssorhynchus subgenus, with the aim of detecting differences between both subgenera and of estimating the degree of genetic intere specific divergence. Samples from Macapá, State of Amapá and Janauari Lake, near Manaus, State of Amazonas, were analyzed for eight isoenzymatic loci. Analysis revealed differences in the average number of alleles per locus (1.6-2.3 and heterozygosity (0.060-0.284. However, the proportion of polymorphic loci was the same for An. (Nys. darlingi, An. (Nys. triannulatus and An. (Ano. mattogrossensis (50%, but differed for An. (Nys. albitarsis (62.5% and An. (Ano. intermedius (25%. Only the IDH1 (P > 0.5 locus in all species studied was in Hardy-Weinberg equilibrium. The fixation index demonstrated elevated genetic structuring among species, based on values of Fst = 0.644 and genetic distance (0.344-0.989. Genetic difference was higher between An. (Nys. triannulatus and An. (Ano. intermedius (0.989 and smaller between An. (Nys. albitarsis sensu lato and An. (Nys. darlingi (0.344. The data show interspecific genetic divergence which differs from the phylogenetic hypothesis based on morphological characters.

  13. Mermithid nematodes found in adult Anopheles from southeastern Senegal

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    Kobylinski Kevin C

    2012-06-01

    Full Text Available Abstract Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551 of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal

  14. Comparative Studies on the Stenogamous and Eurygamous Behavior of Eight Anopheles Species of the Hyrcanus Group (Diptera: Culicidae in Thailand

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    Adulsak Wijit

    2016-03-01

    Full Text Available Establishment of laboratory colony is essential for mosquito-borne-disease research. Mating behavior of stenogamous Anopheles peditaeniatus and seven eurygamous species (Anopheles argyropus, Anopheles crawfordi, Anopheles nigerrimus, Anopheles nitidus, Anopheles paraliae (=An. lesteri, Anopheles pursati and Anopheles sinensis, were investigated and compared in this study. The self-mating success of adult mosquitoes in different size cages at two density resting surface (DRS values, 3.6 and 7.2, was statistically significant between stenogamous and eurygamous species. The results obtained from comparative measurements of specific characters in adult females (maxillary palpomere and antennal sensilla characters and males (wing and genitalia indicate those characters might influence the mating success of An. peditaeniatus in a small cage. The gonostylus of An. peditaeniatus was shorter than the eurygamous species. Additionally, the lower frequency of clasper movement and shorter mating time could be important mechanisms that control the stenogamous behavior of An. peditaeniatus. Interestingly, for the first time, a cluster of large sensilla coeloconica was recorded on the antenna of An. argyropus and An. peditaeniatus females. There was no statistically significant difference in the mean number per female of those large antennal sensilla coeloconica among six of the eurygamous species.

  15. Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia.

    Science.gov (United States)

    Herrera-Varela, Manuela; Orjuela, Lorena I; Peñalver, Cilia; Conn, Jan E; Quiñones, Martha L

    2014-11-01

    Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

  16. Species-specific chemosensory gene expression in the olfactory organs of the malaria vector Anopheles gambiae

    NARCIS (Netherlands)

    Hodges, Theresa K.; Cosme, Luciano V.; Athrey, Giridhar; Pathikonda, Sharmila; Takken, Willem; Slotman, Michel A.

    2014-01-01

    Background: The malaria mosquito Anopheles gambiae has a high preference for human hosts, a characteristic that contributes greatly to its capacity for transmitting human malaria. A sibling species, An. quadriannulatus, has a quite different host preference and feeds mostly on bovids. For this re

  17. Genomic and evolutionary analyses of Tango transposons in Aedes aegypti, Anopheles gambiae and other mosquito species.

    Science.gov (United States)

    Coy, M R; Tu, Z

    2007-08-01

    Tango is a transposon of the Tc1 family and was originally discovered in the African malaria mosquito, Anopheles gambiae. Here we report a systematic analysis of the genome sequence of the yellow fever mosquito, Aedes aegypti, which uncovered three distinct Tango transposons. We name the only An. gambiae Tango transposon AgTango1 and the three Ae. aegypti Tango elements AeTango1-3. Like AgTango1, AeTango1 and AeTango2 elements both have members that retain characteristics of autonomous elements such as intact open reading frames and terminal inverted repeats (TIRs). AeTango3 is a degenerate transposon with no full-length members. All full-length Tango transposons contain subterminal direct repeats within their TIRs. AgTango1 and AeTango1-3 form a single clade among other Tc1 transposons. Within this clade, AgTango1 and AeTango1 are closely related and share approximately 80% identity at the amino acid level, which exceeds the level of similarity of the majority of host genes in the two species. A survey of Tango in other mosquito species was carried out using degenerate PCR. Tango was isolated and sequenced in all members of the An. gambiae species complex, Aedes albopictus and Ochlerotatus atropalpus. Oc. atropalpus contains a rich diversity of Tango elements, while Tango elements in Ae. albopictus and the An. gambiae species complex all belong to Tango1. No Tango was detected in Culex pipiens quinquefasciatus, Anopheles stephensi, Anopheles dirus, Anopheles farauti or Anopheles albimanus using degenerate PCR. Bioinformatic searches of the Cx. p. quinquefasciatus (~10 x coverage) and An. stephensi (0.33 x coverage) databases also failed to uncover any Tango elements. Although other evolutionary scenarios cannot be ruled out, there are indications that Tango1 underwent horizontal transfer among divergent mosquito species.

  18. Mitochondrial genome sequences reveal deep divergences among Anopheles punctulatus sibling species in Papua New Guinea

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    Logue Kyle

    2013-02-01

    Full Text Available Abstract Background Members of the Anopheles punctulatus group (AP group are the primary vectors of human malaria in Papua New Guinea. The AP group includes 13 sibling species, most of them morphologically indistinguishable. Understanding why only certain species are able to transmit malaria requires a better comprehension of their evolutionary history. In particular, understanding relationships and divergence times among Anopheles species may enable assessing how malaria-related traits (e.g. blood feeding behaviours, vector competence have evolved. Methods DNA sequences of 14 mitochondrial (mt genomes from five AP sibling species and two species of the Anopheles dirus complex of Southeast Asia were sequenced. DNA sequences from all concatenated protein coding genes (10,770 bp were then analysed using a Bayesian approach to reconstruct phylogenetic relationships and date the divergence of the AP sibling species. Results Phylogenetic reconstruction using the concatenated DNA sequence of all mitochondrial protein coding genes indicates that the ancestors of the AP group arrived in Papua New Guinea 25 to 54 million years ago and rapidly diverged to form the current sibling species. Conclusion Through evaluation of newly described mt genome sequences, this study has revealed a divergence among members of the AP group in Papua New Guinea that would significantly predate the arrival of humans in this region, 50 thousand years ago. The divergence observed among the mtDNA sequences studied here may have resulted from reproductive isolation during historical changes in sea-level through glacial minima and maxima. This leads to a hypothesis that the AP sibling species have evolved independently for potentially thousands of generations. This suggests that the evolution of many phenotypes, such as insecticide resistance will arise independently in each of the AP sibling species studied here.

  19. Reticulate Speciation and Barriers to Introgression in the Anopheles gambiae Species Complex.

    Science.gov (United States)

    Crawford, Jacob E; Riehle, Michelle M; Guelbeogo, Wamdaogo M; Gneme, Awa; Sagnon, N'Fale; Vernick, Kenneth D; Nielsen, Rasmus; Lazzaro, Brian P

    2015-11-28

    Speciation as a process remains a central focus of evolutionary biology, but our understanding of the genomic architecture and prevalence of speciation in the face of gene flow remains incomplete. The Anopheles gambiae species complex of malaria mosquitoes is a radiation of ecologically diverse taxa. This complex is well-suited for testing for evidence of a speciation continuum and genomic barriers to introgression because its members exhibit partially overlapping geographic distributions as well as varying levels of divergence and reproductive isolation. We sequenced 20 genomes from wild A. gambiae s.s., Anopheles coluzzii, Anopheles arabiensis, and compared these with 12 genomes from the "GOUNDRY" subgroup of A. gambiae s.l. Amidst a backdrop of strong reproductive isolation, we find strong evidence for a speciation continuum with introgression of autosomal chromosomal regions among species and subgroups. The X chromosome, however, is strongly differentiated among all taxa, pointing to a disproportionately large effect of X chromosome genes in driving speciation among anophelines. Strikingly, we find that autosomal introgression has occurred from contemporary hybridization between A. gambiae and A. arabiensis despite strong divergence (∼5× higher than autosomal divergence) and isolation on the X chromosome. In addition to the X, we find strong evidence that lowly recombining autosomal regions, especially pericentromeric regions, serve as barriers to introgression secondarily to the X. We show that speciation with gene flow results in genomic mosaicism of divergence and introgression. Such a reticulate gene pool connecting vector taxa across the speciation continuum has important implications for malaria control efforts.

  20. Description of Anopheles gabonensis, a new species potentially involved in rodent malaria transmission in Gabon, Central Africa.

    Science.gov (United States)

    Rahola, Nil; Makanga, Boris; Yangari, Patrick; Jiolle, Davy; Fontenille, Didier; Renaud, François; Ollomo, Benjamin; Ayala, Diego; Prugnolle, Franck; Paupy, Christophe

    2014-12-01

    The genus Anopheles includes mosquito vectors of human malaria and arboviruses. In sub-Saharan Africa, the anopheline fauna is rich of nearly 150 species, few of which are anthropophilic and capable of transmitting pathogens to humans. Some of the remaining species are found in forests far from human environments and are vectors of wildlife pathogens. The diversity and the biology of these species have yet to be fully described. As a contribution to furthering knowledge of sylvan Anophelinae, using morphological and molecular tools we describe a new Anopheles species collected in Gabon (Central Africa), which we have named Anopheles gabonensis n. sp. We also molecularly screened this species to detect infections by Plasmodium parasites. The results showed the species to have been infected by Plasmodium vinckei, a rodent parasite. We discuss the role of An. gabonensis n. sp. in the transmission of P. vinckei in the rainforest areas of Central Africa and its potential to transfer pathogens to humans.

  1. Phylogeny of anopheline (Diptera: Culicidae) species in southern Africa, based on nuclear and mitochondrial genes.

    Science.gov (United States)

    Norris, Laura C; Norris, Douglas E

    2015-06-01

    A phylogeny of anthropophilic and zoophilic anopheline mosquito species was constructed, using the nuclear internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome oxidase subunit I (COI) genes. The ITS2 alignment, typically difficult due to its noncoding nature and large size variations, was aided by using predicted secondary structure, making this phylogenetically useful gene more amenable to investigation. This phylogeny is unique in explicitly including zoophilic, non-vector anopheline species in order to illustrate their relationships to malaria vectors. Two new, cryptic species, Anopheles funestus-like and Anopheles rivulorum-like, were found to be present in Zambia for the first time. Sequences from the D3 region of the 28S rDNA suggest that the Zambian An. funestus-like may be a hybrid or geographical variant of An. funestus-like, previously reported in Malawi. This is the first report of An. rivulorum-like sympatric with An. rivulorum (Leeson), suggesting that these are separate species rather than geographic variants.

  2. Phylogenetics and Srf Analysis of Mitochondrial DNA COII Gene in Anopheles Species (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Monika Sharma

    2011-07-01

    Full Text Available Mitochondrial DNA COII gene was used to study the interspecific variation and molecular analysis among six species of genus Anopheles belonging to subgenus Cellia i.e. An. stephensi, An. culicifacies, An. maculatus, An. subpictus, An. annularis and An. splendidus. The sequence was found to be AT rich with maximum of 75.07% in An. culicifacies. The sequence analysis revealed the number of transversions to be more than transitions which is opposite of the general contention with transitions being more frequent than transversions in mitochondrial genes. However, among the Anopheles species, the maximum number of substitutions was found in An. maculatus. The phylogenetic analysis using the three methods MP, ML and NJ methods was also carried out for which Cx. quinquefasciatus was taken as outgroup. Analysis showed that An. stephensi and An. culicifacies shared a close genetic homology while An. annularis and An. splendidus made another group with identical genetic qualities. To the contrary, An. subpictus and An. maculatus had hypervariable non-homologous genomic qualities. Short tandem as well as nontandem repeats were also studied using SRF (Spectral Repeat Finder programme. The repeats were conserved in all the species except certain polymorphic repeats such as TAT and TTTAT were present in An. stephensi whereas no polymorphic repeats were present in An. subpictus. Identification of repeats is crucial to shed light on the function and structure of proteins, and explain their evolutionary past.

  3. Taxonomy Icon Data: Anopheles stephensi [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Anopheles stephensi Anopheles stephensi Arthropoda Anopheles_stephensi_L.png Anopheles_steph...ensi_NL.png Anopheles_stephensi_S.png Anopheles_stephensi_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anoph...eles+stephensi&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&...t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&t=S htt...p://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Anopheles+stephensi&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=149 ...

  4. Observations on sporozoite detection in naturally infected sibling species of the Anopheles culicifacies complex and variant of Anopheles stephensi in India

    Indian Academy of Sciences (India)

    Susanta Kumar Ghosh; Satyanarayan Tiwari; Kamaraju Raghavendra; Tiruchinapalli Sundaraj; Aditya Prasad Dash

    2008-09-01

    Sporozoites were detected in naturally infected sibling species of the primary rural vector Anopheles culicifacies complex in two primary health centres (PHCs) and a variant of the urban vector Anopheles stephensi in Mangalore city, Karnataka, south India while carrying out malaria outbreak investigations from 1998–2006. Sibling species of An. culicifacies were identified based on the banding patterns on ovarian polytene chromosomes, and variants of An. stephensi were identified based on the number of ridges on the egg floats. Sporozoites were detected in the salivary glands by the dissection method. Of the total 334 salivary glands of An. culicifacies dissected, 17 (5.08%) were found to be positive for sporozoites. Of the 17 positive samples, 11 were suitable for sibling species analysis; 10 were species A (an efficient vector) and 1 was species B (a poor vector). Out of 46 An. stephensi dissected, one was sporozoite positive and belonged to the type form (an efficient vector). In malaria epidemiology this observation is useful for planning an effective vector control programme, because each sibling species/variant differs in host specificity, susceptibility to malarial parasites, breeding habitats and response to insecticides.

  5. Cytogenetic evidence for a species complex within Anopheles pseudopunctipennis theobald (Diptera: Culicidae).

    Science.gov (United States)

    Coetzee, M; Estrada-Franco, J G; Wunderlich, C A; Hunt, R H

    1999-04-01

    Anopheles pseudopunctipennis was collected from Acapulco, Mexico and Sallee River, Grenada, West Indies and used in cross-mating experiments. Larvae from the cross, Mexico female X Grenada male, died in the third instar. However, adult progeny were obtained from the reciprocal cross Grenada female x Mexico male. These hybrid males had testes with apparently normal appearance but some without viable sperm. Polytene chromosomes obtained from hybrid females exhibited extensive asynapsis of the X chromosomes. Previously undescribed fixed inversion differences between the two populations were noted on the X chromosome. It is concluded that the two populations belong to different species. The Grenada population is designated An. pseudopunctipennis species C, since it is the third taxon recognized in this species complex.

  6. Anopheles gambiae immune responses to human and rodent Plasmodium parasite species.

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    Yuemei Dong

    2006-06-01

    Full Text Available Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito's immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. Invasion by P. berghei had a more profound impact on the mosquito transcriptome, including a variety of functional gene classes, while P. falciparum elicited a broader immune response at the gene transcript level. Ingestion of human malaria-infected blood lacking invasive ookinetes also induced a variety of immune genes, including several anti-Plasmodium factors. Twelve selected genes were assessed for effect on infection with both parasite species and bacteria using RNAi gene silencing assays, and seven of these genes were found to influence mosquito resistance to both parasite species. An MD2-like receptor, AgMDL1, and an immunolectin, FBN39, showed specificity in regulating only resistance to P. falciparum, while the antimicrobial peptide gambicin and a novel putative short secreted peptide, IRSP5, were more specific for defense against the rodent parasite P. berghei. While all the genes that affected Plasmodium development also influenced mosquito resistance to bacterial infection, four of the antimicrobial genes had no effect on Plasmodium development. Our study shows that the impact of P. falciparum and P. berghei infection on A. gambiae biology at the gene transcript level is quite diverse, and the defense against the two Plasmodium species is mediated by antimicrobial factors with both universal and Plasmodium-species specific activities. Furthermore, our data indicate that the mosquito is capable of sensing infected blood constituents in the absence

  7. Anopheles culicifacies: siblings species composition and its relationship to malaria incidence.

    Science.gov (United States)

    Subbarao, S K; Vasantha, K; Raghavendra, K; Sharma, V P; Sharma, G K

    1988-03-01

    Entomological and epidemiological surveys in May, August and November 1985 and March 1986 were conducted in villages in Bulandshahr, a western district in Uttar Pradesh and in three eastern districts, Jaunpur, Ballia and Saran. In Bulandshahr, Anopheles culicifacies sibling species A and B were found, with a predominance of species A. Both Plasmodium vivax and P. falciparum were present and the malaria incidence remained high (SPR, 6-50%) indicating an active transmission. In contrast, in three eastern districts predominance of species B with an occasional occurrence of species A was observed. Malaria cases were almost absent in Ballia and Saran and in Jaunpur 10.3% slide positivity rate was observed in May but in later surveys cases were considerably lower (SPR, 0.5-2.9%) indicating the absence of indigenous transmission. In the eastern districts, malaria parasites are regularly brought in from endemic areas by the migrant labor population. Although An. culicifacies s.l. occurs in both the areas, the difference in malaria incidence appears to be due to the difference in the composition of the sibling species which is, the predominant presence of species A in the western district and its absence in eastern districts. This indicates that species A is responsible for active malaria transmission while species B is not.

  8. Distribution of the species of the Anopheles gambiae complex and first evidence of Anopheles merus as a malaria vector in Madagascar

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    Le Goff Gilbert

    2003-10-01

    Full Text Available Abstract Background Members of the Anopheles gambiae complex are amongst the best malaria vectors in the world, but their vectorial capacities vary between species and populations. A large-scale sampling of An. gambiae sensu lato was carried out in various bioclimatic domains of Madagascar. Local abundance of an unexpected member of this complex raised questions regarding its role in malaria transmission. Methods Sampling took place at 38 sites and 2,067 females were collected. Species assessment was performed using a PCR targeting a sequence in the IGS of the rDNA. Analysis focused on the relative prevalence of the species per site, bioclimatic domain and altitude. Infectivity of Anopheles merus was assessed using an ELISA to detect the presence of malarial circumsporozoite protein in the head-thorax. Results Three species were identified: An. gambiae, Anopheles arabiensis and An. merus. The distribution of each species is mainly a function of bioclimatic domains and, to a lesser extent, altitude. An. arabiensis is present in all bioclimatic domains with highest prevalence in sub-humid, dry and sub-arid domains. An. gambiae has its highest prevalence in the humid domain, is in the minority in dry areas, rare in sub-humid and absent in sub-arid domains. An. merus is restricted to the coastal fringe in the south and west; it was in the majority in one southern village. The majority of sites were sympatric for at least two of the species (21/38 and two sites harboured all three species. The role of An. merus as malaria vector was confirmed in the case of two human-biting females, which were ELISA-positive for Plasmodium falciparum. Conclusion Despite the huge environmental (mainly man-made changes in Madagascar, the distribution of An. gambiae and An. arabiensis appears unchanged for the past 35 years. The distribution of An. merus is wider than was previously known, and its effectiveness as a malaria vector has been shown for the first time; this

  9. [The Anopheles fauna and the transmission of human malaria in Kinshasa (Zaire)].

    Science.gov (United States)

    Karch, S; Asidi, N; Manzambi, Z M; Salaun, J J

    1992-01-01

    A longitudinal epidemiological study of malaria and its vectors was conducted in Kinshasa. 264 night-bite collections on human bait (1,056 man nights) and 384 collections of the house-resting fauna were carried out from April 1989 to October 1990. The anophelian fauna was identified and inventoried, 7 Anopheles species were found: Anopheles gambiae, An. funestus, An. paludis, An. hancocki, An. counstani, An. brunnipes, and An. nili. A single species, An. gambiae s. l. is responsible for the transmission of malaria, it represents 93.27% of the anopheline fauna. The average number of anophele bites man day was 16.28 bites/man/night, it varied between 1 b/m/n in urban area to 26.05 b/m/n in semi-rural area. The average of the sporozoite index for An. gambiae was 3.3%, but it varied from 0% in the urban area to 6.52% in the semi-rural area. The entomological inoculation rate (h) was 197 infective bites per year. This rate fluctuated from 1 infective bite each 128 nights in urban area to 1.7 infective night-bite in semi-rural area. Other epidemiological index were also determined: the level of daily survival rate (p = 8.75 days), the vectorial capacity of 17.97 and the Macdonald's stability 3.5 bites on man taken by a vector during its entire lifetime.

  10. Susceptibility of eight species members in the Anopheles hyrcanus group to nocturnally subperiodic Brugia malayi

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    Saeung Atiporn

    2013-01-01

    Full Text Available Abstract Background Filariasis, caused by Brugia malayi, is a public health problem in Thailand. Currently, at least two locations in southern Thailand are reported to be active endemic areas. Two and four Mansonia species are primary and secondary vectors, respectively, of the nocturnally subperiodic race, whereas, Coquillettidia crassipes is a vector of the diurnally subperiodic race. Although several Anopheles species have been incriminated extensively as natural and/or suspected vectors of B. malayi, little is known about vector competence between indigenous Anopheles and this filaria in Thailand. Thus, the susceptibility levels of eight species members in the Thai An. hyrcanus group to nocturnally subperiodic B. malayi are presented herein, and the two main refractory factors that affect them in different degrees of susceptibility have been elucidated. Methods Aedes togoi (a control vector, An. argyropus, An. crawfordi, An. nigerrimus, An. nitidus, An. paraliae, An. peditaeniatus, An. pursati and An. sinensis were allowed to feed artificially on blood containing B. malayi microfilariae, and dissected 14 days after feeding. To determine factors that take effect at different susceptibility levels, stain-smeared blood meals were taken from the midguts of Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus immediately after feeding, and their dissected-thoraxes 4 days post blood-feedings were examined consecutively for microfilariae and L1 larvae. Results The susceptibility rates of Ae. togoi, An. peditaeniatus, An. crawfordi, An. nigerrimus, An. argyropus, An. pursati, An. sinensis, An. paraliae and An. nitidus to B. malayi were 70–95%, 70–100%, 80–85%, 50–65%, 60%, 60%, 10%, 5%, and 0%, respectively. These susceptibility rates related clearly to the degrees of normal larval development in thoracic muscles, i.e., Ae. togoi, An. peditaeniatus, An. crawfordi, An. paraliae, An. sinensis and An. nitidus

  11. Species-richness of the Anopheles annulipes Complex (Diptera: Culicidae) Revealed by Tree and Model-Based Allozyme Clustering Analyses

    Science.gov (United States)

    2007-01-01

    and systematics ofAnopheles: insights from a molecular phy· logeny of Australasian mosquitoes. Molecular Phylogenetics and Evolution 9: 262-275. Foley... systematics and pop- ulation studies. Sydney: Academic Press. Roscnberg NA, Burke T, Elo K, Feldman MW, Freidlin PJ, Groenen MAM, Hillel J, Maki·Taniia...of molecular-functional variation patterns among butterfly species complexes IColias: Lepidoptera , Pieridae). Molecular Ecology 12: 1265-1275. © 2007

  12. Anopheles gambiae immune responses to human and rodent Plasmodium parasite species.

    OpenAIRE

    Yuemei Dong; Ruth Aguilar; Zhiyong Xi; Emma Warr; Emmanuel Mongin; George Dimopoulos

    2006-01-01

    Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito's immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. I...

  13. Six new species of the Anopheles leucosphyrus group, reinterpretation of An. elegans and vector implications.

    Science.gov (United States)

    Sallum, M A M; Peyton, E L; Wilkerson, R C

    2005-06-01

    Among Oriental anopheline mosquitoes (Diptera: Culicidae), several major vectors of forest malaria belong to the group of Anopheles (Cellia) leucosphyrus Dönitz. We have morphologically examined representative material (> 8000 specimens from seven countries) for taxonomic revision of the Leucosphyrus Group. Six new species are here described from adult, pupal and larval stages (with illustrations of immature stages) and formally named as follows: An. latens n. sp. (= An. leucosphyrus species A of Baimai et al., 1988b), An. cracens n. sp., An. scanloni n. sp., An. baimaii n. sp. (formerly An. dirus species B, C, D, respectively), An. mirans n. sp. and An. recens n. sp. Additionally, An. elegans (James) is redescribed and placed in the complex of An. dirus Peyton & Harrison (comprising An. baimaii, An. cracens, An. dirus, An. elegans, An. nemophilous Peyton and Ramalingam, An. scanloni and An. takasagoensis Morishita) of the Leucosphyrus Subgroup, together with An. baisasi Colless and the An. leucosphyrus complex (comprising An. balabacensis Baisas, An. introlatus Baisas, An. latens and An. leucosphyrus). Hence, the former Elegans Subgroup is renamed the Hackeri Subgroup (comprising An. hackeri Edwards, An. pujutensis Colless, An. recens and An. sulawesi Waktoedi). Distribution data and bionomics of the newly defined species are given, based on new material and published records, with discussion of morphological characters for species distinction and implications for ecology and vector roles of such species. Now these and other members of the Leucosphyrus Group are identifiable, it should be possible to clarify the medical importance and distribution of each species. Those already regarded as vectors of human malaria are: An. baimaii[Bangladesh, China (Yunnan), India (Andamans, Assam, Meghalaya, West Bengal), Myanmar, Thailand]; An. latens[Borneo (where it also transmits Bancroftian filariasis), peninsular Malaysia, Thailand]; probably An. cracens (Sumatra

  14. Seasonal population changes and malaria transmission potential of Anopheles pharoensis and the minor anophelines in Mwea Irrigation Scheme, Kenya.

    Science.gov (United States)

    Mukiama, T K; Mwangi, R W

    1989-05-01

    A study in 1984 and 1985 showed that Anopheles gambiae s.l. and An. pharoensis were the major anophelines in Mwea Irrigation Scheme, Kenya, constituting 83.86% and 15.69% of the catch respectively. Four minor species made up the remaining 0.45%. The irrigation phase of the rice cultivation cycle in August, which linked the flooding effects of the two rainy seasons, resulted in major population increases of An. pharoensis and enabled continuous breeding for up to 9 months per year. The average of mean monthly proportions of unfed, bloodfed, and gravid females was 26.6, 58.8, and 14.6% respectively. The Plasmodium falciparum sporozoite rates for An. pharoensis were 1.3% by ELISA and 0.68% by dissection, while those for An. funestus were 1.7% by ELISA and 1.25% by dissection. An. pharoensis can contribute to the epidemiology of Malaria in the Mwea area.

  15. Mosquito species diversity and abundance in relation to land use in a riceland agroecosystem in Mwea, Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Shililu, Josephat; Jacob, Benjamin; Gu, Weidong; Githure, John; Novak, Robert

    2006-06-01

    We conducted an entomological survey to determine the mosquito species diversity and abundance in relation to land use in the Mwea rice scheme, Kenya. Adult mosquitoes were collected by indoor spraying of houses and outdoors by CDC light traps in three villages representing planned (Mbuinjeru) and unplanned (Kiamachiri) rice agroecosystems and a non-irrigated agroecosystem (Murinduko). During the 12-month sampling period, a total of 98,708 mosquitoes belonging to five genera and 25 species were collected. The five most common species collected during this study were Anopheles arabiensis Patton (52.5%), Culex quinquefasciatus Say (36.7%), Anopheles pharoensis Theobald (5.2%), Anopheles coustani Laveran (1.4%), and Anopheles funestus Giles (1.3%). Anopheles arabiensis, Cx quinquefasciatus, and An. pharoensis were more abundant in rice agroecosystems than in the non-irrigated agroecosystem, and in planned than in the unplanned rice agroecosystems. In contrast, An. funestus was more abundant in the non-irrigated agroecosystem. The mosquito species diversity (H) and evenness (E(H)) in the non-irrigated agroecosystem (Shannon diversity Index, H = 1.507, EH = 0.503) was significantly higher than in the rice agroecosystems (H) = 0.968, E(H) = 0.313, unplanned; and H= 1.040, E(H) = 0.367 planned). Results of lag cross correlation analysis revealed a strong relationship between rainfall and the abundance of An. arabiensis, and C. quinquefasciatus in the non-irrigated agroecosystem but not in the rice agroecosystems. It is inferred from the data that different levels of habitat perturbations with regard to rice cultivation have different effects on mosquito diversity and abundance. This provides an understanding of how mosquito diversity is impacted by different habitat management and rice cropping strategies.

  16. INSECTICIDAL ACTIVITIES OF ESSENTIAL OILS EXTRACTED FROM THREE SPECIES OF POACEAE ON ANOPHELES GAMBIAE SPP, MAJOR VECTOR OF MALARIA

    Directory of Open Access Journals (Sweden)

    Dominique C. K. Sohounhloué

    2010-12-01

    Full Text Available In this paper, the insecticidal activities on Anopheles gambiae spp of the essential oils (EO extracted from the dry leaves of some species collected in Benin were studied. The essential oil yields are 2.8, 1.7 and 1.4�0respectively for Cymbopogon schoanenthus (L. Spreng (CS, Cymbopogon citratus Stapf. (CC and Cymbopogon giganteus (Hochst. Chiov (CG. The GC/MS analysis showed that the EO of CS had a larger proportion in oxygenated monoterpenes (86.3�20whereas those of the sheets of CC and CG are relatively close proportions (85.5�0and 82.7�0respectively with. The piperitone (68.5�  2-carene (11.5� and -eudesmol (4.6�20are the major components of the EO of CS while trans para-mentha-1(7,8-dien-2-ol (31.9� trans para-mentha-2,8-dien-1-ol (19.6� cis para-mentha-2,8-dien-1-ol (7.2� trans piperitol (6.3�20and limonene (6.3�20prevailed in the EO of CG. The EO of CC revealed a rich composition in geranial (41.3� neral (33� myrcene (10.4� and geraniol (6.6� The biological tests have shown that these three EO induced 100�0mortality of Anopheles gambiae to 1.1, 586.58 and 1549 µg•cm-2 respectively for CC, CS and CG. These effects are also illustrated by weak lethal concentration for 50�0anopheles population (CC: 0.306; CS: 152.453 and CG: 568.327 µg•cm-2 in the same order of reactivity. The EO of CC appeared most active on two stocks (sensitive and resistant of Anopheles gambiae.

  17. Larvicidal properties of two asclepiadaceous plant species against the mosquito Anopheles arabiensis Patton (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Amal Elsayed Edriss

    2013-01-01

    Full Text Available Certain mosquito species are important vectors of fatal human diseases, among which Anopheles arabiensis is known to be associated with malaria transmission in different tropical and subtropical areas. Since chemical control of mosquitoes was linked with numerous drawbacks, like resistance development, the search for effective environmentally sound alternatives is urgently needed. Therefore, it was aimed by this study to evaluate some extracts prepared from two asclepiadaceous plants, viz., Solenostemma argel “Hargel” (seeds and leaves and Calotropis procera “Usher” (leaves and flowers, as natural larvicides against An. arabiensis. The main parameters included bioassays of treatments for knockdown and residual effects, besides phytochemical analysis of the tested extracts. The results revealed variable groups of secondary metabolites in the two plants, with S. argel seemed to be the richest one. Hence, S. argel extracts caused higher larval mortalities than those of C. procera. This could be ascribed to some potent secondary metabolites in the former plant, which needs further studies. Almost all the high concentrations of S. argel extracts exerted the highest knockdown effect (90% mortality after 24 h, which were comparable with those obtained by two standard insecticides. The highest doses of petroleum ether and water extracts of this plant also manifested significantly higher residual effects than the other extracts after three days following treatments, but were surpassed by the chemical insecticides thereafter. However, S. argel seed petroleum ether extract at 0.5% was the most effective of all botanicals up to three weeks of exposure. This extract needs to be evaluated under field conditions for proper exploitation as mosquito larvicide.

  18. The role of reactive oxygen species in Anopheles aquasalis response to Plasmodium vivax infection.

    Directory of Open Access Journals (Sweden)

    Ana C Bahia

    Full Text Available Malaria affects millions of people worldwide and hundreds of thousands of people each year in Brazil. The mosquito Anopheles aquasalis is an important vector of Plasmodium vivax, the main human malaria parasite in the Americas. Reactive oxygen species (ROS have been shown to have a role in insect innate immune responses as a potent pathogen-killing agent. We investigated the mechanisms of free radicals modulation after A. aquasalis infection with P. vivax. ROS metabolism was evaluated in the vector by studying expression and activity of three key detoxification enzymes, one catalase and two superoxide dismutases (SOD3A and SOD3B. Also, the involvement of free radicals in the mosquito immunity was measured by silencing the catalase gene followed by infection of A. aquasalis with P. vivax. Catalase, SOD3A and SOD3B expression in whole A. aquasalis were at the same levels of controls at 24 h and upregulated 36 h after ingestion of blood containing P. vivax. However, in the insect isolated midgut, the mRNA for these enzymes was not regulated by P. vivax infection, while catalase activity was reduced 24 h after the infectious meal. RNAi-mediated silencing of catalase reduced enzyme activity in the midgut, resulted in increased P. vivax infection and prevalence, and decreased bacterial load in the mosquito midgut. Our findings suggest that the interactions between A. aquasalis and P. vivax do not follow the model of ROS-induced parasite killing. It appears that P. vivax manipulates the mosquito detoxification system in order to allow its own development. This can be an indirect effect of fewer competitive bacteria present in the mosquito midgut caused by the increase of ROS after catalase silencing. These findings provide novel information on unique aspects of the main malaria parasite in the Americas interaction with one of its natural vectors.

  19. Amazon Anopheles Biology. 12. Occurrence of Anopheles Species, Malaria Control and Transmission Dynamics in the Urban Zone of Ariquemes (Rondonia)

    Science.gov (United States)

    1988-01-01

    anophelines collected were captured at this site. In view of this characteris- 21 tic , Gurgel was designated a Collection Station, and samplings were taken...Diptera-Culicidae): sua importancia na transmissdo da maldria. Contribution toward understanding of the species of the Kertszia subgenus (Diptera...R.G. & MARQUES, A.P. - Algumas obser- vag6es sobre a biologia dos anofelinos de importancia epidemiol6- gica de Beldm, Par&. Some observations on

  20. Dichotomous electrophoretic taxonomic key for identification of sibling species A, B, and C of the Anopheles quadrimaculatus complex (Diptera: Culicidae).

    Science.gov (United States)

    Narang, S K; Kaiser, P E; Seawright, J A

    1989-03-01

    Samples of 17 populations of Anopheles quadrimaculatus Say from Florida, Alabama, Arkansas, Louisiana, Mississippi, Tennessee, New York, and New Jersey were analyzed for genetic variability at 33 enzyme loci. Statistical analysis of electromorph frequency distributions indicated that sympatric sibling (morphologically indistinguishable) species occurred in about 59% of the populations tested. The association of polytene chromosome and electrophoretic patterns of individual field-collected females confirmed species-specific diagnostic allozymes, which were useful in identifying sibling species A, B, and C and in estimating the proportions of each species at the 17 collection sites. A dichotomous electrophoretic key is presented for the identification of sibling species of the An. quadrimaculatus complex. The electrophoretic method is better than the ovarian polytene chromosome method, because mosquitoes of both sexes and females irrespective of their gonotrophic condition can be identified.

  1. Comparative performance of the Mbita trap, CDC light trap and the human landing catch in the sampling of Anopheles arabiensis, An. funestus and culicine species in a rice irrigation in western Kenya

    NARCIS (Netherlands)

    Mathenge, E.M.; Misiani, G.O.; Oulo, D.O.; Irungu, L.W.; Ndegwa, P.N.; Smith, T.A.; Killeen, G.F.; Knols, B.G.J.

    2005-01-01

    Background: Mosquitoes sampling is an important component in malaria control. However, most of the methods used have several shortcomings and hence there is a need to develop and calibrate new methods. The Mbita trap for capturing host-seeking mosquitoes was recently developed and successfully teste

  2. Molecular taxonomy provides new insights into anopheles species of the neotropical arribalzagia series.

    Directory of Open Access Journals (Sweden)

    Giovan F Gómez

    Full Text Available Phylogenetic analysis of partial mitochondrial cytochrome oxidase c subunit I (COI and nuclear internal transcribed spacer 2 (ITS2 sequences were used to evaluate initial identification and to investigate phylogenetic relationships of seven Anopheles morphospecies of the Arribalzagia Series from Colombia. Phylogenetic trees recovered highly supported clades for An. punctimaculas.s., An. calderoni, An. malefactor s.l., An. neomaculipalpus, An. apicimacula s.l., An. mattogrossensis and An. peryassui. This study provides the first molecular confirmation of An. malefactorfrom Colombia and discovered conflicting patterns of divergence for the molecular markers among specimens from northeast and northern Colombia suggesting the presence of two previously unrecognized Molecular Operational Taxonomic Units (MOTUs. Furthermore, two highly differentiated An. apicimacula MOTUs previously found in Panama were detected. Overall, the combined molecular dataset facilitated the detection of known and new Colombian evolutionary lineages, and constitutes the baseline for future research on their bionomics, ecology and potential role as malaria vectors.

  3. Strong larvicidal activity of three species of Spilanthes (Akarkara) against malaria (Anopheles stephensi Liston, Anopheles culicifacies, species C) and filaria vector (Culex quinquefasciatus Say).

    Science.gov (United States)

    Pandey, Vibha; Agrawal, Veena; Raghavendra, K; Dash, A P

    2007-12-01

    A system for biocontrol of malaria and filarial mosquito vectors has been developed using herbal extracts of three Spilanthes species, S. acmella L.var oleraceae Clarke, S. calva L. and S. paniculata Wall ex DC. Cent percent mortalities was achieved against the late third/early fourth instar larvae of A. stephensi Liston, A. culicifacies species C and C. quinquefasciatus Say using crude hexane extract obtained from flower heads of Spilanthes spp. Of the three plant species, S. acmella extract proved to be the most effective in inducing complete lethality at minimum doses, the respective LC50 and LC90 values being 4.57 and 7.83 (A. stephensi), 0.87 and 1.92 (A. culicifacies) and 3.11 and 8.89 ppm (C. quinquefasciatus). This was followed by S. calva and S. paniculata extracts, respectively. This is the first report of achieving cent percent lethality against these mosquito larvae using minimal doses of plant extracts from this or any other plant species.

  4. Bionomics of Anopheline species and malaria transmission dynamics along an altitudinal transect in Western Cameroon

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    Toto Jean-Claude

    2010-05-01

    Full Text Available Abstract Background Highland areas of Africa are mostly malaria hypoendemic, due to climate which is not appropriate for anophelines development and their reproductive fitness. In view of designing a malaria control strategy in Western Cameroon highlands, baseline data on anopheline species bionomics were collected. Methods Longitudinal entomological surveys were conducted in three localities at different altitudinal levels. Mosquitoes were captured when landing on human volunteers and by pyrethrum spray catches. Sampled Anopheles were tested for the presence of Plasmodium circumsporozoite proteins and their blood meal origin with ELISA. Entomological parameters of malaria epidemiology were assessed using Mac Donald's formula. Results Anopheline species diversity and density decreased globally from lowland to highland. The most aggressive species along the altitudinal transect was Anopheles gambiae s.s. of S molecular form, followed in the lowland and on the plateau by An. funestus, but uphill by An. hancocki. An. gambiae and An. ziemanni exhibited similar seasonal biting patterns at the different levels, whereas different features were observed for An. funestus. Only indoor resting species could be captured uphill; it is therefore likely that endophilic behaviour is necessary for anophelines to climb above a certain threshold. Of the ten species collected along the transect, only An. gambiae and An. funestus were responsible for malaria transmission, with entomological inoculation rates (EIR of 90.5, 62.8 and zero infective bites/human/year in the lowland, on the plateau and uphill respectively. The duration of gonotrophic cycle was consistently one day shorter for An. gambiae as compared to An. funestus at equal altitude. Altitudinal climate variations had no effect on the survivorship and the subsequent life expectancy of the adult stage of these malaria vectors, but most probably on aquatic stages. On the contrary increasing altitude

  5. rDNA-ITS2 based species-diagnostic polymerase chain reaction assay for identification of sibling species of Anopheles fluviatilis in Iran.

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    Dezfouli, S R Naddaf; Oshaghi, M A; Vatandoost, H; Assmar, M

    2003-01-01

    A species-specific polymerase chain reaction (PCR) assay using primers already designed, based on differences in the nucleotides of the second internal transcribed spacer (ITS2), was used to identify the species composition of the Anopheles fluviatilis complex in Iran. All the amplified DNA samples obtained from specimens collected from different areas using different collection methods yielded to a fragment of 450 bp size, a PCR product corresponding to the species denoted as Y. Some 21 ITS2 region of Iranian specimens were sequenced and compared with the already published sequence data of species Y from India. The sequence data of the Iranian specimens were 100% identical to that of the Indian specimens, and hence confirmed the PCR assay results. Species Y is presumably species T in India, which has no role in the transmission of malaria, whereas mosquitos of An. fluviatilis are known as a secondary vector in Iran. This conflict will remain to be solved by further biological and molecular studies.

  6. Malaria vectors in the Republic of Benin: distribution of species and molecular forms of the Anopheles gambiae complex.

    Science.gov (United States)

    Djogbénou, Luc; Pasteur, Nicole; Bio-Bangana, Sahabi; Baldet, Thierry; Irish, Seth R; Akogbeto, Martin; Weill, Mylène; Chandre, Fabrice

    2010-05-01

    Members of the Anopheles gambiae complex are among the best malaria vectors in the world, but their vectorial capacities vary between species and populations. A large-scale sampling of An. gambiae sensu lato was carried out in 2006 and 2007 in various bioclimatic areas of Benin (West Africa). The objective of this study was to collate data on the relative frequencies of species and forms within the An. gambiae complex and to produce a map of their spatial distribution. Sampling took place at 30 sites and 2122 females were analyzed. Two species were identified through molecular methods. The overall collection showed a preponderance of An. gambiae s.s., but unexpectedly, An. arabiensis was reported in the coastal-Guinean bioclimatic area characterized by a mean annual rainfall of >1500 mm where only An. gambiae s.s. was reported previously. Our study of Benin indicates that An. arabiensis would be adapted not only to the urban areas but also to the rural humid regions. Among 1717 An. gambiae s.s., 26.5% were of the M form and 73.3% were S form. Few hybrid specimens between the M and S forms were observed (0.2%). Only the spatial distribution of the M form appears to be mainly a function of bioclimatic area. Factors that influence the distribution of these malaria vectors are discussed. This study underlines the need of further investigations of biological, ecological, and behavioral traits of these species and forms to better appreciate their vectorial capacities. Acquisition of entomological field data appears essential to better estimate the stratification of malaria risk and help improve malaria vector control interventions.

  7. Espécies de Anopheles (Culicidae, Anophelinae em área endêmica de malária, Maranhão, Brasil Species of Anopheles (Culicidae, Anophelinae in a malaria-endemic area, Maranhão, Brazil

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    Maria M dos SP Xavier

    1999-12-01

    Full Text Available OBJETIVO: Estudar a flutuação sazonal, freqüência horária, abundância relativa e riqueza de espécies de Anopheles em ambiente antrópico, para entender a bioecologia do grupo e para a monitorização do programa de controle da malária. MÉTODOS: Os anofelinos foram estudados durante um ano, de outubro de 1996 a setembro de 1997, das 18 às 6 horas, a cada 30 dias, no Município da Raposa, Ilha de São Luís, Maranhão. Utilizou-se o método de captura de fêmeas em iscas humanas no intra e peridomicílio, com tubo de sucção e foco luminoso orientado. RESULTADOS: Foram coletados 1.407 espécimes assim distribuídos: Anopheles aquasalis (82%, Anopheles galvaoi (10,2% e Anopheles albitarsis (6,4%. As demais espécies, Anopheles evansae, Anopheles nuneztovari e Anopheles triannulatus davisi representaram juntas 1,4%. Os anofelinos ocorreram o ano inteiro, principalmente no período chuvoso, sendo mais freqüentes no intra (75,3% do que no peridomicílio (24,7%, preferindo sugar sangue no crepúsculo vespertino e nas primeiras horas da noite. CONCLUSÃO: As variações observadas no comportamento do anofelino mostram que as diferentes espécies vêm adaptando-se, em maior ou menor grau, ao convívio com o homem nas suas habitações.INTRODUCTION: The study of the seasonal fluctuation, nocturnal activity, relative abundance and the richness of Anopheles species in anthropic environment is essential to the understanding of the their bioecology and to the surveillance program of malaria control. METHODS: The Anopheles species were studied from 6 P.M. to 6 A.M., once a month, for one year, from October 1996 to September 1997, in the municipal district of Raposa, of the São Luís island, Maranhão state. The basic method was the capture of female specimens on human baits in peri and intradomicile sites by means of aspiration tube and guided luminous focus. RESULTS: A total of 1.407 specimens were collected and distributed as follow: Anopheles

  8. Population dynamics of sporogony for Plasmodium vivax parasites from western Thailand developing within three species of colonized Anopheles mosquitoes

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    Sattabongkot Jetsumon

    2006-08-01

    Full Text Available Abstract Background The population dynamics of Plasmodium sporogony within mosquitoes consists of an early phase where parasite abundance decreases during the transition from gametocyte to oocyst, an intermediate phase where parasite abundance remains static as oocysts, and a later phase where parasite abundance increases during the release of progeny sporozoites from oocysts. Sporogonic development is complete when sporozoites invade the mosquito salivary glands. The dynamics and efficiency of this developmental sequence were determined in laboratory strains of Anopheles dirus, Anopheles minimus and Anopheles sawadwongporni mosquitoes for Plasmodium vivax parasites circulating naturally in western Thailand. Methods Mosquitoes were fed blood from 20 symptomatic Thai adults via membrane feeders. Absolute densities were estimated for macrogametocytes, round stages (= female gametes/zygotes, ookinetes, oocysts, haemolymph sporozoites and salivary gland sporozoites. From these census data, five aspects of population dynamics were analysed; 1 changes in life-stage prevalence during early sporogony, 2 kinetics of life-stage formation, 3 efficiency of life-stage transitions, 4 density relationships between successive life-stages, and 5 parasite aggregation patterns. Results There was no difference among the three mosquito species tested in total losses incurred by P. vivax populations during early sporogony. Averaged across all infections, parasite populations incurred a 68-fold loss in abundance, with losses of ca. 19-fold, 2-fold and 2-fold at the first (= gametogenesis/fertilization, second (= round stage transformation, and third (= ookinete migration life-stage transitions, respectively. However, total losses varied widely among infections, ranging from 6-fold to over 2,000-fold loss. Losses during gametogenesis/fertilization accounted for most of this variability, indicating that gametocytes originating from some volunteers were more fertile than

  9. The Anopheles gambiae oxidation resistance 1 (OXR1 gene regulates expression of enzymes that detoxify reactive oxygen species.

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    Giovanna Jaramillo-Gutierrez

    Full Text Available BACKGROUND: OXR1 is an ancient gene, present in all eukaryotes examined so far that confers protection from oxidative stress by an unknown mechanism. The most highly conserved region of the gene is the carboxyl-terminal TLDc domain, which has been shown to be sufficient to prevent oxidative damage. METHODOLOGY/PRINCIPAL FINDINGS: OXR1 has a complex genomic structure in the mosquito A. gambiae, and we confirm that multiple splice forms are expressed in adult females. Our studies revealed that OXR1 regulates the basal levels of catalase (CAT and glutathione peroxidase (Gpx expression, two enzymes involved in detoxification of hydrogen peroxide, giving new insight into the mechanism of action of OXR1. Gene silencing experiments indicate that the Jun Kinase (JNK gene acts upstream of OXR1 and also regulates expression of CAT and GPx. Both OXR1 and JNK genes are required for adult female mosquitoes to survive chronic oxidative stress. OXR1 silencing decreases P. berghei oocyst formation. Unexpectedly, JNK silencing has the opposite effect and enhances Plasmodium infection in the mosquito, suggesting that JNK may also mediate some, yet to be defined, antiparasitic response. CONCLUSION: The JNK pathway regulates OXR1 expression and OXR1, in turn, regulates expression of enzymes that detoxify reactive oxygen species (ROS in Anopheles gambiae. OXR1 silencing decreases Plasmodium infection in the mosquito, while JNK silencing has the opposite effect and enhances infection.

  10. Inferring selection in the Anopheles gambiae species complex: an example from immune-related serine protease inhibitors

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    Little Tom J

    2009-06-01

    Full Text Available Abstract Background Mosquitoes of the Anopheles gambiae species complex are the primary vectors of human malaria in sub-Saharan Africa. Many host genes have been shown to affect Plasmodium development in the mosquito, and so are expected to engage in an evolutionary arms race with the pathogen. However, there is little conclusive evidence that any of these mosquito genes evolve rapidly, or show other signatures of adaptive evolution. Methods Three serine protease inhibitors have previously been identified as candidate immune system genes mediating mosquito-Plasmodium interaction, and serine protease inhibitors have been identified as hot-spots of adaptive evolution in other taxa. Population-genetic tests for selection, including a recent multi-gene extension of the McDonald-Kreitman test, were applied to 16 serine protease inhibitors and 16 other genes sampled from the An. gambiae species complex in both East and West Africa. Results Serine protease inhibitors were found to show a marginally significant trend towards higher levels of amino acid diversity than other genes, and display extensive genetic structuring associated with the 2La chromosomal inversion. However, although serpins are candidate targets for strong parasite-mediated selection, no evidence was found for rapid adaptive evolution in these genes. Conclusion It is well known that phylogenetic and population history in the An. gambiae complex can present special problems for the application of standard population-genetic tests for selection, and this may explain the failure of this study to detect selection acting on serine protease inhibitors. The pitfalls of uncritically applying these tests in this species complex are highlighted, and the future prospects for detecting selection acting on the An. gambiae genome are discussed.

  11. Six New Species of the Anopheles leucosphyrus Group, Reinterpretation of An. elegans and Vector Implications

    Science.gov (United States)

    2005-06-01

    vivax, Wuchereria, Culicidae, filaria vector, forest malaria vectors, malaria transmission, new species, morphology, mosquito systematics, Oriental...and filaria (Wuchereria spp.) parasites among primates in and near forests. For example, An. latens (which has been largely misidentified as An...species (Baimai elal., 1988c) that may also contribute to the transmission of both malaria and filaria parasites. Additionally, All. cracclls is

  12. Chromosomal inversions, natural selection and adaptation in the malaria vector Anopheles funestus

    NARCIS (Netherlands)

    Ayala, Diego; Fontaine, Michael C; Cohuet, Anna; Fontenille, Didier; Vitalis, Renaud; Simard, Frédéric

    2011-01-01

    Chromosomal polymorphisms, such as inversions, are presumably involved in the rapid adaptation of populations to local environmental conditions. Reduced recombination between alternative arrangements in heterozygotes may protect sets of locally adapted genes, promoting ecological divergence and pote

  13. Male motion coordination in swarming Anopheles gambiae and Anopheles coluzzii

    Science.gov (United States)

    The Anopheles gambiae species complex comprises the primary vectors of malaria in much of sub-Saharan Africa; most of the mating in these species occurs in swarms composed almost entirely of males. Intermittent, parallel flight patterns in such swarms have been observed, but a detailed description o...

  14. LARVICIDAL ACTIVITY OF Bacillus sphaericus 2362 AGAINST Anopheles nuneztovari, Anopheles darlingi AND Anopheles braziliensis (DIPTERA, CULICIDAE

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    RODRIGUES Iléa Brandão

    1999-01-01

    Full Text Available In this present study, preliminary data was obtained regarding the mortality rate of the Amazonian anophelines, Anopheles nuneztovari, Anopheles darlingi and Anopheles braziliensis when subjected to treatment with Bacillus sphaericus strain 2362, the WHO standard strain. Initially, experiments were conducted to test the mortality rate of the three species of anopheline larvae. The third larval instar of An. nuneztovari and the second and third larval instars of An. darlingi proved to be the least susceptible. In other experiments, the same three mosquito species were tested with the standard strain 2362, An. nuneztovari was the least susceptible to this insect pathogen, while An. braziliensis was the most susceptible. This latter species showed a difference in the level of LC50 concentration, when compared to the former, of 2.4, 2.5 and 1.8 in readings taken 24, 48 and 72 hours after exposure to the bacillus.

  15. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

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    Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

  16. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background: Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (specie

  17. Insecticidal potency of Aspergillus terreus against larvae and pupae of three mosquito species Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

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    Ragavendran, Chinnasamy; Natarajan, Devarajan

    2015-11-01

    Microbial control agents offer alternatives to chemical pest control, as they can be more selective than chemical insecticides. The present study evaluates the mosquito larvicidal and pupicidal potential of fungus mycelia using ethyl acetate and methanol solvent extracts produced by Aspergillus terreus against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti. The A. terreus mycelia were extracted after 15 days from Sabouraud dextrose broth medium. The ethyl acetate extracts showed lethal concentration that kills 50% of the exposed larvae (LC50) and lethal concentration that kills 90% of the exposed larvae (LC90) values of the first, second, third, and fourth instar larvae of An. stephensi (LC50 = 97.410, 102.551, 29.802, and 8.907; LC90 = 767.957, 552.546, 535.474, and 195.677 μg/ml), Cx. quinquefasciatus (LC50 = 89.584, 74.689, 68.265, and 67.40; LC90 = 449.091, 337.355, 518.793, and 237.347 μg/ml), and Ae. aegypti (LC50 = 83.541, 84.418, 80.407, and 95.926; LC90 = 515.464, 443.167, 387.910, and 473.998 μg/ml). Pupicidal activity of mycelium extracts was tested against An. stephensi (LC50 = 25.228, LC90 = 140.487), Cx. quinquefasciatus (LC50 = 54.525, LC90 = 145.366), and Ae. aegypti (LC50 = 10.536, LC90 = 63.762 μg/ml). At higher concentration (500 μg/ml), mortality starts within the first 6 h of exposure. One hundred percent mortality occurs at 24-h exposure. The overall result observed that effective activity against selected mosquito larvae and pupae after 24 h was a dose and time-dependent activity. These ensure that the resultant mosquito population reduction is substantial even where the larvicidal and pupicidal potential is minimal. The FTIR spectra of ethyl acetate extract reflect prominent peaks (3448.32, 3000.36, 2914.59, 2118.73, 1668.21, 1436.87, 1409.02, 954.33, 901.13, and 704.67 cm(-1)). The spectra showed a sharp absorption band at 1314.66 cm(-1) assigned to wagging vibration of

  18. Cryptic Species in the Anopheles (Nyssorhynchus) albitarsis (Diptera: Culicidae) Complex: Incongruence Between Random Amplified Polymorphic DNA-Polymerase Chain Reaction Identification and Analysis of Mitochondrial DNA COI Gene Sequences

    Science.gov (United States)

    2005-11-01

    SYSTEMATICS Cryptic Species in the Anopheles (Nyssorhynchus) albitarsis (Diptera: Culicidae) Complex: Incongruence Between Random Amplified...J.M.,O.Pellmyr, J.N.Thompson, andR.G.Harrison. 1994. Phylogeny of Greya ( Lepidoptera : Prodoxidae), based on nucleotide sequence variation in

  19. Impact of insecticide-treated materials on filaria transmission by the various species of vector mosquito in Africa.

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    Pedersen, E M; Mukoko, D A

    2002-12-01

    Nocturnally periodic bancroftian filariasis is maintained by three mainly endophilic vectors in East Africa: Culex quinquefasciatus, Anopheles funestus and the An. gambiae complex. Permethrin-impregnated bednets provide considerable protection against these mosquitoes, but the species respond differently. The degree of protection conferred by treated bednets was determined in Kenyan communities where all three vectors actively transmit Wuchereria bancrofti. The annual transmission potential in the communities (i.e. an estimate of the number of human infective, third-stage larvae of W. bancrofti inoculated into each villager each year) was reduced by 92%, through the nets' impact on vector biting rates (reduced by 22%) and their cumulative impact on the annual infective biting rate (reduced by 95%). Thus a modest reduction in the numbers of mosquitoes biting humans, attributable to the use of the insecticide-treated nets, strongly suppressed the risk of W. bancrofti transmission.

  20. Incomplete concerted evolution and reproductive isolation at the rDNA locus uncovers nine cryptic species within Anopheles longirostris from Papua New Guinea

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    Cooper Robert D

    2010-12-01

    Full Text Available Abstract Background Nuclear ribosomal DNA (rDNA genes and transcribed spacers are highly utilized as taxonomic markers in metazoans despite the lack of a cohesive understanding of their evolution. Here we follow the evolution of the rDNA second internal transcribed spacer (ITS2 and the mitochondrial DNA cytochrome oxidase I subunit in the malaria mosquito Anopheles longirostris from Papua New Guinea (PNG. This morphospecies inhabits a variety of ecological environments indicating that it may comprise a complex of morphologically indistinguishable species. Using collections from over 70 sites in PNG, the mtDNA was assessed via direct DNA sequencing while the ITS2 was assessed at three levels - crude sequence variation through restriction digest, intragenomic copy variant organisation (homogenisation through heteroduplex analysis and DNA sequencing via cloning. Results Genetic evaluation of over 300 individuals revealed that A. longirostris comprises eight ITS2 PCR-RFLP genotypes and nine ITS2 heteroduplex genotypes showing distinct copy variant organization profiles after PCR amplification. Seven of these nine genotypes were found to be sympatric with other genotypes. Phylogenetic analysis of cloned ITS2 PCR products and mtDNA COI confirmed all nine clades with evidence of reproductive isolation at the rDNA locus. Compensatory base changes in the ITS2 secondary structure or in pseudoknots were absent when closely related species were assessed. Individuals from each ITS2 genotype showed the same copy variant heteroduplex profile suggesting that the rDNA array is fixed within each genotype. Conclusion The centromere-proximal position of the rDNA array in Anopheles mosquitoes has probably reduced interchromosomal recombination leaving intrachromosomal events responsible for the observed pattern of concerted evolution we see in these mosquitoes. The stability of these intragenomic ITS2 copy variants within individuals and interbreeding populations

  1. Variations in susceptibility to common insecticides and resistance mechanisms among morphologically identified sibling species of the malaria vector Anopheles subpictus in Sri Lanka

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    Surendran Sinnathamby N

    2012-02-01

    Full Text Available Abstract Background Anopheles subpictus s.l., an important malaria vector in Sri Lanka, is a complex of four morphologically identified sibling species A-D. Species A-D reportedly differ in bio-ecological traits that are important for vector control. We investigated possible variations that had not been reported previously, in the susceptibility to common insecticides and resistance mechanisms among the An. subpictus sibling species. Methods Adult An. subpictus were collected from localities in four administrative districts in the dry zone of Sri Lanka. Single female isoprogeny lines were established and sibling species status determined according to reported egg morphology. World Health Organization's standard protocols were used for insecticide bioassays and biochemical assays to determine insecticide susceptibility and resistance mechanisms. Susceptibility of mosquitoes was tested against DDT (5%, malathion (4%, deltamethrin (0.05% and λ-cyhalothrin (0.05%. Biochemical basis for resistance was determined through assaying for esterase, glutathione-S-transferase and monooxygenase activities and the insensitivity of acetycholinesterase (AChE to propoxur inhibition. Results All sibling species were highly resistant to DDT. However there were significant differences among the sibling species in their susceptibility to the other tested insecticides. Few species A could be collected for testing, and where testing was possible, species A tended to behave more similarly to species C and D than to B. Species B was more susceptible to all the tested insecticides than the other sibling species. This difference may be attributed to the predominance of species B in coastal areas where selection pressure due to indoor residual spraying of insecticides (IRS was lower. However there were significant differences between the more inland species C and D mainly towards pyrethroids. Higher GST activities in species C and D might have contributed to their greater

  2. Bionomics of Anopheles spp. (Diptera: Culicidae) in a malaria endemic region of Sukabumi, West Java, Indonesia.

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    Stoops, Craig A; Rusmiarto, Saptoro; Susapto, Dwiko; Munif, Amurl; Andris, Heri; Barbara, Kathryn A; Sukowati, Supratman

    2009-12-01

    A 15-month bionomic study of Anopheles species was conducted in two ecologically distinct villages (coastal and upland) of Sukabumi District, West Java, Indonesia from June 2006 to September 2007. Mosquitoes were captured using human-landing collections at both sites. During the study, a total of 17,100 Anopheles mosquitoes comprising 13 Anopheles species were caught: 9,151 at the coastal site and 7,949 at the upland site. Anopheles barbirostris, Anopheles maculatus, and Anopheles vagus were the predominant species caught at the coastal site, and Anopheles aconitus, Anopheles barbirostris, and An. maculatus predominated in the upland site. Overall, species were exophagic at both sites, but there was variation between species. Anopheles aconitus was endophagic at the coastal site, exophagic at the upland site, collected most often in April 2007 and had a peak landing time between 22:00 and 23:00. Anopheles sundaicus was only collected at the coastal site, exophagic, collected most often in October 2006, and had a peak landing time between 19:00 and 20:00. Potential malaria vector species such An. aconitus, An. maculatus, and An. sundaicus were present throughout the year. None of the 7,770 Anopheles tested using CSP-ELISA were positive for malaria, although the risk for malaria outbreaks in Sukabumi district remains high.

  3. Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil

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    Terry A. Klein

    1991-03-01

    Full Text Available Mosquito collections were made in and near Costa Marques, Rondonia, Brazil, to determine anopheline anthropophilic/zoophilic behavior. Collections from a non-illuminated, bovine-baited trap and indoor and outdoor human-bait collections were compared. Anopheles darlingi and Anopheles deaneorum were more anthropophilic than the other anophelines collected. The remainder of the Anopheles species were collected much morefrequently in bovine-baited traps than in human-bait collections. Anopheles darlingi and An. deaneorum were more frequently collected inside houses than the other anopheline species. But, when collections were made in a house with numerous openings in the walls, there were few differences in the percentages of each species biting man indoors versus outdoors. Anopheles darlingi was the predominant mosquito collected, both inside and outside houses, and had the strongest anthropophilic feeding behavior of the anophelines present.Para determinar o comportamento antropofilico e zoofilico dos anofelinos, foram capturados mosquitos na periferia e na zona urbana de Costa Marques, Rondônia, Brasil. Foram comparadas as capturas feitas à noite, com iscas bovinas e humanas, dentro efora de casa. O Anopheles darlingi e o Anopheles deaneorumforam mais antropojilicos do que os outros anofelinos capturados. O restante das espécies anofelinas foi capturado mais freqüentemente nas iscas bovinas do que nas humanas. Anopheles darlingi e Anopheles deaneorumforam capturados dentro de casa com mais freqüência do que as outras espécies anofelinas. Porém, quando a captura foi feita em casas com muitas aberturas nas paredes houve pouca diferença nas porcentagens de cada espécie sugadora de humanos dentro efora de casa. Anopheles darlingi foi o mosquito capturado com mais freqüência, dentro e fora de casa, e apresentava maior antropofilia em relação aos outros anofelinos presentes.

  4. Vector competence of Anopheles and Culex mosquitoes for Zika virus

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    Dodson, Brittany L.

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus. PMID:28316896

  5. Vector competence of Anopheles and Culex mosquitoes for Zika virus

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    Brittany L. Dodson

    2017-03-01

    Full Text Available Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  6. Vector competence of Anopheles and Culex mosquitoes for Zika virus.

    Science.gov (United States)

    Dodson, Brittany L; Rasgon, Jason L

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  7. Mathematical evaluation of community level impact of combining bed nets and indoor residual spraying upon malaria transmission in areas where the main vectors are Anopheles arabiensis mosquitoes

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    Okumu Fredros O

    2013-01-01

    whether they are delivered as LLINs or IRS. The insecticidal action of LLINs and IRS probably already approaches their absolute limit of potential impact upon this persistent vector so personal protection of nets should be enhanced by improving the physical integrity and durability. Combining LLINs and non-pyrethroid IRS in residual transmission systems may nevertheless be justified as a means to manage insecticide resistance and prevent potential rebound of not only An. arabiensis, but also more potent, vulnerable and historically important species such as Anopheles gambiae and Anopheles funestus.

  8. Linking land cover and species distribution models to project potential ranges of malaria vectors: an example using Anopheles arabiensis in Sudan and Upper Egypt

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    Fuller Douglas O

    2012-08-01

    Full Text Available Abstract Background Anopheles arabiensis is a particularly opportunistic feeder and efficient vector of Plasmodium falciparum in Africa and may invade areas outside its normal range, including areas separated by expanses of barren desert. The purpose of this paper is to demonstrate how spatial models can project future irrigated cropland and potential, new suitable habitat for vectors such as An. arabiensis. Methods Two different but complementary spatial models were linked to demonstrate their synergy for assessing re-invasion potential of An. arabiensis into Upper Egypt as a function of irrigated cropland expansion by 2050. The first model (The Land Change Modeler was used to simulate changes in irrigated cropland using a Markov Chain approach, while the second model (MaxEnt uses species occurrence points, land cover and other environmental layers to project probability of species presence. Two basic change scenarios were analysed, one involving a more conservative business-as-usual (BAU assumption and second with a high probability of desert-to-cropland transition (Green Nile to assess a broad range of potential outcomes by 2050. Results The results reveal a difference of 82,000 sq km in potential An. arabiensis range between the BAU and Green Nile scenarios. The BAU scenario revealed a highly fragmented set of small, potential habitat patches separated by relatively large distances (maximum distance = 64.02 km, mean = 12.72 km, SD = 9.92, while the Green Nile scenario produced a landscape characterized by large patches separated by relatively shorter gaps (maximum distance = 49.38, km, mean = 4.51 km, SD = 7.89 that may be bridged by the vector. Conclusions This study provides a first demonstration of how land change and species distribution models may be linked to project potential changes in vector habitat distribution and invasion potential. While gaps between potential habitat patches remained large in the

  9. The fine-scale genetic structure of the malaria vectors Anopheles funestus and Anopheles gambiae (Diptera: Culicidae) in the north-eastern part of Tanzania

    NARCIS (Netherlands)

    Gélin, P.; Magalon, H.; Drakeley, C.; Maxwell, C.; Magesa, S.; Takken, W.; Boëte, C.

    2016-01-01

    Understanding the impact of altitude and ecological heterogeneity at a fine scale on the populations of malaria vectors is essential to better understand and anticipate eventual epidemiological changes. It could help to evaluate the spread of alleles conferring resistance to insecticides and also

  10. Environmental factors associated with spatial and temporal distribution of Anopheles (Diptera: Culicidae) larvae in Sukabumi, West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Gionar, Yoyo R; Shinta; Sismadi, Priyanto; Elyazar, Iqbal R F; Bangs, Michael J; Sukowati, Supratman

    2007-07-01

    A 12-mo ecological study of the spatial-temporal distribution of immature stages of Anopheles species was conducted in Sukabumi District, West Java, Indonesia. The study characterized 1,600 sites from a contiguous coastal and hill zone (0-800-m elevation) of which 64% contained Anopheles larvae. Principal component and multiple logistic regression analyses identified ecological parameters associated with presence of nine [Anopheles aconitus Doenitz, Anopheles annularis Van de Wulp, Anopheles barbirostris Van der Wulp, Anopheles flavirostris (Ludlow), Anopheles insulaeflorum (Swellengrebel and Swellengrebel de Graaf), Anopheles kochi Doenitz, Anopheles maculatus Theobald, Anopheles sundaicus (Rodenwaldt), and Anopheles vagus Doenitz] of 15 Anopheles species collected. Combined data for all nine species showed increased Anopheles presence associated with wet season periods and higher elevation habitats exhibiting reduced tree canopy coverage, higher water temperatures, and shallower water depths. Habitat variables measured included topography (elevation), water conditions (temperature, pH, salinity depth, and velocity), habitat characteristics (substrate and canopy cover), density and type of aquatic vegetation coverage (riparian, floating, and emergent), and distance from nearest human habitation. Significant relationships were found for nine species when using all habitats in the analysis. Habitat characteristics for three species were refined. An. aconitus and An. barbirostris were associated with higher elevation rice, Oryza savita L., paddies with relatively shallow water depths, higher water temperatures, higher acidity and salinity concentrations, and a greater average distance from human habitation. An. vagus presence in rice paddies was associated with lower elevation fields, deeper and cooler water, less acidic and saline conditions, and habitats closer to human dwellings. Overall, the distribution of Anopheles species in Sukabumi was found to be nonrandom

  11. The complete mitochondrial genome of Anopheles minimus (Diptera: Culicidae) and the phylogenetics of known Anopheles mitogenomes.

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    Hua, Ya-Qiong; Ding, Yi-Ran; Yan, Zhen-Tian; Si, Feng-Ling; Luo, Qian-Chun; Chen, Bin

    2016-06-01

    Anopheles minimus is an important vector of human malaria in southern China and Southeast Asia. The phylogenetics of mosquitoes has not been well resolved, and the mitochondrial genome (mtgenome) has proven to be an important marker in the study of evolutionary biology. In this study, the complete mtgenome of An. minimus was sequenced for the first time. It is 15 395 bp long and encodes 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and a non-coding region. The gene organization is consistent with those of known Anopheles mtgenomes. The mtgenome performs a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. All 13 PCGs prefer to use the codon UUA (Leu), ATN as initiation codon but cytochrome-oxidase subunit 1 (COI) and ND5, with TCG and GTG, and TAA as termination codon, but COI, COII, COIII and ND4, all with the incomplete T. tRNAs have the typical clover-leaf structure, but tRNA(Ser(AGN)) is consistent with known Anopheles mtgenomes. The control region includes a conserved T-stretch and a (TA)n stretch, and has the highest A+T content at 93.1%. The phylogenetics of An. minimus with 18 other Anopheles species was constructed by maximum likelihood and Bayesian inference, based on concatenated PCG sequences. The subgenera, Cellia and Anopheles, and Nyssorhynchus and Kerteszia have mutually close relationships, respectively. The Punctulatus group and Leucosphyrus group of Neomyzomyia Series, and the Albitarsis group of Albitarsis Series were suggested to be monophyletic. The monophyletic status of the subgenera, Cellia, Anopheles, Nyssorhynchus and Kerteszia need to be further elucidated.

  12. Espécies de Anopheles no município de Pinheiro (Maranhão, área endêmica de malária Species of Anopheles in Pinheiro municipality (Maranhão, endemic area of malaria

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    Yrla Nívea Oliveira-Pereira

    2000-10-01

    Full Text Available A riqueza, abundância relativa, flutuação sazonal, preferência por ambiente (peri e intradomicílio e horários de hematofagismo de espécies de Anopheles foram estudados no município de Pinheiro, Maranhão. As fêmeas foram capturadas mensalmente sobre iscas humanas de maio/1998 a abril/1999, das 18 às 6 horas. Foram coletados 1.321 espécimens pertencentes a 10 espécies de Anopheles, todas do subgênero Nyssorhynchus: A. argyritarsis com 62%, A. darlingi (21,7%, A. albitarsis (4,5%, A. galvaoi (4%, A. triannulatus (3,1% e A. evansae (2,8%. As espécies A. nuneztovari, A. braziliensis, A. rondoni e A. strodei representaram juntas 1,9%. Os anofelinos ocorreram o ano todo, não havendo diferença significativa no número de exemplares capturados entre as estações chuvosa (51,7% e seca (48,3%. A freqüência dos anofelinos no peridomicílio foi significativamente maior (p The Anophelae species of the municipal district of Pinheiro, Maranhão State, Brazil, were studied, considering their variety, relative abundance, seasonal fluctuation, preference by the peri and intra domiciles as well as the hours of hematophagism. The females were captured using human bait, on a monthly basis from May/1998 to April/1999, from 6 p.m. to 6 a.m. A total of 1,321 specimens of 10 species were captured, all belonging to the subgenus Nyssorhynchus. The most frequent species were A. argyritarsis (62%, A. darlingi (21.7%, A. albitarsis (4.5%, A. galvaoi (4.0%, A. triannulatus (3.1% and A. evansae (2.8%. The species A. nuneztovari, A. braziliensis, A. rondoni and A. strodei together represented 1.9%. The anophelines occurred all year round, with no significant difference in the number of specimens captured between the rainy (51.7% and dry season (48.3%. The frequency of the females in the peridomicile was significantly higher (p < 0.01 (82%, than in the intradomicile (18%, preferring to suck blood at dusk and in the first hours of the night.

  13. Diversity of the Bacterial Microbiota of Anopheles Mosquitoes from Binh Phuoc Province, Vietnam.

    Science.gov (United States)

    Ngo, Chung T; Romano-Bertrand, Sara; Manguin, Sylvie; Jumas-Bilak, Estelle

    2016-01-01

    The naturally acquired microbiota of Anopheles can influence vector's susceptibility to Plasmodium and its capacity to transmit them. Microbiota modification is a new challenge to limit disease transmission but it still needs advanced knowledges on bacterial community in Anopheles, especially in wild and infected specimens from diverse origin and species. Bacterial culture and 16S rRNA gene-PCR associated to Temporal Temperature Gradient Electrophoresis (TTGE) were applied to explore the bacterial diversity in the abdomen of 100 wild specimens (eight Anopheles species) collected in the Binh Phuoc Province, Vietnam. Culture and PCR-TTGE were complementary. The bacterial richness of the mosquito collection encompassed 105 genera belonging to seven phyla, mostly Proteobacteria, Firmicutes, and Actinobacteria. Staphylococcus, Clostridium, and Bacillus in Firmicutes were the most prevalent genera. However, Proteobacteria represented by 57 genera was the most diversified phylum in Anopheles microbiota. The high overall of Anopheles-associated bacteria is confirmed with, to our knowledge, 51 genera described for the first time in Anopheles microbiota. However, the diversity per specimen was low with average diversity index and the average Shannon-Wiener score (H) of 4.843 and 5.569, respectively. The most represented bacterial genera were present in microbiota share by Anopheles from Binh Phuoc was very narrow, suggesting that Anopheles microbiota was greatly influenced by local environments. The repertory of bacterial genera in two specimens of An. dirus and An. pampanai naturally infected by Plasmodium vivax was also described as preliminary results. Finally, this study completed the repertory of bacteria associated to wild Anopheles. Anopheles associated-bacteria appeared specimen-dependent rather than mosquitoe species- or group-dependent. Their origin and the existence of Anopheles-specific bacterial taxa are discussed.

  14. "Use of Random Amplified Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR and ITS2 PCR assays for differentiation of populations and putative sibling species of Anopheles fluviatilis (Diptera: Culicidae in Iran"

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    SR Naddaf Dezfouli

    2002-09-01

    Full Text Available Anopheles fluviatilis complex is known to be a vector of malaria in Iran. Since mosquitoes of this species cover a wide geographical range in Iran, they might have evolved into different separated populations. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR assay was used to differentiate geographic populations of this species. DNA was extracted from individual mosquitoes from 8 localities in 4 south and southeast provinces and amplified in PCR reactions using 18 single primers of arbitrary nucleotide sequence. Results of RAPD-PCR showed that Kazeroun populations could simply be differentiated from other populations using a diagnostic fragment amplified with primer UBC-306. But other populations could not be differentiated either visually or by means of statistical analysis. Moreover ITS2 fragments of some selected specimens were amplified using a pair of universal primer and sequenced as a key standard for detection of putative sibling species. Sequence analysis of the ITS2 fragments revealed a very high (100% homology among the populations. These findings are crucial in epidemiological studies concerning relatedness of geographic populations and vector movement in the region. Results of RAPD-PCR and ITS2 analysis suggest that this taxon in Iran comprises of only one species with a low genetic variation among geographic populations.

  15. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

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    Takken Willem

    2010-01-01

    Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

  16. Genetic compatibility between Anopheles lesteri from Korea and Anopheles paraliae from Thailand

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    Kritsana Taai

    2013-05-01

    Full Text Available To assess differentiation and relationships between Anopheles lesteri and Anopheles paraliae we established three and five iso-female lines of An. lesteri from Korea and An. paraliae from Thailand, respectively. These isolines were used to investigate the genetic relationships between the two taxa by crossing experiments and by comparing DNA sequences of ribosomal DNA second internal transcribed spacer (ITS2 and mitochondrial DNA cytochrome c oxidase subunit I (COI and subunit II (COII. Results of reciprocal and F1-hybrid crosses between An. lesteri and An. paraliae indicated that they were compatible genetically producing viable progenies and complete synaptic salivary gland polytene chromosomes without inversion loops in all chromosome arms. The pairwise genetic distances of ITS2, COI and COII between these morphological species were 0.040, 0.007-0.017 and 0.008-0.011, respectively. The specific species status of An. paraliae in Thailand and/or other parts of the continent are discussed.

  17. Diversification of the Genus Anopheles and a Neotropical Clade from the Late Cretaceous.

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    Lucas A Freitas

    Full Text Available The Anopheles genus is a member of the Culicidae family and consists of approximately 460 recognized species. The genus is composed of 7 subgenera with diverse geographical distributions. Despite its huge medical importance, a consensus has not been reached on the phylogenetic relationships among Anopheles subgenera. We assembled a comprehensive dataset comprising the COI, COII and 5.8S rRNA genes and used maximum likelihood and Bayesian inference to estimate the phylogeny and divergence times of six out of the seven Anopheles subgenera. Our analysis reveals a monophyletic group composed of the three exclusively Neotropical subgenera, Stethomyia, Kerteszia and Nyssorhynchus, which began to diversify in the Late Cretaceous, at approximately 90 Ma. The inferred age of the last common ancestor of the Anopheles genus was ca. 110 Ma. The monophyly of all Anopheles subgenera was supported, although we failed to recover a significant level of statistical support for the monophyly of the Anopheles genus. The ages of the last common ancestors of the Neotropical clade and the Anopheles and Cellia subgenera were inferred to be at the Late Cretaceous (ca. 90 Ma. Our analysis failed to statistically support the monophyly of the Anopheles genus because of an unresolved polytomy between Bironella and A. squamifemur.

  18. Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence

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    Lwetoijera Dickson W

    2009-12-01

    Full Text Available Abstract Background Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana isolates have been shown to infect and reduce the survival of mosquito vectors. Methods Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates M. anisopliae ICIPE-30 and B. bassiana I93-925 on infection and survival rates of female Anopheles gambiae sensu stricto. Test concentrations and exposure times ranged between 1 × 107 - 4 × 1010 conidia m-2 and 15 min - 6 h. In co-formulations, 2 × 1010 conidia m-2 of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 109, 2 × 1010 or 4 × 1010. Results Mosquito survival varied with conidia concentration; 2 × 1010 conidia m-2 was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d. Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence. Conclusion Both fungus isolates are effective and persistent at low concentrations and short exposure times.

  19. The evolution of the Anopheles 16 genomes project

    NARCIS (Netherlands)

    Neafsey, Daniel E.; Christophides, George K.; Collins, Frank H.; Emrich, Scott J.; Fontaine, Michael C.; Gelbart, William; Hahn, Matthew W.; Howell, Paul I.; Kafatos, Fotis C.; Lawson, Daniel; Muskavitch, Marc A. T.; Waterhouse, Robert M.; Williams, Louise J.; Besansky, Nora J.

    2013-01-01

    We report the imminent completion of a set of reference genome assemblies for 16 species of Anopheles mosquitoes. In addition to providing a generally useful resource for comparative genomic analyses, these genome sequences will greatly facilitate exploration of the capacity exhibited by some Anophe

  20. "LABORATORY EXPERIMENTS ON THE IRRITABILITY OF ANOPHELES ATROPARVUS AND ANOPHELES STEPHENSI TO DDT "

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    N. Eshghy

    1977-07-01

    Full Text Available Two strains of Anopheles atroparvus, one resistant and another sceptible to DDT and two of Anopheles stephensi, one resistant and one susceptible to DDT were tested for their irritability to DDT. Various laboratory investigations of the effects of insecticides on mosquito behavior and their irritability were carried out. In these series of experiments a comparison was made between the results obtained by a tentative method proposed in 1960 by the WHO, Expert Committee on Insecticides in which the mosquitoes are confined over the treated surface in a small plastic chamber and in a large cage. Under the large cage conditions DDT-resistant A. stephensi were more readily irritated by the insecticide than a susceptible strain of the same species

  1. Variability and genetic differentiation among Anopheles (Ano. intermedius Chagas, 1908 and Anopheles (Ano. mattogrossensis Lutz & Neiva, 1911 (Diptera: Culicidae from the Brazilian Amazon

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    Joselita Maria Mendes dos Santos

    2005-10-01

    Full Text Available Anopheles (Anopheles intermedius and Anopheles (Ano. mattogrossensis are Brazilian anopheline species belonging to the scarcely studied Anopheles subgenus. Few studies have been done on the genetic differentiation of these species. Both species have been found infected by Plasmodium and are sympatric with other anopheline species from the Nyssorhynchus subgenus. Eighteen enzymatic loci were analyzed in larval specimens of An. intermedius and An. mattogrossensis aiming to estimate the variability and genetic differentiation between these species. An. mattogrossensis population showed higher genetic variability (P = 44.4 and Ho = 0.081 ± 0.031 than that of An. intermedius (P = 33.3 and Ho = 0.048 ± 0.021. Most analyzed loci showed genotypic frequencies according to Hardy-Weinberg equilibrium, except for LAP1 and LAP2 in An. intermedius, and EST1 and PGM loci in An. mattogrossensis. The genetic distance between these species (D = 0.683 was consistent with the inter-specific values reported for Anopheles subgenus. We verified that the polymorphism and heterozygosity percentile values found in both species and compared to those in the literature, showed no relation between the level of isozyme variability and geographical distribution. The low variability found in these two species is probably more related to the niche they occupy than to their geographic distribution.

  2. Molecular comparison of topotypic specimens confirms Anopheles (Nyssorhynchus dunhami Causey (Diptera: Culicidae in the Colombian Amazon

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    Freddy Ruiz

    2010-11-01

    Full Text Available The presence of Anopheles (Nyssorhynchus dunhami Causey in Colombia (Department of Amazonas is confirmed for the first time through direct comparison of mtDNA cytochrome c oxidase I (COI barcodes and nuclear rDNA second internal transcribed spacer (ITS2 sequences with topotypic specimens of An. dunhami from Tefé, Brazil. An. dunhami was identified through retrospective correlation of DNA sequences following misidentification as Anopheles nuneztovari s.l. using available morphological keys for Colombian mosquitoes. That An. dunhami occurs in Colombia and also possibly throughout the Amazon Basin, is of importance to vector control programs, as this non-vector species is morphologically similar to known malaria vectors including An. nuneztovari, Anopheles oswaldoi and Anopheles trinkae. Species identification of An. dunhami and differentiation from these closely related species are highly robust using either DNA ITS2 sequences or COI DNA barcode. DNA methods are advocated for future differentiation of these often sympatric taxa in South America.

  3. Insecticide susceptibility of Anopheles coluzzii and Anopheles gambiae mosquitoes in Ibadan, Southwest Nigeria.

    Science.gov (United States)

    Okorie, P N; Ademowo, O G; Irving, H; Kelly-Hope, L A; Wondji, C S

    2015-03-01

    The emergence of insecticide resistance in Anopheles (Diptera: Culicidae) mosquitoes has great implications for malaria control in Nigeria. This study aimed to determine the dynamics of insecticide susceptibility levels and the frequency of knock-down resistance (kdr) mutations (L1014F) in wild Anopheles coluzzii Coetzee & Wilkerson sp. n. and Anopheles gambiae Giles from the Ojoo and Bodija areas of Ibadan, in southwest Nigeria. Insecticide susceptibility to pyrethroids, organophosphates, carbamates and organochlorines was assessed using World Health Organization (WHO) bioassays. A subset of the mosquitoes exposed to pyrethroids and DDT was used for species and molecular form identification; kdr genotyping was determined using the TaqMan real-time polymerase chain reaction assay. The mosquitoes were resistant to pyrethroids and DDT but completely susceptible to organophosphates and carbamates. Bodija samples (n = 186) consisted of An. gambiae (91.4%) and An. coluzzii (8.1%) and included one An. coluzzii/An. gambiae hybrid specimen. All mosquitoes screened in Ojoo (n = 26) were An. gambiae. The 1014F kdr mutation was detected at frequencies of 24.5 and 5.8% in Bodija and Ojoo, respectively. No correlation was observed between kdr genotypes and resistance phenotypes. The results indicate that metabolic resistance probably plays an important role in the development of resistance and highlight the need to implement insecticide resistance management strategies.

  4. Efficacy of essential oil from Cananga odorata (Lamk.) Hook.f. & Thomson (Annonaceae) against three mosquito species Aedes aegypti (L.), Anopheles dirus (Peyton and Harrison), and Culex quinquefasciatus (Say).

    Science.gov (United States)

    Soonwera, Mayura

    2015-12-01

    The essential oil of Cananga odorata flowers was evaluated for oviposition-deterrent, ovicidal, insecticidal, and repellent activities toward three mosquito species: Aedes aegypti, Anopheles dirus, and Culex quinquefasciatus. Oviposition deterrence of the oil was evaluated on gravid females using oviposition deterrence bioassay. The results showed that 10 % Ca. odorata exhibited high percent effective repellency against oviposition at 99.4 % to Ae. aegypti, 97.1 % to An. dirus, and 100 % to Cx. quinquefasciatus. Ca. odorata oil was tested for ovicidal activity. Regression equations revealed that the ovicidal rates were positively correlated with the concentrations of the essential oil. As the concentration of essential oil increased from 1, 5, and up to 10 % concentration, the ovicidal rate increased accordingly. Larvicidal activity of the oils was used on immature stages (third and fourth instar lavae and pupae). The maximum larval mortality was found with 10 % Ca. odorata against immature stages, and there were LC50 values ranged from 10.4 to 10.5 % (for Ae. aegypti), aegypti), 98.4 % (for An. dirus), and 100 % (for Cx. quinquefasciatus), with EC50 values of 6.2, 4.7, and 5.4 %, respectively. It gave moderate mortality rates after 24 and 48 h of exposure. Ca. odorata oil was assessed for repellency to females by using the modified K&D module. Ten percent Ca. odorata oil gave the strongest value against Ae. aegypti, An. dirus, and Cx. quinquefasciatus, with percentage repellency of 66, 92, and 90 %, respectively. This study demonstrates the potential for the essential oil of Ca. odorata essential oil to be used as a botanical insecticide against three mosquito species.

  5. Fauna and some biological characteristics of Anopheles mosquitoes (Diptera:Culicidae) in Kalaleh County, Golestan Province, northeast of lran

    Institute of Scientific and Technical Information of China (English)

    Aioub Sofizadeh; Hamideh Edalat; Mohammad Reza Abai; Ahmad Ali Hanafi-Bojd

    2016-01-01

    Objective: To determine fauna and some ecological aspects of Anopheles mosquitoes in northeast of Iran. Methods: In this descriptive study, 3 villages in Kalaleh County were selected in different geographical zones. Anopheles mosquitoes were collected biweekly from May to October using standard dipping method for larvae, and hand catch, total catch, artificial pit shelter as well as night-biting collections on human and animal baits for adults. Results: Totally 399 larvae and 2 602 adults of Anopheles mosquitoes were collected and identified as 2 species: Anopheles superpictus s.l. (An. superpictus s.l.) and Anopheles maculipennis s.l. The dominant species was An. superpictus s.l. (92.1%). Activity of these mosquitoes found to be started from middle of May and extended till September with two peaks of activity in July and August. Conclusions: An. superpictus s.l. as one of the main malaria vectors in Iran as well as some other parts of the world is the dominant species in the study area. This species has high potential for transmission and possibility of establishing a transmission cycle with low abundance. Other species, Anopheles maculipennis s.l. also has introduced as a malaria vector in northern parts of Iran. As this Anopheles is a complex species, genetic studies are recommended to determine the members of this complex in the study area.

  6. Malaria in Africa: vector species' niche models and relative risk maps.

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    Alexander Moffett

    Full Text Available A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km. Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes. For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The "additive" model assumes no interaction; the "minimax" model assumes maximum relative risk due to any vector in a cell; and the "competitive exclusion" model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease.

  7. Identifying Anophele fauna in Qayenat city in the South khorasan Province (2010-2011

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    Hossien Borna

    2013-08-01

    Full Text Available Background and Aim: Biological vectors of malaria are only anopheles mosquitoes. Since the vector control without identifying them and understanding their biology is not possible, the present study was designed to identify anopheles fauna in different areas of Qayenat city and their internal or external shelters.   Materials and Methods: Larvae, pupae, and adults of anopheles mosquitoes were collected from their internal and external shelters in rural areas in plains and mountainous spots in Qayenat city during a cross-sectional and descriptive study between April 2010 and October 2011. This was done either singularly or collectively through taking samples of the larvae from various inhabitats through scooping. The caught samples were transferred to laboratory in order to determine their type using the valid key to identify adult anopheles and larvae in Iran (Shahgvdyan.   Results: A total of 2165 samples including 1711 larvae and 454 adults were collected from different parts of Qayenat city. After identification and validation of the samples 4 species of Anopheles were diagnosed. The samples were superpictus, multicolor, sacharovi, and turkhodai with the percent 72.2%, 27.9%, 0.44%, and 0.44% respectively. Most abundant Anopheles were reported to exist in the months of July and August.   Conclusion: Regarding the high frequency of superpictus anopheles in the area and its condition, it is necessary to make essential provision for a comprehensive program to control malaria In order to prevent outbreaks of the epidemic in suitable seasons of the year.

  8. Discovery of flavivirus-derived endogenous viral elements in Anopheles mosquito genomes supports the existence of Anopheles-associated insect-specific flaviviruses.

    Science.gov (United States)

    Lequime, Sebastian; Lambrechts, Louis

    2017-01-01

    The Flavivirus genus encompasses several arboviruses of public health significance such as dengue, yellow fever, and Zika viruses. It also includes insect-specific flaviviruses (ISFs) that are only capable of infecting insect hosts. The vast majority of mosquito-infecting flaviviruses have been associated with mosquito species of the Aedes and Culex genera in the Culicinae subfamily, which also includes most arbovirus vectors. Mosquitoes of the Anophelinae subfamily are not considered significant arbovirus vectors; however, flaviviruses have occasionally been detected in field-caught Anopheles specimens. Whether such observations reflect occasional spillover or laboratory contamination or whether Anopheles mosquitoes are natural hosts of flaviviruses is unknown. Here, we provide in silico and in vivo evidence of transcriptionally active, flavivirus-derived endogenous viral elements (EVEs) in the genome of Anopheles minimus and Anopheles sinensis. Such non-retroviral endogenization of RNA viruses is consistent with a shared evolutionary history between flaviviruses and Anopheles mosquitoes. Phylogenetic analyses of the two newly described EVEs support the existence of a distinct clade of Anopheles-associated ISFs.

  9. Susceptibility of Anopheles gambiae and Anopheles stephensi to tropical isolates of Plasmodium falciparum

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    Ranford-Cartwright Lisa C

    2007-10-01

    Full Text Available Abstract Background The susceptibility of anopheline mosquito species to Plasmodium infection is known to be variable with some mosquitoes more permissive to infection than others. Little work, however, has been carried out investigating the susceptibility of major malaria vectors to geographically diverse tropical isolates of Plasmodium falciparum aside from examining the possibility of infection extending its range from tropical regions into more temperate zones. Methods This study investigates the susceptibility of two major tropical mosquito hosts (Anopheles gambiae and Anopheles stephensi to P. falciparum isolates of different tropical geographical origins. Cultured parasite isolates were fed via membrane feeders simultaneously to both mosquito species and the resulting mosquito infections were compared. Results Infection prevalence was variable with African parasites equally successful in both mosquito species, Thai parasites significantly more successful in An. stephensi, and PNG parasites largely unsuccessful in both species. Conclusion Infection success of P. falciparum was variable according to geographical origin of both the parasite and the mosquito. Data presented raise the possibility that local adaptation of tropical parasites and mosquitoes has a role to play in limiting gene flow between allopatric parasite populations.

  10. Bacterial diversity associated with wild caught Anopheles mosquitoes from Dak Nong Province, Vietnam using culture and DNA fingerprint.

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    Chung Thuy Ngo

    Full Text Available Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study.The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR - TTGE method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota.The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes.Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes.

  11. Bacterial Diversity Associated with Wild Caught Anopheles Mosquitoes from Dak Nong Province, Vietnam Using Culture and DNA Fingerprint

    Science.gov (United States)

    Ngo, Chung Thuy; Aujoulat, Fabien; Veas, Francisco; Jumas-Bilak, Estelle; Manguin, Sylvie

    2015-01-01

    Background Microbiota of Anopheles midgut can modulate vector immunity and block Plasmodium development. Investigation on the bacterial biodiversity in Anopheles, and specifically on the identification of bacteria that might be used in malaria transmission blocking approaches, has been mainly conducted on malaria vectors of Africa. Vietnam is an endemic country for both malaria and Bancroftian filariasis whose parasitic agents can be transmitted by the same Anopheles species. No information on the microbiota of Anopheles mosquitoes in Vietnam was available previous to this study. Method The culture dependent approach, using different mediums, and culture independent (16S rRNA PCR – TTGE) method were used to investigate the bacterial biodiversity in the abdomen of 5 Anopheles species collected from Dak Nong Province, central-south Vietnam. Molecular methods, sequencing and phylogenetic analysis were used to characterize the microbiota. Results and Discussion The microbiota in wild-caught Anopheles was diverse with the presence of 47 bacterial OTUs belonging to 30 genera, including bacterial genera impacting Plasmodium development. The bacteria were affiliated with 4 phyla, Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria, the latter being the dominant phylum. Four bacterial genera are newly described in Anopheles mosquitoes including Coxiella, Yersinia, Xanthomonas, and Knoellia. The bacterial diversity per specimen was low ranging from 1 to 4. The results show the importance of pairing culture and fingerprint methods to better screen the bacterial community in Anopheles mosquitoes. Conclusion Sampled Anopheles species from central-south Vietnam contained a diverse bacterial microbiota that needs to be investigated further in order to develop new malaria control approaches. The combination of both culture and DNA fingerprint methods allowed a thorough and complementary screening of the bacterial community in Anopheles mosquitoes. PMID:25747513

  12. The Genome of Anopheles darlingi, the main neotropical malaria vector

    Science.gov (United States)

    Marinotti, Osvaldo; Cerqueira, Gustavo C.; de Almeida, Luiz Gonzaga Paula; Ferro, Maria Inês Tiraboschi; Loreto, Elgion Lucio da Silva; Zaha, Arnaldo; Teixeira, Santuza M. R.; Wespiser, Adam R.; Almeida e Silva, Alexandre; Schlindwein, Aline Daiane; Pacheco, Ana Carolina Landim; da Silva, Artur Luiz da Costa; Graveley, Brenton R.; Walenz, Brian P.; Lima, Bruna de Araujo; Ribeiro, Carlos Alexandre Gomes; Nunes-Silva, Carlos Gustavo; de Carvalho, Carlos Roberto; Soares, Célia Maria de Almeida; de Menezes, Claudia Beatriz Afonso; Matiolli, Cleverson; Caffrey, Daniel; Araújo, Demetrius Antonio M.; de Oliveira, Diana Magalhães; Golenbock, Douglas; Grisard, Edmundo Carlos; Fantinatti-Garboggini, Fabiana; de Carvalho, Fabíola Marques; Barcellos, Fernando Gomes; Prosdocimi, Francisco; May, Gemma; de Azevedo Junior, Gilson Martins; Guimarães, Giselle Moura; Goldman, Gustavo Henrique; Padilha, Itácio Q. M.; Batista, Jacqueline da Silva; Ferro, Jesus Aparecido; Ribeiro, José M. C.; Fietto, Juliana Lopes Rangel; Dabbas, Karina Maia; Cerdeira, Louise; Agnez-Lima, Lucymara Fassarella; Brocchi, Marcelo; de Carvalho, Marcos Oliveira; Teixeira, Marcus de Melo; Diniz Maia, Maria de Mascena; Goldman, Maria Helena S.; Cruz Schneider, Maria Paula; Felipe, Maria Sueli Soares; Hungria, Mariangela; Nicolás, Marisa Fabiana; Pereira, Maristela; Montes, Martín Alejandro; Cantão, Maurício E.; Vincentz, Michel; Rafael, Miriam Silva; Silverman, Neal; Stoco, Patrícia Hermes; Souza, Rangel Celso; Vicentini, Renato; Gazzinelli, Ricardo Tostes; Neves, Rogério de Oliveira; Silva, Rosane; Astolfi-Filho, Spartaco; Maciel, Talles Eduardo Ferreira; Ürményi, Turán P.; Tadei, Wanderli Pedro; Camargo, Erney Plessmann; de Vasconcelos, Ana Tereza Ribeiro

    2013-01-01

    Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi. PMID:23761445

  13. Anopheles Maculatus (Diptera: Culicidae) from the Type Locality of Hong Kong and Two New Species of the Maculatus Complex from the Philippines

    Science.gov (United States)

    1990-12-01

    distinguish two morphotypes from single localities. For this reason we believe that the two forms represent repro- ductively isolated species which are...tergum; 9- II-IV short, blunt, peglike; 9-V-W long, pointed, spine - like; 9-11 transparent, 9-III-VII lightly to darkly pigmented; ratio of length...Pecten plate with 3-12 long and 4-9 short spines . Seta 1-X simple, long, 1.05-1.54 length of saddle; 2-X more pectinate than plumose, with 16-20

  14. Investigation on Anopheles Species and Their Composition in Villages at Different Altitudes of Motuo County, Tibet Autonomous Region%西藏墨脱县不同海拔地区按蚊构成调查

    Institute of Scientific and Technical Information of China (English)

    武松; 汤林华; 周水森; 黄芳; 许国君; 王多全; 蒋伟康; 卓玛央金

    2011-01-01

    , the mosquitoes were killed by chloroform and dried on silica-gel, and transported to the laboratory where they were stored at -20X1. Species of Anopheles maculatus complex were identified with multiple PCR method. Results 5 410 anopheline mosquitoes were collected. Two mosquitoes were captured in high altitude village, one was Anopheles gigas baUieyi, while the other was damaged and unable to identify. There were 541 (36.9%) An. Pseudowillmori, 906 An. Will-mori (61.7%) and 21 An. Peditaeniatus (1.4%) collected in semi-high altitude villages; 260 (763%) An.pseudowillmori, 2 Anwillmori (0.6%) and 79 An. Peditaeniatus (232%) trapped in middle altitude village; and 3 265 (90.7%) An. Pseudow-illitnori, 19 An. Willmori (05%) and 315 An. Peditaeniatus (8.8%) trapped in low altitude villages. Conclusion An.Pseudowtilmori, An. Willmori and An.peditaeniatus make the main anopheline composition. The proportion of An. Willmori is higher than An. Pseudowtilmori in semi-high alititude villages, while An. Pseudowtilmori take the absolute predominance in middle and low altitude villages.

  15. A maleness gene in the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Krzywinska, Elzbieta; Dennison, Nathan J; Lycett, Gareth J; Krzywinski, Jaroslaw

    2016-07-01

    The molecular pathways controlling gender are highly variable and have been identified in only a few nonmammalian model species. In many insects, maleness is conferred by a Y chromosome-linked M factor of unknown nature. We have isolated and characterized a gene, Yob, for the M factor in the malaria mosquito Anopheles gambiae Yob, activated at the beginning of zygotic transcription and expressed throughout a male's life, controls male-specific splicing of the doublesex gene. Silencing embryonic Yob expression is male-lethal, whereas ectopic embryonic delivery of Yob transcripts yields male-only broods. This female-killing property may be an invaluable tool for creation of conditional male-only transgenic Anopheles strains for malaria control programs.

  16. Was Anopheles donaldi a vector of malaria in Kuala Lumpur, Malaysia, in the past?

    Science.gov (United States)

    Reid, J A

    1980-01-01

    Anopheles donaldi Reid, a member of the A. barbirostris species group, is a vector of human filariasis and probably malaria. The discovery of some old specimens of this species, collected in Kuala Lumpur town where it no longer occurs, together with evidence from the literature about past malaria in the town, suggest that donaldi may have played a part in transmitting that malaria.

  17. Composition of Anopheles coluzzii and Anopheles gambiae microbiota from larval to adult stages.

    Science.gov (United States)

    Gimonneau, Geoffrey; Tchioffo, Majoline T; Abate, Luc; Boissière, Anne; Awono-Ambéné, Parfait H; Nsango, Sandrine E; Christen, Richard; Morlais, Isabelle

    2014-12-01

    During their immature life stages, malaria mosquitoes are exposed to a wide array of microbes and contaminants from the aquatic habitats. Although prior studies have suggested that environmental exposure shapes the microbial community structure in the adult mosquito, most reports have focused on laboratory-based experiments and on a single mosquito epithelium, the gut. In this study, we investigated the influence of the breeding site on the development of the Anopheles coluzzii and Anopheles gambiae microbiota in natural conditions. We characterized bacterial communities from aquatic habitats, at surface microlayer and subsurface water levels, to freshly emerge adult mosquitoes using multiplexed 16S rRNA gene pyrosequencing and we separately analyzed the microbiota associated with the different epithelia of adult individual, midguts, ovaries and salivary glands. We found that the distribution of bacterial communities in the aquatic habitats differed according to the depth of water collections. Inter-individual variation of bacterial composition was large in larvae guts but adult mosquitoes from a same breeding site shared quite similar microbiota. Although some differences in bacterial abundances were highlighted between the different epithelia of freshly emerged An. coluzzii and An. gambiae, an intriguing feature from our study is the particular similarity of the overall bacterial communities. Our results call for further investigations on the bacterial population dynamics in the different tissues to determine the distinctive characteristics of each microbiota during the mosquito lifespan and to identify specific interactions between certain key phyla or species and the insect life history traits.

  18. Anopheles moucheti and Anopheles vinckei are candidate vectors of ape Plasmodium parasites, including Plasmodium praefalciparum in Gabon.

    Science.gov (United States)

    Paupy, Christophe; Makanga, Boris; Ollomo, Benjamin; Rahola, Nil; Durand, Patrick; Magnus, Julie; Willaume, Eric; Renaud, François; Fontenille, Didier; Prugnolle, Franck

    2013-01-01

    During the last four years, knowledge about the diversity of Plasmodium species in African great apes has considerably increased. Several new species were described in chimpanzees and gorillas, and some species that were previously considered as strictly of human interest were found to be infecting African apes. The description in gorillas of P. praefalciparum, the closest relative of P. falciparum which is the main malignant agent of human malaria, definitively changed the way we understand the evolution and origin of P. falciparum. This parasite is now considered to have appeared recently, following a cross-species transfer from gorillas to humans. However, the Plasmodium vector mosquito species that have served as bridge between these two host species remain unknown. In order to identify the vectors that ensure ape Plasmodium transmission and evaluate the risk of transfer of these parasites to humans, we carried out a field study in Gabon to capture Anopheles in areas where wild and semi-wild ape populations live. We collected 1070 Anopheles females belonging to 15 species, among which An. carnevalei, An. moucheti and An. marshallii were the most common species. Using mtDNA-based PCR tools, we discovered that An. moucheti, a major human malaria vector in Central Africa, could also ensure the natural transmission of P. praefalciparum among great apes. We also showed that, together with An. vinckei, An. moucheti was infected with P. vivax-like parasites. An. moucheti constitutes, therefore, a major candidate for the transfer of Plasmodium parasites from apes to humans.

  19. Responsiveness of Anopheles maculipennis to different imagicides during resurgent malaria

    Institute of Scientific and Technical Information of China (English)

    Vatandoost Hasasan; Zahirnia Amir Hossein

    2010-01-01

    Objective: To determine the susceptibility of main malaria vector in Astra County, borderline of Iran and Republic of Azerbaijan for better control. Methods:Susceptibility of Anopheles maculipennis to diagnostic doses of DDT 4%, dieldrin 0.4%, malathion 5%, lambdacyhalothrin 0.1%, and delamethrin 0.025%, was tested according to method recommended by WHO. All the impregnated papers were provided by WHO. Results: It was shown that this species exhibited resistance to DDT, dieldrin, whereas susceptible to malathrion, lambdacyhalothrin and deltamethrin. Conclusions:Findings of susceptibility tests of this species provided a clue for control of malaria vector in the region.

  20. KEANEKARAGAMAN JENIS NYAMUK Anopheles DI DAERAH DENGAN ATAU TANPA KEBUN SALAK DI KABUPATEN BANJARNEGARA

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    Dyah Widiastuti

    2012-11-01

    Full Text Available Anopheles has been known as vectors of malaria and filaria. A research which was aimed to evaluate the diversity of Anopheles mosquitoes at Salak and Non Salak Areas was conducted. This Research located in Banjarnegara Regency which lay in a mountainous in the middle of Central Java (7'12"- 7'31 N and 109'20"-109'45"W. The location was divided into two groups i.e. (1 Kendaga Village (Banjarmangu Subdistrict representing of Salak area, (2 Badakarya Village (Punggelan Subdistrict representing Non Salak area. Mosquitoes were collected by landing and resting collection methods. All mosquitoes were anaesthetized with chloroform and identified under microscope. Shanon-Weaver Index and Eveness Index were measured to evaluate the diversity of Anopheles mosquitoes. The results showed there were 6 species of Anopheles from both areas i.e. A. aconitus. A. balabacensis. A. barbirostris. A. kochi. A. vagus and A. maculatus. Result of examination by Independent Sample T-Test indicated that the diversity index value between two areas were not significantly different. Keywords: Anopheles, diversity, salakarea, non salakarea

  1. Anopheles (Nyssorhynchus) Pictipennis: A New Mosquito Record from the Atacama Region of Northern Chile

    Science.gov (United States)

    2008-01-01

    Santiago, this species rarely feeds on humans, but it is highly attracted to domestic animals (Linthicum 1988). In this paper, we report An. (N...Mosq Control Assoc 12:619-626. Neghme AR. 1943. Contribucion a la biologia del Anopheles pictipenllis (Philippi, 1865). I. Communica- cion

  2. Effectiveness of synthetic versus natural human volatiles as attractants for Anopheles gambiae (Diptera: Culicidae) sensu stricto

    NARCIS (Netherlands)

    Smallegange, R.C.; Knols, B.G.J.; Takken, W.

    2010-01-01

    Females of the African malaria vector, Anopheles gambiae Giles sensu stricto, use human volatiles to find their blood-host. Previous work has shown that ammonia, lactic acid, and aliphatic carboxylic acids significantly affect host orientation and attraction of this species, In the current study, th

  3. Olfaction in the malaria mosquito Anopheles gambiae : Electrophysiology and identification of kairomones

    NARCIS (Netherlands)

    Meijerink, J.

    1999-01-01

    Female mosquitoes of the species Anopheles gambiae Giles sensu stricto are important vectors of human malaria in Africa. It is generally assumed that they locate their human host by odours. These odours are detected by olfactory receptor neurons situated within cuticular extensions on the antenna. T

  4. Feeding and survival of the malaria vector Anopheles gambiae on plants growing in Kenia

    NARCIS (Netherlands)

    Impoinvil, D.E.; Kongere, J.O.; Foster, W.A.; Njiru, B.N.; Killeen, G.F.; Githure, J.I.; Beier, J.C.; Hassanali, A.; Knols, B.G.J.

    2004-01-01

    The propensity of the malaria vector mosquito Anopheles gambiae Giles (Diptera: Culicidae) to ingest sugars from various plants, and subsequent survival rates, were assessed with laboratory-reared males and females offered eight species of plants commonly cultivated and/or growing wild in western Ke

  5. Ecology of Anopheles Stephensi in a Malarious Area, Southeast of Iran

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    Norair Piazak

    2012-01-01

    Full Text Available District of Jiroft is situated in south-east of Iran which is one of the malarious regions. Anopheles stephensi is considered as one of the main malaria vector in this region. Ecology of this species was studied in the area to understand its vector behavior for implementation of effective vector control measures. Different methods like total catch, pit shelter, night bite collection on human and animal, larval dipping methods were used for species identification, seasonal activity, anthropophilic index and egg morphological characteristics. Anthropophilicity index was assessed by ELISA test. Activity of Anopheles species started at the beginning of April, and its peak occurs in late spring. The larvae were found in the river bed with pools, stagnant streams, slow foothill streams, temporary pools, and slowly moving water with and without vegetation, drainage containers of air conditioner and palm irrigation canals. From different methods of adult collection, it was found that spray sheet collection is the appropriate method. ELISA testing of 144 blood meals of females revealed the anthropophilicity of 11.8% indicating host preference on animal, mainly cow. Ridge length and their number on the egg floats confirmed Anopheles stephensi mysorensis form. This study showed that Anopheles stephensi is the main vector of malaria in the region, although some other species may play a role. Our findings could provide a valuable clue for epidemiology and control of malaria in the southeast of Iran.

  6. HABITAT PERKEMBANGBIAKAN DAN AKTIVITAS MENGGIGIT NYAMUK ANOPHELES SUNDAICUS DAN ANOPHELES SUBPICTUS DI PURWOREJO, JAWA TENGAH

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    Supratman Sukowati

    2012-11-01

    Full Text Available Malaria continues to be a public health problem, it causes morbidity, mortality as well as outbreak in several remote areas in Indonesia. Vector control remains the most effective measure to prevent malaria transmission. The understanding of mosquito species, its bio-ecology, and the characteristic of their habitats are very important to formulate the vector control strategy. It was recognized that there are many aspects of behavior that are directly and indirectly important in the prevention and control of malaria. One of the main cause of malaria control failure due to lack of understanding vector spesies and its bio-ecology.This paper reported the study of breeding places and biting activities of malaria vector Anophles sundaicus and An. subpictus from coastal area of Purworejo area in year 2004. Natural population of anopheline species was sampled from larval survey, landing collection, animal resting collection, resting collection to study the larval habitat, biting activities, resting habit and biting sites. Nine species of anopheline werefound in Jati Malang e.g. An. sundaicus, An. subpictus, An. barbirostris, An. vagus, An. aconitus, An.indefinitus, An. tesselatus, An. nigerrimus, An. annularis. In Gedangan village was found 5 species of Anopheles e.g. An. sundaicus, An. subpictus, An. barbirostris, An. vagus, and An. aconitus.The breeding places of Anopheles spp. are varied, in Jati Malang and Gedangan were found lagoon, brackish water fish-pond, rice field, freshwater fishpond, irrigation channel, and pit hole. Therefore, the breeding places of An. sundaicus and An. subpictus confined in the lagoon and brackish water fish ponds, with its characteristics e.g. water temperature ranges 25,6°C-27,8°C, pH ranges 7,2-7,6, water salinity 3,0-3,4%, and water dept is 20,3 cm-25,2 cm, muddy undergroud, stagnant or slow running water with the water weed mostly green algae (Chlorophyta and lichen.The biting activities of An. sundaicus and An

  7. Identification of field caught Anopheles gambiae s.s. and Anopheles arabiensis by TaqMan single nucleotide polymorphism genotyping

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    Bayoh Nabie M

    2007-02-01

    Full Text Available Abstract Background Identification of Anopheles gambiae s.s. and Anopheles arabiensis from field-collected Anopheles gambiae s.l. is often necessary in basic and applied research, and in operational control programmes. The currently accepted method involves use of standard polymerase chain reaction amplification of ribosomal DNA (rDNA from the 3' 28S to 5' intergenic spacer region of the genome, and visual confirmation of amplicons of predicted size on agarose gels, after electrophoresis. This report describes development and evaluation of an automated, quantitative PCR method based upon TaqMan™ single nucleotide polymorphism (SNP genotyping. Methods Standard PCR, and TaqMan SNP genotyping with newly designed primers and fluorophore-labeled probes hybridizing to sequences of complementary rDNA specific for either An. gambiae s.s. or An. arabiensis, were conducted in three experiments involving field-collected An. gambiae s.l. from western Kenya, and defined laboratory strains. DNA extraction was from a single leg, sonicated for five minutes in buffer in wells of 96-well PCR plates. Results TaqMan SNP genotyping showed a reaction success rate, sensitivity, and species specificity comparable to that of standard PCR. In an extensive field study, only 29 of 3,041 (0.95% were determined to be hybrids by TaqMan (i.e., having rDNA sequences from both species, however, all but one were An. arabiensis by standard PCR, suggesting an acceptably low (ca. 1% error rate for TaqMan genotyping in mistakenly identifying species hybrids. Conclusion TaqMan SNP genotyping proved to be a sensitive and rapid method for identification of An. gambiae s.l. and An. arabiensis, with a high success rate, specific results, and congruence with the standard PCR method.

  8. Confirmation of Anopheles (Anopheles calderoni Wilkerson, 1991 (Diptera: Culicidae in Colombia and Ecuador through molecular and morphological correlation with topotypic material

    Directory of Open Access Journals (Sweden)

    Ranulfo González

    2010-12-01

    Full Text Available The morphologically similar taxa Anopheles calderoni, Anopheles punctimacula, Anopheles malefactor and Anopheles guarao are commonly misidentified. Isofamilies collected in Valle de Cauca, Colombia, showed morphological characters most similar to An. calderoni, a species which has never previously been reported in Colombia. Although discontinuity of the postsubcostal pale spots on the costa (C and first radial (R1 wing veins is purportedly diagnostic for An. calderoni, the degree of overlap of the distal postsubcostal spot on C and R1 were variable in Colombian specimens (0.003-0.024. In addition, in 98.2% of larvae, seta 1-X was located off the saddle and seta 3-C had 4-7 branches in 86.7% of specimens examined. Correlation of DNA sequences of the second internal transcribed spacer and mtDNA cytochrome c oxidase subunit I gene (COI barcodes (658 bp of the COI gene generated from Colombian progeny material and wild-caught mosquitoes from Ecuador with those from the Peruvian type series of An. calderoni confirmed new country records. DNA barcodes generated for the closely related taxa, An. malefactor and An. punctimacula are also presented for the first time. Examination of museum specimens at the University of the Valle, Colombia, revealed the presence of An. calderoni in inland localities across Colombia and at elevations up to 1113 m.

  9. Odour sensitivity of antennal olfactory cells underlying grooved pegs of Anopheles gambiae s.s. and An. quadriannulatus

    NARCIS (Netherlands)

    van den Broek, IVF; den Otter, CJ

    2000-01-01

    In female mosquitoes of the anthropophilic species Anopheles gambiae Giles s.s. and the zoophilic An. quadriannulatus Theobald single sensillum recordings from grooved pegs were made. In both species, the majority of these sensilla responded to ammonium hydroxide, butylamine and propanoic acid, wher

  10. Manutenção em laboratório de Anopheles albitarsis e Anopheles aquasalis por copulacao induzida Laboratory maintence of Anopheles albitarsis and Anopheles aquasalis by induced copulation

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    Mercia E. Arruda

    1982-03-01

    Full Text Available Introduzimos a técnica da copulação induzida para a manutenção e criação em cativeiro, do Anopheles albitarsis e do A. aquasalis, objetivando facilitar futuros trabalhoscom estas espécies de difícil cruzamento espontâneo em laboratório.Many species of mosquitoes are unsuited to life in a laboratory because they fail to copulate in cages. This situation may be largely eliminated by the technique in current use for manually inducing inseminations as outlined. We have used this technique for the first time in relation to Anopheles albitarsis and A. aquasalis, species of malaria vectors which are difficult to mate spontaneously in captivity. The pre-mating age of the males and the temperature at which they are held affect the ability of male to transfer sperm. Mating males 8 to 14 days old with females at any age, resulted in a high order of insemination. Temperature of 25°C and humidity of 80% RH enhanced the degree of insemination.

  11. Molecular evolution and population genetics of a Gram-negative binding protein gene in the malaria vector Anopheles gambiae (sensu lato)

    OpenAIRE

    Salgueiro, Patrícia; Lopes, Ana Sofia; Mendes, Cristina; Charlwood, Jacques Derek; Arez, Ana Paula; Pinto, João; Silveira, Henrique

    2016-01-01

    Background Clarifying the role of the innate immune system of the malaria vector Anopheles gambiae is a potential way to block the development of the Plasmodium parasites. Pathogen recognition is the first step of innate immune response, where pattern recognition proteins like GNBPs play a central role. Results We analysed 70 sequences of the protein coding gene GNBPB2 from two species, Anopheles gambiae (s.s.) and An. coluzzii, collected in six African countries. We detected 135 segregating ...

  12. Locomotor behavioral responses of Anopheles minimus and Anopheles harrisoni to alpha-cypermethrin in Thailand.

    Science.gov (United States)

    Malaithong, Naritsara; Tisgratog, Rungarun; Tainchum, Krajana; Prabaripai, Atchariya; Juntarajumnong, Waraporn; Bangs, Michael J; Chareonviriyaphap, Theeraphap

    2011-09-01

    Excito-repellency responses of 3 test populations, representing 2 sibling species within the Minimus Complex, Anopheles minimus and An. harrisoni, were characterized for contact irritant and noncontact repellent actions of chemicals during and after exposure to alpha-cypermethrin at half the recommended field (0.010 g/m2), the recommended field (0.020 g/m2), and double the recommended field concentration (0.040 g/m2), using an excito-repellency escape chamber system. Two field populations of An. minimus and An. harrisoni collected from the malaria-endemic areas in Tak and Kanchanuburi provinces in western Thailand, respectively, were tested along with a laboratory population of An. minimus maintained since 1993. Females of all 3 test populations rapidly escaped after direct contact with treated surfaces for each concentration. In general, increased escape responses in the An. minimus test populations were proportionate to increased insecticide dosages. The greatest escape response for An. harrisoni was observed at the operational field concentration of alpha-cypermethrin. The noncontact repellency response to alpha-cypermethrin was comparatively weak for all 3 test populations, but significantly different from each paired contact test and respective noncontact controls. We conclude that strong contact irritancy is a major action of alpha-cypermethrin, whereas noncontact repellency plays no role in the escape responses of 2 species in the Minimus Complex in Thailand.

  13. Predicting the potential distribution of main malaria vectors Anopheles stephensi, An. culicifacies s.l. and An. fluviatilis s.l. in Iran based on maximum entropy model.

    Science.gov (United States)

    Pakdad, Kamran; Hanafi-Bojd, Ahmad Ali; Vatandoost, Hassan; Sedaghat, Mohammad Mehdi; Raeisi, Ahmad; Moghaddam, Abdolreza Salahi; Foroushani, Abbas Rahimi

    2017-05-01

    Malaria is considered as a major public health problem in southern areas of Iran. The goal of this study was to predict best ecological niches of three main malaria vectors of Iran: Anopheles stephensi, Anopheles culicifacies s.l. and Anopheles fluviatilis s.l. A databank was created which included all published data about Anopheles species of Iran from 1961 to 2015. The suitable environmental niches for the three above mentioned Anopheles species were predicted using maximum entropy model (MaxEnt). AUC (area under Roc curve) values were 0.943, 0.974 and 0.956 for An. stephensi, An. culicifacies s.l. and An. fluviatilis s.l respectively, which are considered as high potential power of model in the prediction of species niches. The biggest bioclimatic contributor for An. stephensi and An. fluviatilis s.l. was bio 15 (precipitation seasonality), 25.5% and 36.1% respectively, followed by bio 1 (annual mean temperature), 20.8% for An. stephensi and bio 4 (temperature seasonality) with 49.4% contribution for An. culicifacies s.l. This is the first step in the mapping of the country's malaria vectors. Hence, future weather situation can change the dispersal maps of Anopheles. Iran is under elimination phase of malaria, so that such spatio-temporal studies are essential and could provide guideline for decision makers for IVM strategies in problematic areas.

  14. New selenoproteins identified in silico from the genome of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    JIANG Liang; LIU Qiong; CHEN Ping; GAO ZhongHong; XU HuiBi

    2007-01-01

    Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins, where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine. The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species. Available computational tools fail to correctly predict selenoproteins. Thus, we developed a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information, several programs were edited with PERL language to identify selenocysteine insertion sequence (SECIS) element, the coding potential of TGA codons, and cysteine-containing homologs of selenoprotein genes. Our results showed that 11365 genes were terminated with TGA codons, 918 of which contained SECIS elements. Similarity search revealed that 58genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons. Finally, 7genes were found to fully meet requirements for selenoproteins, although they have not been annotated as selenoproteins in NCBI databases. Deduced from their basic properties, the newly found selenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles' vectorial capacity of Plasmodium. This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.

  15. Spatial association between malaria vector species richness and malaria in Colombia.

    Science.gov (United States)

    Fuller, Douglas O; Alimi, Temitope; Herrera, Socrates; Beier, John C; Quiñones, Martha L

    2016-06-01

    Malaria transmission in Colombia is highly variable in space and time. Using a species distribution model, we mapped potential distribution of five vector species including Anopheles albimanus, Anopheles calderoni, Anopheles darlingi, Anopheles neivai, and Anopheles nuneztovari in five Departments of Colombia where malaria transmission remains problematic. We overlaid the range maps of the five species to reveal areas of sympatry and related per-pixel species richness to mean annual parasite index (API) for 2011-2014 mapped by municipality (n = 287). The relationship between mean number of vector species per municipality and API was evaluated using a Poisson regression, which revealed a highly significant relationship between species richness and API (p = 0 for Wald Chi-Square statistic). The results suggest that areas of relatively high transmission in Colombia typically contain higher number of vector species than areas with unstable transmission and that future elimination strategies should account for vector species richness.

  16. Seasonality and Locality Affect the Diversity of Anopheles gambiae and Anopheles coluzzii Midgut Microbiota from Ghana.

    Science.gov (United States)

    Akorli, Jewelna; Gendrin, Mathilde; Pels, Nana Adjoa P; Yeboah-Manu, Dorothy; Christophides, George K; Wilson, Michael D

    2016-01-01

    Symbiotic bacteria can have important implications in the development and competence of disease vectors. In Anopheles mosquitoes, the composition of the midgut microbiota is largely influenced by the larval breeding site, but the exact factors shaping this composition are currently unknown. Here, we examined whether the proximity to urban areas and seasons have an impact on the midgut microbial community of the two major malaria vectors in Africa, An. coluzzii and An. gambiae. Larvae and pupae were collected from selected habitats in two districts of Ghana during the dry and rainy season periods. The midgut microbiota of adults that emerged from these collections was determined by 454-pyrosequencing of the 16S ribosomal DNA. We show that in both mosquito species, Shewanellaceae constituted on average of 54% and 73% of the midgut microbiota from each site in the dry and rainy season, respectively. Enterobacteriaceae was found in comparatively low abundance below 1% in 22/30 samples in the dry season, and in 25/38 samples in the rainy season. Our data indicate that seasonality and locality significantly affect both the diversity of microbiota and the relative abundance of bacterial families with a positive impact of dry season and peri-urban settings.

  17. Seasonality and Locality Affect the Diversity of Anopheles gambiae and Anopheles coluzzii Midgut Microbiota from Ghana

    Science.gov (United States)

    Gendrin, Mathilde; Pels, Nana Adjoa P.; Yeboah-Manu, Dorothy; Christophides, George K.; Wilson, Michael D.

    2016-01-01

    Symbiotic bacteria can have important implications in the development and competence of disease vectors. In Anopheles mosquitoes, the composition of the midgut microbiota is largely influenced by the larval breeding site, but the exact factors shaping this composition are currently unknown. Here, we examined whether the proximity to urban areas and seasons have an impact on the midgut microbial community of the two major malaria vectors in Africa, An. coluzzii and An. gambiae. Larvae and pupae were collected from selected habitats in two districts of Ghana during the dry and rainy season periods. The midgut microbiota of adults that emerged from these collections was determined by 454-pyrosequencing of the 16S ribosomal DNA. We show that in both mosquito species, Shewanellaceae constituted on average of 54% and 73% of the midgut microbiota from each site in the dry and rainy season, respectively. Enterobacteriaceae was found in comparatively low abundance below 1% in 22/30 samples in the dry season, and in 25/38 samples in the rainy season. Our data indicate that seasonality and locality significantly affect both the diversity of microbiota and the relative abundance of bacterial families with a positive impact of dry season and peri-urban settings. PMID:27322614

  18. Genomic Dark Matter Illuminated: Anopheles Y Chromosomes.

    Science.gov (United States)

    Redmond, Seth N; Neafsey, Daniel E

    2016-08-01

    Hall et al. have strategically used long-read sequencing technology to characterize the structure and highly repetitive content of the Y chromosome in Anopheles malaria mosquitoes. Their work confirms that this important but elusive heterochromatic sex chromosome is evolving extremely rapidly and harbors a remarkably small number of genes.

  19. Paridade de Anopheles cruzii em Floresta Ombrófila Densa no Sul do Brasil Anopheles cruzii parity in dense rain forest in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Ana Caroline Dalla Bona

    2006-12-01

    Full Text Available OBJETIVO: Conhecer a paridade e desenvolvimento ovariano da espécie Anopheles cruzii, durante os períodos estacionais. MÉTODOS: As capturas foram realizadas quinzenalmente, no período matutino, de abril/2004 a abril/2005, no Parque Estadual do Palmito, município de Paranaguá litoral do Estado do Paraná. Mosquitos adultos foram capturados usando a técnica pouso homem. As dissecções foram feitas utilizando-se a técnica de Detinova e de Polovodova e a avaliação do desenvolvimento folicular, segundo os critérios de Christophers e Mer. RESULTADOS: Foram dissecadas 208 fêmeas de Anopheles cruzii. A maioria das fêmeas dissecadas nas estações eram nulíparas. Sendo que 14,4% eram nulíparas com folículo além do estádio II de Christophers & Mer, o que evidencia o exercício da hematofagia previamente à primeira oviposição. Observou-se que as populações de Anopheles cruzii são constituídas de indivíduos jovens, talvez em razão da alta mortalidade de fêmeas paridas. CONCLUSÕES: A provável discordância gonotrófica das fêmeas dissecadas é importante do ponto de vista epidemiológico, considerando que a fêmea pode procurar mais de um hospedeiro para completar a maturação dos seus ovos.OBJECTIVE: To determine the parity and ovarian development of Anopheles cruzii species during the seasons. METHODS: Collections were carried out fortnightly in the morning in the Palmito State Park in the municipality of Paranaguá, Southern Brazil, between April 2004 and April 2005. Adult mosquitoes were captured using human landing rate. Dissections were performed using Detinova's and Polovodova's methods and follicular development was assessed following Christophers and Mer's criteria. RESULTS: A total of 208 specimens of Anopheles cruzii were dissected. Most females dissected were nulliparous in the seasons; 14.4% of them were found to be nulliparous above Christophers and Mer's stage II, which shows previous blood meal prior to the

  20. Man-biting activity of Anopheles (Nyssorhynchus albimanus and An. (Kerteszia neivai (Diptera: Culicidae in the Pacific Lowlands of Colombia

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    Yezid Solarte

    1996-04-01

    Full Text Available The daily man-biting activity of Anopheles (Nyssorhynchus albimanus and An. (Kerteszia neivai was determined in four ecologically distinct settlements of the Naya River, Department of Valle, Colombia. Differences were found among the settlements with respect to the mosquito species present, intradomiciliary and extradomiciliary biting activity and population densities.

  1. Use of Near-Infrared Spectroscopy to Age-Grade and Identify Siblings of Anopheles Gambiae Complex

    Science.gov (United States)

    We used near-infrared spectroscopy (NIRS) to rapidly and non-destructively determine species and age of Anopheles gambiae ss (G3, Mali-NIH, Kisumu, ZANU, and Ifakara strains) and An. arabiensis (Dongola, KGB, and Ifakara strains). We developed NIR calibrations using mosquitoes reared and scanned at ...

  2. An Annotated Checklist of the Anopheles of Thailand (Diptera : Culicidae) (Thai National Scientific Papers, Fauna Series Number 2)

    Science.gov (United States)

    1968-08-01

    Discussion: In most urban and agricultura ! areas of Thailand this is the most abundant Anopheles species encountered. The larvae are found in wide variety of...Entomological Society of America : Washington.) TAUSATHIT. Prasit, TH \\vAR:\\v.\\R\\, Bunyong, CH YL~IVYOO, Skol. and KAMPANARDSAENY~KARA. Chaiyan (1962

  3. Genomic islands of speciation in Anopheles gambiae.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available The African malaria mosquito, Anopheles gambiae sensu stricto (A. gambiae, provides a unique opportunity to study the evolution of reproductive isolation because it is divided into two sympatric, partially isolated subtaxa known as M form and S form. With the annotated genome of this species now available, high-throughput techniques can be applied to locate and characterize the genomic regions contributing to reproductive isolation. In order to quantify patterns of differentiation within A. gambiae, we hybridized population samples of genomic DNA from each form to Affymetrix GeneChip microarrays. We found that three regions, together encompassing less than 2.8 Mb, are the only locations where the M and S forms are significantly differentiated. Two of these regions are adjacent to centromeres, on Chromosomes 2L and X, and contain 50 and 12 predicted genes, respectively. Sequenced loci in these regions contain fixed differences between forms and no shared polymorphisms, while no fixed differences were found at nearby control loci. The third region, on Chromosome 2R, contains only five predicted genes; fixed differences in this region were also verified by direct sequencing. These "speciation islands" remain differentiated despite considerable gene flow, and are therefore expected to contain the genes responsible for reproductive isolation. Much effort has recently been applied to locating the genes and genetic changes responsible for reproductive isolation between species. Though much can be inferred about speciation by studying taxa that have diverged for millions of years, studying differentiation between taxa that are in the early stages of isolation will lead to a clearer view of the number and size of regions involved in the genetics of speciation. Despite appreciable levels of gene flow between the M and S forms of A. gambiae, we were able to isolate three small regions of differentiation where genes responsible for ecological and behavioral

  4. Limited Diversity of Anopheles Darlingi in The Peruvian Amazon Region of Iquitos

    OpenAIRE

    Pinedo-Cancino, Viviana; Sheen, Patricia; Tarazona-Santos, Eduardo; OSWALD, WILLIAM E.; JERI, CESAR; VITTOR, AMY YOMIKO; Patz, Jonathan A.; Gilman, Robert H.

    2006-01-01

    Anopheles darlingi is the most important malaria vector in the Amazon basin of South America, and is capable of transmitting both Plasmodium falciparum and P. vivax. To understand the genetic structure of this vector in the Amazonian region of Peru, a simple polymerase chain reaction (PCR)-based test to identify this species of mosquito was used. A random amplified polymorphic DNA-PCR was used to study genetic variation at the micro-geographic level in nine geographically separate populations...

  5. Metabolic and Target-Site Mechanisms Combine to Confer Strong DDT Resistance in Anopheles gambiae

    OpenAIRE

    2014-01-01

    The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible ...

  6. Larvicidal, oviposition, and ovicidal effects of Artemisia annua (Asterales: Asteraceae) against Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Cheah, Shao-Xiong; Tay, Jia-Wei; Chan, Lai-Keng; Jaal, Zairi

    2013-09-01

    This study focuses on the larvicidal, oviposition, and ovicidal effects of a crude extract of Artemisia annua against Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus. Dried cells of Artemisia annua from cell suspension cultures were extracted using hexane. The extract showed moderate larvicidal effects against mosquitoes. At 24-h post treatment, the LC50 values for Anopheles sinensis, Aedes aegypti, and Culex quinquefasciatus were recorded as 244.55, 276.14, and 374.99 ppm, respectively. The percentage mortality of larvae was directly proportional to the tested concentration. Anopheles sinensis was found to be the most susceptible species, whereas Culex quinquefasciatus was the most tolerant to the Artemisia annua extract. The results indicated that the Artemisia annua extract showed concentration-dependent oviposition deterrent activity and had a strong deterrent effect. At 500 ppm, the percentage effective repellency was more than 85% compared with the control group for all the species, with oviposition activity index values of -0.94, -0.95, and -0.78 for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. In the ovicidal assay, the percentage hatchability of eggs after treatment with 500 ppm of Artemisia annua extract was significantly lower than the control, with values of 48.84 ± 4.08, 38.42 ± 3.67, and 79.35 ± 2.09% for Aedes aegypti, Anopheles sinensis, and Culex quinquefasciatus, respectively. Artemisia annua was found to be more effective against Aedes aegypti and Anopheles sinensis compared with Culex quinquefasciatus. This study indicated that crude extract of A. annua could be a potential alternative for use in vector management programs.

  7. Insecticide resistance status in Anopheles gambiae in southern Benin

    Directory of Open Access Journals (Sweden)

    Corbel Vincent

    2010-03-01

    Full Text Available Abstract Background The emergence of pyrethroid resistance in Anopheles gambiae has become a serious concern to the future success of malaria control. In Benin, the National Malaria Control Programme has recently planned to scaling up long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS for malaria prevention. It is, therefore, crucial to monitor the level and type of insecticide resistance in An. gambiae, particularly in southern Benin where reduced efficacy of insecticide-treated nets (ITNs and IRS has previously been reported. Methods The protocol was based on mosquito collection during both dry and rainy seasons across forty districts selected in southern Benin. Bioassay were performed on adults collected from the field to assess the susceptibility of malaria vectors to insecticide-impregnated papers (permethrin 0.75%, delthamethrin 0.05%, DDT 4%, and bendiocarb 0.1% following WHOPES guidelines. The species within An. gambiae complex, molecular form and presence of kdr and ace-1 mutations were determined by PCR. Results Strong resistance to permethrin and DDT was found in An. gambiae populations from southern Benin, except in Aglangandan where mosquitoes were fully susceptible (mortality 100% to all insecticides tested. PCR showed the presence of two sub-species of An. gambiae, namely An. gambiae s.s, and Anopheles melas, with a predominance for An. gambiae s.s (98%. The molecular M form of An. gambiae was predominant in southern Benin (97%. The kdr mutation was detected in all districts at various frequency (1% to 95% whereas the Ace-1 mutation was found at a very low frequency (≤ 5%. Conclusion This study showed a widespread resistance to permethrin in An. gambiae populations from southern Benin, with a significant increase of kdr frequency compared to what was observed previously in Benin. The low frequency of Ace-1 recorded in all populations is encouraging for the use of bendiocarb as an alternative insecticide to

  8. Anopheles darlingi and Anopheles marajoara (Diptera: Culicidae susceptibility to pyrethroids in an endemic area of the Brazilian Amazon

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    Allan Kardec Ribeiro Galardo

    2015-12-01

    Full Text Available Abstract: INTRODUCTION: This study aimed to evaluate the susceptibility of Anopheles darlingi Root (1926 and Anopheles marajoara Galvão & Damasceno (1942 to pyrethroids used by the National Malaria Control Program in Brazil. METHODS: Mosquitoes from Amapá, Brazilian Amazon, were assessed for resistance to cypermethrin, deltamethrin, and alpha-cypermethrin. Insecticide-impregnated bottles were used as suggested by the CDC/Atlanta. RESULTS: Diagnostic dose for Anopheles darlingi was 12.5µg/bottle during 30 min of exposure. Concentrations for Anopheles marajoara were 20µg/bottle of cypermethrin and deltamethrin and 12.5µg/bottle of alpha-cypermethrin. CONCLUSIONS : No resistance was recorded for Anopheles darlingi , but Anopheles marajoara requires attention.

  9. BIONOMIK NYAMUK MANSONIA DAN ANOPHELES DI DESA KARYA MAKMUR, KABUPATEN OKU TIMUR

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    Yanelza Supranelfy

    2016-09-01

    Full Text Available Abstract Lymphatic filariasis is still become the health problem in Indonesia, the disease almost found inthe entire area with fairly high level endemicity. Karya Makmur Village, Madang Suku III District, EastOgan Komering Ulu Regency, South Sumatera Province in 2007 has micofilariae rate of 1,05% based fromblood survey. The aims of the research is to identify vector and the breeding habitat. This research has beenconducted in Karya Makmur Village from May to November 2011. This type of research is noninterventionstudy with spot survey research design. Mosquitoes collection using human landing andresting collection methods, while mosquito larvae were collected from breeding sites. This research found14 species of Mansonia and Anopheles were collected and the species were Mansonia uniformis, Ma.annulata, Ma. indiana, Ma. dives, Ma. bonneae, Ma. annulifera, Anopheles nigerrimus , An. annularis, An.maculatus, An. letifer, An. vagus, An. barbumbrosus, An. barbirostris and An. tesselatus. Mansoniauniformis and Anopheles nigerrimus was confirmed as filariasis vector but none containing microfilariae.Breeding habitat of Anopheles have water temperature 280C — 300C and pH 7 with vegetation (grass andEichhornia crassipes / water hyacinth and predator (Oreochromis niloticus / nile tilapia and Aplocheiluspanchax / fish head lead. Thus the community are expected to behave positively, especially avoidmosquito bites and manipulate the environment that potentially as mosquito larvae breeding habitat.Keywords: Mansonia, Anopheles, filariasis, Karya Makmur Village AbstrakFilariasis limfatik masih merupakan masalah kesehatandi Indonesia, penyebaran penyakit ini hampirdi seluruh wilayah dan dibeberapa daerah dengan tingkatendemic yang cukup tinggi. Desa Karya Makmur, Kecamatan Madang SukuIII, Kabupaten Ogan KomeringUlu Timur, Propinsi Sumatera Selatan pada tahun2007, mikrofilariarate sebesar1,05% berdasarkansurvey darah jari. Tujuan penelitian untuk mengetahui

  10. Engineered anopheles immunity to Plasmodium infection.

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    Yuemei Dong

    2011-12-01

    Full Text Available A causative agent of human malaria, Plasmodium falciparum, is transmitted by Anopheles mosquitoes. The malaria parasite is under intensive attack from the mosquito's innate immune system during its sporogonic development. We have used genetic engineering to create immune-enhanced Anopheles stephensi mosquitoes through blood meal-inducible expression of a transgene encoding the IMD pathway-controlled NF-kB Rel2 transcription factor in the midgut and fat-body tissue. Transgenic mosquitoes showed greater resistance to Plasmodium and microbial infection as a result of timely concerted tissue-specific immune attacks involving multiple effectors. The relatively weak impact of this genetic modification on mosquito fitness under laboratory conditions encourages further investigation of this approach for malaria control.

  11. An expression map for Anopheles gambiae

    OpenAIRE

    MacCallum Robert M; Redmond Seth N; Christophides George K

    2011-01-01

    Abstract Background Quantitative transcriptome data for the malaria-transmitting mosquito Anopheles gambiae covers a broad range of biological and experimental conditions, including development, blood feeding and infection. Web-based summaries of differential expression for individual genes with respect to these conditions are a useful tool for the biologist, but they lack the context that a visualisation of all genes with respect to all conditions would give. For most organisms, including A....

  12. KONFIRMASI STATUS ANOPHELES VAGUS SEBAGAI VEKTOR PENDAMPING SAAT KEJADIAN LUAR BIASA MALARIA DI KABUPATEN SUKABUMI INDONESIA

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    Amrul Munif

    2012-11-01

    Full Text Available Confirmation A nopheles Vagus As Vector Implicated Malaria Outbreak In Sukabumi District, Indonesia.A study on adult anopheline of malaria vector incrimination for the vector status ofAn. aconitus, An.sundaicus and An. barbirostris, An. vagus were infected with malaria parasites was conducted in Simpenan sub-district, Sukabumi district, West Java from January 2003 to February 2003. The observation of the identification of Anopheles spp. and its relationship with outbreak malaria as well as the determination of Anopheles spp. as malaria vectors in endemic areas should be given attention as an effort in preventing malaria outbreaks. Adult mosquitoes were collected from human bait indoor and outdoor catches. Mosquitoes head-thoraces were tested for the presence of circumsporozoite of Plasmodium falciparum and P. vivax for the presence of human blood by ELISA. A total of 3,308 female anophelines representing 9 spesies were collected. Nine identified Anopheles species ie: An.aconitus, An.sundaicus, An maculatus, An.indefinitus, An. vagus, An. baezai, An.kochi, An.barbirostris and An.annularis, recorded during outbreak, were the main vectors of malaria in the Simpenan district. Malaria parasite infections were seen in nine mosquito species, with natural infection 0.12% of the positive An. vagus mosquitoes containing P. faciparum. An. vagus occurring in abundance, was involved in malaria transmission in outbreak period. The average inoculation rate was 0,213 While there was strong ELISA-based evidence implicating An. vagus as a dominant vector. Of these, An.aconitus, An.maculatus and An.sundaicus are suspected primary malaria vector in Simpenan sub-district, Sukabumi district, Indonesia, but An. vagus has been implicated with certainty in malaria transmission in the country.Keywords: Anopheles, vagus, vector status, ELISA, outbreak, implicated vector

  13. Distribución espacial de Anopheles pseudopunctipennis en las Yungas de Salta, Argentina Spatial distribution of Anopheles pseudopunctipennis in the Yungas de Salta rainforest, Argentina

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    María Julia Dantur Juri

    2005-08-01

    Full Text Available OBJETIVO: Comparar la abundancia de Anopheles pseudopunctipennis, y otros anofelinos, en tres zonas silvestres y modificadas por el hombre, a fin de verificar en qué medida tales diferencias ambientales afectan la distribución espacial de estos mosquitos. MÉTODOS: Se realizaron muestreos mensuales (diciembre de 2001 a diciembre de 2002, con trampas de luz CDC con CO2, en cada sitio de muestreo (selva, borde de selva y peridomicilio. En el peridomicilio, además, dos operadores aspiraron mosquitos posados sobre las paredes. Se estimaron índices de diversidad y abundancia de especies, y se intentó caracterizar a los ambientes estudiados mediante ANOVA, cálculo de cosenos y análisis de agrupamientos. RESULTADOS: Anopheles pseudopunctipennis fue la especie más abundante. Se colectaron también An. argyritarsis, An. nuneztovari, An. rangeli y An. strodei. Excepto An. nuneztovari que no se capturó en el peridomicilio, las demás se colectaron en los tres ambientes. No hubo diferencias en los índices de diversidad, ni tampoco entre los ambientes estudiados; sin embargo, el análisis de agrupamiento separó el borde de la selva, donde todas las especies fueron más abundantes en general. CONCLUSIONES: El borde de la selva fue el ambiente que presentó la mayor abundancia, representando, además del peridomicilio, un ambiente de alto riesgo para la transmisión del paludismo.OBJECTIVE: To compare the abundance of Anopheles pseudopunctipennis and other anopheline mosquitoes in three different wild areas, modified by human activities, and to verify how environmental differences affect the spatial distribution of these mosquitoes. METHODS: Samples were collected monthly from December 2001 to December 2002 in Yungas de Salta, Argentina. CO2 -baited CDC light traps were placed at each sample site (forest, transition area and peridomiciliary area. In the peridomiciliary area, two agents also suctioned mosquitoes from house walls. Species diversity

  14. Laboratory studies on the olfactory behaviour of Anopheles quadriannulatus

    NARCIS (Netherlands)

    Pates, H.V.; Takken, W.; Curtis, C.F.

    2005-01-01

    The host preference of Anopheles quadriannulatus Theobald (Diptera: Culicidae), the zoophilic member of the malaria mosquito complex Anopheles gambiae Giles, was investigated in a dual-choice olfactometer. Naïve female mosquitoes were exposed to CO2, acetone, 1-octen-3-ol, and skin emanations from c

  15. The neotype of anopheles albitarsis (Diptera: culicidae O neótipo de Anopheles albitarsis (Diptera: Culicidae

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    Maria Goreti Rosa-Freitas

    1989-09-01

    Full Text Available Anopheles albitarsis neotype is described from specimens collected in Baradero, Argentina, in Shannon's trap, in horse and pig stables and on the progeny of engorded females. The description includes illustrations of adult female, male and female genitalias, scanning electron miscroscopy of the eggs and complete chaetotaxy of pupa and larva. The importance for electing a neotype is based on the realization that An. albitarsis is a complex of cryptic species. It is an attempt to provide typt-locality specimens with which other memebers of the group can be compared.O neótipo de Anopheles albitarsis é descrito a partir de espécimens coletados em armadilha tipo Shannon, em estábulos de cavalos e porcos e progênies de fêmeas ingurgitadas em Baradero, Argentina, localidade-tipo da espécie. A descrição inclui ilustrações da fêmea adulda, genitálias masculina e feminina, ovos em microscopia eletrônica de varredura e da quetotaxia completa das larvas de 4º estádio e pupas. A eleição de um neótipo para albitarsis baseia-se em dados recentes que apontam a espécie como um complexo de espécies crípticas, o que evidencia a importância de uma descrição detalhada de espécimens da localidade-tipo com o qual outros membros do grupo possam ser comparados.

  16. Population genetic structure of Anopheles arabiensis and Anopheles gambiae in a malaria endemic region of southern Tanzania

    NARCIS (Netherlands)

    K.R. Ng'habi; B.G.J. Knols; Y. Lee; H.M. Ferguson; G.C. Lanzaro

    2011-01-01

    Background: Genetic diversity is a key factor that enables adaptation and persistence of natural populations towards environmental conditions. It is influenced by the interaction of a natural population's dynamics and the environment it inhabits. Anopheles gambiae s.s. and Anopheles arabiensis are t

  17. Physico-chemical characteristics of Anopheles culicifacies and Anopheles varuna breeding water in a dry zone stream in Sri Lanka

    DEFF Research Database (Denmark)

    Piyaratne, M K; Amerasinghe, F P; Amerasinghe, P H;

    2005-01-01

    BACKGROUND & OBJECTIVES: Selected physico-chemical characteristics of flowing and pooled water in a stream that generated two malaria vectors, Anopheles culicifacies s.l. Giles and Anopheles varuna Iyengar, were investigated during August-September 1997 and July 1998 at the Upper Yan Oya watershed...

  18. Anopheles (Anopheles) Lesteri Biases and Hu (Diptera: Culicidae): Neotype Designation and Description

    Science.gov (United States)

    2005-06-30

    Anopheles) anthropoplwglts: Ma 1981: 1I (key; distribution, China: Fukien. Kiangsi. Kiangsu. Kwangsi. Kweichow. Shanghai. provinces south of Yantze River ...lowing: Taina Litwak for her illustrations; Bel Rueda, Buddy Buenavista. Lerma Bue- navista. Benjie Puma. and Modesta Coro- nado-Puma for their help in

  19. New selenoproteins identified in silico from the genome of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins,where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine.The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species.Available computational tools fail to correctly predict selenoproteins.Thus,we devel-oped a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information,several programs were edited with PERL language to identify selenocysteine insertion sequence(SECIS)element,the coding potential of TGA codons,and cys-teine-containing homologs of selenoprotein genes.Our results showed that 11365 genes were termi-nated with TGA codons,918 of which contained SECIS elements.Similarity search revealed that 58 genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons.Finally,7 genes were found to fully meet requirements for selenoproteins,although they have not been anno-tated as selenoproteins in NCBI databases.Deduced from their basic properties,the newly found se-lenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles’ vectorial capacity of Plasmodium.This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.

  20. Robust and regulatory expression of defensin A gene driven by vitellogenin promoter in transgenic Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    CHEN XiaoGuang; ZHANG YaJing; ZHENG XueLi; WANG ChunMei

    2007-01-01

    The use of genetically modified mosquitoes to reduce or replace field populations is a new strategy to control mosquito-borne diseases. The precondition of the implementation of this strategy is the ability to manipulate the genome of mosquitoes and to induce specific expression of the effector molecules driven by a suitable promoter. The objective of this study is to evaluate the expression of defensin A gene of Anopheles sinensis under the control of a vitellogenin promoter in transgenic Anopheles stephensi. The regulatory region of Anopheles gambiae vitellogenin was cloned and subcloned into transfer vector pSLFa consisting of an expression cassette with defensin A coding sequence. Then, the expression cassette was transferred into transformation vector pBac[3xP3-DsRedafm] using Asc I digestion. The recombinant plasmid DNA of pBac[3xP3DsRed-AgVgT2-DefA] and helper plasmid DNA of phsp-pBac were micro-injected into embryos of An. stephensi. The positive transgenic mosquitoes were screened by observing specific red fluorescence in the eyes of G1 larvae. Southern blot analysis showed that a single-copy transgene integrated into the genome of An. stephensi. RT-PCR analysis showed that the defensin A gene expressed specifically in fat bodies of female mosquitoes after a blood meal. Interestingly, the mRNA of defensin A is more stable compared with that of the endogenous vitellogenin gene. After multiple blood meals, the expression of defensin A appeared as a reducible and non-cycling type, a crucial feature for its anti-pathogen effect. From data above, we concluded that the regulatory function of the Vg promoter and the expression of defensin A gene were relatively conserved in different species of anopheles mosquitoes. These molecules could be used as candidates in the development of genetically modified mosquitoes.

  1. Karakteristik Habitat Larva Anopheles spp. di Desa Sungai Nyamuk, Daerah Endemik Malaria di Kabupaten Nunukan, Kalimantan Utara

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    Sugiarto Sugiarto

    2016-07-01

    Full Text Available A research about Habitat Characteristics of Anopheles spp. larvae was done in Sungai Nyamuk Village, Nunukan District, North Kalimantan Province from August 2010 to January 2012. This research aims to analyse the characteristics of breeding places of Anopheles spp. The larvae taken from various types of habitat with detention and maintained until it was developed into mosquitoes, then later identified. The results showed that there are four types of potential breeding places of Anopheles spp. ie lagoon, ditches, fish ponds and marshes. Anopheles types that are found consist of five species, namely An. vagus, An. subpictus, An. sundaicus, An. indefinitus dan An. peditaeniatus. Types of potential breeding places are dominated by the unused fish pond, with the substrate in the form of mud and water is not flowing, located around settlements surrounded by grasses, shrubs and trees. Breeding places contains of aquatic plants such as grasses and moss. Predators are found in the form of a dragonfly nymph, crustaceans, tadpoles and small fish. Early malaria vector control at the level of the larvae is a critical point of the success of malaria elimination programs in endemic areas.

  2. Effect of Bacillus sphaericus Neide on Anopheles (Diptera: Culicidae and associated insect fauna in fish ponds in the Amazon

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    Francisco Augusto da Silva Ferreira

    2015-09-01

    Full Text Available ABSTRACTWe analyzed the effects of Bacillus sphaericus on Anopheles larvae and on the associated insect fauna in fish farming ponds. Five breeding sites in the peri-urban area of the city of Manaus, AM, Brazil, were studied. Seven samples were collected from each breeding site and B. sphaericus was applied and reapplied after 15 days. The samples were made at 24 h before application, 24 h post-application and 5 and 15 days post-application. We determined abundance, larval reduction and larval density for Anopheles, and abundance, richness, Shannon diversity index and classified according to the functional trophic groups for associated insect fauna. A total of 904 Anopheles larvae were collected and distributed into five species. Density data and larval reduction demonstrated the rapid effect of the biolarvicide 24 h after application. A total of 4874 associated aquatic insects belonging to six orders and 23 families were collected. Regression analysis of diversity and richness indicated that the application of the biolarvicide had no influence on these indices and thus no effect on the associated insect fauna for a period of 30 days. B. sphaericus was found to be highly effective against the larvae of Anopheles, eliminating the larvae in the first days after application, with no effect on the associated insect fauna present in the fish ponds analyzed.

  3. Remotely-sensed land use patterns and the presence of Anopheles larvae (Diptera: Culicidae) in Sukabumi, West Java, Indonesia.

    Science.gov (United States)

    Stoops, Craig A; Gionar, Yoyo R; Shinta; Sismadi, Priyanto; Rachmat, Agus; Elyazar, Iqbal F; Sukowati, Supratman

    2008-06-01

    Land use patterns and the occurrence of Anopheles species larvae were studied in Sukabumi District, West Java, Indonesia, from October 2004 to September 2005. Two land use maps derived using remote sensing were used. One map derived from Quickbird satellite images of 150 km2 of the Simpenan and Ciemas subdistricts (106 degrees 27' 53"-106 degrees 38' 38" E and 6 degrees 59' 59"-7 degrees 8' 46" S) in Sukabumi and one using ASTER images covering 4,000 km2 of Sukabumi District from 106 degrees 22' 15"-107 degrees 4' 1" E and 6 degrees 42' 50" - 7 degrees 26' 13" S. There was a total of 11 Anopheles spp. collected from 209 sampling locations in the area covered by the Quickbird image and a total of 15 Anopheles spp. collected from 1,600 sampling locations in the area covered by the ASTER map. For the area covered by the land use maps, ten species were found to have statistically positive relationships between land use class and species presence: Anopheles aconitus, An. annularis, An. barbirostris. An. flavirostris, An. insulaeflorum, An. kochi, An. maculatus, An. subpictus, An. sundaicus, and An. vagus. Quickbird and ASTER satellite images both produced land maps that were adequate for predicting species presence in an area. The land use classes associated with malaria vector breeding were rice paddy (An. aconitus, An. subpictus), plantation located near or adjacent to human settlements (An. maculatus), bush/shrub (An. aconitus, An. maculatus, An. sundaicus), bare land, and water body land use on the coast located < or = 250 m of the beach (An. sundaicus). Understanding the associations of habitat and species in one area, predictions of species presence or absence can be made prior to a ground survey allowing for accurate vector survey and control planning.

  4. Neuropeptides and Peptide Hormones in Anopheles gambiae

    Science.gov (United States)

    Riehle, Michael A.; Garczynski, Stephen F.; Crim, Joe W.; Hill, Catherine A.; Brown, Mark R.

    2002-10-01

    The African malaria mosquito, Anopheles gambiae, is specialized for rapid completion of development and reproduction. A vertebrate blood meal is required for egg production, and multiple feedings subsequently allow transmission of malaria parasites, Plasmodium spp. Regulatory peptides from 35 genes annotated from the A. gambiae genome likely coordinate these and other physiological processes. Plasmodium parasites may affect actions of newly identified insulin-like peptides, which coordinate growth and reproduction of its vector, A. gambiae, as in Drosophila melanogaster, Caenorhabditis elegans, and mammals. This genomic information provides a basis to expand understanding of hematophagy and pathogen transmission in this mosquito.

  5. Anopheles (Anopheles) forattinii: a New Species in Series Arribalzagia (Diptera: Culicidae)

    Science.gov (United States)

    1999-05-01

    Smithsonian Institution, Washington, DC 20560. ’ Ndcleo de Pesquisa Taxon6mica e Sistematica em Entomologia MBdica (NUPTEM), Departamento de Epidemiologia...anofelinos das regioes nordestinas e amazonica do Brasil. Rev. Serv. Esp. I: 827-965. Forattini, 0. P. 1962. Entomologia medica. vol. I. Parte Geral

  6. Resistance Mechanisms of Anopheles stephensi (Diptera: Culicidae to Temephos

    Directory of Open Access Journals (Sweden)

    Aboozar Soltani

    2015-10-01

    Full Text Available Background: Anopheles stephensi is a sub-tropical species and has been considered as one of the most important vector of human malaria throughout the Middle East and South Asian region including the malarious areas of southern Iran. Current reports confirmed An. stephensi resistance to temephos in Oman and India. However, there is no comprehensive research on mechanisms of temephos resistance in An. stephensi in the literature. This study was designed in order to clarify the enzymatic and molecular mechanisms of temephos resistance in this species.Methods: Profile activities of α- and ß-esterases, mixed function oxidase (MFO, glutathione-S-transferase (GST, insensitive acetylcholinesterase, and para-nitrophenyl acetate (PNPA-esterase enzymes were tested for An. stephensi strain with resistance ratio of 15.82 to temephos in comparison with susceptible strain.Results: Results showed that the mean activity of α-EST, GST and AChE enzymes were classified as altered indicating metabolic mechanisms have considerable role in resistance of An. stephensi to temephos. Molecular study using PCR-RFLP method to trace the G119S mutation in ACE-1 gene showed lack of the mutation responsible for organophosphate insecticide resistance in the temephos-selected strain of An. stephensi.Conclusion: This study showed that the altered enzymes but not targets site insensitivity of ACE-1 are responsible for temephos resistance in An. stephensi in south of Iran.

  7. Resting behaviour, ecology and genetics of malaria vectors in large scale agricultural areas of Western Kenya.

    Science.gov (United States)

    Githeko, A K; Service, M W; Mbogo, C M; Atieli, F K

    1996-12-01

    In Kenya indoor and outdoor resting densities of Anopheles arabiensis and Anopheles funestus at the Ahero rice irrigation scheme, and Anopheles gambiae s.s., An. arabiensis and An. funestus at the Miwani sugar belt were assessed for 13 months by pyrethrum spray collections in houses and granaries. The vector's house leaving behaviour was evaluated with exit traps and it was noted that early exophily (i.e., deliberate) was not detected in any of the vectors. Assortative indoor/outdoor resting behaviour was studied by a capture-mark-release-recapture method and showed that in An. arabiensis both indoor and outdoor resting traits were present in the same individuals. Samples of half-gravid female An. gambiae s.l. were chromosomally identified either as Anopheles gambiae s.s. or An. arabiensis and in a subsample chromosomal inversions were read. Anopheles gambiae s.s. and An. arabiensis had the 2Rb inversion but in addition the 2La inversion was found in An. gambiae s.s. and this is an indication of low chromosomal variation. At Ahero An. arabiensis was most abundant when the rice crop was immature and An. funestus when the crop was mature. This succession of vectors facilitated the transmission of malaria throughout the year. At Miwani, An. gambiae s.l. population peaked during the long rains but the proportion of An. arabiensis was highest during the dry season. The indoor resting density of males of the three vector species was less than half of the females.

  8. Mosquitocidal activity of Polygala arvensis Willd against Aedes aegypti (Linn., Anopheles stephensi (Liston. and Culex quinquefasciatus (Say. (Diptera: Culicidae

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    M. Deepa

    2014-12-01

    Full Text Available To determine the larvicidal, ovicidal and repellent activities of benzene and methanol extract of Polygala arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus Twenty five 3rd instar larvae of selected mosquitoes species were exposed to various concentrations (60-300 ppm and were assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC50 values of the P. Arvensis leaf extract was determined following Probit analysis. The ovicidal activity was determined against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus exposed to variousconcentrations were tested under laboratory conditions and the hatch rates were assessed 120hrs post treatment. The repellent efficacy was determined against selected mosquitoes at three concentrations viz., 1.0, 2.0 and 3.0 mg/cm2 under the laboratory conditions. The LC50 and LC90 values of benzene and methanol extract of P. arvensis against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus larvae in 24 h were 75.32, 88.26, 82.46, 58.21, 46.37, 42.68 and 260.48, 275.26, 251.39, 208.45, 189.82 and 130.44 ppm, respectively. It has been noticed that the higher concentrations of P. arvensis extractspossesses strong ovicidal activity at 200 ppm concentration against Ae. aegypti, An. stephensi and C. quinquefasciatus, no egg hatchability was recorded. In the same way, methanol extracts showed maximum ovicidal activity followed by benzene extract against selected vector mosquitoes. In repellent activity, among two extracts tested P. arvensis methanol extract had strong repellent action against selected mosquitoes as it provided 100% protection against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus for 280min. From the results it can be concluded the P. arvensis extract was an excellent potential for controlling Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes.

  9. Synergism between ammonia, lactic acid and carboxylic acids as kairomones in the host-seeking behaviour of the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae)

    NARCIS (Netherlands)

    Smallegange, R.C.; Qiu, Y.T.; Loon, van J.J.A.; Takken, W.

    2005-01-01

    Host odours play a major role in the orientation and host location of blood-feeding mosquitoes. Anopheles gambiae Giles sensu stricto, which is the most important malaria vector in Africa, is a highly anthropophilic mosquito species, and the host-seeking behaviour of the females of this mosquito is

  10. The effect of water physical quality and water level changes on the occurrence and density of larvae of Anopheles mosquitoes around the shoreline of the Koka reservoir, Central Ethiopia

    Directory of Open Access Journals (Sweden)

    S. Kibret

    2010-08-01

    Full Text Available Entomological studies to determine the effect of the physical characteristics of larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae and on the spatial and temporal formation of larval breeding habitats were conducted in two villages at Koka reservoir between August and December 2007. Of the two study villages, Ejersa is in close proximity to the reservoir, and Kuma is 5 km away from it. Data on the type, number and physical characteristics of Anopheles larval breeding habitat, species composition and densities of anopheles mosquitoes in and around the study villages were investigated and recorded. Meteorological and reservoir water level data were compared with availability of Anopheles larval breeding sites and densities. Entomological data from the weekly larval collections showed that Anopheles pharoensis Theobald, Anopheles gambiae s.l. Giles, Anopheles coustani Laveran and Anopheles squamosus Theobald were breeding in the study area. The mean larval density of A. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitats than in turbid and relatively deep aquatic habitats (F=16.97, pF=6.03, pA. pharoensis in habitat with floating vegetation and with relatively shady conditions was significantly higher than that of less shaded aquatic habitat and greater emergent vegetation (F=15.75, pF=10.56, pAnopheles larvae with water temperature of the breeding habitat and daily minimum atmospheric temperature (r=0.541, pr=0.604, pr=0.605, pAnopheles larval count, and the density of Anopheles mosquitoes in the vicinity. The proliferation of suitable breeding habitats around the reservoir villages is strongly associated with reservoir water level changes. This is particularly important for A. pharoensis and A. arabiensis which are important vectors of malaria in the area. Further investigation on the species diversity, physical and chemical habitat characteristics and

  11. Scanning electron microscopic (Sem studies on fourth instar larva and pupa of Anopheles (Cellia stephensi Liston (Anophelinae: Culicidae

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    Jagbir Singh Kirti

    2014-12-01

    Full Text Available Anopheles (Cellia stephensi Liston is a major vector species of malaria in Indian subcontinent. Taxonomists have worked on its various morphological aspects and immature stages to explore additional and new taxonomic attributes. Scanning electron microscopic (SEM studies have been conducted on the fourth instar larva and pupa of An. stephensi to find additional taxonomic features for the first time from Punjab state.

  12. Mosquito Larvicidal Potential of Gossypium hirsutum (Bt cotton) Leaves Extracts against Aedes aegypti and Anopheles stephensi larvae.

    OpenAIRE

    Patil, Chandrashekhar D; Hemant P Borase; Salunkhe, Rahul B; Rahul K Suryawanshi; Narkhade, Chandrakant P; Salunke, Bipinchandra K.; Satish V Patil

    2014-01-01

    Background: We aimed to extract the ingredients from leaves of Gossypium hirsutum (Bt cotton) using different solvents and evaluate for potential use to control different larval stages of mosquito species, Aedes aegypti and Anopheles stephensi. Methods: Qualitative and quantitative estimation of ingredients from Go. hirsutum (Bt) plant extract was carried out and their inhibitory action against mosquito larvae was determined using mosquito larvicidal assay. Results: LC50 values of water, etha...

  13. The polymorphism and the geographical distribution of the knockdown resistance (kdr of Anopheles sinensis in the Republic of Korea

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    Kang Seunghyun

    2012-05-01

    Full Text Available Abstract Background In the Republic of Korea (ROK, six sibling species of the Anopheles sinensis complex are considered the vector species of malaria, but data on their susceptibilities to malaria and vector capacities have been controversial. The intensive use of insecticides has contributed to the rapid development and spread of insecticide resistance in the An. sinensis complex. Knockdown resistance (kdr to pyrethroids and DDT in the An. sinensis complex is associated with a mutation in codon 1014 of the voltage-gated sodium channel (VGSC gene. Because the degree of insecticide resistance varies among mosquito species and populations, the detection of kdr mutations among the six sibling species of the An. sinensis complex is a prerequisite for establishing effective long-term vector control strategies in the ROK Methods In order to investigate species-specific kdr mutations, An. sinensis complex specimens have been collected from 22 sites in the ROK. Because of the difficulties with species identifications that are based only on morphological characteristics, molecular identification methods have been conducted on every specimen. Part of the IIS6 domain of the VGSC was polymerase chain reaction-amplified and directly sequenced. Results The molecular analyses revealed that mutations existed at codon 1014 only in An. sinensis sensu stricto and no mutations were found in the other five Anopheles species. In An. sinensis s.s., one wild type (TTG L1014 and three mutant types (TTT L1014F, TTC L1014F, and TGT L1014C of kdr alleles were detected. The TTC L1014F mutation was observed for the first time in this species. Conclusions The fact that the highly polymorphic kdr gene is only observed in An. sinensis s.s., out of the six Anopheles species and their geographical distribution suggest the need for future studies of insecticide resistance monitoring and investigations of species-specific resistance mechanisms in order to build successful malaria

  14. Innate immunity against malaria parasites in Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Yang Chenand; Zhi-Hui Weng; Liangbiao Zheng

    2008-01-01

    Malaria continues to exert a huge toll in the world today, causing approximately 400 million cases and killing between 1-2 million people annually. Most of the malaria burden is borne by countries in Africa. For this reason, the major vector for malaria in this continent, Anopheles gambiae, is under intense study. With the completion of the draft sequence of this important vector, efforts are underway to develop novel control strategies.One promising area is to harness the power of the innate immunity of this mosquito species to block the transmission of the malaria parasites. Recent studies have demonstrated that Toll and Imd signaling pathways and other immunity-related genes (encoding proteins possibly function in recognition or as effector molecules) play significant roles in two different arms of innate immunity: level of infection intensity and melanization of Plasmodium oocysts.The challenges in the future are to understand how the functions of these different genes are coordinated in defense against malaria parasites, and if different arms of innate immunity are cross-regulated or coordinated.

  15. Biology, distribution and control of Anopheles (Cellia) minimus in the context of malaria transmission in northeastern India.

    Science.gov (United States)

    Dev, Vas; Manguin, Sylvie

    2016-11-15

    Among six dominant mosquito vector species involved in malaria transmission in India, Anopheles minimus is a major species in northeast India and held responsible for focal disease outbreaks characterized by high-rise of Plasmodium falciparum infections and attributable death cases. It has been now genetically characterized that among the three-member species of the Minimus Complex spread in Asia, An. minimus (former species A) is prevalent in India including northeastern states and east-central state of Odisha. It is recorded in all seasons and accounts for perennial transmission evidenced by records of sporozoite infections. This species is highly anthropophilic, and largely endophilic and endophagic, recorded breeding throughout the year in slow flowing seepage water streams. The populations of An. minimus in India are reported to be highly diverse indicating population expansion with obvious implications for judicious application of vector control interventions. Given the rapid ecological changes due to deforestation, population migration and expansion and developmental activities, there is scope for further research on the existence of potential additional sibling species within the An. minimus complex and bionomics studies on a large geographical scale for species sanitation. For control of vector populations, DDT continues to be applied on account of retaining susceptibility status even after decades of residual spraying. Anopheles minimus is a highly adaptive species and requires continuous and sustained efforts for its effective control to check transmission and spread of drug-resistant malaria. Anopheles minimus populations are reportedly diminishing in northeastern India whereas it has staged comeback in east-central State of Odisha after decades of disappearance with its eco-biological characteristics intact. It is the high time to siege the opportunity for strengthening interventions against this species for its population diminution to sub

  16. An overview of malaria transmission from the perspective of Amazon Anopheles vectors

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    Paulo FP Pimenta

    2015-02-01

    Full Text Available In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.

  17. Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe

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    Romi Roberto

    2011-01-01

    Full Text Available Abstract Background There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, Anopheles atroparvus. Levels of population differentiation of An. atroparvus from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission. Methods Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatellite loci and geometric morphometrics on 21 wing landmarks. Results Levels of genetic diversity were comparable to those reported for tropical malaria vectors. Low levels of genetic (0.004 FST An. atroparvus populations spanning over 3,000 km distance. Genetic differentiation (0.202 FST An. atroparvus and Anopheles maculipennis s.s. Differentiation between sibling species was not so evident at the phenotype level. Conclusions Levels of population differentiation within An. atroparvus were low and not correlated with geographic distance or with putative physical barriers to gene flow (Alps and Pyrenées. While these results may suggest considerable levels of gene flow, other explanations such as the effect of historical population perturbations can also be hypothesized.

  18. Molecular confirmation of the occurrence in Germany of Anopheles daciae (Diptera, Culicidae

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    Kronefeld Mandy

    2012-11-01

    Full Text Available Abstract Background Anopheles daciae, a newly described member of the Maculipennis group, was recently reported from western, southern and eastern Europe. Before its recognition, it had commonly been listed under the name of An. messeae, due to its extreme morphological and genetic similarities. As the sibling species of the Maculipennis group are known to differ in their vector competences for malaria parasites and other pathogens, the occurrence of An. daciae in a given region might have an impact on the epidemiology of mosquito-borne diseases. Mosquito collections from different localities in Germany were therefore screened for An. daciae. Methods Adult and immature Maculipennis group mosquitoes were collected between May 2011 and June 2012 at 23 different sites in eight federal states of Germany. A standard PCR assay was used to differentiate the previously known sibling species while the ITS2 rDNA of specimens preliminarily identified as An. messeae/daciae was sequenced and analysed for species-specific nucleotide differences. Results Four hundred and seventy-seven Anopheles specimens were successively identified to Maculipennis group level by morphology and to species level by DNA-based methods. Four species of the Maculipennis group were registered: An. messeae (n = 384, An. maculipennis (n = 82, An. daciae (n = 10 and An. atroparvus (n = 1. Anopheles daciae occurred at four sites in three federal states of Germany, three of the sites being located in north-eastern Germany (federal states of Brandenburg and Saxony while one collection site was situated in the northern Upper Rhine Valley in the federal state of Hesse, south-western Germany. Conclusions The detection of An. daciae represents the first recognition of this species in Germany where it was found to occur in sympatry with An. messeae and An. maculipennis. As the collection sites were in both north-eastern and south-western parts of Germany, the species is

  19. Effects of Anti-Mosquito Salivary Glands and Deglycosylated Midgut Antibodies of Anopheles stephensi on Fecundity and Longevity

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    H Mohammadzadeh Hajipirloo

    2005-09-01

    Full Text Available With the aim of controlling malaria by reducing vector population, the effects of antibodies produced against salivary glands and deglycosylated midgut antigens of Anopheles stephensi mosquitoes on fecundity and longevity of the same species were tested. Three deglycosylated preparations of midgut and two preparations of salivary glands were produced, conjugated with aluminum hydroxide gel, and subcutaneously injected to shoulders of TO (Turner Out-bred mice. After 4 immunizations and assurance of enough antibody production against utilized antigenic suspensions, effects of blood feeding on immunized and control mice were assayed. Insoluble preparation of midgut showed the strongest effect with 23.5% reduction in egg laying, and increasing death rate of vectors in third day after feeding. No significant reduction in fecundity or survivorship was seen with other preparations. Anopheles midgut insoluble antigens are potential candidates for designing vaccines against malaria vectors and further investigations need to be done to find effective antigens and the best way of their use.

  20. Spatio-temporal variations of Anopheles coluzzii and An. gambiae and their Plasmodium infectivity rates in Lobito, Angola.

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    Carnevale, Pierre; Toto, Jean-Claude; Besnard, Patrick; Santos, Maria Adelaide Dos; Fortes, Filomeno; Allan, Richard; Manguin, Sylvie

    2015-06-01

    From 2003 to 2007, entomological surveys were conducted in Lobito town (Benguela Province, Angola) to determine which Anopheles species were present and to identify the vectors responsible for malaria transmission in areas where workers of the Sonamet Company live. Two types of surveys were conducted: (1) time and space surveys in the low and upper parts of Lobito during the rainy and dry periods; (2) a two-year longitudinal study in Sonamet workers' houses provided with long-lasting insecticide-treated nets (LLIN), "PermaNet," along with the neighboring community. Both species, An. coluzzii (M molecular form) and An. gambiae (S molecular form), were collected. Anopheles coluzzii was predominant during the dry season in the low part of Lobito where larvae develop in natural ponds and temporary pools. However, during the rainy season, An. gambiae was found in higher proportions in the upper part of the town where larvae were collected in domestic water tanks built near houses. Anopheles melas and An. listeri were captured in higher numbers during the dry season and in the low part of Lobito where larvae develop in stagnant brackish water pools. The infectivity rates of An. gambiae s.l. varied from 0.90% to 3.41%.

  1. Systematics and Population Level Analysis of Anopheles darlingi

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    Conn JE

    1998-01-01

    Full Text Available A new phylogenetic analysis of the Nyssorhynchus subgenus (Danoff-Burg and Conn, unpub. data using six data sets {morphological (all life stages; scanning electron micrographs of eggs; nuclear ITS2 sequences; mitochondrial COII, ND2 and ND6 sequences} revealed different topologies when each data set was analyzed separately but no heterogeneity between the data sets using the arn test. Consequently, the most accurate estimate of the phylogeny was obtained when all the data were combined. This new phylogeny supports a monophyletic Nyssorhynchus subgenus but both previously recognized sections in the subgenus (Albimanus and Argyritarsis were demonstrated to be paraphyletic relative to each other and four of the seven clades included species previously placed in both sections. One of these clades includes both Anopheles darlingi and An. albimanus, suggesting that the ability to vector malaria effectively may have originated once in this subgenus. Both a conserved (315 bp and a variable (425 bp region of the mitochondrial COI gene from 15 populations of An. darlingi from Belize, Bolivia, Brazil, French Guiana, Peru and Venezuela were used to examine the evolutionary history of this species and to test several analytical assumptions. Results demonstrated (1 parsimony analysis is equally informative compared to distance analysis using NJ; (2 clades or clusters are more strongly supported when these two regions are combined compared to either region separately; (3 evidence (in the form of remnants of older haplotype lineages for two colonization events; and (4 significant genetic divergence within the population from Peixoto de Azevedo (State of Mato Grosso, Brazil. The oldest lineage includes populations from Peixoto, Boa Vista (State of Roraima and Dourado (State of São Paulo.

  2. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

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    H Vatandoost

    2007-06-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  3. Ecology of Anopheles dthali Patton in Bandar Abbas District, Hormozgan Province, Southern Iran

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    H Vatandoost

    2007-05-01

    Full Text Available Ecology of Anopheles dthali was studied in Bandar Abbas County, where there is indigenous malaria. Anopheles dthali plays as a secondary malaria vector in the region. It is active throughout the year in mountainous area with two peaks of activity, whereas in coastal area it has one peak. There is no report of hibernation or aestivation for this species in the re¬gion. Precipitin tests on specimens from different parts showed that 15.6-20.8% were positive for human blood. This species usually rests outdoors. It has different larval habitats. Insecticides susceptibility tests on adult females exhibited susceptibil¬ity to all insecticides recommended by WHO. LT50 for the currently used insecticide, lambda-cyhalothrin, is measured less than one minute. The irritability tests to pyrethroid insecticides, showed that permethrin and lambda-cyhalothrin had more irritancy compared to deltamethrin and cyfluthrin. Larval bioassay using malathion, chlorpyrifos, temephos and fenithrothion did not show any sing of resistance to these larvicides at the diagnostic dose. It is recommended that all the decision makers should consider the results of our study for any vector control measures in the region.

  4. Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis

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    Lee, Sang Joon; Kang, Dooho; Lee, Seung Chul; Ha, Young-Ran

    2016-02-01

    Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.

  5. The genetics of inviability and male sterility in hybrids between Anopheles gambiae and An. arabiensis.

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    Slotman, M; Della Torre, A; Powell, J R

    2004-05-01

    Male hybrids between Anopheles gambiae and An. arabiensis suffer from hybrid sterility, and inviability effects are sometimes present as well. We examined the genetic basis of these reproductive barriers between the two species, using 21 microsatellite markers. Generally, recessive inviability effects were found on the X chromosome of gambiae that are incompatible with at least one factor on each arabiensis autosome. Inviability is complete when the gambiae and arabiensis inviability factors are hemi- or homozygous. Using a QTL mapping approach, regions that contribute to male hybrid sterility were also identified. The X chromosome has a disproportionately large effect on male hybrid sterility. Additionally, several moderate-to-large autosomal QTL were found in both species. The effect of these autosomal QTL is contingent upon the presence of an X chromosome from the other species. Substantial regions of the autosomes do not contribute markedly to male hybrid sterility. Finally, no evidence for epistatic interactions between conspecific sterility loci was found.

  6. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV).

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    Suzuki, Yasutsugu; Barik, Tapan K; Johnson, Rebecca M; Rasgon, Jason L

    2015-07-29

    AgDNV is a powerful gene transduction tool and potential biological control agent for Anopheles mosquitoes. Using a GFP reporter virus system, we investigated AgDNV host range specificity in four arthropod cell lines (derived from An. gambiae, Aedes albopictus and Drosophila melanogaster) and six mosquito species from 3 genera (An. gambiae, An. arabiensis, An. stephensi, Ae. albopictus, Ae. aegypti and Culex tarsalis). In vitro, efficient viral invasion, replication and GFP expression was only observed in MOS55 An. gambiae cells. In vivo, high levels of GFP were observed in An. gambiae mosquitoes. Intermediate levels of GFP were observed in the closely related species An. arabiensis. Low levels of GFP were observed in An. stephensi, Ae. albopictus, Ae. aegypti and Cx. tarsalis. These results suggest that AgDNV is a specific gene transduction tool for members of the An. gambiae species complex, and could be potentially developed into a biocontrol agent with minimal off-target effects.

  7. Human exposure to anopheline mosquitoes occurs primarily indoors, even for users of insecticide-treated nets in Luangwa Valley, South-east Zambia

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    Seyoum Aklilu

    2012-05-01

    Full Text Available Abstract Background Current front line malaria vector control methods such as indoor residual spraying (IRS and long-lasting insecticidal nets (LLINs, rely upon the preference of many primary vectors to feed and/or rest inside human habitations where they can be targeted with domestically-applied insecticidal products. We studied the human biting behaviour of the malaria vector Anopheles funestus Giles and the potential malaria vector Anopheles quadriannulatus Theobald in Luangwa valley, south-east Zambia. Methods Mosquitoes were collected by human landing catch in blocks of houses with either combined use of deltamethrin-based IRS and LLINs or LLINs alone. Human behaviour data were collected to estimate how much exposure to mosquito bites indoors and outdoors occurred at various times of the night for LLIN users and non-users. Results Anopheles funestus and An. quadriannulatus did not show preference to bite either indoors or outdoors: the proportions [95% confidence interval] caught indoors were 0.586 [0.303, 0.821] and 0.624 [0.324, 0.852], respectively. However, the overwhelming majority of both species were caught at times when most people are indoors. The proportion of mosquitoes caught at a time when most people are indoors were 0.981 [0.881, 0.997] and 0.897 [0.731, 0.965], respectively, so the proportion of human exposure to both species occuring indoors was high for individuals lacking LLINs (An. funestus: 0.983 and An. quadriannulatus: 0.970, respectively. While LLIN users were better protected, more than half of their exposure was nevertheless estimated to occur indoors (An. funestus: 0.570 and An. quadriannulatus: 0.584. Conclusions The proportion of human exposure to both An. funestus and An. quadriannulatus occuring indoors was high in the area and hence both species might be responsive to further peri-domestic measures if these mosquitoes are susceptible to insecticidal products.

  8. Ecotope-Based Entomological Surveillance and Molecular Xenomonitoring of Multidrug Resistant Malaria Parasites in Anopheles Vectors

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    Prapa Sorosjinda-Nunthawarasilp

    2014-01-01

    Full Text Available The emergence and spread of multidrug resistant (MDR malaria caused by Plasmodium falciparum or Plasmodium vivax have become increasingly important in the Greater Mekong Subregion (GMS. MDR malaria is the heritable and hypermutable property of human malarial parasite populations that can decrease in vitro and in vivo susceptibility to proven antimalarial drugs as they exhibit dose-dependent drug resistance and delayed parasite clearance time in treated patients. MDR malaria risk situations reflect consequences of the national policy and strategy as this influences the ongoing national-level or subnational-level implementation of malaria control strategies in endemic GMS countries. Based on our experience along with current literature review, the design of ecotope-based entomological surveillance (EES and molecular xenomonitoring of MDR falciparum and vivax malaria parasites in Anopheles vectors is proposed to monitor infection pockets in transmission control areas of forest and forest fringe-related malaria, so as to bridge malaria landscape ecology (ecotope and ecotone and epidemiology. Malaria ecotope and ecotone are confined to a malaria transmission area geographically associated with the infestation of Anopheles vectors and particular environments to which human activities are related. This enables the EES to encompass mosquito collection and identification, salivary gland DNA extraction, Plasmodium- and species-specific identification, molecular marker-based PCR detection methods for putative drug resistance genes, and data management. The EES establishes strong evidence of Anopheles vectors carrying MDR P. vivax in infection pockets epidemiologically linked with other data obtained during which a course of follow-up treatment of the notified P. vivax patients receiving the first-line treatment was conducted. For regional and global perspectives, the EES would augment the epidemiological surveillance and monitoring of MDR falciparum and

  9. Engineered resistance to Plasmodium falciparum development in transgenic Anopheles stephensi.

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    Alison T Isaacs

    2011-04-01

    Full Text Available Transposon-mediated transformation was used to produce Anopheles stephensi that express single-chain antibodies (scFvs designed to target the human malaria parasite, Plasmodium falciparum. The scFvs, m1C3, m4B7, and m2A10, are derived from mouse monoclonal antibodies that inhibit either ookinete invasion of the midgut or sporozoite invasion of salivary glands. The scFvs that target the parasite surface, m4B7 and m2A10, were fused to an Anopheles gambiae antimicrobial peptide, Cecropin A. Previously-characterized Anopheles cis-acting DNA regulatory elements were included in the transgenes to coordinate scFv production with parasite development. Gene amplification and immunoblot analyses showed promoter-specific increases in transgene expression in blood-fed females. Transgenic mosquito lines expressing each of the scFv genes had significantly lower infection levels than controls when challenged with P. falciparum.

  10. Metabolic Pathways in Anopheles stephensi mitochondria

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    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A.; Luckhart, Shirley

    2017-01-01

    No studies have been performed on mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that significantly impact malaria parasite transmission in endemic regions. Here, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells (ASE line) from Anopheles stephensi, a major vector of malaria in India, Southeast Asia and parts of the Middle East. ASE cell mitochondria shared many features in common with mammalian muscle mitochondria, despite the fact that these cells have a larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays a major role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize Pro at a rate comparable with that of α-glycerophosphate. However, the Pro pathway appeared to differ from the currently accepted pathway, in that ketoglutarate could be catabolyzed completely by the Krebs cycle or via transamination depending on the ATP need. PMID:18588503

  11. Metabolic pathways in Anopheles stephensi mitochondria.

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    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A; Luckhart, Shirley

    2008-10-15

    No studies have been performed on the mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that have a significant impact on malaria parasite transmission in endemic regions. In the present study, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells [ASE (Anopheles stephensi Mos. 43) cell line] from A. stephensi, a major vector of malaria in India, South-East Asia and parts of the Middle East. ASE cell mitochondria share many features in common with mammalian muscle mitochondria, despite the fact that these cells are of larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays as major a role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize proline at a rate comparable with that of alpha-glycerophosphate. However, the proline pathway appeared to differ from the currently accepted pathway, in that oxoglutarate could be catabolized completely by the tricarboxylic acid cycle or via transamination, depending on the ATP need.

  12. [The distribution of the mosquitoes of the Anopheles maculipennis complex (Diptera, Culicidae, Anophelinae) in Central Asia].

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    Zvantsov, A B; Gordeev, M I; Goriacheva, I I; Ezhov, M N

    2014-01-01

    The polymerase chain reaction-restriction fragment length polymorphism method, cytogenetic analysis, and investigation of egg exochorion have indicated that three representatives of the Anopheles maculipennis complex (subgenus Anopheles): An artemievi Gordeev et al., An. messeae Falleroni, and An. marinius Shingarev. An. messeae is a European-Siberian species that has extended the southern border of its habitat and has been distributed in the south of Kazakhstan and in the north of Kyrgyzstan. In, Kyrgyzstan, An. messeae inhabiting the plains of Europe and Siberia is encountered rather high up in the mountains: the highest point where this species is found is at 1,879 m above sea level. An. artemievi is present in the highland and piedmont regions of Central Asia (Uzbekistan, Kyrgyzstan, southern Kazakhstan, and northern Tajikistan) and in the intermountain basins (Naryn and Fergana ones). The single finding of this species is in south-eastern Turkmenistan. On the contrary, An. martinius tends to be in the plains and occurs in north-eastern Turkmenistan, Karakalpakstan, and Kazakhstan (Kzyl-Orda). On the other hand, a population of this species is found in proximity to the foothills of the Gissar Range in the east of Uzbekistan. An.maculipennis s.str. is not seen in Central Asia. Early evidence for the presence of both An. maculipennis s.str. and An. martinius in Kopet Dag (Southern Turkmenistan) is rather questionable. It is not improbable that these data are appropriate for either the newly described species An.persiensis or the scientifically new representative of the An. maculipennis complex.

  13. Distribution of the main malaria vectors in Kenya

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    Hay Simon I

    2010-03-01

    Full Text Available Abstract Background A detailed knowledge of the distribution of the main Anopheles malaria vectors in Kenya should guide national vector control strategies. However, contemporary spatial distributions of the locally dominant Anopheles vectors including Anopheles gambiae, Anopheles arabiensis, Anopheles merus, Anopheles funestus, Anopheles pharoensis and Anopheles nili are lacking. The methods and approaches used to assemble contemporary available data on the present distribution of the dominant malaria vectors in Kenya are presented here. Method Primary empirical data from published and unpublished sources were identified for the period 1990 to 2009. Details recorded for each source included the first author, year of publication, report type, survey location name, month and year of survey, the main Anopheles species reported as present and the sampling and identification methods used. Survey locations were geo-positioned using national digital place name archives and on-line geo-referencing resources. The geo-located species-presence data were displayed and described administratively, using first-level administrative units (province, and biologically, based on the predicted spatial margins of Plasmodium falciparum transmission intensity in Kenya for the year 2009. Each geo-located survey site was assigned an urban or rural classification and attributed an altitude value. Results A total of 498 spatially unique descriptions of Anopheles vector species across Kenya sampled between 1990 and 2009 were identified, 53% were obtained from published sources and further communications with authors. More than half (54% of the sites surveyed were investigated since 2005. A total of 174 sites reported the presence of An. gambiae complex without identification of sibling species. Anopheles arabiensis and An. funestus were the most widely reported at 244 and 265 spatially unique sites respectively with the former showing the most ubiquitous distribution

  14. Genetic population structure of Anopheles gambiae in Equatorial Guinea

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    Caccone Adalgisa

    2007-10-01

    Full Text Available Abstract Background Patterns of genetic structure among mosquito vector populations in islands have received particular attention as these are considered potentially suitable sites for experimental trials on transgenic-based malaria control strategies. In this study, levels of genetic differentiation have been estimated between populations of Anopheles gambiae s.s. from the islands of Bioko and Annobón, and from continental Equatorial Guinea (EG and Gabon. Methods Genotyping of 11 microsatellite loci located in chromosome 3 was performed in three island samples (two in Bioko and one in Annobón and three mainland samples (two in EG and one in Gabon. Four samples belonged to the M molecular form and two to the S-form. Microsatellite data was used to estimate genetic diversity parameters, perform demographic equilibrium tests and analyse population differentiation. Results High levels of genetic differentiation were found between the more geographically remote island of Annobón and the continent, contrasting with the shallow differentiation between Bioko island, closest to mainland, and continental localities. In Bioko, differentiation between M and S forms was higher than that observed between island and mainland samples of the same molecular form. Conclusion The observed patterns of population structure seem to be governed by the presence of both physical (the ocean and biological (the M-S form discontinuity barriers to gene flow. The significant degree of genetic isolation between M and S forms detected by microsatellite loci located outside the "genomic islands" of speciation identified in A. gambiae s.s. further supports the hypothesis of on-going incipient speciation within this species. The implications of these findings regarding vector control strategies are discussed.

  15. PROPOXUR SELECTION OF THE ADULTS OF ANOPHELES STEPHENSI FROM MINAB, SOUTH OF IRAN

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    H. Edalat

    1997-10-01

    Full Text Available Anopheles stephensi is the main malaria vector in south of Iran. It has been known to be resistant to DDT, malathion and dieldrin. After appearance of resistance the area was treated with propoxur, at the rate of 2 g/m2 twice a year for 14 successive years. This species is still susceptible to propoxur. In order to forecast the possibility of development of propoxur resistance in An.stephensi, the females of this species were put under the pressure of propoxur for 14 generations in 1988. Fourteen generations of propoxur selection on the adult females of An.stephensi resulted in an increase in LT60 from 8.5 min to 24.30 minutes, i.e. 2.86 fold increase in tolerance.

  16. RESISTANCE OF ANOPHELES STEPHENSI LISTON TO MALATHION IN THE PROVICE OF FARS, SOUTHERN IRAN

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    N.Eshghy

    1985-08-01

    Full Text Available Anopheles Stephensi is an important malaria vector in southern Iran. This species developed resistance to DDT in 1975 and subsequently to dieldrin in 1960. Since 1968 this species has been under pressure of malathin house sprayin. 50% w.d.p. , 2g/m2, 1-2 rounds per year. Susceptibility tests carried out with malathion impregnated papers during 1979 showed that An.stephensi has acquired resistant to malathion too. With regard to the 0.1% propoxur, a study was carried out to obtain base-line data in the localities under routine observations and also the discriminating dosage that could kill 100% of An.stephensi. The objective of the present paper is to summarize and discuss briefly the field investigations concerning insecticide resistance in An.stephensi.

  17. “Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes”

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    Neafsey, Daniel E.; Waterhouse, Robert M.; Abai, Mohammad R.; Aganezov, Sergey S.; Alekseyev, Max A.; Allen, James E.; Amon, James; Arcà, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A.; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W.; Blandin, Stephanie A.; Brockman, Andrew I.; Burkot, Thomas R.; Burt, Austin; Chan, Clara S.; Chauve, Cedric; Chiu, Joanna C.; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L.M.; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B.; Guelbeogo, Wamdaogo M.; Hall, Andrew B.; Han, Mira V.; Hlaing, Thaung; Hughes, Daniel S.T.; Jenkins, Adam M.; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G.; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C.; Kirmitzoglou, Ioannis K.; Koekemoer, Lizette L.; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K.N.; Lirakis, Manolis; Lobo, Neil F.; Lowy, Ernesto; MacCallum, Robert M.; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N.; Moore, Wendy; Murphy, Katherine A.; Naumenko, Anastasia N.; Nolan, Tony; Novoa, Eva M.; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A.; Pakpour, Nazzy; Papathanos, Philippos A.; Peery, Ashley N.; Povelones, Michael; Prakash, Anil; Price, David P.; Rajaraman, Ashok; Reimer, Lisa J.; Rinker, David C.; Rokas, Antonis; Russell, Tanya L.; Sagnon, N'Fale; Sharakhova, Maria V.; Shea, Terrance; Simão, Felipe A.; Simard, Frederic; Slotman, Michel A.; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J.; Thomas, Gregg W.C.; Tojo, Marta; Topalis, Pantelis; Tubio, José M.C.; Unger, Maria F.; Vontas, John; Walton, Catherine; Wilding, Craig S.; Willis, Judith H.; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M.; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K.; Collins, Frank H.; Cornman, Robert S.; Crisanti, Andrea; Donnelly, Martin J.; Emrich, Scott J.; Fontaine, Michael C.; Gelbart, William; Hahn, Matthew W.; Hansen, Immo A.; Howell, Paul I.; Kafatos, Fotis C.; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A.T.; Ribeiro, José M.; Riehle, Michael A.; Sharakhov, Igor V.; Tu, Zhijian; Zwiebel, Laurence J.; Besansky, Nora J.

    2015-01-01

    Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover, but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. PMID:25554792

  18. BEBERAPA ASPEK BIONOMIK ANOPHELES SP DI KABUPATEN SUMBA TENGAH, PROVINSI NUSA TENGGARA TIMUR

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    Ni Wayan Dewi Adyana

    2012-07-01

    Full Text Available Research Some Aspects of Anopheles sp Bionomik in Central Sumba Regency, Province of East Nusa Tenggara. Committed in the territory Maradesa Health Center. Data were collected by catching adult mosquitoes by using bait People inside and outside the home, a collection of breaks in the wall and at home, continued with larval surveys in all potential breeding places.  The results showed that the biting behavior tends eksofagik found on An. kochi, An. aconitus and An.barbirostris with bite density peaks in An. aconitus (0.6 persons/hour with a biting peak at 20:00 to 21:00. Behavior tends eksofilik break in An. kochi, An. aconitus, An. tesselatus, An. barbirostris, An. vagus, An.flavirostris, An. maculatus and An. indefinitus with the highest density in An.aconitus (0.9 persons/hour at 1:00 a.m. to 2:00 a.m. Anopheles larvae breeding places found in the small hole in the ground, creek, wetland, non-permanent irrigation, water reservoirs in the vegetable garden, ditches, puddles, swamps, springs, with species that are found as An.kochi, An.aconitus, An. tesselatus, An. barbirostris, An. vagus, An. flavirostris, An. maculatus, An. indefinitus and An. annullaris

  19. KOMPOSISI UMUR NYAMUK ANOPHELES sp YANG DIDUGA SEBAGAI VEKTOR DI DAERAH PEGUNUNGAN KECAMATAN LENGKONG, KABUPATEN SUKABUMI

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    Mardiana Mardiana

    2012-11-01

    Full Text Available Anopheles mosquito could be as a disease vector if having age for the growth of malaria parasitein its body. The research was conducted by catching mosquito in nature, namely: using human collection,wall-resting collection, around cattle and using light trap. The caught mosquito was assessing its proportionof parous and longevity, the composition of parous proportion in each species difference, namely: An.aconitvs reached its highest 0.8 and its lowest 0.2. An. barbirostris reached its highest 0.55 and its lowest0.02. The low Index parous indicates that mosquito could not transmit plasmodium to human. The estimation of An.aconitus age reaches the highest of 8.58 days and the lowest 1.23 days. At the age of 8.58 days An.aconitus is able to grow plasmodium in its body. The estimation of An. barbirostris age reachesits highest of 3.49 days and its lowest 1.3 days. An. maculatus age reached its highest age of 2.65 days and its lowest 1.44 days. The mosquito with short age could not be as a malaria vector. It is concluded that An.aconitus was potential as malaria vector. Key words: Anopheles sp, age composition, vector, hill

  20. Spermless males elicit large-scale female responses to mating in the malaria mosquito Anopheles gambiae

    Science.gov (United States)

    Thailayil, Janis; Magnusson, Kalle; Godfray, H. Charles J.; Crisanti, Andrea; Catteruccia, Flaminia

    2011-01-01

    Anopheles gambiae sensu stricto is the major vector of malaria, a disease with devastating consequences for human health. Given the constant spread of the disease, alternative approaches to the use of insecticides are urgently needed to control vector populations. Females of this species undergo large behavioral changes after mating, which include a life-long refractoriness to further insemination and the induction of egg laying in blood-fed individuals. Genetic control strategies aimed at impacting Anopheles fertility through the release of sterile males are being advocated to reduce the size of mosquito field populations. Such strategies depend on the ability of the released sterile males to mate successfully with wild females and to switch off the female receptivity to further copulation. Here we evaluate the role of sperm in regulating female behavioral responses after mating in An. gambiae. We developed spermless males by RNAi silencing of a germ cell differentiation gene. These males mated successfully and preserved standard accessory gland functions. Females mated to spermless males exhibited normal postcopulatory responses, which included laying large numbers of eggs upon blood feeding and becoming refractory to subsequent insemination. Moreover, spermless males induced transcriptional changes in female reproductive genes comparable to those elicited by fertile males. Our data demonstrate that, in contrast to Drosophila, targeting sperm in An. gambiae preserves normal male and female reproductive behavior for the traits and time frame analyzed and validate the use of approaches based on incapacitation or elimination of sperm for genetic control of vector populations to block malaria transmission. PMID:21825136

  1. FAUNA ANOPHELES DI DAERAH PANTAI BEKAS HUTAN MANGROVE KECAMATAN PADANG CERMIN KABUPATEN LAMPUNG SELATAN

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    N. Sushanti Idris-Idram

    2012-09-01

    Full Text Available Intensive mosquito collections were carried out in two villages in subdistrict of Padangcermin during 1992-1993. The method of mosquito collections consisted of night landing on man indoor and outdoor, night resting indoor and outdoor around cattle shelters, light trap in cattle shelters, daytime resting indoor and outdoor, as well as larvae collections to identify anophelines breeding sites. Sixteen anophelines i.e. Anopheles sundaicus, An. subpictus, An. vagus, An. indefinitus, An. nigerrimus, An. peditaeniatus, An. kochi, An. barbirostris, An. bambumbrosus, An. annularis, An. separatus, An. tesselatus, An. aconitus, An. umbrosus, An. leucosphyrus and An. letifer were collected. Among these mosquitos, An. sundaicus was found predominant, followed by An. vagus and An. subpictus. Other species were collected in small numbers. The behavior of Anopheles sundaicus, An. subpictus and An. vagus were exophagic and endophilic. The larvae of An. sundaicus was found only in brackish standing water such as abandoned shrimp ponds, An. subpictus in brackish standing water as well as fresh standing water, while An. vagus was found only in fresh standing water. Breeding sites of An. sundaicus was characterized by pond with floating algae while An. subpictus and An. vagus were not depending on vegetation.

  2. Fitness consequences of Anopheles gambiae population hybridization

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    Beier John C

    2005-09-01

    Full Text Available Abstract Background The use of transgenic mosquitoes with parasite inhibiting genes has been proposed as an integral strategy to control malaria transmission. However, release of exotic transgenic mosquitoes will bring in novel alleles along with parasite-inhibiting genes that may have unknown effects on native populations. Thus it is necessary to study the effects and dynamics of fitness traits in native mosquito populations in response to the introduction of novel genes. This study was designed to evaluate the dynamics of fitness traits in a simulation of introduction of novel alleles under laboratory conditions using two strains of Anopheles gambiae: Mbita strain from western Kenya and Ifakara strain from Tanzania. Methods The dynamics of fitness traits were evaluated under laboratory conditions using the two An. gambiae strains. These two geographically different strains were cross-bred and monitored for 20 generations to score fecundity, body size, blood-meal size, larval survival, and adult longevity, all of which are important determinants of the vector's potential in malaria transmission. Traits were analysed using pair-wise analysis of variance (ANOVA for fecundity, body size, and blood-meal size while survival analysis was performed for larval survival and adult longevity. Results Fecundity and body size were significantly higher in the progeny up to the 20th generation compared to founder strains. Adult longevity had a significantly higher mean up to the 10th generation and average blood-meal size was significantly larger up to the 5th generation, indicating that hybrids fitness is enhanced over that of the founder strains. Conclusion Hybridization of the two mosquito populations used in this study led to increased performance in the fitness traits studied. Given that the studied traits are important determinants of the vector's potential to transmit malaria, these results suggest the need to release genetically modified mosquitoes

  3. Cannibalism and predation among larvae of the Anopheles gambiae complex

    NARCIS (Netherlands)

    Koenraadt, C.J.M.; Takken, W.

    2003-01-01

    Among the aquatic developmental stages of the Anopheles gambiae complex (Diptera: Culicidae), both inter- and intra-specific interactions influence the resulting densities of adult mosquito populations. For three members of the complex, An. arabiensis Patton, An. quadriannulatus (Theobald) and An. g

  4. Ecology of Anopheles spp. in Central Lombok Regency

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    Majematang Mading

    2014-06-01

    Full Text Available Malaria remains a public health problem in West Nusa Tenggara Province. Central Lombok District is one of the areas with high case of malaria. Annual Malaria Incidence (AMI was increased from 5.9 ‰ in 2006, 6.7‰ up to 8.1‰ in 2008. The objective of the study is to describe the ecological condition of Anopheles spp. through observation, measurement of environmental variables, larvae and adult collection. This research was an observational research with cross-sectional study. The population of this study is all mosquitos and breeding habitats of Anopheles spp. that exist in the research location. Ecological observations carried out on anopheles breeding habitats including acidity, salinity, shaded places and aquatic biota. Air temperature and humidity measured at the adult mosquitoes trapping sites. The result showed that pH values of water is around 9.00, salinity in the breeding habitats around 14 ppm, and water biota (i.e. moss, grass, shrimps, fishes, tadpoles and crabs surrounded by bushes with larvae density 0,1-28,8 each dipping. The air measurement at the time was between 23°-27° Celsius and 65%-84% humidity. This research concludes that ecology and environmental conditions were supporting the development of larvae and adult mosquito of Anopheles spp.

  5. Description of the egg of Anopheles (Anopheles intermedius (Peryassu, 1908 (Diptera: Culicidae by scanning electron microscopy

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    Oswaldo Paulo Forattini

    1997-01-01

    Full Text Available The egg of Anopheles (Anopheles intermedius (Peryassu, 1908 is described and illustrated with scanning electron micrographs. Literature data on An. (Ano. maculipes (Theobald, 1903 is providedOs ovos de An. intermedius foram descritos e ilustrados por Costa Lima (1929. Este autor, baseando-se nos desenhos de Peryassu (1908 para An. maculipes, chamou atenção para o fato do ovo desta espécie ser semelhante ao de An. maculipes. Posteriormente, Causey e col. (1944, estudando os ovos de An. intermedius e An. maculipes ao estereomicroscópio, diferenciou-os por caracteres da franja. Em An. intermedius a franja é oblíqua ao eixo longitudinal do ovo, mas perpendicular em An. maculipes. Causey e col. (1944 ilustraram as variações morfológicas que encontraram na franja do ovo de An. intermedius. Os autores observaram que a franja apresentava-se descotínua em alguns espécimens de An. intermedius, tornando-se em pequenos círculos nessa região. Embora semelhante ao de An. maculipes, os ovos de An. intermedius podem ser facilmente reconhecidos por características da franja, flutuadores e tubérculos lobados, como pode ser observado na descrição. Contudo, será necessário estudar a morfologia dos ovos de outras espécies do subgênero para que se possa estabelecer as diferenças e fazer comparações precisas entre as espécies

  6. Malaria vectors in the Brazilian Amazon: Anopheles of the subgenus Nyssorhynchus Anopheles do subgênero Nyssorhynchus, vetores da malária na Amazônia brasileira

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    Wanderli Pedro TADEI

    2000-04-01

    Full Text Available Various species of Anopheles (Nyssorhynchus were studied in the Amazon with the objective of determining their importance as malaria vectors. Of the 33 known Anopheles species occurring in the Amazon, only 9 were found to be infected with Plasmodium. The different species of this subgenus varied both in diversity and density in the collection areas. The populations showed a tendency towards lower density and diversity in virgin forest than in areas modified by human intervention. The principal vector, An. darlingi, is anthropophilic with a continuous activity cycle lasting the entire night but peaking at sunset and sunrise. These species (Nyssorhynchus are peridomiciliary, entering houses to feed on blood and immediately leaving to settle on nearby vegetation. Anopheles nuneztovari proved to be zoophilic, crepuscular and peridomiciliary. These habits may change depending on a series of external factors, especially those related to human activity. There is a possibility that sibling species exist in the study area and they are being studied with reference to An. darlingi, An. albitarsis and An. nuneztovari. The present results do not suggest the existence of subpopulations of An. darlingi in the Brazilian Amazon.Várias espécies de Anopheles (Nyssorhynchus foram estudadas na Amazônia a fim de se determinar sua importância na transmissão da malária. Das 33 espécies de Anopheles de ocorrência conhecida na Amazônia, apenas 8 foram encontradas infectadas por Plasmodium. O principal vetor, An. darlingi, é antropofílico com um ciclo contínuo de atividade que dura a noite inteira mas que tem picos ao anoitecer e ao amanhecer. As diferentes espécies desse subgênero variaram tanto em diversidade como em densidade nas áreas de coleta. A população de anofelinos apresentou tendências de menor densidade e diversidade em florestas virgens do que em áreas que sofreram intervenção humana. Essas espécies (Nyssorhynchus são peridomiciliares

  7. Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania

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    Stefan Dongus

    2009-05-01

    Full Text Available A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2 was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92. Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

  8. Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania.

    Science.gov (United States)

    Dongus, Stefan; Nyika, Dickson; Kannady, Khadija; Mtasiwa, Deo; Mshinda, Hassan; Gosoniu, Laura; Drescher, Axel W; Fillinger, Ulrike; Tanner, Marcel; Killeen, Gerry F; Castro, Marcia C

    2009-05-01

    A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2) was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92). Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

  9. An allele-specific polymerase chain reaction assay for the differentiation of members of the Anopheles culicifacies complex

    Indian Academy of Sciences (India)

    O P Singh; Geeta Goswami; N Nanda; K Raghavendra; D Chandra; S K Subbarao

    2004-09-01

    Anopheles culicifacies, the principal vector of malaria in India, is a complex of five cryptic species which are morphologically indistinguishable at any stage of life. In view of the practical difficulties associated with classical cytotaxonomic method for the identification of members of the complex, an allele-specific polymerase chain reaction (ASPCR) assay targeted to the D3 domain of 28S ribosomal DNA was developed. The assay discriminates An. culicifacies species A and D from species B, C and E. The assay was validated using chromosomally-identified specimens of An. culicifacies from different geographical regions of India representing different sympatric associations. The assay correctly differentiates species A and D from species B, C and E. The possible use of this diagnostic assay in disease vector control programmes is discussed.

  10. Morphology of the larvae, male genitalia and DNA sequences of Anopheles (Kerteszia pholidotus (Diptera: Culicidae from Colombia

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    Jesús Eduardo Escovar

    2014-07-01

    Full Text Available Since 1984, Anopheles (Kerteszia lepidotus has been considered a mosquito species that is involved in the transmission of malaria in Colombia, after having been incriminated as such with epidemiological evidence from a malaria outbreak in Cunday-Villarrica, Tolima. Subsequent morphological analyses of females captured in the same place and at the time of the outbreak showed that the species responsible for the transmission was not An. lepidotus, but rather Anopheles pholidotus. However, the associated morphological stages and DNA sequences of An. pholidotus from the foci of Cunday-Villarrica had not been analysed. Using samples that were caught recently from the outbreak region, the purpose of this study was to provide updated and additional information by analysing the morphology of female mosquitoes, the genitalia of male mosquitoes and fourth instar larvae of An. pholidotus, which was confirmed with DNA sequences of cytochrome oxidase I and rDNA internal transcribed spacer. A total of 1,596 adult females were collected in addition to 37 larval collections in bromeliads. Furthermore, 141 adult females, which were captured from the same area in the years 1981-1982, were analysed morphologically. Ninety-five DNA sequences were analysed for this study. Morphological and molecular analyses showed that the species present in this region corresponds to An. pholidotus. Given the absence of An. lepidotus, even in recent years, we consider that the species of mosquitoes that was previously incriminated as the malaria vector during the outbreak was indeed An. pholidotus, thus ending the controversy.

  11. Changes in vector species composition and current vector biology and behaviour will favour malaria elimination in Santa Isabel Province, Solomon Islands

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    Beebe Nigel W

    2011-09-01

    Full Text Available Abstract Background In 2009, Santa Isabel Province in the Solomon Islands embarked on a malaria elimination programme. However, very little is known in the Province about the anopheline fauna, which species are vectors, their bionomics and how they may respond to intensified intervention measures. The purpose of this study was to provide baseline data on the malaria vectors and to ascertain the possibility of successfully eliminating malaria using the existing conventional vector control measures, such as indoor residual spraying (IRS and long-lasting insecticidal nets (LLIN. Methods Entomological surveys were undertaken during October 2009. To determine species composition and distribution larval surveys were conducted across on the whole island. For malaria transmission studies, adult anophelines were sampled using human landing catches from two villages - one coastal and one inland. Results Five Anopheles species were found on Santa Isabel: Anopheles farauti, Anopheles hinesorum, Anopheles lungae, Anopheles solomonis, and Anopheles nataliae. Anopheles hinesorum was the most widespread species. Anopheles farauti was abundant, but found only on the coast. Anopheles punctulatus and Anopheles koliensis were not found. Anopheles farauti was the only species found biting in the coastal village, it was incriminated as a vector in this study; it fed early in the night but equally so indoors and outdoors, and had a low survival rate. Anopheles solomonis was the main species biting humans in the inland village, it was extremely exophagic, with low survival rates, and readily fed on pigs. Conclusion The disappearance of the two major vectors, An. punctulatus and An. koliensis, from Santa Isabel and the predominance of An. hinesorum, a non-vector species may facilitate malaria elimination measures. Anopheles farauti was identified as the main coastal vector with An. solomonis as a possible inland vector. The behaviour of An. solomonis is novel as it has

  12. Comparative Vector Bionomics and Morphometrics of Two Genetically Distinct Field Populations of Anopheles darlingi Root from Belize, Central America and Zungarococha, Peru, South America

    Science.gov (United States)

    2014-01-31

    Sociedade Brasileira de Medicina Tropical 46: 172-7 64. Garrett-Jones C. 1964. The Human Blood Index of Malaria Vectors in Relation to...Revista da Sociedade Brasileira de Medicina Tropical 24: 13-20 94. Klingenberg CP. 2002. Morphometrics and the role of the phenotype in studies of the...Anopheles species from Porto Velho, Rondonia state, western Amazon, Brazil. Revista do Instituto de Medicina Tropical de Sao Paulo 54:331-5 125. Morales

  13. Effect of discriminative plant-sugar feeding on the survival and fecundity of Anopheles gambiae

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    Jackson Robert R

    2007-08-01

    Full Text Available Abstract Background A previous study showed for Anopheles gambiae s.s. a gradation of feeding preference on common plant species growing in a malaria holoendemic area in western Kenya. The present follow-up study determines whether there is a relationship between the mosquito's preferences and its survival and fecundity. Methods Groups of mosquitoes were separately given ad libitum opportunity to feed on five of the more preferred plant species (Hamelia patens, Parthenium hysterophorus, Ricinus communis, Senna didymobotrya, and Tecoma stans and one of the less preferred species (Lantana camara. The mosquitoes were monitored daily for survival. Sugar solution (glucose 6% and water were used as controls. In addition, the fecundity of mosquitoes on each plant after (i only one blood meal (number of eggs oviposited, and (ii after three consecutive blood meals (proportion of females ovipositing, number of eggs oviposited and hatchability of eggs, was determined. The composition and concentration of sugar in the fed-on parts of each plant species were determined using gas chromatography. Using SAS statistical package, tests for significant difference of the fitness values between mosquitoes exposed to different plant species were conducted. Results and Conclusion Anopheles gambiae that had fed on four of the five more preferred plant species (T. stans, S. didymobotrya, R. communis and H. patens, but not P. hysterophorus lived longer and laid more eggs after one blood meal, when compared with An. gambiae that had fed on the least preferred plant species L. camara. When given three consecutive blood-meals, the percentage of females that oviposited, but not the number of eggs laid, was significantly higher for mosquitoes that had previously fed on the four more preferred plant species. Total sugar concentration in the preferred plant parts was significantly correlated with survival and with the proportion of females that laid eggs. This effect was

  14. Anopheles plumbeus (Diptera: Culicidae in Europe: a mere nuisance mosquito or potential malaria vector?

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    Schaffner Francis

    2012-11-01

    Full Text Available Abstract Background Anopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria. Methods Anopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy. Results A total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae. However, the number of sporozoites produced was significantly lower in infected An. plumbeus. Conclusion The results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and

  15. Diversidade de Culicidae durante os períodos crepusculares em bioma de Floresta Atlântica e paridade de Anopheles cruzii (Diptera: Culicidae Diversity of Culicidae during the crepuscular periods in Atlantic Forest biome and parity of Anopheles cruzii (Diptera: Culicidae

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    Ana C. D. Bona

    2008-03-01

    dense rain forest in Atlantic Forest, located in the State of the Paraná, named of Palmito State Park. The captures were performed two days in a month, during December 2006 to March 2007, occurring in the matutine and vespertine crepuscular periods. The captures were executed before twilight until after twilight. Twenty five species that belong to Culicidae were identified, the tree most abundant species were Anopheles cruzii (65.2%, Culex sachettae Sirivanakarn & Jacob, 1982 (11.2% e Anopheles bellator Dyar & Knab, 1906 (8.5%. According to variance analysis, significant difference in frequency, was detected between crepuscular periods, for the following species: Aedes scapularis (Rondone, 1848 (p = 0. 03651, Coquillettidia chrysonotum (Peryassu, 1922 (p = 0. 00795, Mansonia fonsecai (Pinto, 1932 (p = 0. 00804, e Runchomyia theobaldi Lane & Cerqueira, 1934 (p = 0. 01996. The tree most captured species didn't show a significant correlation to the climatic factors. The rate parity of Anopheles cruzii was 48%. Didn't have correlation between the abundance with the rate parity. The twilight influences the behavior of Culicidae species. The similarity comparison between matutine and vespertine crepuscular periods revealed an elevated resemblance in the specific composition. A. cruzii was dominant specie in the crepuscular periods. The diversity in the crepuscular periods was considered decrease.

  16. The impact of insecticides management linked with resistance expression in Anopheles spp. populations

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    Guilherme Liberato da Silva

    2016-07-01

    Full Text Available Abstract The resistance of some species of Anopheles to chemical insecticides is spreading quickly throughout the world and has hindered the actions of prevention and control of malaria. The main mechanism responsible for resistance in these insects appears to be the target site known as knock-down resistance (kdr, which causes mutations in the sodium channel. Even so, many countries have made significant progress in the prevention of malaria, focusing largely on vector control through long-lasting insecticide nets (LLINs, indoor residual spraying and (IRS of insecticides. The objective of this review is to contribute with information on the more applied insecticides for the control of the main vectors of malaria, its effects, and the different mechanisms of resistance. Currently it is necessary to look for others alternatives, e.g. biological control and products derived from plants and fungi, by using other organisms as a possible regulator of the populations of malaria vectors in critical outbreaks.

  17. Anopheles barbirostris Confirmation as Malaria Vector in Waikabubak through the Detection of Circumsporozoit Protein

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    Yuneu Yuliasih

    2012-06-01

    Full Text Available Anopheline species confirmed as malaria vector if the salivary gland contained sporozoites. One of the method to confirmed it was through an Enzyme-Linked Immunosorbent Assay (ELISA. The aim of this study was to investigate the presence of circum sporozoite protein (CSP in the mosquito of Anopheles barbirostris with ELISA method. The study was conducted in malaria endemic area named Modu Waimaringu Village, Waikabubak District, Sumba Barat Regency in March 2011. The study design was cross-sectional study, mosquito for the ELISA test were collected only from animal bait. ELISA method examination used on An. barbirostris body parts (i.e. the head-thorax where sporozoites of P. falciparum or P. Vivax possibly be found. The results showed that 40 samples of An. barbirostris mosquitoes which acquired from the mosquite bait in Modu Waimaringu Village was negative (100%. It means that there was no CSP found and An. barbirostris was not a malaria vector in the area

  18. Repellency effect of forty-one essential oils against Aedes, Anopheles, and Culex mosquitoes.

    Science.gov (United States)

    Amer, Abdelkrim; Mehlhorn, Heinz

    2006-09-01

    Since ancient times, plant products were used in various aspects. However, their use against pests decreased when chemical products became developed. Recently, concerns increased with respect to public health and environmental security requiring detection of natural products that may be used against insect pests. In this study, 41 plant extracts and 11 oil mixtures were evaluated against the yellow fever mosquito, Aedes aegypti (Linnaeus), the malaria vector, Anopheles stephensi (Liston), and the filariasis and encephalitis vector, Culex quinquefasciatus (Say) (Diptera: Culicidae) using the skin of human volunteers to find out the protection time and repellency. The five most effective oils were those of Litsea (Litsea cubeba), Cajeput (Melaleuca leucadendron), Niaouli (Melaleuca quinquenervia), Violet (Viola odorata), and Catnip (Nepeta cataria), which induced a protection time of 8 h at the maximum and a 100% repellency against all three species. This effect needs, however, a peculiar formulation to fix them on the human skin.

  19. Quetzal: a transposon of the Tc1 family in the mosquito Anopheles albimanus.

    Science.gov (United States)

    Ke, Z; Grossman, G L; Cornel, A J; Collins, F H

    1996-10-01

    A member of the Tc1 family of transposable elements has been identified in the Central and South American mosquito Anopheles albimanus. The full-length Quetzal element is 1680 base pairs (bp) in length, possesses 236 bp inverted terminal repeats (ITRs), and has a single open reading frame (ORF) with the potential of encoding a 341-amino-acid (aa) protein that is similar to the transposases of other members of the Tc1 family, particularly elements described from three different Drosophila species. The approximately 10-12 copies per genome of Quetzal are found in the euchromatin of all three chromosomes of A. albimanus. One full-length clone, Que27, appears capable of encoding a complete transposase and may represent a functional copy of this element.

  20. Systematic studies on Anopheles galvaoi Causey, Deane & Deane from the subgenus Nysssorhynchus blanchard (Diptera: Culicidae

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    Maria Anice Mureb Sallum

    2002-12-01

    Full Text Available Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabaldón and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.

  1. Limited Diversity of Anopheles Darlingi in The Peruvian Amazon Region of Iquitos

    Science.gov (United States)

    PINEDO-CANCINO, VIVIANA; SHEEN, PATRICIA; TARAZONA-SANTOS, EDUARDO; OSWALD, WILLIAM E.; JERI, CESAR; VITTOR, AMY YOMIKO; PATZ, JONATHAN A.; GILMAN, ROBERT H.

    2006-01-01

    Anopheles darlingi is the most important malaria vector in the Amazon basin of South America, and is capable of transmitting both Plasmodium falciparum and P. vivax. To understand the genetic structure of this vector in the Amazonian region of Peru, a simple polymerase chain reaction (PCR)-based test to identify this species of mosquito was used. A random amplified polymorphic DNA-PCR was used to study genetic variation at the micro-geographic level in nine geographically separate populations of An. darlingi collected in areas with different degrees of deforestation surrounding the city of Iquitos. Within-population genetic diversity in nine populations, as quantified by the expected heterozygosity (HE), ranged from 0.27 to 0.32. Average genetic distance (FST) among these populations was 0.017. These results show that the nine studied populations are highly homogeneous, suggesting that strategies can be developed to combat this malaria vector as a single epidemiologic unit. PMID:16896125

  2. Studies on the bionomics of Anopheles dirus (Culicidae: Diptera) in Mudon, Mon State, Myanmar.

    Science.gov (United States)

    Oo, Thin Thin; Storch, Volker; Becker, Norbert

    2002-06-01

    This study examined some environmental factors influencing the larval habitats of Anopheles dirus (breeding in wells) in Mudon, Myanmar, from May 1998 to March 2000. The larval/pupal density was found to be directly proportional to rainfall and indirectly proportional to the well water level. Shade, vegetation and debris on the surface of well water were important factors influencing the abundance of the aquatic stages of An. dirus. Salinity had an inverse correlation with the larval and pupal density. Other mosquito species associated with An. dirus were identified. Important predators of the mosquito larvae were larvivorous fish, damselfly and dragonfly nymphs. All wells examined were lined with lateritic rocks. Chemical analysis of water samples from wells was conducted.

  3. Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Malongo, Bernard B.; Simonsen, Paul E.

    2016-01-01

    and adsorption to sediments, the ivermectin exposure-risk to aquatic organisms dwelling in different strata of water bodies varies. This study assessed the survival of larvae of Anopheles gambiae Giles and Culex quinquefasciatus Say, when exposed to low concentrations of ivermectin under laboratory conditions......Background: Ivermectin is used extensively globally for treatment of helminthic and ectoparasitic infections in animals and humans. The effect of excreted ivermectin on non-target organisms in aquatic and terrestrial environments has been increasingly reported. Due to its low water solubility....... Methods: A total of 1800 laboratory reared mosquito larvae of each species were used in the bioassays. Twelve replicates were performed, each testing 6 concentrations of ivermectin (0.0, 0.001, 0.01, 0.1, 1.0 and 10.0 parts per million (ppm)) against third instar larvae of An. gambiae and Cx...

  4. Evolutionary dynamics of the Ty3/gypsy LTR retrotransposons in the genome of Anopheles gambiae.

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    Jose Manuel C Tubio

    Full Text Available Ty3/gypsy elements represent one of the most abundant and diverse LTR-retrotransposon (LTRr groups in the Anopheles gambiae genome, but their evolutionary dynamics have not been explored in detail. Here, we conduct an in silico analysis of the distribution and abundance of the full complement of 1045 copies in the updated AgamP3 assembly. Chromosomal distribution of Ty3/gypsy elements is inversely related to arm length, with densities being greatest on the X, and greater on the short versus long arms of both autosomes. Taking into account the different heterochromatic and euchromatic compartments of the genome, our data suggest that the relative abundance of Ty3/gypsy LTRrs along each chromosome arm is determined mainly by the different proportions of heterochromatin, particularly pericentric heterochromatin, relative to total arm length. Additionally, the breakpoint regions of chromosomal inversion 2La appears to be a haven for LTRrs. These elements are underrepresented more than 7-fold in euchromatin, where 33% of the Ty3/gypsy copies are associated with genes. The euchromatin on chromosome 3R shows a faster turnover rate of Ty3/gypsy elements, characterized by a deficit of proviral sequences and the lowest average sequence divergence of any autosomal region analyzed in this study. This probably reflects a principal role of purifying selection against insertion for the preservation of longer conserved syntenyc blocks with adaptive importance located in 3R. Although some Ty3/gypsy LTRrs show evidence of recent activity, an important fraction are inactive remnants of relatively ancient insertions apparently subject to genetic drift. Consistent with these computational predictions, an analysis of the occupancy rate of putatively older insertions in natural populations suggested that the degenerate copies have been fixed across the species range in this mosquito, and also are shared with the sibling species Anopheles arabiensis.

  5. Relationship of Remote Sensing Normalized Differential Vegetation Index to Anopheles Density and Malaria Incidence Rate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the relationship of remote sensing normalized differential vegetation index (NDVI) to Anopheles density and malaria incidence rate. Methods Data of monthly average climate, environment, Anopheles density and malaria incidence rate, and remote sensing NDVI were collected from 27 townships of 10 counties in southeastern Yunnan Province from 1984 to 1993. The relationship of remote sensing ecological proxy index, NDVI, to Anopheles density and malaria incidence rate was studied by principal component analysis, factor analysis and grey correlation analysis. Results The correlation matrix showed that NDVI highly correlated with Anopheles density in 4 townships of Mengla, Jinghong, and Yuanjiang counties, but in other 23 townships the relationship was not clear. Principal component and factor analyses showed that remote sensing NDVI was the representative index of the first principal component and the first common factor of Anopheles density evaluation. Grey correlation analysis showed that in rainy season NDVI had a high grey correlation with Anopheles density and malaria incidence rate. The grey correlation analysis showed that in rainy season the grey degree of NDVI correlated with Anopheles. Minimus density was 0.730, and 0.713 with Anopheles sinensis density, and 0.800 with malarial incidence rate. Conclusion Remote sensing NDVI can serve as a sensitive evaluation index of Anopheles density and malaria incidence rate.

  6. The emergence of insecticide resistance in central Mozambique and potential threat to the successful indoor residual spraying malaria control programme

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    Wilding Craig S

    2011-05-01

    Full Text Available Abstract Background Malaria vector control by indoor residual spraying was reinitiated in 2006 with DDT in Zambézia province, Mozambique. In 2007, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of this programme as carried out by the Malaria Decision Support Project. Methods Mosquitoes were captured daily through a series of 114 window exit traps located at 19 sentinel sites, identified to species and analysed for sporozoites. Anopheles mosquitoes were collected resting indoors and tested for insecticide resistance following the standard WHO protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 15 years. Results A total of 3,769 and 2,853 Anopheles gambiae s.l. and Anopheles funestus, respectively, were captured from window exit traps throughout the period. In 2010 resistance to the pyrethroids lambda-cyhalothrin and permethrin and the carbamate, bendiocarb was detected in An. funestus. In 2006, the sporozoite rate in An. gambiae s.s. was 4% and this reduced to 1% over 4 rounds of spraying. The sporozoite rate for An. funestus was also reduced from 2% to 0 by 2008. Of the 437 Anopheles arabiensis identified, none were infectious. Overall prevalence of P. falciparum in the sentinel sites fell from 60% to 32% between October 2006 and October 2008. Conclusion Both An. gambiae s.s. and An. funestus were controlled effectively with the DDT-based IRS programme in Zambézia, reducing disease transmission and burden. However, the discovery of pyrethroid resistance in the province and Mozambique's policy change away from DDT to pyrethroids for IRS threatens the gains made here.

  7. [Malaria mosquitoes (Diptera, Culicidae, Anopheles) of North Tajikistan, their ecology, and role in the transmission of malaria pathogens].

    Science.gov (United States)

    Kadamov, D S; Zvantseva, A B; Karimov, S S; Gordeev, M I; Goriacheva, I I; Ezhov, M N; Tadzhiboev, A

    2012-01-01

    Five species of malaria mosquitoes: An. artemievi, An. claviger, An. hyrcanus, An. superpictus, and An. pulcherrimus were found in North Tajikistan in 2006 - 2007. Species affiliation was identified according to the morphological signs of their larvae and imagoes, and by using the polymerase chain reaction-restriction fragment length polymorphism analysis. There was a larger number of An. hyrcanus (34%), An. artemievi (29%), and An. pulcherrimus (24%) and a smaller number of An. superpictus (11%); and An. claviger was few (2%). The hatching sites of the above species and the preferred types of their day refuges were found. The intensity of attack of different Anopheles species on humans and animals was studied. Among the North Tajikistan malaria mosquitoes, An. pulcherrimus and An. superpictus are of the greatest epidemiological importance as vehicles for transmission of malaria pathogens. An. artemievi and An. hyrcanus are minor vehicles. At present, An. claviger is of no epidemiological significance in transmitting malaria in North Tajikistan.

  8. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    OpenAIRE

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The i...

  9. Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

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    Mwangangi Joseph M

    2010-08-01

    Full Text Available Abstract Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru, unplanned rice cultivation (Kiamachiri and non-irrigated (Murinduko agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252, respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval

  10. Isoenzymatic analysis of four Anopheles (Kerteszia) bellator Dyar & Knab (Diptera: Culicidae) populations.

    Science.gov (United States)

    de Carvalho-Pinto, Carlos José; Lourenço-de-Oliveira, Ricardo

    2003-12-01

    Anopheles bellator is a small silvatic bromelia-breeding mosquito and is a primary human malaria vector species in Southern Brazil. The bromelia-breeding habitat of the species should accompany the Atlantic forest coastal distribution, where bromeliads are abundant. Nonetheless, records on An. bellator collections show a gap in the species geographical distribution. An. bellator has been recorded in Southern Brazil and in the Brazilian states of Bahia and Paraíba. It appears again in the island of Trinidad, in Trinidad and Tobago. The aim of this work was to measure gene flow between different populations of An. bellator collected in the northern and southern extremes of the geographic distribution of this species. Mosquitoes were captured in forest borders in Santa Catarina, São Paulo, and Bahia states in Brazil and in the island of Trinidad in Republic of Trinidad and Tobago. Genetic distances varied between 0.076 and 0.680, based on enzymatic profiles from 11 distinct isoenzymes. Results indicate the existence of low-level gene flow between Brazilian populations of An. bellator, and a gene flow was even lower between the Brazilian and the Trinidad populations. This finding lead us to hypothesize that An. bellator did not spread along the coast, but reached northeastern areas through inland routes.

  11. Isoenzymatic analysis of four Anopheles (Kerteszia bellator Dyar & Knab (Diptera: Culicidae populations

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    Carvalho-Pinto Carlos José de

    2003-01-01

    Full Text Available Anopheles bellator is a small silvatic bromelia-breeding mosquito and is a primary human malaria vector species in Southern Brazil. The bromelia-breeding habitat of the species should accompany the Atlantic forest coastal distribution, where bromeliads are abundant. Nonetheless, records on An. bellator collections show a gap in the species geographical distribution. An. bellator has been recorded in Southern Brazil and in the Brazilian states of Bahia and Paraíba. It appers again in the island of Trinidad, in Trinidad and Tobago. The aim of this work was to measure gene flow between different populations of An. bellator collected in the northern and southern extremes of the geographic distribution of this species. Mosquitoes were captured in forest borders in Santa Catarina, São Paulo, and Bahia states in Brazil and in the island of Trinidad in Republic of Trinidad and Tobago. Genetic distances varied between 0.076 and 0.680, based on enzymatic profiles from 11 distinct isoenzymes. Results indicate the existence of low-level gene flow between Brazilian populations of An. bellator, and a gene flow was even lower between the Brazilian and the Trinidad populations. This finding lead us to hypothesize that An. bellator did not spread along the coast, but reached northeastern areas through inland routes.

  12. Low linkage disequilibrium in wild Anopheles gambiae s.l. populations

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    Harris Caroline

    2010-09-01

    Full Text Available Abstract Background In the malaria vector Anopheles gambiae, understanding diversity in natural populations and genetic components of important phenotypes such as resistance to malaria infection is crucial for developing new malaria transmission blocking strategies. The design and interpretation of many studies here depends critically on Linkage disequilibrium (LD. For example in association studies, LD determines the density of Single Nucleotide Polymorphisms (SNPs to be genotyped to represent the majority of the genomic information. Here, we aim to determine LD in wild An. gambiae s.l. populations in 4 genes potentially involved in mosquito immune responses against pathogens (Gambicin, NOS, REL2 and FBN9 using previously published and newly generated sequences. Results The level of LD between SNP pairs in cloned sequences of each gene was determined for 7 species (or incipient species of the An. gambiae complex. In all tested genes and species, LD between SNPs was low: even at short distances (2 2 ranged from 0.073 to 0.766. In most genes and species LD decayed very rapidly with increasing inter-marker distance. Conclusions These results are of great interest for the development of large scale polymorphism studies, as LD generally falls below any useful limit. It indicates that very fine scale SNP detection will be required to give an overall view of genome-wide polymorphism. Perhaps a more feasible approach to genome wide association studies is to use targeted approaches using candidate gene selection to detect association to phenotypes of interest.

  13. Identification of one capa and two pyrokinin receptors from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Olsen, Stine S; Cazzamali, Giuseppe; Williamson, Michael

    2007-01-01

    We cloned the cDNA of three evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae and functionally expressed them in Chinese hamster ovary cells. One receptor, Ang-Capa-R, was only activated by the two Anopheles capa neuropeptides Ang-capa-1 (GPTVGLFAFPRVa...

  14. KARAKTERISTIK TEMPAT PERKEMBANGBIAKAN LARVA ANOPHELES DI DESA BULUBETE KECAMATAN DOLO SELATAN KABUPATEN SIGI PROVINSISULAWESI TENGAH

    OpenAIRE

    Bustam; Ruslan; Erniwati

    2008-01-01

    Malaria merupakan penyakit infeksi yang disebabkan oleh plasmodium yang ditularkan melalui gigitan nyamuk Anopheles, merupakan suatu penyakit yang mengancam umat manusia terutama yang tinggal di daerah tropik dan sub tropic. Penelitian ini bertujuan untuk mengetahui gambaran tentang kepadatan jentik vektor Malaria berdasarkan Karakteristik tempat perkembangbiakan nyamuk Anopheles di Desa Bulubete Kecamatan Dolo Selatan Kabupaten Sigi Provinsi Sulawesi Tengah. Jenis penelitian yang digunakan...

  15. Tingkat Kepadatan Larva Anopheles spp. di Delta Lakkang Kecamatan Tallo Makassar

    OpenAIRE

    Mardilah

    2016-01-01

    Telah dilakukan penelitian tentang tingkat kepadatan larva Anopheles spp di Delta Lakkang Kecamatan Tallo. Penelitian bertujuan untuk mengetahui tingkat kepadatan larva dan faktor-faktor yang mempengaruhi. Metode yang digunakan adalah metode observasi dengan mengambil larva nyamuk selanjutnya dipelihara kemudian dilakukan perhitungan tingkat kepadatan larva. Hasil penelitian menunjukkan bahwa tingkat kepadatan larva Anopheles tertinggi ditemukan di bagian barat dengan jumlah larva 179 larva p...

  16. Knockdown resistance in Anopheles vagus, An. sinensis, An. paraliae and An. peditaeniatus populations of the Mekong region

    Directory of Open Access Journals (Sweden)

    Keokenchanh Kalouna

    2010-07-01

    Full Text Available Abstract Background In the Mekong region (Vietnam, Cambodia and Laos, a large investigation was conducted to assess the susceptibility of Anopheles species against DDT and pyrethroids. In this study, the resistance status of the potential malaria vectors An. vagus, An. sinensis, An. paraliae and An. peditaeniatus was assessed. Methods Bioassays were performed on field collected unfed female mosquitoes using the standard WHO susceptibility tests. In addition, the DIIS6 region of the para-type sodium channel gene was amplified and sequenced and four allele-specific PCR assays were developed to assess the kdr frequencies. Results In Southern Vietnam all species were DDT and pyrethroid resistant, which might suggest the presence of a kdr resistance mechanism. Sequence-analysis of the DIIS6 region of the para-type sodium channel gene revealed the presence of a L1014S kdr mutation in An. vagus, An. sinensis and An. paraliae. In An. peditaeniatus, a low frequency L1014S kdr mutation was found in combination with a high frequency L1014F kdr mutation. For pyrethroids and DDT, no genotypic differentiation was found between survivors and non-survivors for any of these species. In the two widespread species, An. vagus and An. sinensis, kdr was found only in southern Vietnam and in Cambodia near the Vietnamese border. Conclusions Different levels of resistance were measured in Laos, Cambodia and Vietnam. The kdr mutation in different Anopheles species seems to occur in the same geographical area. These species breed in open agricultural lands where malaria endemicity is low or absent and vector control programs less intensive. It is therefore likely that the selection pressure occurred on the larval stages by insecticides used for agricultural purposes.

  17. The role of cow urine in the oviposition site preference of culicine and Anopheles mosquitoes

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    Kweka Eliningaya J

    2011-09-01

    Full Text Available Abstract Background Chemical and behavioural ecology of mosquitoes plays an important role in the development of chemical cue based vector control. To date, studies available have focused on evaluating mosquito attractants and repellents of synthetic and human origins. This study, however, was aimed at seasonal evaluation of the efficiency of cow urine in producing oviposition cues to Anopheles gambiae s.l. and Culex quinquefasciatus in both laboratory and field conditions. Methods Oviposition response evaluation in laboratory conditions was carried out in mosquito rearing cages. The oviposition substrates were located in parallel or in diagonal positions inside the cage. Urine evaluation against gravid females of An. arabiensis and Cx. quinquefasciatus was carried out at Day 1, Day 3 and Day 7. Five millilitres (mls of cow urine was added to oviposition substrate while de-chlorinated water was used as a control. In field experiments, 500 mls of cow urine was added in artificial habitats with 2500 mls of de-chlorinated water and 2 kgs of soil. The experiment was monitored for thirty consecutive days, eggs were collected daily from the habitats at 7.00 hrs. Data analysis was performed using parametric and non-parametric tests for treatments and controls while attraction of the oviposition substrate in each species was presented using Oviposition Activity Index (OAI. Results The OAI was positive with ageing of cattle urine in culicine species in both laboratory and field experiments. The OAI for anopheline species was positive with fresh urine. The OAI during the rainy season was positive for all species tested while in the dry season the OAI for culicine spp and Anopheles gambiae s.l., changed with time from positive to negative values. Based on linear model analysis, seasons and treatments had a significant effect on the number of eggs laid in habitats, even though the number of days had no effect. Conclusion Oviposition substrates treated with

  18. Genome-Wide Divergence in the West-African Malaria Vector Anopheles melas

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    Kevin C. Deitz

    2016-09-01

    Full Text Available Anopheles melas is a member of the recently diverged An. gambiae species complex, a model for speciation studies, and is a locally important malaria vector along the West-African coast where it breeds in brackish water. A recent population genetic study of An. melas revealed species-level genetic differentiation between three population clusters. An. melas West extends from The Gambia to the village of Tiko, Cameroon. The other mainland cluster, An. melas South, extends from the southern Cameroonian village of Ipono to Angola. Bioko Island, Equatorial Guinea An. melas populations are genetically isolated from mainland populations. To examine how genetic differentiation between these An. melas forms is distributed across their genomes, we conducted a genome-wide analysis of genetic differentiation and selection using whole genome sequencing data of pooled individuals (Pool-seq from a representative population of each cluster. The An. melas forms exhibit high levels of genetic differentiation throughout their genomes, including the presence of numerous fixed differences between clusters. Although the level of divergence between the clusters is on a par with that of other species within the An. gambiae complex, patterns of genome-wide divergence and diversity do not provide evidence for the presence of pre- and/or postmating isolating mechanisms in the form of speciation islands. These results are consistent with an allopatric divergence process with little or no introgression.

  19. Site-specific genetic engineering of the Anopheles gambiae Y chromosome.

    Science.gov (United States)

    Bernardini, Federica; Galizi, Roberto; Menichelli, Miriam; Papathanos, Philippos-Aris; Dritsou, Vicky; Marois, Eric; Crisanti, Andrea; Windbichler, Nikolai

    2014-05-27

    Despite its function in sex determination and its role in driving genome evolution, the Y chromosome remains poorly understood in most species. Y chromosomes are gene-poor, repeat-rich and largely heterochromatic and therefore represent a difficult target for genetic engineering. The Y chromosome of the human malaria vector Anopheles gambiae appears to be involved in sex determination although very little is known about both its structure and function. Here, we characterize a transgenic strain of this mosquito species, obtained by transposon-mediated integration of a transgene construct onto the Y chromosome. Using meganuclease-induced homologous repair we introduce a site-specific recombination signal onto the Y chromosome and show that the resulting docking line can be used for secondary integration. To demonstrate its utility, we study the activity of a germ-line-specific promoter when located on the Y chromosome. We also show that Y-linked fluorescent transgenes allow automated sex separation of this important vector species, providing the means to generate large single-sex populations. Our findings will aid studies of sex chromosome function and enable the development of male-exclusive genetic traits for vector control.

  20. Some ecological attributes of malarial vector Anopheles superpictus Grassi in endemic foci in southeastern Iran

    Institute of Scientific and Technical Information of China (English)

    Jalil Nejati; Hasan Vatandoost; Mohammad Ali Oshghi; Masud Salehi; Ehssan Mozafari; Seyed Hasan Moosa-Kazemi

    2013-01-01

    Objective:To determine the bionomics and susceptibility status of the malarial vector Anopheles superpictus (An. superpictus) to different insecticides in the Sistan-Baluchestan province which has the highest malarial prevalence in Iran. Methods:Different sampling methods, in addition to scoring abdominal conditions, were used to define the seasonal activity and endo/exophilic behavior of this species. In addition, the standard WHO susceptibility tests were applied on adult field strains. Results: Most adult mosquitoes were collected from outdoor shelters. The peak of seasonal activity of An. superpictus occurred at the end of autumn. Most larvae were collected from natural and permanent breeding places with full sunlight and no vegetation. Blood feeding activities occurred around midnight. Compared with the abdominal conditions of adult mosquitoes collected indoors, the abdominal conditions of adult mosquitoes collected outdoors were gravid and semigravid. This species was suspected to be resistant to DDT, but was susceptible to other insecticides. Conclusions:An. superpictus was present in almost all outdoor shelters, and the ratios of gravid, semigravid/unfed, and freshly fed confirmed that this species had a higher tendency to rest outdoors than indoors. This behavior can protect An. superpictus from indoor residual spraying in this malarious area. To the best of our knowledge, this is the first report on the susceptibility status of An. superpictus in Southeastern Iran. We do not suggest the use of DDT for indoor residual spraying in southeast Iran.

  1. High malaria transmission in a forested malaria focus in French Guiana: How can exophagic Anopheles darlingi thwart vector control and prevention measures?

    Science.gov (United States)

    Vezenegho, Samuel B; Adde, Antoine; de Santi, Vincent Pommier; Issaly, Jean; Carinci, Romuald; Gaborit, Pascal; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

    2016-01-01

    In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities. PMID:27653361

  2. High malaria transmission in a forested malaria focus in French Guiana: How can exophagic Anopheles darlingi thwart vector control and prevention measures?

    Science.gov (United States)

    Vezenegho, Samuel B; Adde, Antoine; Pommier de Santi, Vincent; Issaly, Jean; Carinci, Romuald; Gaborit, Pascal; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

    2016-09-01

    In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities.

  3. INKRIMINASI VEKTOR MALARIA DAN IDENTIFIKASI PAKAN DARAH PADA NYAMUK AnopHELEs SPP DI KECAMATAN BOROBUDUR, KABUPATEN MAGELANG

    Directory of Open Access Journals (Sweden)

    Umi Widyastuti

    2013-12-01

    abdomennya, dipencet di atas kertas Whatman dan digunakan  untuk  ELISA  pakan  darah.  Hasil  penelitian  menunjukkan  bahwa An.  aconitus  rentan  terhadap P. falciparum dengan angka sporozoit sebesar 0,07 % di Giripurno dan sporozoit P. vivax tidak ditemukan, sedangkan di Giritengah, An. balabacensis rentan terhadap P. falciparum dengan angka sporozoit 4,17 % dan sporozoit P. vivax tidak ditemukan. Proporsi An. aconitus menghisap darah manusia (HBI sebesar 10,34 % di Giripurno dan 5,97 % di Giritengah. An balabacensis dan An. barbirostris menunjukkan HBI sebesar 37,50 % dan 5,88% di Giritengah. Angka paritas dan kepadatan An. aconitus di Giripurno relatif lebih tinggi dibanding di Giritengah, sebaliknya An. balabacensis lebih tinggi di Giritengah dibanding di Giripurno.Kata kunci: malaria, Elisa sporozoit, Elisa pakan darah.AbstractMalaria is still a health problem in Magelang Regency, especially in the Borobudur Subdistrict. The Annual Parasite Incidence (API in the last two years were 0.19 in 2004 and increased 0.34 in 2005, were considered as malarious areas with Low Case Incidence (LCI. The increase of malaria cases in Borobudur Subdistrict is related to the presence of Anopheline mosquitoes which serve as potential vector. The vectorial competence of Anopheline mosquitoes in Borobudur Subdistrict has not been reported yet. Several species such as Anopheles aconitus, An. maculatus, An. barbirostris and An. balabacensis are suspected as potential malaria vectors in this area. The objective of this study was to determine the Anophelene mosquitoes susceptibility to Plasmodia and its anthropophilic characteristic. The susceptibility of mosquito to Plasmodia was measured by detection of sporozoite protein antigen (Circum Sporozoite Protein/ CSP of P. falciparum or P. vivax on the head-thorax of all parous mosquitoes. The anthropophilic characteristic was measured by detection of human blood on the abdomen of blood fed and half gravid mosquitoes. Both of these

  4. Effect of Novaluron (Rimon 10 EC) on the mosquitoes Anopheles albimanus, Anopheles pseudopunctipennis, Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from Chiapas, Mexico.

    Science.gov (United States)

    Arredondo-Jiménez, J I; Valdez-Delgado, K M

    2006-12-01

    Dengue fever is a serious problem in Mexico and vector control has not been effective enough at preventing outbreaks. Malaria is largely under control, but it is important that new control measures continue to be developed. Novaluron, a novel host-specific insect growth regulator and chitin synthesis inhibitor, has proved to be effective against agricultural pests, but its efficacy against larval mosquito vectors under field conditions remains unknown. In accordance with the World Health Organization Pesticide Evaluation Scheme, phase I, II and III studies were conducted to evaluate the efficacy and residual effect of Novaluron (Rimon 10 EC, Makhteshim, Beer-Sheva, Israel) on the malaria vectors Anopheles albimanus Wiedemann (Diptera: Culicidae) and Anopheles pseudopunctipennis Theobald, the dengue vectors Aedes aegypti (L) and Aedes albopictus Skuse and the nuisance mosquito Culex quinquefasciatus Say. Laboratory susceptibility tests yielded diagnostic concentrations for all five target species. Field trials to identify the optimum field dosage of Novaluron against Anopheles mosquitoes were carried out under semi-natural conditions in artificial plots and in vessels with wild mosquitoes. Efficacy was measured by monitoring mortality of larvae and pupae and the percentage of inhibition of emergence from floating cages. Dosages of Novaluron for field tests were based on pupal LC(99) (lethal concentration 99%) of An. pseudopunctipennis (0.166 mg/L) in plots and average pupal LC(99) of Ae. aegypti and Ae. albopictus (0.55 mg/L). At all dosages tested, Novaluron significantly reduced larval populations of An. albimanus, Culex coronator Dyar & Knab, Ae. albopictus and Cx. quinquefasciatus by approximately 90%, inhibited adult emergence of An. albimanus and An. pseudopunctipennis by approximately 97% for almost 4 months in experimental plots, and inhibited adult emergence of Ae. aegypti and Ae. albopictus by approximately 97% for up to 14 weeks. Recommended dosages of

  5. Efficacy of herbal essential oils as insecticide against Aedes aegypti (Linn.), Culex quinquefasciatus (Say) and Anopheles dirus (Peyton and Harrison).

    Science.gov (United States)

    Phasomkusolsil, Siriporn; Soonwera, Mayura

    2011-09-01

    The essential oils of Cananga odorata (ylang ylang), Citrus sinensis (orange), Cymbopogon citratus (lemongrass), Cymbopogon nardus (citronella grass), Eucalyptus citriodora (eucalyptus), Ocimum basilicum (sweet basil) and Syzygium aromaticum (clove), were tested for their insecticide activity against Aedes aegypti, Culex quinquefasciatus and Anopheles dirus using the WHO standard susceptibility test. These were applied in soybean oil at dose of 1%, 5% and 10% (w/v). C. citratus had the KT, values against the three mosquito species tested but the knockdown rates (at 10, 30 and 60 minutes) were lower than some essential oils. C. citratus oil had high insecticidal activity against Ae. aegypti, Cx. quinquefasciatus and An. dirus, with LC50 values of < 0.1, 2.22 and < 0.1%, respectively. Ten percent C. citratus gave the highest mortality rates (100%) 24 hours after application. This study demonstrates the potential for the essential oil of C. citratus to be used as an insecticide against 3 species of mosquitoes.

  6. First report of Metarhizium anisopliae IP 46 pathogenicity in adult Anopheles gambiae s.s. and An. arabiensis (Diptera; Culicidae

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    Lyimo Issa N

    2009-12-01

    Full Text Available Abstract The entomopathogenic fungus Metarhizium anisopliae isolate IP 46, originating from a soil sample collected in 2001 in the Cerrado of Central Brazil, was tested for its ability to reduce the survival of adult male and female Anopheles gambiae s.s. and An. arabiensis mosquitoes. A 6-h exposure to the fungus coated on test paper at a concentration of 3.3 × 106 conidia cm-2 reduced the daily survival of both mosquito species (HR = 3.14, p An. gambiae s.s relative to An. arabiensis (HR = 1.38, p 95% of mosquito cadavers in the treatment groups. The results indicate that M. anisopliae IP 46 has the potential to be a bio-control agent for African malaria vector species, and is a suitable candidate for further research and development.

  7. Behavioral heterogeneity of Anopheles darlingi (Diptera: Culicidae) and malaria transmission dynamics along the Maroni River, Suriname, French Guiana.

    Science.gov (United States)

    Hiwat, H; Issaly, J; Gaborit, P; Somai, A; Samjhawan, A; Sardjoe, P; Soekhoe, T; Girod, R

    2010-03-01

    The border area between Suriname and French Guiana is considered the most affected malaria area in South America. A one-year cooperative malaria vector study was performed by the two countries, between March 2004 and February 2005, in four villages. Anopheles darlingi proved to be the most abundant anopheline species. Human biting rates differed between villages. The differential effect of high rainfall on mosquito densities in the villages suggests variation in breeding sites. Overall parity rates were low, with means varying from 0.31 to 0.56 per study site. Of the 2045 A. darlingi mosquitoes collected, 13 were found to be infected with Plasmodium: ten P. falciparum, two P. malariae and one mixed P. malariae/P. vivax. The overall annual entomological inoculation rates in the villages ranged from 8.7 to 66.4. There was an apparent lack of relationship between number of malaria cases and periods of high mosquito density. The tendency of Anopheles darlingi to bite during sleeping hours provides opportunity for malaria control using impregnated bed nets, a strategy just introduced in Suriname that may also find its way into French Guiana.

  8. Salivary Gland Proteome during Adult Development and after Blood Feeding of Female Anopheles dissidens Mosquitoes (Diptera: Culicidae)

    Science.gov (United States)

    Phattanawiboon, Benjarat; Jariyapan, Narissara; Mano, Chonlada; Roytrakul, Sittiruk; Paemanee, Atchara; Sor-Suwan, Sriwatapron; Sriwichai, Patchara; Saeung, Atiporn; Bates, Paul A.

    2016-01-01

    Understanding changes in mosquito salivary proteins during the time that sporozoite maturation occurs and after blood feeding may give information regarding the roles of salivary proteins during the malarial transmission. Anopheles dissidens (formerly Anopheles barbirostris species A1) is a potential vector of Plasmodium vivax in Thailand. In this study, analyses of the proteomic profiles of female An. dissidens salivary glands during adult development and after blood feeding were carried out using two-dimensional gel electrophoresis coupled with nano-liquid chromatography-mass spectrometry. Results showed at least 17 major salivary gland proteins present from day one to day 21 post emergence at 8 different time points sampled. Although there was variation observed, the patterns of protein expression could be placed into one of four groups. Fifteen protein spots showed significant depletion after blood feeding with the percentages of the amount of depletion ranging from 8.5% to 68.11%. The overall results identified various proteins, including a putative mucin-like protein, an anti-platelet protein, a long form D7 salivary protein, a putative gVAG protein precursor, a D7-related 3.2 protein, gSG7 salivary proteins, and a gSG6 protein. These results allow better understanding of the changes of the salivary proteins during the adult mosquito development. They also provide candidate proteins to investigate any possible link or not between sporozoite maturation, or survival of skin stage sporozoites, and salivary proteins. PMID:27669021

  9. Genotyping of chloroquine resistant Plasmodium falciparum in wild caught Anopheles minimus mosquitoes in a malaria endemic area of Assam, India.

    Science.gov (United States)

    Sarma, D K; Mohapatra, P K; Bhattacharyya, D R; Mahanta, J; Prakash, A

    2014-09-01

    We validated the feasibility of using Plasmodium falciparum, the human malaria parasite, DNA present in wild caught vector mosquitoes for the characterization of chloroquine resistance status. House frequenting mosquitoes belonging to Anopheles minimus complex were collected from human dwellings in a malaria endemic area of Assam, Northeast India and DNA was extracted from the head-thorax region of individual mosquitoes. Anopheles minimus complex mosquitoes were identified to species level and screened for the presence of Plasmodium sp. using molecular tools. Nested PCR-RFLP method was used for genotyping of P. falciparum based on K76T mutation in the chloroquine resistance transporter (pfcrt) gene. Three of the 27 wild caught An. minimus mosquitoes were harbouring P. falciparum sporozoites (positivity 11.1%) and all 3 were had 76T mutation in the pfcrt gene, indicating chloroquine resistance. The approach of characterizing antimalarial resistance of malaria parasite in vector mosquitoes can potentially be used as a surveillance tool for monitoring transmission of antimalarial drug resistant parasite strains in the community.

  10. Genetic Structure of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) in Colombia

    Science.gov (United States)

    2010-01-01

    simultaneously for all the populations studied and population pairs using R ST software. 30 From these heterogeneity statis- tics , theoretical gene-flow...statis- tic was used, the average values ranged from 0.042 to 0.047, depending on the procedures used. This statistic again showed a moderate divergence...S , Suárez M , Sánchez G , Quiñones M , Herrera M , 1987 . Uso de la técnica inmunoradiometrica (IRMA) en Anopheles de Colombia para la

  11. Bioinformatics-Based Identification of Chemosensory Proteins in African Malaria Mosquito, Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Zhengxi Li; Zuorui Shen; Jingjiang Zhou; Lin Field

    2003-01-01

    Chemosensory proteins (CSPs) are identifiable by four spatially conserved Cysteine residues in their primary structure or by two disulfide bridges in their tertiary structure according to the previously identified olfactory specific-D related proteins. A genomics- and bioinformatics-based approach is taken in the present study to identify the putative CSPs in the malaria-carrying mosquito, Anopheles gambiae. The results show that five out of the nine annotated candidates are the most possible Anopheles CSPs of A. gambiae. This study lays the foundation for further functional identification of Anopheles CSPs, though all of these candidates need additional experimental verification.

  12. Insecticide resistance in Anopheles gambiae from south-western Chad, Central Africa

    Directory of Open Access Journals (Sweden)

    Etang Josiane

    2008-09-01

    Full Text Available Abstract Background Indoor residual spraying and insecticide-treated nets (ITN are essential components of malaria vector control in Africa. Pyrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. However, there is growing concern that pyrethroid resistance may threaten the sustainability of ITN scaling-up programmes. Here, insecticide susceptibility was investigated in Anopheles gambiae sensu lato from an area of large scale ITN distribution programme in south-western Chad. Methods Susceptibility to 4% DDT, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb and 5% malathion was assessed using the WHO standard procedures for adult mosquitoes. Tests were carried out with two to four days-old, non-engorged female mosquitoes. The An. gambiae Kisumu strain was used as a reference. Knockdown effect was recorded every 5 min and mortality scored 24 h after exposure. Mosquitoes were identified to species and molecular form by PCR-RFLP and genotypes at the kdr locus were determined in surviving specimens by Hot Oligonucleotide Ligation Assay (HOLA. Results During this survey, full susceptibility to malathion was recorded in all samples. Reduced susceptibility to bendiocarb (mortality rate of 96.1% was found in one sample out of nine assayed. Increased tolerance to pyrethroids was detected in most samples (8/9 with mortality rates ranging from 70.2 to 96.6% for deltamethrin and from 26.7 to 96.3% for permethrin. Pyrethroid tolerance was not associated with a significant increase of knock-down times. Anopheles arabiensis was the predominant species of the An. gambiae complex in the study area, representing 75 to 100% of the samples. Screening for kdr mutations detected the L1014F mutation in 88.6% (N = 35 of surviving An. gambiae sensu stricto S form mosquitoes. All surviving An. arabiensis (N = 49 and M form An. gambiae s.s. (N = 1 carried the susceptible allele

  13. Differentially expressed genes between female and male adult Anopheles anthropophagus.

    Science.gov (United States)

    Geng, Yi-Jie; Gao, Shi-Tong; Huang, Da-Na; Zhao, Yi-Rui; Liu, Jian-ping; Li, Xiao-Heng; Zhang, Ren-Li

    2009-09-01

    The aim of the present study was to identify sex-specific genes in adult Anopheles anthropophagus. As the major malaria vector and Brugia malayi vector in the Asian continent, female Anopheles mosquitoes take blood meals and transmit pathogens through this pathway, while males are nectar feeders. This complex behavior is controlled at several levels, but is probably initiated by the genetic background difference between these two groups. In our study, a subtractive cDNA library for female A. anthropophagus was constructed using the suppression subtractive hybridization (SSH) technique and then 3,074 clones from the female SSH library were analyzed using a microarray-based survey. Genes that were expressed differentially according to sex in A. anthropophagus were screened using real-time polymerase chain reaction and reverse transcription polymerase chain reaction. In our results, we report a series of genes which may be involved in female-specific mosquito behavior, including an inorganic phosphate transporter, a serine protease, the salivary protein GP35-2, and the D7 cluster salivary protein. These findings will provide clues to the nature of insect vectors and open up unprecedented opportunities to develop novel strategies for the control of mosquito-borne diseases.

  14. Incrimination of Anopheles (Nyssorhynchus rangeli and An. (Nys. oswaldoi as natural vectors of Plasmodium vivax in Southern Colombia

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    Martha L Quiñones

    2006-09-01

    Full Text Available Malaria transmission in the Southern Colombian state of Putumayo continues despite the absence of traditional vector species, except for the presence of Anopheles darlingi near the southeastern border with the state of Amazonas. In order to facilitate malaria vector incrimination in Putumayo, 2445 morphologically identified Anopheles females were tested for natural infection of Plasmodium vivax by ELISA. Specimens tested included An. apicimacula (n = 2, An. benarrochi B (n = 1617, An. darlingi (n = 29, An. mattogrossensis (n = 7, An. neomaculipalpus (n = 7, An. oswaldoi (n = 362, An. peryassui (n = 1, An. punctimacula (n = 1, An. rangeli (n = 413, and An. triannulatus (n = 6. Despite being overwhelmingly the most anthropophilic species in the region and comprising 66.1% of the mosquitoes tested, An. benarrochi B was not shown to be a vector. Thirty-five An. rangeli and one An. oswaldoi were naturally infected with P. vivax VK210. Sequence data were generated for the nuclear second internal transcriber space region of 31 of these 36 vivax positive mosquitoes (86.1% to confirm their morphological identification. An. oswaldoi is known to be a species complex in Latin America, but its internal taxonomy remains unresolved. Herein we show that the An. oswaldoi found in the state of Putumayo is genetically similar to specimens from the state of Amapá in Brazil and from the Ocama region in the state of Amazonas in Venezuela, and that this form harbors natural infections of P. vivax. That An. rangeli and this member of the An. oswaldoi complex are incriminated as malaria vectors in Putumayo, is a novel finding of significance for malaria control in Southern Colombia, and possibly in other areas of Latin America.

  15. Annotation and analysis of a large cuticular protein family with the R&R Consensus in Anopheles gambiae

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    He Ningjia

    2008-01-01

    Full Text Available Abstract Background The most abundant family of insect cuticular proteins, the CPR family, is recognized by the R&R Consensus, a domain of about 64 amino acids that binds to chitin and is present throughout arthropods. Several species have now been shown to have more than 100 CPR genes, inviting speculation as to the functional importance of this large number and diversity. Results We have identified 156 genes in Anopheles gambiae that code for putative cuticular proteins in this CPR family, over 1% of the total number of predicted genes in this species. Annotation was verified using several criteria including identification of TATA boxes, INRs, and DPEs plus support from proteomic and gene expression analyses. Two previously recognized CPR classes, RR-1 and RR-2, form separate, well-supported clades with the exception of a small set of genes with long branches whose relationships are poorly resolved. Several of these outliers have clear orthologs in other species. Although both clades are under purifying selection, the RR-1 variant of the R&R Consensus is evolving at twice the rate of the RR-2 variant and is structurally more labile. In contrast, the regions flanking the R&R Consensus have diversified in amino-acid composition to a much greater extent in RR-2 genes compared with RR-1 genes. Many genes are found in compact tandem arrays that may include similar or dissimilar genes but always include just one of the two classes. Tandem arrays of RR-2 genes frequently contain subsets of genes coding for highly similar proteins (sequence clusters. Properties of the proteins indicated that each cluster may serve a distinct function in the cuticle. Conclusion The complete annotation of this large gene family provides insight on the mechanisms of gene family evolution and clues about the need for so many CPR genes. These data also should assist annotation of other Anopheles genes.

  16. Laser induced mortality of Anopheles stephensi mosquitoes

    Science.gov (United States)

    Keller, Matthew D.; Leahy, David J.; Norton, Bryan J.; Johanson, Threeric; Mullen, Emma R.; Marvit, Maclen; Makagon, Arty

    2016-02-01

    Small, flying insects continue to pose great risks to both human health and agricultural production throughout the world, so there remains a compelling need to develop new vector and pest control approaches. Here, we examined the use of short (mosquitoes, which were chosen as a representative species. The mortality of mosquitoes exposed to laser pulses of various wavelength, power, pulse duration, and spot size combinations was assessed 24 hours after exposure. For otherwise comparable conditions, green and far-infrared wavelengths were found to be more effective than near- and mid-infrared wavelengths. Pulses with larger laser spot sizes required lower lethal energy densities, or fluence, but more pulse energy than for smaller spot sizes with greater fluence. Pulse duration had to be reduced by several orders of magnitude to significantly lower the lethal pulse energy or fluence required. These results identified the most promising candidates for the lethal laser component in a system being designed to identify, track, and shoot down flying insects in the wild.

  17. Evidence of natural Wolbachia infections in field populations of Anopheles gambiae

    Science.gov (United States)

    Baldini, Francesco; Segata, Nicola; Pompon, Julien; Marcenac, Perrine; Robert Shaw, W.; Dabiré, Roch K.; Diabaté, Abdoulaye; Levashina, Elena A.; Catteruccia, Flaminia

    2014-01-01

    Wolbachia are maternally transmitted intracellular bacteria that invade insect populations by manipulating their reproduction and immunity and thus limiting the spread of numerous human pathogens. Experimental Wolbachia infections can reduce Plasmodium numbers in Anopheles mosquitoes in the laboratory, however, natural Wolbachia infections in field anophelines have never been reported. Here we show evidence of Wolbachia infections in Anopheles gambiae in Burkina Faso, West Africa. Sequencing of the 16S rRNA gene identified Wolbachia sequences in both female and male germlines across two seasons, and determined that these sequences are vertically transmitted from mother to offspring. Whole-genome sequencing of positive samples suggests that the genetic material identified in An. gambiae belongs to a novel Wolbachia strain, related to but distinct from strains infecting other arthropods. The evidence of Wolbachia infections in natural Anopheles populations promotes further investigations on the possible use of natural Wolbachia–Anopheles associations to limit malaria transmission. PMID:24905191

  18. Avoidance behavior to essential oils by Anopheles minimus, a malaria vector in Thailand

    Science.gov (United States)

    Excito-repellency tests were used to characterize behavioral responses of laboratory colonized Anopheles minimus, a malaria vector in Thailand, using four essential oils, citronella (Cymbopogom nadus), hairy basil (Ocimum americanum), sweet basil (Ocimum basilicum), vetiver (Vetiveria zizanioides), ...

  19. BEBERAPA ASPEK PERILAKU NYAMUK Anopheles barbirostris DI KABUPATEN SUMBA TENGAH TAHUN 2011

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    Monika Noshirma

    2013-02-01

    Full Text Available Abstract Some aspects of Anopheles barbirostris behavior in Central Sumba Regency was conducted in July– October in District Umbu Ratu Nggai (Village Padira Tana which represents in mountain ecology and the district of Mamboro (Manu Wollu Village representing the coastal ecology. Both villages are selected to have high malaria cases during the past year. The objective of the study is to determine Some aspect of Anopheles barbirostris behavior in Central Sumba Regency. The result showed that the characteristics of  breeding habitats of Anopheles barbirostris in the padira tana village is in fields (both in use, not use or ready for planting and in kobakan. in Manu Wolu Village the breeding habitats are in former ponds, puddles an kobakan. The bitting activity of Anopheles barbirostris the in Padira Tana Village highest in July (MBR = 0.08 outside the house,  while in Manu Wolu Village bite out of the house in July and October (MBR = 0.04. in the Padira Tana Village and Manu Wollu village the Anopheles barbirostris is most prevalent in the cage with peak hours 11.00 pm to 04.00 am. Keyword: some aspect of vector behavior, Anopheles barbirostris Abstrak Studi beberapa aspek perilaku vektor malaria Anopheles barbirostris di Kabupaten Sumba Tengah dilaksanakan pada bulan Juli – Oktober di 2 Kecamatan yaitu Kecamatan Umbu Ratu (Desa Padira Tana yang mewakili ekologi pegunungan dan Kecamatan Mamboro (Desa Manu Wolu yang mewakili ekologi pantai. Kedua desa yang dipilih mempunyai kasus malaria tinggi selama satu tahun terakhir. Tujuan penelitian ini untuk mengetahui beberapa aspek perilaku vektor Anopheles barbirostris di Kabupaten Sumba Tengah. Hasil penelitian menunjukan bahwa karakteristik habitat perkembangbiakan Anopheles barbirostris di desa Padira Tana adalah sawah (baik yang terpakai, tidak dipakai maupun siap tanam dan di kobakan. Sedangkan di desa Manu Wolu ditemukan di bekas kolam, kubangan dan kobakan.    Kepadatan nyamuk An

  20. Genetic diversity and gene flow of humans, Plasmodium falciparum, and Anopheles farauti s.s. of Vanuatu: inferred malaria dispersal and implications for malaria control.

    Science.gov (United States)

    Lum, J K; Kaneko, A; Taleo, G; Amos, M; Reiff, D M

    2007-08-01

    A comparison of the patterns of gene flow within and between islands and the genetic diversities of the three species required for malaria transmission (humans, Plasmodium falciparum, and Anopheles farauti s.s.) within the model island system of Vanuatu, shows that the active dispersal of An. farauti s.s. is responsible for within island movement of parasites. In contrast, since both P. falciparum and An. farauti s.s. populations are largely restricted to islands, movement of parasites between islands is likely due to human transport. Thus, control of vectors is crucial for controlling malaria within islands, while control of human movement is essential to control malaria transmission across the archipelago.

  1. Molecular Comparison of Topotypic Specimens Confirms Anopheles (Nyssorhynchus) dunhami Causey (Diptera: Culicidae) in the Colombian Amazon

    Science.gov (United States)

    2010-11-01

    of Health, Albany, NY, USA 5Facultad de Medicina , Universidad Nacional de Colombia, Bogotá, Colombia 6Programa de Estudio y Control de Enfermedades...Tropicales, Facultad de Medicina , Universidad de Antioquia, Medellín, Colombia The presence of Anopheles (Nyssorhynchus) dunhami Causey in Colombia...Anopheles nuneztovari C used in this study, alongside GenBank accessions for second internal transcribed spacer (ITS2) and cytochrome c oxidase I (COI

  2. Hemozoin activates the innate immune system and reduces Plasmodium berghei infection in Anopheles gambiae

    OpenAIRE

    Simões, Maria L; Gonçalves, Luzia; Silveira, Henrique

    2015-01-01

    Background Malaria is a worldwide infectious disease caused by Plasmodium parasites and transmitted by female Anopheles mosquitoes. The malaria vector mosquito Anopheles can trigger effective mechanisms to control completion of the Plasmodium lifecycle; the mosquito immune response to the parasite involves several pathways which are not yet well characterized. Plasmodium metabolite hemozoin has emerged as a potent immunostimulator of mammalian tissues. In this study, we aim to investigate the...

  3. Host choice and multiple blood feeding behaviour of malaria vectors and other anophelines in Mwea rice scheme, Kenya

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    Jacob Benjamin G

    2008-02-01

    Full Text Available Abstract Background Studies were conducted between April 2004 and February 2006 to determine the blood-feeding pattern of Anopheles mosquitoes in Mwea Kenya. Methods Samples were collected indoors by pyrethrum spay catch and outdoors by Centers for Disease Control light traps and processed for blood meal analysis by an Enzyme-linked Immunosorbent Assay. Results A total of 3,333 blood-fed Anopheles mosquitoes representing four Anopheles species were collected and 2,796 of the samples were assayed, with Anopheles arabiensis comprising 76.2% (n = 2,542 followed in decreasing order by Anopheles coustani 8.9% (n = 297, Anopheles pharoensis 8.2% (n = 272 and Anopheles funestus 6.7% (n = 222. All mosquito species had a high preference for bovine (range 56.3–71.4% over human (range 1.1–23.9% or goat (0.1–2.2% blood meals. Some individuals from all the four species were found to contain mixed blood meals. The bovine blood index (BBI for An. arabiensis was significantly higher for populations collected indoors (71.8%, than populations collected outdoors (41.3%, but the human blood index (HBI did not differ significantly between the two populations. In contrast, BBI for indoor collected An. funestus (51.4% was significantly lower than for outdoor collected populations (78.0% and the HBI was significantly higher indoors (28.7% than outdoors (2.4%. Anthropophily of An. funestus was lowest within the rice scheme, moderate in unplanned rice agro-ecosystem, and highest within the non-irrigated agro-ecosystem. Anthropophily of An. arabiensis was significantly higher in the non-irrigated agro-ecosystem than in the other agro-ecosystems. Conclusion These findings suggest that rice cultivation has an effect on host choice by Anopheles mosquitoes. The study further indicate that zooprophylaxis may be a potential strategy for malaria control, but there is need to assess how domestic animals may influence arboviruses epidemiology before adapting the strategy.

  4. Larvicidal activity of Morinda citrifolia L. (Noni) (Family: Rubiaceae) leaf extract against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti.

    Science.gov (United States)

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Shanthakumar, Shanmugam Perumal; Vincent, Savariar; Hwang, Jiang-Shiou

    2012-10-01

    Morinda citrifolia leaf extract was tested for larvicidal activity against three medically important mosquito vectors such as malarial vector Anopheles stephensi, dengue vector Aedes aegypti, and filarial vector Culex quinquefasciatus. The plant material was shade dried at room temperature and powdered coarsely. From the leaf, 1-kg powder was macerated with 3.0 L of hexane, chloroform, acetone, methanol, and water sequentially for a period of 72 h each and filtered. The yield of extracts was hexane (13.56 g), chloroform (15.21 g), acetone (12.85 g), methanol (14.76 g), and water (12.92 g), respectively. The extracts were concentrated at reduced temperature on a rotary vacuum evaporator and stored at a temperature of 4°C. The M. citrifolia leaf extract at 200, 300, 400, 500, and 600 ppm caused a significant mortality of three mosquito species. Hexane, chloroform, acetone, and water caused moderate considerable mortality; however, the highest larval mortality was methanolic extract, observed in three mosquito vectors. The larval mortality was observed after 24-h exposure. No mortality was observed in the control. The third larvae of Anopheles stephensi had values of LC(50) = 345.10, 324.26, 299.97, 261.96, and 284.59 ppm and LC(90) = 653.00, 626.58, 571.89, 505.06, and 549.51 ppm, respectively. The Aedes aegypti had values of LC(50) = 361.75, 343.22, 315.40, 277.92, and 306.98 ppm and LC(90) = 687.39, 659.02, 611.35, 568.18, and 613.25 ppm, respectively. The Culex quinquefasciatus had values of LC(50) = 382.96, 369.85, 344.34, 330.42, and 324.64 ppm and LC(90) = 726.18, 706.57, 669.28, 619.63, and 644.47 ppm, respectively. The results of the leaf extract of M. citrifolia are promising as good larvicidal activity against the mosquito vector Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. This is a new eco-friendly approach for the control of vector control programs. Therefore, this study provides first report on the larvicidal activities against three

  5. The Genetic Basis of Host Preference and Resting Behavior in the Major African Malaria Vector, Anopheles arabiensis

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    Main, Bradley J; Lee, Yoosook; Ferguson, Heather M.; Kreppel, Katharina S.; Kihonda, Anicet; Govella, Nicodem J.; Collier, Travis C.; Cornel, Anthony J.; Eskin, Eleazar; Kang, Eun Yong; Nieman, Catelyn C.; Weakley, Allison M.; Lanzaro, Gregory C.

    2016-01-01

    Malaria transmission is dependent on the propensity of Anopheles mosquitoes to bite humans (anthropophily) instead of other dead end hosts. Recent increases in the usage of Long Lasting Insecticide Treated Nets (LLINs) in Africa have been associated with reductions in highly anthropophilic and endophilic vectors such as Anopheles gambiae s.s., leaving species with a broader host range, such as Anopheles arabiensis, as the most prominent remaining source of transmission in many settings. An. arabiensis appears to be more of a generalist in terms of its host choice and resting behavior, which may be due to phenotypic plasticity and/or segregating allelic variation. To investigate the genetic basis of host choice and resting behavior in An. arabiensis we sequenced the genomes of 23 human-fed and 25 cattle-fed mosquitoes collected both in-doors and out-doors in the Kilombero Valley, Tanzania. We identified a total of 4,820,851 SNPs, which were used to conduct the first genome-wide estimates of “SNP heritability” for host choice and resting behavior in this species. A genetic component was detected for host choice (human vs cow fed; permuted P = 0.002), but there was no evidence of a genetic component for resting behavior (indoors versus outside; permuted P = 0.465). A principal component analysis (PCA) segregated individuals based on genomic variation into three groups which were characterized by differences at the 2Rb and/or 3Ra paracentromeric chromosome inversions. There was a non-random distribution of cattle-fed mosquitoes between the PCA clusters, suggesting that alleles linked to the 2Rb and/or 3Ra inversions may influence host choice. Using a novel inversion genotyping assay, we detected a significant enrichment of the standard arrangement (non-inverted) of 3Ra among cattle-fed mosquitoes (N = 129) versus all non-cattle-fed individuals (N = 234; χ2, p = 0.007). Thus, tracking the frequency of the 3Ra in An. arabiensis populations may be of use to infer

  6. Sugar-fermenting yeast as an organic source of carbon dioxide to attract the malaria mosquito Anopheles gambiae

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    Spitzen Jeroen

    2010-10-01

    Full Text Available Abstract Background Carbon dioxide (CO2 plays an important role in the host-seeking process of opportunistic, zoophilic and anthropophilic mosquito species and is, therefore, commonly added to mosquito sampling tools. The African malaria vector Anopheles gambiae sensu stricto is attracted to human volatiles augmented by CO2. This study investigated whether CO2, usually supplied from gas cylinders acquired from commercial industry, could be replaced by CO2 derived from fermenting yeast (yeast-produced CO2. Methods Trapping experiments were conducted in the laboratory, semi-field and field, with An. gambiae s.s. as the target species. MM-X traps were baited with volatiles produced by mixtures of yeast, sugar and water, prepared in 1.5, 5 or 25 L bottles. Catches were compared with traps baited with industrial CO2. The additional effect of human odours was also examined. In the laboratory and semi-field facility dual-choice experiments were conducted. The effect of traps baited with yeast-produced CO2 on the number of mosquitoes entering an African house was studied in the MalariaSphere. Carbon dioxide baited traps, placed outside human dwellings, were also tested in an African village setting. The laboratory and semi-field data were analysed by a χ2-test, the field data by GLM. In addition, CO2 concentrations produced by yeast-sugar solutions were measured over time. Results Traps baited with yeast-produced CO2 caught significantly more mosquitoes than unbaited traps (up to 34 h post mixing the ingredients and also significantly more than traps baited with industrial CO2, both in the laboratory and semi-field. Adding yeast-produced CO2 to traps baited with human odour significantly increased trap catches. In the MalariaSphere, outdoor traps baited with yeast-produced or industrial CO2 + human odour reduced house entry of mosquitoes with a human host sleeping under a bed net indoors. Anopheles gambiae s.s. was not caught during the field trials

  7. SUSCEPTIBILITY TESTS OF ANOPHELES STEPHENSI WITH SOME CHLORINE, PHOSPHORUS, CARBAMATE AND PYRETILROID INSECTICICDES IN SOUTH OF IRAN

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    M.Iranpour

    1993-12-01

    Full Text Available Susceptibility tests were carried out on Anopheles stephensi with D.D.T(4%, dieldrin (4%, malathion(5%, propoxus (0.1%, primphos-methyl (O.lmg/cm2, lambda-cyhalothrin (0.1%, permethrin (0.25% and deltamethrin (0.025% during 1990-94 in Minab county, soutern Iran, using W.H.O standard method. Results showed that An. stephensi was susceptible to malathion, propoxur, primphos - methyl, lambda- cyhalothrin permethrin and deltamethrin, also LT5O was 5,19.5, less than 1.less than 1,3 and less than 1 minute, respectively. Results indicated that An.stephensi was still resistant to D.D.T and dieldrin but susceptibility level has increased. Mortality rate was 36.1 and 80.6 when the species was exposed to D.D.T and dieldrin impregnated papers for 60 minutes, respectively.

  8. Mosquito mass rearing technology: a cold-water vortex device for continuous unattended separation of Anopheles arabiensis pupae from larvae.

    Science.gov (United States)

    Balestrino, Fabrizio; Gilles, Jérémie R L; Soliban, Sharon M; Nirschl, Anton; Benedict, Quentin E; Benedict, Mark Q

    2011-09-01

    In mass rearing of anopheline mosquitoes, pupae are usually separated from larvae on a daily basis to prevent unwanted adult emergence from trays. Depending on the device and species, 2 physical characteristics have most often been used for separation: buoyant density and size. In this report, we describe a system for continuous separation of Anopheles arabiensis larvae from pupae based on the natural difference in buoyant density and behavior between the 2 stages. We determined that temperatures 4-15 degrees C caused neither mortality nor reduction in likelihood of pupation or emergence. Separation improved as temperatures decreased down to 4 degrees C. We devised and demonstrated a 15 degrees C water vortex separator that we anticipate can process approximately 1 million larvae and pupae per hour with a < 0.3% pupal contamination rate and which operates unattended.

  9. DNA barcoding reveals both known and novel taxa in the Albitarsis Group (Anopheles: Nyssorhynchus of Neotropical malaria vectors

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    Ruiz-Lopez Freddy

    2012-02-01

    Full Text Available Abstract Background Mosquitoes belonging to the Albitarsis Group (Anopheles: Nyssorhynchus are of importance as malaria vectors across the Neotropics. The Group currently comprises six known species, and recent studies have indicated further hidden biodiversity within the Group. DNA barcoding has been proposed as a highly useful tool for species recognition, although its discriminatory utility has not been verified in closely related taxa across a wide geographic distribution. Methods DNA barcodes (658 bp of the mtDNA Cytochrome c Oxidase - COI were generated for 565 An. albitarsis s.l. collected in Argentina, Brazil, Colombia, Paraguay, Trinidad and Venezuela over the past twenty years, including specimens from type series and type localities. Here we test the utility of currently advocated barcoding methodologies, including the Kimura-two-parameter distance model (K2P and Neighbor-joining analysis (NJ, for determining species delineation within mosquitoes of the Neotropical Albitarsis Group of malaria vectors (Anopheles: Nyssorhynchus, and compare results with Bayesian analysis. Results Species delineation through barcoding analysis and Bayesian phylogenetic analysis, fully concur. Analysis of 565 sequences (302 unique haplotypes resolved nine NJ tree clusters, with less than 2% intra-node variation. Mean intra-specific variation (K2P was 0.009 (range 0.002 - 0.014, whereas mean inter-specific divergence were several-fold higher at 0.041 (0.020 - 0.056, supporting the reported "barcoding gap". These results show full support for separate species status of the six known species in the Albitarsis Group (An. albitarsis s.s., An. albitarsis F, An. deaneorum, An. janconnae, An. marajoara and An. oryzalimnetes, and also support species level status for two previously detected lineages - An. albitarsis G &An. albitarsis I (designated herein. In addition, we highlight the presence of a unique mitochondrial lineage close to An. deaneorum and An

  10. Aspectos ecológicos de Anopheles cruzii e Culex ribeirensis (Diptera, Culicidae da Mata Atlântica de Morretes, Paraná, Brasil Ecological aspects of Anopheles cruzii and Culex ribeirensis (Diptera, Culicidae in Atlantic Forest of Morretes, Paraná, Brazil

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    Luiz Gonzaga dos Santos-Neto

    2008-01-01

    the year from 6 p.m. to 6 a.m., with total work hours of 144. A number of 1,408 specimens of mosquitoes was obtained (409 at canopy level and 999 near the ground, belonging to 10 genera and 31 species. Anopheles cruzii and Culex ribeirensis were predominant and are the main subjects of the present study. Difference was not observed between the traps for Anopheles cruzii. However, the higher number of Culex ribeirensis was collected in CDC-M/ground. According to time intervals, Anopheles cruzii showed peaks in the early hours of the night, and decreased progressively until dawn, without a secondary peak. As for the monthly distribution, Anopheles cruzii was more frequent in April and May 1995 and March 1996. Correlations between specimens and temperature or rainfall were not significant. The flight activity of Culex ribeirensis was more intense from 10 p.m. until 4 a.m., but significant peaks were not observed. The monthly distribution of Culex ribeirensis showed peaks in December and January. Significant correlation of this culicine was found for temperature and rainfall. First records for Paraná State: Ochlerotatus rhyacophilus, Culex misionensis, Culex pedroi, Culex ribeirensis and Culex zeteki.

  11. Three years of insecticide resistance monitoring in Anopheles gambiae in Burkina Faso: resistance on the rise?

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    Badolo Athanase

    2012-07-01

    Full Text Available Abstract Background and methods A longitudinal Anopheles gambiae s.l. insecticide-resistance monitoring programme was established in four sentinel sites in Burkina Faso. For three years, between 2008 and 2010, WHO diagnostic dose assays were used to measure the prevalence of resistance to all the major classes of insecticides at the beginning and end of the malaria transmission season. Species identification and genotyping for target site mutations was also performed and the sporozoite rate in adults determined. Results At the onset of the study, resistance to DDT and pyrethroids was already prevalent in An. gambiae s.l. from the south-west of the country but mosquitoes from the two sites in central Burkina Faso were largely susceptible. Within three years, DDT and permethrin resistance was established in all four sites. Carbamate and organophosphate resistance remains relatively rare and largely confined to the south-western areas although a small number of bendiocarb survivors were found in all sites by the final round of monitoring. The ace-1R target site resistance allele was present in all localities and its frequency exceeded 20% in 2010 in two of the sites. The frequency of the 1014F kdr mutation increased throughout the three years and by 2010, the frequency of 1014F in all sites combined was 0.02 in Anopheles arabiensis, 0.56 in An. gambiae M form and 0.96 in An. gambiae S form. This frequency did not differ significantly between the sites. The 1014S kdr allele was only found in An. arabiensis but its frequency increased significantly throughout the study (P = 0.0003 and in 2010 the 1014S allele frequency was 0.08 in An. arabiensis. Maximum sporozoite rates (12% were observed in Soumousso in 2009 and the difference between sites is significant for each year. Conclusion Pyrethroid and DDT resistance is now established in An. gambiae s.l. throughout Burkina Faso. Results from diagnostic dose assays are highly variable within and

  12. Metabolic and target-site mechanisms combine to confer strong DDT resistance in Anopheles gambiae.

    Science.gov (United States)

    Mitchell, Sara N; Rigden, Daniel J; Dowd, Andrew J; Lu, Fang; Wilding, Craig S; Weetman, David; Dadzie, Samuel; Jenkins, Adam M; Regna, Kimberly; Boko, Pelagie; Djogbenou, Luc; Muskavitch, Marc A T; Ranson, Hilary; Paine, Mark J I; Mayans, Olga; Donnelly, Martin J

    2014-01-01

    The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible strains of An. gambiae, revealed a non-synonymous polymorphism (I114T), proximal to the DDT binding domain, which segregated with strain phenotype. Recombinant protein expression and DDT metabolism analysis revealed that the proteins from the susceptible strain lost activity at higher DDT concentrations, characteristic of substrate inhibition. The effect of I114T on GSTE2 protein structure was explored through X-ray crystallography. The amino acid exchange in the DDT-resistant strain introduced a hydroxyl group nearby the hydrophobic DDT-binding region. The exchange does not result in structural alterations but is predicted to facilitate local dynamics and enzyme activity. Expression of both wild-type and 114T alleles the allele in Drosophila conferred an increase in DDT tolerance. The 114T mutation was significantly associated with DDT resistance in wild caught M-form populations and acts in concert with target-site mutations in the voltage gated sodium channel (Vgsc-1575Y and Vgsc-1014F) to confer extreme levels of DDT resistance in wild caught An. gambiae.

  13. Avoidance Behavior to Essential Oils by Anopheles minimus, a Malaria Vector in Thailand.

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    Nararak, Jirod; Sathantriphop, Sunaiyana; Chauhan, Kamal; Tantakom, Siripun; Eiden, Amanda L; Chareonviriyaphap, Theeraphap

    2016-03-01

    Essential oils extracted from 4 different plant species--citronella (Cymbopogon nardus), hairy basil (Ocimum americanum), sweet basil (Ocimum basilicum), and vetiver (Vetiveria zizanioides)-were investigated for their irritant and repellent activities against Anopheles minimus, using an excito-repellency test system. Pure essential oils were used in absolute ethanol at the concentrations of 0.5%, 1%, 2.5%, and 5% (v/v) compared with deet. At the lowest concentration of 0.5%, hairy basil displayed the best irritant and repellent effects against An. minimus. Citronella and vetiver at 1-5% showed strong irritant effects with>80% escape, while repellent effects of both oils were observed at 1% and 2.5% citronella (73-89% escape) and at 5% vetiver (83.9% escape). Sweet basil had only moderate irritant action at 5% concentration (69.6% escape) and slightly repellent on test mosquitoes (<50% escape). The results found that hairy basil, citronella, and vetiver are promising potential mosquito repellent products for protection against An. minimus.

  14. Sexual transfer of the steroid hormone 20E induces the postmating switch in Anopheles gambiae

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    Gabrieli, Paolo; Kakani, Evdoxia G.; Mitchell, Sara N.; Mameli, Enzo; Want, Elizabeth J.; Mariezcurrena Anton, Ainhoa; Serrao, Aurelio; Baldini, Francesco; Catteruccia, Flaminia

    2014-01-01

    Female insects generally mate multiple times during their lives. A notable exception is the female malaria mosquito Anopheles gambiae, which after sex loses her susceptibility to further copulation. Sex in this species also renders females competent to lay eggs developed after blood feeding. Despite intense research efforts, the identity of the molecular triggers that cause the postmating switch in females, inducing a permanent refractoriness to further mating and triggering egg-laying, remains elusive. Here we show that the male-transferred steroid hormone 20-hydroxyecdysone (20E) is a key regulator of monandry and oviposition in An. gambiae. When sexual transfer of 20E is impaired by partial inactivation of the hormone and inhibition of its biosynthesis in males, oviposition and refractoriness to further mating in the female are strongly reduced. Conversely, mimicking sexual delivery by injecting 20E into virgin females switches them to an artificial mated status, triggering egg-laying and reducing susceptibility to copulation. Sexual transfer of 20E appears to incapacitate females physically from receiving seminal fluids by a second male. Comparative analysis of microarray data from females after mating and after 20E treatment indicates that 20E-regulated molecular pathways likely are implicated in the postmating switch, including cytoskeleton and musculature-associated genes that may render the atrium impenetrable to additional mates. By revealing signals and pathways shaping key processes in the An. gambiae reproductive biology, our data offer new opportunities for the control of natural populations of malaria vectors. PMID:25368171

  15. The spatial distribution of Anopheles gambiae sensu stricto and An. arabiensis (Diptera: Culicidae in Mali

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    N. Sogoba

    2007-05-01

    Full Text Available Variations in the biology and ecology and the high level of genetic polymorphism of malaria vectors in Africa highlight the value of mapping their spatial distribution to enhance successful implementation of integrated vector management. The objective of this study was to collate data on the relative frequencies of Anopheles gambiae s.s. and An. arabiensis mosquitoes in Mali, to assess their association with climate and environmental covariates, and to produce maps of their spatial distribution. Bayesian geostatistical logistic regression models were fitted to identify environmental determinants of the relative frequencies of An. gambiae s.s. and An. arabiensis species and to produce smooth maps of their geographical distribution. The frequency of An. arabiensis was positively associated with the normalized difference vegetation index, the soil water storage index, the maximum temperature and the distance to water bodies. It was negatively associated with the minimum temperature and rainfall. The predicted map suggests that, in West Africa, An. arabiensis is concentrated in the drier savannah areas, while An. gambiae s.s. prefers the southern savannah and land along the rivers, particularly the inner delta of Niger. Because the insecticide knockdown resistance (kdr gene is reported only in An. gambiae s.s. in Mali, the maps provide valuable information for vector control. They may also be useful for planning future implementation of malaria control by genetically manipulated mosquitoes.

  16. Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis

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    Maharaj Rajendra

    2012-09-01

    Full Text Available Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic, that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Methods Extracts of a selection of plant taxa sourced in South Africa were tested for larvicidal properties in an applicable assay. Thirty 3rd instar Anopheles arabiensis larvae were exposed to various extract types (dichloromethane, dichloromethane/methanol (1:1, methanol and purified water of each species investigated. Mortality was evaluated relative to the positive control Temephos (Mostop; Agrivo, an effective emulsifiable concentrate larvicide. Results Preliminary screening of crude extracts revealed substantial variation in toxicity with 24 of the 381 samples displaying 100% larval mortality within the seven day exposure period. Four of the high activity plants were selected and subjected to bioassay guided fractionation. The results of the testing of the fractions generated identified one fraction of the plant, Toddalia asiatica as being very potent against the An. arabiensis larvae. Conclusion The present study has successfully identified a plant with superior larvicidal activity at both the crude and semi pure fractions generated through bio-assay guided fractionation. These results have initiated further research into isolating the active compound and developing a malaria vector control tool.

  17. GNBP domain of Anopheles darlingi: are polymorphic inversions and gene variation related to adaptive evolution?

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    Bridi, L C; Rafael, M S

    2016-02-01

    Anopheles darlingi is the main malaria vector in humans in South America. In the Amazon basin, it lives along the banks of rivers and lakes, which responds to the annual hydrological cycle (dry season and rainy season). In these breeding sites, the larvae of this mosquito feed on decomposing organic and microorganisms, which can be pathogenic and trigger the activation of innate immune system pathways, such as proteins Gram-negative binding protein (GNBP). Such environmental changes affect the occurrence of polymorphic inversions especially at the heterozygote frequency, which confer adaptative advantage compared to homozygous inversions. We mapped the GNBP probe to the An. darlingi 2Rd inversion by fluorescent in situ hybridization (FISH), which was a good indicator of the GNBP immune response related to the chromosomal polymorphic inversions and adaptative evolution. To better understand the evolutionary relations and time of divergence of the GNBP of An. darlingi, we compared it with nine other mosquito GNBPs. The results of the phylogenetic analysis of the GNBP sequence between the species of mosquitoes demonstrated three clades. Clade I and II included the GNBPB5 sequence, and clade III the sequence of GNBPB1. Most of these sequences of GNBP analyzed were homologous with that of subfamily B, including that of An. gambiae (87 %), therefore suggesting that GNBP of An. darling belongs to subfamily B. This work helps us understand the role of inversion polymorphism in evolution of An. darlingi.

  18. Molecular characterization, biological forms and sporozoite rate of Anopheles stephensi in southern Iran

    Institute of Scientific and Technical Information of China (English)

    Ali Reza Chavshin; Mohammad Ali Oshaghi; Hasan Vatandoost; Ahmad Ali Hanafi-Bojd; Ahmad Raeisi; Fatemeh Nikpoor

    2014-01-01

    Objective: To identify the biological forms, sporozoite rate and molecular characterization of the Anopheles stephensi (An. stephensi) in Hormozgan and Sistan-Baluchistan provinces, the most important malarious areas in Iran. Methods: Wild live An. stephensi samples were collected from different malarious areas in southern Iran. The biological forms were identified based on number of egg-ridges. Molecular characterization of biological forms was verified by analysis of the mitochondrial cytochrome oxidase subunit I and II (mtDNA-COI/COII). The Plasmodium infection was examined in the wild female specimens by species-specific nested–PCR method. Results: Results showed that all three biological forms including mysorensis, intermediate and type are present in the study areas. Molecular investigations revealed no genetic variation between mtDNA COI/COII sequences of the biological forms and no Plasmodium parasites was detected in the collected mosquito samples. Conclusions:Presence of three biological forms with identical sequences showed that the known biological forms belong to a single taxon and the various vectorial capacities reported for these forms are more likely corresponded to other epidemiological factors than to the morphotype of the populations. Lack of malaria parasite infection in An. stephensi, the most important vector of malaria, may be partly due to the success and achievement of ongoing active malaria control program in the region.

  19. Indication of pyrethroid resistance in the main malaria vectorAnopheles stephensi from Iran

    Institute of Scientific and Technical Information of China (English)

    Hassan Vatandoost; Ahmad Ali Hanafi-Bojd

    2012-01-01

    Objective:To investiagte insecticide resistance in target species for better insecticide resistance managemnet in malaria control programs.Methods:The status of insecticide resistance to different imagicides inAnopheles stephensi(An. stephensi) includingDDT4%, lambdacyhalothrin 0.50%, deltamethrin0.05%, permethrin0.75%, cyfluthrin0.15% and etofenprox0.50% was performed according toWHO standard method.Results:The mortality rate to lambdacyhalothrin, permethrin, cyfluthrin, deltamethrin, etofenprox andDDT was(88.0±3.2),(92.0±2.7),(52.0±5.0),(96.0±2.2),(90.0±3.0) and(41.0±5.7) percent, respectively at diagnostic dose for one hour exposure time followed by24 h recovery period.Conclusions:These results showed first indication of pyrethroid resistance inAn. stephensiin a malarious area, from southernIran.There is widespread, multiple resistances in the country inAn. stephensi to organochlorine and some report of tolerance to organophosphate insecticides and recently to pyrethroids.However, results of this paper will provide a clue for monitoring and mapping of insecticide resistance in the main malaria vector for implementation of any vector control.

  20. Development of the bi-partite Gal4-UAS system in the African malaria mosquito, Anopheles gambiae.

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    Amy Lynd

    Full Text Available Functional genetic analysis in Anopheles gambiae would be greatly improved by the development of a binary expression system, which would allow the more rapid and flexible characterisation of genes influencing disease transmission, including those involved in insecticide resistance, parasite interaction, host and mate seeking behaviour. The Gal4-UAS system, widely used in Drosophila melanogaster functional genetics, has been significantly modified to achieve robust application in several different species. Towards this end, previous work generated a series of modified Gal4 constructs that were up to 20 fold more active than the native gene in An. gambiae cells. To examine the Gal4-UAS system in vivo, transgenic An. gambiae driver lines carrying a modified Gal4 gene under the control of the carboxypeptidase promoter, and responder lines carrying UAS regulated luciferase and eYFP reporter genes have been created. Crossing of the Gal4 and UAS lines resulted in progeny that expressed both reporters in the expected midgut specific pattern. Although there was minor variation in reporter gene activity between the different crosses examined, the tissue specific expression pattern was consistent regardless of the genomic location of the transgene cassettes. The results show that the modified Gal4-UAS system can be used to successfully activate expression of transgenes in a robust and tissue specific manner in Anopheles gambiae. The midgut driver and dual reporter responder constructs are the first to be developed and tested successfully in transgenic An. gambiae and provide the basis for further advancement of the system in this and other insect species.

  1. Organization of olfactory centres in the malaria mosquito Anopheles gambiae

    Science.gov (United States)

    Riabinina, Olena; Task, Darya; Marr, Elizabeth; Lin, Chun-Chieh; Alford, Robert; O'Brochta, David A.; Potter, Christopher J.

    2016-01-01

    Mosquitoes are vectors for multiple infectious human diseases and use a variety of sensory cues (olfactory, temperature, humidity and visual) to locate a human host. A comprehensive understanding of the circuitry underlying sensory signalling in the mosquito brain is lacking. Here we used the Q-system of binary gene expression to develop transgenic lines of Anopheles gambiae in which olfactory receptor neurons expressing the odorant receptor co-receptor (Orco) gene are labelled with GFP. These neurons project from the antennae and maxillary palps to the antennal lobe (AL) and from the labella on the proboscis to the suboesophageal zone (SEZ), suggesting integration of olfactory and gustatory signals occurs in this brain region. We present detailed anatomical maps of olfactory innervations in the AL and the SEZ, identifying glomeruli that may respond to human body odours or carbon dioxide. Our results pave the way for anatomical and functional neurogenetic studies of sensory processing in mosquitoes. PMID:27694947

  2. Predation efficiency of Anopheles gambiae larvae by aquatic predators in western Kenya highlands

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    Nyindo Mramba

    2011-07-01

    Full Text Available Abstract Background The current status of insecticide resistance in mosquitoes and the effects of insecticides on non-target insect species have raised the need for alternative control methods for malaria vectors. Predation has been suggested as one of the important regulation mechanisms for malaria vectors in long-lasting aquatic habitats, but the predation efficiency of the potential predators is largely unknown in the highlands of western Kenya. In the current study, we examined the predation efficiency of five predators on Anopheles gambiae s.s larvae in 24 hour and semi- field evaluations. Methods Predators were collected from natural habitats and starved for 12 hours prior to starting experiments. Preliminary experiments were conducted to ascertain the larval stage most predated by each predator species. When each larval instar was subjected to predation, third instar larvae were predated at the highest rate. Third instar larvae of An. gambiae were introduced into artificial habitats with and without refugia at various larval densities. The numbers of surviving larvae were counted after 24 hours in 24. In semi-field experiments, the larvae were counted daily until they were all either consumed or had developed to the pupal stage. Polymerase chain reaction was used to confirm the presence of An. gambiae DNA in predator guts. Results Experiments found that habitat type (P P P P An. gambiae DNA was found in at least three out of ten midguts for all predator species. Gambusia affins was the most efficient, being three times more efficient than tadpoles. Conclusion These experiments provide insight into the efficiency of specific natural predators against mosquito larvae. These naturally occurring predators may be useful in biocontrol strategies for aquatic stage An. gambiae mosquitoes. Further investigations should be done in complex natural habitats for these predators.

  3. Molecular evolution of immune genes in the malaria mosquito Anopheles gambiae.

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    Tovi Lehmann

    Full Text Available BACKGROUND: As pathogens that circumvent the host immune response are favoured by selection, so are host alleles that reduce parasite load. Such evolutionary processes leave their signature on the genes involved. Deciphering modes of selection operating on immune genes might reveal the nature of host-pathogen interactions and factors that govern susceptibility in host populations. Such understanding would have important public health implications. METHODOLOGY/FINDINGS: We analyzed polymorphisms in four mosquito immune genes (SP14D1, GNBP, defensin, and gambicin to decipher selection effects, presumably mediated by pathogens. Using samples of Anopheles arabiensis, An. quadriannulatus and four An. gambiae populations, as well as published sequences from other Culicidae, we contrasted patterns of polymorphisms between different functional units of the same gene within and between populations. Our results revealed selection signatures operating on different time scales. At the most recent time scale, within-population diversity revealed purifying selection. Between populations and between species variation revealed reduced differentiation (GNBP and gambicin at coding vs. noncoding- regions, consistent with balancing selection. McDonald-Kreitman tests between An. quadriannulatus and both sibling species revealed higher fixation rate of synonymous than nonsynonymous substitutions (GNBP in accordance with frequency dependent balancing selection. At the longest time scale (>100 my, PAML analysis using distant Culicid taxa revealed positive selection at one codon in gambicin. Patterns of genetic variation were independent of exposure to human pathogens. SIGNIFICANCE AND CONCLUSIONS: Purifying selection is the most common form of selection operating on immune genes as it was detected on a contemporary time scale on all genes. Selection for "hypervariability" was not detected, but negative balancing selection, detected at a recent evolutionary time scale

  4. Molecular Evolution of Immune Genes in the Malaria Mosquito Anopheles gambiae

    Science.gov (United States)

    Lehmann, Tovi; Hume, Jen C. C.; Licht, Monica; Burns, Christopher S.; Wollenberg, Kurt; Simard, Fred; Ribeiro, Jose' M. C.

    2009-01-01

    Background As pathogens that circumvent the host immune response are favoured by selection, so are host alleles that reduce parasite load. Such evolutionary processes leave their signature on the genes involved. Deciphering modes of selection operating on immune genes might reveal the nature of host-pathogen interactions and factors that govern susceptibility in host populations. Such understanding would have important public health implications. Methodology/Findings We analyzed polymorphisms in four mosquito immune genes (SP14D1, GNBP, defensin, and gambicin) to decipher selection effects, presumably mediated by pathogens. Using samples of Anopheles arabiensis, An. quadriannulatus and four An. gambiae populations, as well as published sequences from other Culicidae, we contrasted patterns of polymorphisms between different functional units of the same gene within and between populations. Our results revealed selection signatures operating on different time scales. At the most recent time scale, within-population diversity revealed purifying selection. Between populations and between species variation revealed reduced differentiation (GNBP and gambicin) at coding vs. noncoding- regions, consistent with balancing selection. McDonald-Kreitman tests between An. quadriannulatus and both sibling species revealed higher fixation rate of synonymous than nonsynonymous substitutions (GNBP) in accordance with frequency dependent balancing selection. At the longest time scale (>100 my), PAML analysis using distant Culicid taxa revealed positive selection at one codon in gambicin. Patterns of genetic variation were independent of exposure to human pathogens. Significance and Conclusions Purifying selection is the most common form of selection operating on immune genes as it was detected on a contemporary time scale on all genes. Selection for “hypervariability” was not detected, but negative balancing selection, detected at a recent evolutionary time scale between sibling

  5. Unbiased Characterization of Anopheles Mosquito Blood Meals by Targeted High-Throughput Sequencing.

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    Logue, Kyle; Keven, John Bosco; Cannon, Matthew V; Reimer, Lisa; Siba, Peter; Walker, Edward D; Zimmerman, Peter A; Serre, David

    2016-03-01

    Understanding mosquito host choice is important for assessing vector competence or identifying disease reservoirs. Unfortunately, the availability of an unbiased method for comprehensively evaluating the composition of insect blood meals is very limited, as most current molecular assays only test for the presence of a few pre-selected species. These approaches also have limited ability to identify the presence of multiple mammalian hosts in a single blood meal. Here, we describe a novel high-throughput sequencing method that enables analysis of 96 mosquitoes simultaneously and provides a comprehensive and quantitative perspective on the composition of each blood meal. We validated in silico that universal primers targeting the mammalian mitochondrial 16S ribosomal RNA genes (16S rRNA) should amplify more than 95% of the mammalian 16S rRNA sequences present in the NCBI nucleotide database. We applied this method to 442 female Anopheles punctulatus s. l. mosquitoes collected in Papua New Guinea (PNG). While human (52.9%), dog (15.8%) and pig (29.2%) were the most common hosts identified in our study, we also detected DNA from mice, one marsupial species and two bat species. Our analyses also revealed that 16.3% of the mosquitoes fed on more than one host. Analysis of the human mitochondrial hypervariable region I in 102 human blood meals showed that 5 (4.9%) of the mosquitoes unambiguously fed on more than one person. Overall, analysis of PNG mosquitoes illustrates the potential of this approach to identify unsuspected hosts and characterize mixed blood meals, and shows how this approach can be adapted to evaluate inter-individual variations among human blood meals. Furthermore, this approach can be applied to any disease-transmitting arthropod and can be easily customized to investigate non-mammalian host sources.

  6. Unbiased Characterization of Anopheles Mosquito Blood Meals by Targeted High-Throughput Sequencing.

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    Kyle Logue

    2016-03-01

    Full Text Available Understanding mosquito host choice is important for assessing vector competence or identifying disease reservoirs. Unfortunately, the availability of an unbiased method for comprehensively evaluating the composition of insect blood meals is very limited, as most current molecular assays only test for the presence of a few pre-selected species. These approaches also have limited ability to identify the presence of multiple mammalian hosts in a single blood meal. Here, we describe a novel high-throughput sequencing method that enables analysis of 96 mosquitoes simultaneously and provides a comprehensive and quantitative perspective on the composition of each blood meal. We validated in silico that universal primers targeting the mammalian mitochondrial 16S ribosomal RNA genes (16S rRNA should amplify more than 95% of the mammalian 16S rRNA sequences present in the NCBI nucleotide database. We applied this method to 442 female Anopheles punctulatus s. l. mosquitoes collected in Papua New Guinea (PNG. While human (52.9%, dog (15.8% and pig (29.2% were the most common hosts identified in our study, we also detected DNA from mice, one marsupial species and two bat species. Our analyses also revealed that 16.3% of the mosquitoes fed on more than one host. Analysis of the human mitochondrial hypervariable region I in 102 human blood meals showed that 5 (4.9% of the mosquitoes unambiguously fed on more than one person. Overall, analysis of PNG mosquitoes illustrates the potential of this approach to identify unsuspected hosts and characterize mixed blood meals, and shows how this approach can be adapted to evaluate inter-individual variations among human blood meals. Furthermore, this approach can be applied to any disease-transmitting arthropod and can be easily customized to investigate non-mammalian host sources.

  7. Larvicidal efficacy of monoterpenes against the larvae of Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Eliningaya J.Kweka; Tamires Cardoso Lima; Chrian M.Marciale; Dami?o Pergentino de Sousa

    2016-01-01

    Objective:To evaluate the larvicidal efficacy of eight volatile components of essential oils against 3rd instar larvae of Anopheles gambiae s.s.Methods:Larvicidal effects of each compound were evaluated in both laboratory and semi-field trials.Stock solution was prepared and serial dilutions were made in six concentrations for each compound.A total of 20 larvae were exposed to larvicides for each replicate and monitored at intervals of 12,24,48 and 72 h.Larvae monitoring was done on basis of dead and live larvae in all intervals.Results:All assayed compounds were larvicides and presented varying degrees of larval toxicity,with LC50 values ranging from 1.28 to 1 938.92 mg/L depending on the treatment time(12,24,48 or 72 h).(-)-Perillyl alcohol presented the strongest larvicidal activity towards Anopheles gambiae larvae,with LC50 values of 73.60,18.36,1.72 and1.28 mg/L after 12,24,48 and 72 h of exposure,respectively.The next strongest were(-)-isopulegol(LC50= 135.10,49.39,34.39 and 20.22 mg/L) and(-)-carvone epoxide(LC50= 168.86,124.74,80.84 and 23.46 mg/L).After 12,24 and 48 h of treatment,hydroxydihydrocarvone was the least toxic compound,with LC50 values of 1 938.92,1 172.18 and 401.03 mg/L,respectively.Conclusions:The data obtained in this study suggest that all evaluated monoterpenes,especially(-)-perillyl alcohol,have remarkable larvicidal effects and may be considered as potential sources for the development of suitable natural larvicides for mosquito management programs.Further small-scale field trials should be conducted.

  8. Detoxification enzymes associated with insecticide resistance in laboratory strains of Anopheles arabiensis of different geographic origin

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    Nardini Luisa

    2012-06-01

    Full Text Available Abstract Background The use of insecticides to control malaria vectors is essential to reduce the prevalence of malaria and as a result, the development of insecticide resistance in vector populations is of major concern. Anopheles arabiensis is one of the main African malaria vectors and insecticide resistance in this species has been reported in a number of countries. The aim of this study was to investigate the detoxification enzymes that are involved in An. arabiensis resistance to DDT and pyrethroids. Methods The detoxification enzyme profiles were compared between two DDT selected, insecticide resistant strains of An. arabiensis, one from South Africa and one from Sudan, using the An. gambiae detoxification chip, a boutique microarray based on the major classes of enzymes associated with metabolism and detoxification of insecticides. Synergist assays were performed in order to clarify the roles of over-transcribed detoxification genes in the observed resistance phenotypes. In addition, the presence of kdr mutations in the colonies under investigation was determined. Results The microarray data identifies several genes over-transcribed in the insecticide selected South African strain, while in the Sudanese population, only one gene, CYP9L1, was found to be over-transcribed. The outcome of the synergist experiments indicate that the over-transcription of detoxification enzymes is linked to deltamethrin resistance, while DDT and permethrin resistance are mainly associated with the presence of the L1014F kdr mutation. Conclusions These data emphasise the complexity associated with resistance phenotypes and suggest that specific insecticide resistance mechanisms cannot be extrapolated to different vector populations of the same species.

  9. Molecular population genetics of the NADPH cytochrome P450 reductase (CPR) gene in Anopheles minimus.

    Science.gov (United States)

    Srivastava, Hemlata; Huong, Ngo Thi; Arunyawat, Uraiwan; Das, Aparup

    2014-08-01

    Development of insecticide resistance (IR) in mosquito vectors is a primary huddle to malaria control program. Since IR has genetic basis, and genes constantly evolve with response to environment for adaptation to organisms, it is important to know evolutionary pattern of genes conferring IR in malaria vectors. The mosquito Anopheles minimus is a major malaria vector of the Southeast (SE) Asia and India and is susceptible to all insecticides, and thus of interest to know if natural selection has shaped variations in the gene conferring IR. If not, the DNA fragment of such a gene could be used to infer population structure and demography of this species of malaria vector. We have therefore sequenced a ~569 bp DNA segment of the NADPH cytochrome P450 reductase (CPR) gene (widely known to confer IR) in 123 individuals of An. minimus collected in 10 different locations (eight Indian, one Thai and one Vietnamese). Two Indian population samples were completely mono-morphic in the CPR gene. In general, low genetic diversity was found with no evidence of natural selection in this gene. The data were therefore analyzed to infer population structure and demography of this species. The 10 populations could be genetically differentiated into four different groups; the samples from Thailand and Vietnam contained high nucleotide diversity. All the 10 populations conform to demographic equilibrium model with signature of past population expansion in four populations. The results in general indicate that the An. minimus mosquitoes sampled in the two SE Asian localities contain several genetic characteristics of being parts of the ancestral population.

  10. Intensive trapping of blood-fed Anopheles darlingi in Amazonian Peru reveals unexpectedly high proportions of avian blood-meals

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    Saavedra, Marlon P.; Bickersmith, Sara A.; Prussing, Catharine; Michalski, Adrian; Tong Rios, Carlos; Vinetz, Joseph M.; Conn, Jan E.

    2017-01-01

    Anopheles darlingi, the main malaria vector in the Neotropics, has been considered to be highly anthropophilic. However, many behavioral aspects of this species remain unknown, such as the range of blood-meal sources. Barrier screens were used to collect resting Anopheles darlingi mosquitoes from 2013 to 2015 in three riverine localities (Lupuna, Cahuide and Santa Emilia) in Amazonian Peru. Overall, the Human Blood Index (HBI) ranged from 0.58–0.87, with no significant variation among years or sites. Blood-meal analysis revealed that humans are the most common blood source, followed by avian hosts (Galliformes-chickens and turkeys), and human/Galliforme mixed-meals. The Forage Ratio and Selection Index both show a strong preference for Galliformes over humans in blood-fed mosquitoes. Our data show that 30% of An. darlingi fed on more than one host, including combinations of dogs, pigs, goats and rats. There appears to be a pattern of host choice in An. darlingi, with varying proportions of mosquitoes feeding only on humans, only on Galliformes and some taking mixed-meals of blood (human plus Galliforme), which was detected in the three sites in different years, indicating that there could be a structure to these populations based on blood-feeding preferences. Mosquito age, estimated in two localities, Lupuna and Cahuide, ranged widely between sites and years. This variation may reflect the range of local environmental factors that influence longevity or possibly potential changes in the ability of the mosquito to transmit the parasite. Of 6,204 resting An. darlingi tested for Plasmodium infection, 0.42% were infected with P. vivax. This study provides evidence for the first time of the usefulness of barrier screens for the collection of blood-fed resting mosquitoes to calculate the Human Blood Index (HBI) and other blood-meal sources in a neotropical malaria endemic setting. PMID:28231248

  11. Biologia de Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae en la Costa Pacífica de Colombia: III. Medidas de luminosidad y el comportamiento de picadura Biologia do Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae na costa do Pacífico Colombiano: III - Medições da luminosidade e estudo do comportamento durante o repasto Biology of Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae on the Pacific Coast of Colombia: III. Light intensity measurements and biting behavior

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    César Murillo B.

    1988-04-01

    Full Text Available El estudio del comportamiento de picadura de mosquitos capturados picando humanos en un área despejada del poblado de Charambirá, Chocó, en la costa Pacífica de Colombia, indico que cambios en la intensidad de la luz, influenciaban el início y el fin de la actividad de vuelo de Anopheles (Kerteszia neivai, especie con marcados hábitos crepusculares. Esta especie está considerada como vectora de esa enfermedad, malaria, en la costa pacífica colombiana.O estudo do comportamento de mosquitos capturados picando humanos numa zona desmatada do povoado de Charambirá, Chocó, na costa do Pacífico Colombiano, indicaram que mudanças na intensidade da luz influenciam o início e o fim da atividade de vôo do Anopheles (Kerteszia neivai, verificando-se que o repasto ocorre durante as horas crepusculares. Esta espécie é considerada como vetora da malária na costa do país.The study of mosquitoes captured while biting man in a forest cleared zone of Charambirá, Chocó, on the Pacific Coast of Colombia, indicated that changes in light intensity stimulated the beginning and end of the flight activity of Anopheles (Kerteszia neivai, a species with crepuscular biting behavior incriminated as malaria vector in this region of the county.

  12. The resting sites and blood-meal sources of Anopheles minimus in Taiwan

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    Chen Yung-Chen

    2008-06-01

    Full Text Available Abstract Background The WHO declared Taiwan free from malaria in 1965, but in 2003 the reporting of two introduced cases in a rural area suggested a possible local transmission of this disease. Therefore, understanding the resting sites and the blood sources of Anopheles minimus is crucial in order to provide information for implementing vector control strategies. Methods During a two-year survey, mosquitoes were collected in houses and their surrounding areas and at the bank of larval habitats by backpack aspirators in 17 villages in rural areas of southern and eastern Taiwan for 1 hr. On the same day, blacklight traps were hung downward overnight. Blood-fed mosquito samples were analysed by PCR. Results Of the 195 total households surveyed by backpack aspirators, no Anopheles adults were collected inside the houses, while a single Anopheles minimus and a single Anopheles maculatus were collected outside of the houses. On the same day, 23 An. minimus, two An. maculatus, two Anopheles ludlowae, two Anopheles sinensis, and one Anopheles tessellatus were collected along the bank of larval habitats. In blacklight traps hung outside of the houses in the villages, 69 An. minimus, 62 An. ludlowae, 31 An. sinensis, and 19 An. maculatus were collected. In larval habitats, 98 An. ludlowae, 64 An. minimus, 49 An. sinensis, and 14 An. maculatus were collected. Of a total of 10 blood-fed samples, An. minimus fed on four animals including bovine (60%, dogs (20%, pig (10%, and non-chicken avian (10%. Conclusion Anopheles minimus, an opportunist feeder in Taiwan, was not collected inside the houses, but was found outside of the houses in villages and surrounding larval habitats. Therefore, an outdoor transmission of malaria is likely to occur and, thus, the bed nets, which are favoured for controlling the late biting of An. minimus, should be a very efficient and effective method for those local residents who sleep outdoors. Additionally, space spray of

  13. Sperm quantity and size variation in un-irradiated and irradiated males of the malaria mosquito Anopheles arabiensis Patton

    NARCIS (Netherlands)

    Helinski, M.; Knols, B.G.J.

    2009-01-01

    Anopheles mosquitoes are important candidates for genetic control strategies. However, little is known about sperm quality and quantity as determinants of male reproductive success. In this study, sperm quantity and length variation were assessed in testes of un-irradiated and irradiated Anopheles a

  14. The nicotinic acetylcholine receptor gene family of the malaria mosquito, Anopheles gambiae.

    Science.gov (United States)

    Jones, Andrew K; Grauso, Marta; Sattelle, David B

    2005-02-01

    Nicotinic acetylcholine receptors (nAChRs) mediate fast cholinergic synaptic transmission in the insect nervous system and are targets of widely selling insecticides. We have identified the nAChR gene family from the genome of the malaria mosquito vector, Anopheles gambiae, to be the second complete insect nAChR gene family described following that of Drosophila melanogaster. Like Drosophila, Anopheles possesses 10 nAChR subunits with orthologous relationships evident between the two insects. Interestingly, the Anopheles orthologues of Dbeta2 and Dbeta3 possess the vicinal cysteines that define alpha subunits. As with Dalpha4 and Dalpha6, the Anopheles orthologues are alternatively spliced at equivalent exons. Reverse transcription-polymerase chain reaction analysis shows that RNA A-to-I editing sites conserved between Dalpha6 of Drosophila and alpha7-2 of the tobacco budworm, Heliothis virescens, are not shared with the equivalent nAChR subunit of Anopheles. Indeed, RNA-editing sites identified in functionally significant regions of Dbeta1, Dalpha5, and Dalpha6 are not conserved in the mosquito orthologues, indicating considerable divergence of RNA molecules targeted for editing within the insect order Diptera. These findings shed further light on the diversity of nAChR subunits and may present a useful basis for the development of improved malaria control agents by enhancing our understanding of a validated mosquito insecticide target.

  15. Role of the repartition of wetland breeding sites on the spatial distribution of Anopheles and Culex, human disease vectors in Southern France

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    Fontenille Didier

    2011-05-01

    Full Text Available Abstract Background In this study, carried out in the Camargue region (France, we combined entomological data with geomatic and modelling tools to assess whether the location of breeding sites may explain the spatial distribution of adult mosquitoes. The species studied are important and competent disease vectors in Europe: Culex modestus Ficalbi and Cx. pipiens Linnaeus (West Nile virus, Anopheles atroparvus Van Thiel, a former Plasmodium vector, and An. melanoon Hackett, competent to transmit Plasmodium. Using a logistic regression model, we first evaluated which land cover variables determined the presence of Culex and Anopheles larva. The resulting probability map of larval presence then was used to project the average probability of finding adults in a buffer area. This was compared to the actual number of adults collected, providing a quantitative assessment of adult dispersal ability for each species. Results The distribution of Cx. modestus and An. melanoon is mainly driven by the repartition of irrigated farm fields and reed beds, their specific breeding habitats. The presence of breeding sites explained the distribution of adults of both species. The buffer size, reflecting the adult dispersal ability, was 700 m for Cx. modestus and 1000 m for An. melanoon. The comparatively stronger correlation observed for Cx. modestus suggested that other factors may affect the distribution of adult An. melanoon. We did not find any association between Cx. pipiens larval presence and the biotope due to the species' ubiquist character. Conclusion By applying the same method to different species, we highlighted different strengths of association between land cover (irrigated farm fields and reed beds, larval presence and adult population distribution. This paper demonstrates the power of geomatic tools to quantify the spatial organization of mosquito populations, and allows a better understanding of links between landcover, breeding habitats, presence

  16. Anopheles gambiae Purine Nucleoside Phosphorylase: Catalysis, Structure, and Inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Taylor,E.; Rinaldo-Matthis, A.; Li, L.; Ghanem, M.; Hazleton, K.; Cassera, M.; Almo, S.; Schramm, V.

    2007-01-01

    The purine salvage pathway of Anopheles gambiae, a mosquito that transmits malaria, has been identified in genome searches on the basis of sequence homology with characterized enzymes. Purine nucleoside phosphorylase (PNP) is a target for the development of therapeutic agents in humans and purine auxotrophs, including malarial parasites. The PNP from Anopheles gambiae (AgPNP) was expressed in Escherichia coli and compared to the PNPs from Homo sapiens (HsPNP) and Plasmodium falciparum (PfPNP). AgPNP has kcat values of 54 and 41 s-1 for 2'-deoxyinosine and inosine, its preferred substrates, and 1.0 s-1 for guanosine. However, the chemical step is fast for AgPNP at 226 s-1 for guanosine in pre-steady-state studies. 5'-Deaza-1'-aza-2'-deoxy-1'-(9-methylene)-Immucillin-H (DADMe-ImmH) is a transition-state mimic for a 2'-deoxyinosine ribocation with a fully dissociated N-ribosidic bond and is a slow-onset, tight-binding inhibitor with a dissociation constant of 3.5 pM. This is the tightest-binding inhibitor known for any PNP, with a remarkable Km/Ki* of 5.4 x 107, and is consistent with enzymatic transition state predictions of enhanced transition-state analogue binding in enzymes with enhanced catalytic efficiency. Deoxyguanosine is a weaker substrate than deoxyinosine, and DADMe-Immucillin-G is less tightly bound than DADMe-ImmH, with a dissociation constant of 23 pM for AgPNP as compared to 7 pM for HsPNP. The crystal structure of AgPNP was determined in complex with DADMe-ImmH and phosphate to a resolution of 2.2 Angstroms to reveal the differences in substrate and inhibitor specificity. The distance from the N1' cation to the phosphate O4 anion is shorter in the AgPNP{center_dot}DADMe-ImmH{center_dot}PO4 complex than in HsPNP{center_dot}DADMe-ImmH{center_dot}SO4, offering one explanation for the stronger inhibitory effect of DADMe-ImmH for AgPNP.

  17. Distribuição vertical e sazonal de Anopheles (Kerteszia em Ilha Comprida, SP Vertical and seasonal distribution of Anopheles (Kerteszia in Ilha Comprida, Southeastern Brazil

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    Helene Mariko Ueno

    2007-04-01

    Full Text Available OBJETIVO: Anopheles bellator e An. cruzii são vetores da malária-bromélia, característicos de áreas preservadas. O objetivo do estudo foi analisar a distribuição sazonal e vertical desses anofelinos, visando contribuir para a avaliação do risco de transmissão desse agravo. MÉTODOS: No município de Ilha Comprida, SP, foram instaladas armadilhas luminosas tipo CDC iscadas com gelo seco, das 17 às 20h, a um, seis e 12m do solo, quinzenalmente, de setembro de 2001 a setembro de 2002. A relação da densidade desses anofelinos com o clima foi avaliada pelo coeficiente de Spearman e suas densidades entre os estratos foram comparadas pelo teste não paramétrico de Mann-Whitney. RESULTADOS: Do total de 55.226 mosquitos, 1.341 eram An. bellator (2,4% do total de Culicidae, sendo capturados 278 indivíduos próximo ao solo, 261 a seis metros e 802 na copa (12 m. Na mesma ordem, foram capturados 452, 1.032 e 4.420 adultos de An. cruzii, totalizando 5.904 mosquitos desta espécie (10,7%. Houve correlação positiva entre a densidade das duas espécies com a temperatura máxima, e entre An. bellator e amplitude térmica diária. As densidades das duas espécies foram maiores na copa. Nos três estratos, An. cruzii predominou sobre An. bellator. CONCLUSÕES: Confirmou-se o comportamento acrodendrófilo dessas espécies, principalmente An. cruzii. Após medidas drásticas de controle, esses anofelinos permaneceram na região mas, atualmente, não são alvo de vigilância entomológica. A persistência da transmissão de malária autóctone e o incremento de atividades de ecoturismo na região apontam a necessidade de monitoramento dessas espécies.OBJECTIVE: Anopheles bellator e An. cruzii are vectors of the so-called bromeliad-malaria, typical of conserved areas. The objective was to evaluate the seasonal and vertical distribution of these anophelines, aiming at assessing the risk of malaria transmission. METHODS: In the municipality of Ilha

  18. Impact of insecticide-treated bed nets on malaria transmission indices on the south coast of Kenya

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    Mutuku Francis M

    2011-12-01

    Full Text Available Abstract Background Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline of Anopheles gambiae s.s. relative to Anopheles arabiensis, changes in host feeding preference of malaria vectors, and behavioural shifts to exophagy (outdoor biting for the two important malaria vectors in Africa, An. gambiae s.l. and Anopheles funestus. In southern coastal Kenya, bed net use was negligible in 1997-1998 when Anopheles funestus and An. gambiae s.s. were the primary malaria vectors, with An. arabiensis and Anopheles merus playing a secondary role. Since 2001, bed net use has increased progressively and reached high levels by 2009-2010 with corresponding decline in malaria transmission. Methods To evaluate the impact of the substantial increase in household bed net use within this area on vector density, vector composition, and human-vector contact, indoor and outdoor resting mosquitoes were collected in the same region during 2009-2010 using pyrethrum spray catches and clay pots for indoor and outdoor collections respectively. Information on bed net use per sleeping spaces and factors influencing mosquito density were determined in the same houses using Poisson regression analysis. Species distribution was determined, and number of mosquitoes per house, human-biting rates (HBR, and entomological inoculation rate (EIR were compared to those reported for the same area during 1997-1998, when bed net coverage had been minimal. Results Compared to 1997-1998, a significant decline in the relative proportion of An. gambiae s.s. among collected mosquitoes was noted, coupled with a proportionate increase of An. arabiensis. Following > 5 years of 60-86% coverage with bed nets, the density, human biting rate and EIR of indoor resting mosquitoes were reduced by more than 92% for An. funestus and by 75% for An. gambiae s.l. In addition, the host feeding choice of both vectors shifted more toward non

  19. Determinants of Anopheles seasonal distribution patterns across a forest to periurban gradient near Iquitos, Peru.

    Science.gov (United States)

    Reinbold-Wasson, Drew D; Sardelis, Michael R; Jones, James W; Watts, Douglas M; Fernandez, Roberto; Carbajal, Faustino; Pecor, James E; Calampa, Carlos; Klein, Terry A; Turell, Michael J

    2012-03-01

    As part of a field ecology study of arbovirus and malaria activity in the Amazon Basin, Loreto Department, Peru, we collected mosquitoes landing on humans at a forest site and inside and outside of residences and military barracks at periurban, rural, and village sites. We collected 11 Anopheles spp. from these four sites. An. darlingi, the principal malaria vector in the region, accounted for 98.7% of all Anopheles spp. collected at Puerto Almendra. Peaks in landing activity occurred during the December and April collection periods. However, the percent of sporozoite-positive Anopheles spp. was highest 1-2 months later, when landing activity decreased to approximately 10% of the peak activity periods. At all sites, peak landing activity occurred about 2 hours after sunset. These data provide a better understanding of the taxonomy, population density, and seasonal and habitat distribution of potential malaria vectors within the Amazon Basin region.

  20. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV) in mosquitoes.

    Science.gov (United States)

    Barik, Tapan K; Suzuki, Yasutsugu; Rasgon, Jason L

    2016-01-01

    Anopheles gambiae densovirus (AgDNV) is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP) reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae.

  1. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV in mosquitoes

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    Tapan K. Barik

    2016-11-01

    Full Text Available Anopheles gambiae densovirus (AgDNV is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae.

  2. The effects of plant essential oils on escape response and mortality rate of Aedes aegypti and Anopheles minimus.

    Science.gov (United States)

    Sathantriphop, Sunaiyana; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2015-12-01

    The High Throughput Screening System (HITSS) has been applied in insecticide behavioral response studies with various mosquito species. In general, chemical or natural compounds can produce a range of insect responses: contact irritancy, spatial repellency, knock-down, and toxicity. This study characterized these actions in essential oils derived from citronella, hairy basil, catnip, and vetiver in comparison to DEET and picaridin against Aedes aegypti and Anopheles minimus mosquito populations. Results indicated the two mosquito species exhibited significantly different (P0.05) against Ae. aegypti. Spatial repellency responses were elicited in both mosquito species when exposed to all compounds, but the strength of the repellent response was dependent on compound and concentration. Data show that higher test concentrations had greatest toxic effects on both mosquito populations, but vetiver had no toxic effect on Ae. aegypti and picaridin did not elicit toxicity in either Ae. aegypti or An. minimus at any test concentration. Ultimately, this study demonstrates the ability of the HITSS assay to guide selection of effective plant essential oils for repelling, irritating, and killing mosquitoes.

  3. Observaciones sobre Phlebotomus y Anopheles en el Callejon de Huaylas

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    Arístides Herrer

    1943-03-01

    Full Text Available Se han llevado a cabo observaciones entomológicas en relación con la verruga y el paludismo en la zona del Callejón de Huaylas comprendida desde la ciudad de Yuramarca a la de Huarás, prestando especial atención a la región del Cañón del Pato. Se indica, como resultados de tales observaciones, la presencia de las titiras: Phlebotomus verrucarum, P. peruensis, P. noguchii y una especia nueva, señalando detenidamente las localidades donde se las han encontrado. El P. verrucarum, principal trasmisor de la verruga, se halla a lo largo de toda la zona estudiada, siendo su número bastante reducido en la ciudad de Huarás. Desde Yuramarca hasta cerca de la ciudad de Carás se ha encontrado únicamente el Anopheles pseudopunctipennis, tanto larvas como adultos. Sus criaderos se encuentran principalmente en las márgenes del río Santa, en las de algunos afluentes de éste y en numerosos, manantiales.

  4. Transcriptome analysis of Anopheles stephensi embryo using expressed sequence tags

    Indian Academy of Sciences (India)

    Kaustubh Gokhale; Deepak P Patil; Dhiraj P Dhotre; Rajnikant Dixit; Murlidhar J Mendki; Milind S Patole; Yogesh S Shouche

    2013-06-01

    Germ band retraction (GBR) stage is one of the important stages during insect development. It is associated with an extensive epithelial morphogenesis and may also be pivotal in generation of morphological diversity in insects. Despite its importance, only a handful of studies report the transcriptome repertoire of this stage in insects. Here, we report generation, annotation and analysis of ESTs from the embryonic stage (16–22 h post fertilization) of laboratory-reared Anopheles stephensi mosquitoes. A total of 1002 contigs were obtained upon clustering of 1140 high-quality ESTs, which demonstrates an astonishingly low transcript redundancy (12.1%). Putative functions were assigned only to 213 contigs (21%), comprising mainly of transcripts encoding protein synthesis machinery. Approximately 78% of the transcripts remain uncharacterized, illustrating a lack of sequence information about the genes expressed in the embryonic stages of mosquitoes. This study highlights several novel transcripts, which apart from insect development, may significantly contribute to the essential biological complexity underlying insect viability in adverse environments. Nonetheless, the generated sequence information from this work provides a comprehensive resource for genome annotation, microarray development, phylogenetic analysis and other molecular biology applications in entomology.

  5. Biolistic techniques for transfection of mosquito embryos (Anopheles gambiae).

    Science.gov (United States)

    Mialhe, E; Miller, L H

    1994-05-01

    To compensate for the extremely low rates of transformation by DNA microinjection into mosquito embryos of Anopheles gambiae, biolistic techniques were evaluated for introduction of DNA into large numbers of mosquito embryos. Biolistic experiments were first performed with a commercially available instrument intended for this purpose, according to the recommended procedure. The amount of DNA delivered was measured by the expression of luciferase under the control of the Drosophila heat shock protein (hsp) 70 promoter. Despite attempts to optimize biolistic parameters, the level of luciferase activity was low and highly variable. Two other methods of biolistic delivery of DNA-coated particles in aqueous suspension were then evaluated. One method used the gas explosion of the commercially available instrument (mentioned above) to drive an aqueous suspension of DNA-coated particles at high pressure. This method reproducibly increased the level of expression about 100-fold without greatly reducing embryo viability. Another method, which was recently described for plant transfection, uses lower pressure to deliver the aqueous suspension of DNA-coated particles. The level of expression of luciferase and the survival of embryos were equivalent to that obtained with the instrument modified for aqueous delivery of particles. Thus, both aqueous methods offer the advantages of reproducibly delivering more DNA to the embryos. Moreover, these methods could be suitable for delivering DNA mixed with proteins, such as restriction endonucleases and integrases, that may be destroyed by ethanol precipitation used in the standard PDS-1000/He method.

  6. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The induction is dependent upon the ingestion of infective, sexual-stage parasites, and is not due to opportunistic co-penetration of resident gut micro-organisms into the hemocoel. The response is activated following infection both locally (in the midgut) and systemically (in remaining tissues, presumably fat body and/or hemocytes). The observation that Plasmodium can trigger a molecularly defined immune response in the vector constitutes an important advance in our understanding of parasite-vector interactions that are potentially involved in malaria transmission, and extends knowledge of the innate immune system of insects to encompass responses to protozoan parasites. PMID:9321391

  7. Inactivation of Anopheles gambiae Glutathione Transferase ε2 by Epiphyllocoumarin

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    Patience Marimo

    2016-01-01

    Full Text Available Glutathione transferases (GSTs are part of a major family of detoxifying enzymes that can catalyze the reductive dehydrochlorination of dichlorodiphenyltrichloroethane (DDT. The delta and epsilon classes of insect GSTs have been implicated in conferring resistance to this insecticide. In this study, the inactivation of Anopheles gambiae GSTε2 by epiphyllocoumarin (Tral 1 was investigated. Recombinant AgGSTε2 was expressed in Escherichia coli cells containing a pET3a-AGSTε2 plasmid and purified by affinity chromatography. Tral 1 was shown to inactivate GSTε2 both in a time-dependent manner and in a concentration-dependent manner. The half-life of GSTε2 in the presence of 25 μM ethacrynic acid (ETA was 22 minutes and with Tral 1 was 30 minutes, indicating that Tral 1 was not as efficient as ETA as an inactivator. The inactivation parameters kinact and KI were found to be 0.020 ± 0.001 min−1 and 7.5 ± 2.1 μM, respectively, after 90 minutes of incubation. Inactivation of GSTε2 by Tral 1 implies that Tral 1 covalently binds to this enzyme in vitro and would be expected to exhibit time-dependent effects on the enzyme in vivo. Tral 1, therefore, would produce irreversible effects when used together with dichlorodiphenyltrichloroethane (DDT in malaria control programmes where resistance is mediated by GSTs.

  8. FAUNA DAN TEMPAT PERKEMBANGBIAKAN POTENSIAL NYAMUK Anopheles spp DI KECAMATAN MAYONG, KABUPATEN JEPARA, JAWA TENGAH

    Directory of Open Access Journals (Sweden)

    Mardiana Mardiana

    2012-10-01

    Full Text Available Malaria masih merupakan masalah kesehatan masyarakat di beberapa daerah pedesaan di Jawa Tengah. Usaha pemberantasan malaria telah dilakukan oleh program baik secara kimiawi maupun hayati, guna memutuskan rantai penularan. Penelitian fauna dan tempat perindukan potensial nyamuk Anopheles telah dilakukan di Desa Buaran, Kecamatan Mayong I, Kabupaten Jepara, Jawa Tengah. Penangkapan nyamuk dengan umpan orang dilakukan di dalam dan di luar rumah pada malam hari dari pukul 18.00-24.00 yang masing-masing dilakukan oleh dua orang kolektor. Penangkapan nyamuk yang istirahat di dalam dan luar rumah (vegetasi pada pagi hari dilakukan pukul 06.00-08.00, yang dilakukan satu bulan 4 kali penangkapan selama 6 bulan. Pengambilan larva dan pupa dilakukan dari pukul 06.00-08.00 pagi di tempat genangan air dan sawah serta tempat yang potensial diduga sebagai perindukan Anopheles. Hasil penangkapan selama 6 bulan, diperoleh 1248 ekor nyamuk Anopheles yang terdiri dari 6 spesies yaitu: An. aconitus 442 ekor (35,42%, An. annularis 69 ekor (5,53% , An. barbirostris 30 ekor (2,4%, An. maculatus 2 ekor (0,16%, An. tesselatus 5 ekor (0,40% dan An. vagus 700 ekor (56,09%. Populasi aconitus ditemukan dari penangkapan di luar rumah, pada bulan Juli (56,40%, Agustus (42,80% dan Oktober (39,50% sedangkan pada bulan Mei (52,9%, Juni (44% dan September (50,40% dari penangkapan di kandang sapi. Pengambilan larva dan pupa Anopheles dilakukan di tempat habitat seperti sawah yang pada bulan Aguslus terbanyak ditemukan sebesar 85 (1.70, di sungai ditemukan hanya 4 (0.08 serta di genangan air bekas telapak kaki/kobokan ditemukan sebesar 6 (0.12. Ternyata tempat perindukan yang potensial larva Anopheles pada musim kemarau, ditemukan pada sungai yang ditanami kangkung oleh masyarakat selempat. Kata kunci: Fauna, tempat perindukan, Anopheles, vector

  9. The Maternally Inheritable Wolbachia wAlbB Induces Refractoriness to Plasmodium berghei in Anopheles stephensi

    Science.gov (United States)

    Joshi, Deepak; Pan, Xiaoling; McFadden, Michael J.; Bevins, David; Liang, Xiao; Lu, Peng; Thiem, Suzanne; Xi, Zhiyong

    2017-01-01

    The endosymbiont Wolbachia wAlbB induces refractoriness to Plasmodium falciparum in Anopheles stephensi, the primary mosquito vector of human malaria in the Middle East and South Asia. However, it remains unknown whether such refractoriness can be extended to other malaria species. In particular, it was reported that under very specific conditions, wAlbB can enhance Plasmodium infection in some hosts. Here, we measured the impact of wAlbB on the rodent malaria parasite Plasmodium berghei in A. stephensi by comparing the load of oocysts and sporozoites in midguts and salivary glands, respectively, between wAlbB-infected and -uninfected mosquitoes. To investigate whether wAlbB modulated mosquito immune defense against parasites, we compared the expression of the immune genes, which were previously reported to involve in antimalarial response, in both midguts and the remaining carcass tissues of mosquitoes. The stable association of wAlbB with A. stephensi resulted in reduction of parasites by more than half at the oocyst stage, and up to 91.8% at the sporzoite stage. The anti-plasmodium immune genes, including TEP1, LRIM1, Toll pathway gene Rel1 and the effector Defensin 1, were induced by wAlbB in different mosquito body tissues. These findings suggest that immune priming is a potential cause of wAlbB-mediated antimalarial response in A. stephensi. More importantly, no evidence was found for any enhancement of Plasmodium infection in A. stephensi stably infected with wAlbB. We discuss these findings with possible implementations of Wolbachia for malaria control in disease endemic areas. PMID:28337184

  10. Evidence for X-linked introgression between molecular forms of Anopheles gambiae from Angola.

    Science.gov (United States)

    Choi, K S; Townson, H

    2012-06-01

    The M and S molecular forms of the African malaria vector Anopheles gambiae (Diptera: Culicidae) are morphologically identical incipient species in which reproductive isolation is incomplete, enabling low-level gene flow between forms. In an attempt to find differences between the M and S forms, sequence variation was studied at loci along the X chromosome in adult female An. gambiae from Angola. A high proportion of M form specimens from Angola (79% of the 456 X chromosomes sampled) were found to contain a 16-bp insertion in intron 4 of the X-linked GPRCCK1 locus, relative to the AgamP3 release of the An. gambiae PEST genome sequence. The insertion was in Hardy-Weinberg equilibrium in Angolan M form populations. The same insertion was found in all S form specimens examined, regardless of where in Africa they were sampled, but was absent from a sample of M form specimens collected in Ghana, Bioko and Mali. In M form specimens from Angola, there was an association between alleles at the GPRCCK1 locus and those at a microsatellite locus, AGXH678, close to the centromere of the X chromosome, with significant linkage disequilibrium between loci separated by 0.472 Mbp (P < 0.033). We show that the insertion results from introgression from the S form into the M form, rather than from the retention of an ancestral character. Gene flow from the S to M form could allow genes of adaptive value to be transferred, including those conferring insecticide resistance and others influencing ecology and behaviour, and thus malaria transmission and control. We discuss factors that may have led to this introgression event.

  11. Evaluation of herbal essential oil as repellents against Aedes aegypti (L.) and Anopheles dirus Peyton & Harrion

    Institute of Scientific and Technical Information of China (English)

    Duangkamon Sritabutra; Mayura Soonwera; Sirirat Waltanachanobon; Supaporn Poungjai

    2011-01-01

    Objective: To investigate the repellent activity of herbal essential oils from garlic (Allium sativum), clove (Syzygium aromaticum), lemon grass (Cybopogon citratus), citronella grass (Cymbopogon nardus), peppermint (Mentha piperita), eucalyptus (Eucalyptus globulus), orange (Citrus sinensis) and sweet basil (Ocimum basilicum) and their combinations against Aedes aegypti (Ae. aegypti) (L.) and Anopheles dirus (An. dirus) Peyton & Harrion under laboratory conditions.Methods:In laboratory condition, 0.1 mL of each essential oil was applied to 3-10 cm of exposed area on a volunteer’s forearm. The test was carried out every 30 min until fewer than two mosquitoes bit or land during the 3 min study period and then the repellency test was stopped.Results:Essential oil from lemon grass exhibited protection against biting from two mosquito species, for Ae. aegypti [(98.66±11.56) min protection time and 0.97% biting rate] and for An. dirus [(98.00±15.28) min protection time and 0.80% biting rate]. The combinations from eucalyptus oil and sweet basil oil were effective as repellents and feeding deterrents against Ae. aegypti [(98.87±10.28) min protection time and 0.90% biting rate] and An. dirus [(210±10.70) min protection time and 0.93% biting rate]. All herbal repellents exhibited the period of protection time against Ae. aegypti which was lower than 120 min. Conlussions: It can be concluded that oils of lemon grass and combination from eucalyptus-sweet basil are the most effective in repellent activity.

  12. Larvicidal activity of medicinal plant extracts against Anopheles subpictus & Culex tritaeniorhynchus

    Science.gov (United States)

    Kamaraj, C.; Bagavan, A.; Elango, G.; Zahir, A. Abduz; Rajakumar, G.; Marimuthu, S.; Santhoshkumar, T.; Rahuman, A. Abdul

    2011-01-01

    Background & objectives: Mosquitoes transmit serious human diseases, causing millions of deaths every year and the development of resistance to chemical insecticides resulting in rebounding vectorial capacity. Plants may be alternative sources of mosquito control agents. The present study assessed the role of larvicidal activities of hexane, chloroform, ethyl acetate, acetone, and methanol dried leaf and bark extracts of Annona squamosa L., Chrysanthemum indicum L., and Tridax procumbens L. against the fourth instar larvae of malaria vector, Anopheles subpictus Grassi and Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). Methods: Larvicidal activities of three medicinal plant extracts were studied in the range of 4.69 to 1000 mg/l in the laboratory bioassays against early 4th instar larvae of An. subpictus and Cx. tritaeniorhynchus. The mortality data were subjected to probit analysis to determine the lethal concentrations (LC50 and LC90) to kill 50 and 90 per cent of the treated larvae of the respective species. Results: All plant extracts showed moderate effects after 24 h of exposure; however, the highest toxic effect of bark methanol extract of A. squamosa, leaf ethyl acetate extract of C. indicum and leaf acetone extract of T. procumbens against the larvae of An. subpictus (LC50 = 93.80, 39.98 and 51.57 mg/l) and bark methanol extract of A. squamosa, leaf methanol extract of C. indicum and leaf ethyl acetate extract of T. procumbens against the larvae of Cx. tritaeniorhynchus (LC50 =104.94, 42.29 and 69.16 mg/l) respectively. Interpretation & Conclusions: Our data suggest that the bark ethyl acetate and methanol extract of A. squamosa, leaf ethyl acetate and methanol extract of C. indicum, acetone and ethyl acetate extract of T. procumbens have the potential to be used as an ecofriendly approach for the control of the An. subpictus, and Cx. tritaeniorhynchus. PMID:21808141

  13. Metabolic and target-site mechanisms combine to confer strong DDT resistance in Anopheles gambiae.

    Directory of Open Access Journals (Sweden)

    Sara N Mitchell

    Full Text Available The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible strains of An. gambiae, revealed a non-synonymous polymorphism (I114T, proximal to the DDT binding domain, which segregated with strain phenotype. Recombinant protein expression and DDT metabolism analysis revealed that the proteins from the susceptible strain lost activity at higher DDT concentrations, characteristic of substrate inhibition. The effect of I114T on GSTE2 protein structure was explored through X-ray crystallography. The amino acid exchange in the DDT-resistant strain introduced a hydroxyl group nearby the hydrophobic DDT-binding region. The exchange does not result in structural alterations but is predicted to facilitate local dynamics and enzyme activity. Expression of both wild-type and 114T alleles the allele in Drosophila conferred an increase in DDT tolerance. The 114T mutation was significantly associated with DDT resistance in wild caught M-form populations and acts in concert with target-site mutations in the voltage gated sodium channel (Vgsc-1575Y and Vgsc-1014F to confer extreme levels of DDT resistance in wild caught An. gambiae.

  14. The Anopheles gambiae glutathione transferase supergene family: annotation, phylogeny and expression profiles

    Directory of Open Access Journals (Sweden)

    Rossiter Louise C

    2003-08-01

    Full Text Available Abstract Background Twenty-eight genes putatively encoding cytosolic glutathione transferases have been identified in the Anopheles gambiae genome. We manually annotated these genes and then confirmed the annotation by sequencing of A. gambiae cDNAs. Phylogenetic analysis with the 37 putative GST genes from Drosophila and representative GSTs from other taxa was undertaken to develop a nomenclature for insect GSTs. The epsilon class of insect GSTs has previously been implicated in conferring insecticide resistance in several insect species. We compared the expression level of all members of this GST class in two strains of A. gambiae to determine whether epsilon GST expression is correlated with insecticide resistance status. Results Two A. gambiae GSTs are alternatively spliced resulting in a maximum number of 32 transcripts encoding cytosolic GSTs. We detected cDNAs for 31 of these in adult mosquitoes. There are at least six different classes of GSTs in insects but 20 of the A. gambiae GSTs belong to the two insect specific classes, delta and epsilon. Members of these two GST classes are clustered on chromosome arms 2L and 3R respectively. Two members of the GST supergene family are intronless. Amongst the remainder, there are 13 unique introns positions but within the epsilon and delta class, there is considerable conservation of intron positions. Five of the eight epsilon GSTs are overexpressed in a DDT resistant strain of A. gambiae. Conclusions The GST supergene family in A. gambiae is extensive and regulation of transcription of these genes is complex. Expression profiling of the epsilon class supports earlier predictions that this class is important in conferring insecticide resistance.

  15. Pyrethroid susceptibility and behavioral avoidance in Anopheles epiroticus, a malaria vector in Thailand.

    Science.gov (United States)

    Ritthison, Wanapa; Titgratog, Rungarun; Tainchum, Krajana; Bangs, Michael J; Manguin, Sylvie; Chareonviriyaphap, Theeraphap

    2014-06-01

    The physiological susceptibility to insecticides and the behavioral responses of four wild-caught populations of female Anopheles epiroticus to synthetic pyrethroids (deltamethrin, permethrin, and alpha-cypermethrin) were assessed. Test populations were collected from different localities along the eastern coast, Trat (TR), Songkhla (SK), and Surat Thani (ST) and one population from the western coast, Phang Nga (PN). Results showed that all four populations of An. epiroticus were susceptible to all three synthetic pyrethroids tested. Behavioral responses to test compounds were characterized for all four populations using an excito-repellency test system. TR displayed the strongest contact excitation ('irritancy') escape response (76.8% exposed to deltamethrin, 74.1% permethrin, and 78.4% alpha-cypermethrin), followed by the PN population (24.4% deltamethrin, 35% permethrin, and 34.4% for alpha-cypermethrin) by rapidly escaping test chambers after direct contact with surfaces treated with each active ingredient compared with match-paired untreated controls. Moderate non-contact repellency responses to all three compounds were observed in the TR population but were comparatively weaker than paired contact tests. Few mosquitoes from the SK and ST populations escaped from test chambers, regardless of insecticide tested or type of trial. We conclude that contact excitation was a major behavioral response in two populations of An. epiroticus, whereas two other populations showed virtually no escape response following exposure to the three pyrethroids. The explanation for these large unexpected differences in avoidance responses between pyrethroid-susceptible populations of the same species is unclear and warrants further investigation.

  16. Kinetic properties of alternatively spliced isoforms of laccase-2 from Tribolium castaneum and Anopheles gambiae.

    Science.gov (United States)

    Gorman, Maureen J; Sullivan, Lucinda I; Nguyen, Thi D T; Dai, Huaien; Arakane, Yasuyuki; Dittmer, Neal T; Syed, Lateef U; Li, Jun; Hua, Duy H; Kanost, Michael R

    2012-03-01

    Laccase-2 is a highly conserved multicopper oxidase that functions in insect cuticle pigmentation and tanning. In many species, alternative splicing gives rise to two laccase-2 isoforms. A comparison of laccase-2 sequences from three orders of insects revealed eleven positions at which there are conserved differences between the A and B isoforms. Homology modeling suggested that these eleven residues are not part of the substrate binding pocket. To determine whether the isoforms have different kinetic properties, we compared the activity of laccase-2 isoforms from Tribolium castaneum and Anopheles gambiae. We partially purified the four laccases as recombinant enzymes and analyzed their ability to oxidize a range of laccase substrates. The predicted endogenous substrates tested were dopamine, N-acetyldopamine (NADA), N-β-alanyldopamine (NBAD) and dopa, which were detected in T. castaneum previously and in A. gambiae as part of this study. Two additional diphenols (catechol and hydroquinone) and one non-phenolic substrate (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)) were also tested. We observed no major differences in substrate specificity between the A and B isoforms. Dopamine, NADA and NBAD were oxidized with catalytic efficiencies ranging from 51 to 550 min⁻¹ mM⁻¹. These results support the hypothesis that dopamine, NADA and NBAD are endogenous substrates for both isoforms of laccase-2. Catalytic efficiencies associated with dopa oxidation were low, ranging from 8 to 30 min⁻¹ mM⁻¹; in comparison, insect tyrosinase oxidized dopa with a catalytic efficiency of 201 min⁻¹ mM⁻¹. We found that dopa had the highest redox potential of the four endogenous substrates, and this property of dopa may explain its poor oxidation by laccase-2. We conclude that laccase-2 splice isoforms are likely to oxidize the same substrates in vivo, and additional experiments will be required to discover any isoform-specific functions.

  17. Biochemical characterization of chitin synthase activity and inhibition in the African malaria mosquito, Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Xin Zhang; Kun Yan Zhu

    2013-01-01

    Chitin synthase (CHS) is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control.However,our understanding of biochemical properties of insect CHSs has been very limited.We here report enzymatic and inhibitory properties of CHS prepared from the African malaria mosquito,Anopheles gambiae.Our study,which represents the first time to use a nonradioactive method to assay CHS activity in an insect species,determined the optimal conditions for measuring the enzyme activity,including pH,temperature,and concentrations of the substrate uridine diphosphate N-acetyl-D-glucosamine (UDPGlcNAc) and Mg++.The optimal pH was about 6.5-7.0,and the highest activity was detected at temperatures between 37℃ and 44℃.Dithithreitol is required to prevent melanization of the enzyme extract.CHS activity was enhanced at low concentration of GlcNAc,but inhibited at high concentrations.Proteolytic activation of the activity is significant both in the 500×g supernatant and the 40 000×g pellet.Our study revealed only slight in vitro inhibition ofA.gambiae CHS activity by diflubenzuron and nikkomycin Z at the highest concentration (2.5μmol/L) examined.There was no in vitro inhibition by polyoxin D at any concentration examined.Furthermore,we did not observe any in vivo inhibition of CHS activity by any of these chemicals at any concentration examined.Our results suggest that the inhibition of chitin synthesis by these chemicals is not due to direct inhibition of CHS in A.gambiae.

  18. Molecular evolution of a gene cluster of serine proteases expressed in the Anopheles gambiae female reproductive tract

    Directory of Open Access Journals (Sweden)

    Tramontano Anna

    2011-03-01

    Full Text Available Abstract Background Genes involved in post-mating processes of multiple mating organisms are known to evolve rapidly due to coevolution driven by sexual conflict among male-female interacting proteins. In the malaria mosquito Anopheles gambiae - a monandrous species in which sexual conflict is expected to be absent or minimal - recent data strongly suggest that proteolytic enzymes specifically expressed in the female lower reproductive tissues are involved in the processing of male products transferred to females during mating. In order to better understand the role of selective forces underlying the evolution of proteins involved in post-mating responses, we analysed a cluster of genes encoding for three serine proteases that are down-regulated after mating, two of which specifically expressed in the atrium and one in the spermatheca of A. gambiae females. Results The analysis of polymorphisms and divergence of these female-expressed proteases in closely related species of the A. gambiae complex revealed a high level of replacement polymorphisms consistent with relaxed evolutionary constraints of duplicated genes, allowing to rapidly fix novel replacements to perform new or more specific functions. Adaptive evolution was detected in several codons of the 3 genes and hints of episodic selection were also found. In addition, the structural modelling of these proteases highlighted some important differences in their substrate specificity, and provided evidence that a number of sites evolving under selective pressures lie relatively close to the catalytic triad and/or on the edge of the specificity pocket, known to be involved in substrate recognition or binding. The observed patterns suggest that these proteases may interact with factors transferred by males during mating (e.g. substrates, inhibitors or pathogens and that they may have differently evolved in independent A. gambiae lineages. Conclusions Our results - also examined in light of

  19. A High-Affinity Adenosine Kinase from Anopheles Gambiae

    Energy Technology Data Exchange (ETDEWEB)

    M Cassera; M Ho; E Merino; E Burgos; A Rinaldo-Matthis; S Almo; V Schramm

    2011-12-31

    Genome analysis revealed a mosquito orthologue of adenosine kinase in Anopheles gambiae (AgAK; the most important vector for the transmission of Plasmodium falciparum in Africa). P. falciparum are purine auxotrophs and do not express an adenosine kinase but rely on their hosts for purines. AgAK was kinetically characterized and found to have the highest affinity for adenosine (K{sub m} = 8.1 nM) of any known adenosine kinase. AgAK is specific for adenosine at the nucleoside site, but several nucleotide triphosphate phosphoryl donors are tolerated. The AgAK crystal structure with a bound bisubstrate analogue Ap{sub 4}A (2.0 {angstrom} resolution) reveals interactions for adenosine and ATP and the geometry for phosphoryl transfer. The polyphosphate charge is partly neutralized by a bound Mg{sup 2+} ion and an ion pair to a catalytic site Arg. The AgAK structure consists of a large catalytic core in a three-layer {alpha}/{beta}/{alpha} sandwich, and a small cap domain in contact with adenosine. The specificity and tight binding for adenosine arise from hydrogen bond interactions of Asn14, Leu16, Leu40, Leu133, Leu168, Phe168, and Thr171 and the backbone of Ile39 and Phe168 with the adenine ring as well as through hydrogen bond interactions between Asp18, Gly64, and Asn68 and the ribosyl 2'- and 3'-hydroxyl groups. The structure is more similar to that of human adenosine kinase (48% identical) than to that of AK from Toxoplasma gondii (31% identical). With this extraordinary affinity for AgAK, adenosine is efficiently captured and converted to AMP at near the diffusion limit, suggesting an important role for this enzyme in the maintenance of the adenine nucleotide pool. mRNA analysis verifies that AgAK transcripts are produced in the adult insects.

  20. The dance of male Anopheles gambiae in wild mating swarms.

    Science.gov (United States)

    Butail, Sachit; Manoukis, Nicholas C; Diallo, Moussa; Ribeiro, José M C; Paley, Derek A

    2013-05-01

    An important element of mating in the malaria vector Anopheles gambiae Giles in nature is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and insemination is generally believed to occur. In this study, we mathematically characterize the oscillatory movement of male An. gambiae in terms of an established individual-based mechanistic model that parameterizes the attraction of a mosquito toward the center of the swarm using the natural frequency of oscillation and the resistance to its motion, characterized by the damping ratio. Using three-dimensional trajectory data of ten wild mosquito swarms filmed in Mali, Africa, we show two new results for low and moderate wind conditions, and indicate how these results may vary in high wind. First, we show that in low and moderate wind the vertical component of the mosquito motion has a lower frequency of oscillation and higher damping ratio than horizontal motion. In high wind, the vertical and horizontal motions are similar to one another and the natural frequencies are higher than in low and moderate wind. Second, we show that the predicted average disagreement in the direction of motion of swarming mosquitoes moving randomly is greater than the average disagreement we observed between each mosquito and its three closest neighbors, with the smallest level of disagreement occurring for the nearest neighbor in seven out of 10 swarms. The alignment of the direction of motion between nearest neighbors is the highest in high wind. This result provides evidence for flight-path coordination between swarming male mosquitoes.

  1. Chloroquine mediated modulation of Anopheles gambiae gene expression.

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    Patrícia Abrantes

    Full Text Available BACKGROUND: Plasmodium development in the mosquito is crucial for malaria transmission and depends on the parasite's interaction with a variety of cell types and specific mosquito factors that have both positive and negative effects on infection. Whereas the defensive response of the mosquito contributes to a decrease in parasite numbers during these stages, some components of the blood meal are known to favor infection, potentiating the risk of increased transmission. The presence of the antimalarial drug chloroquine in the mosquito's blood meal has been associated with an increase in Plasmodium infectivity for the mosquito, which is possibly caused by chloroquine interfering with the capacity of the mosquito to defend against the infection. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report a detailed survey of the Anopheles gambiae genes that are differentially regulated by the presence of chloroquine in the blood meal, using an A. gambiae cDNA microarray. The effect of chloroquine on transcript abundance was evaluated separately for non-infected and Plasmodium berghei-infected mosquitoes. Chloroquine was found to affect the abundance of transcripts that encode proteins involved in a variety of processes, including immunity, apoptosis, cytoskeleton and the response to oxidative stress. This pattern of differential gene expression may explain the weakened mosquito defense response which accounts for the increased infectivity observed in chloroquine-treated mosquitoes. CONCLUSIONS/SIGNIFICANCE: The results of the present study suggest that chloroquine can interfere with several putative mosquito mechanisms of defense against Plasmodium at the level of gene expression and highlight the need for a better understanding of the impacts of antimalarial agents on parasite transmission.

  2. The Susceptibility and Behavioral Response of Anopheles Albimanus Weidemann and Anopheles Vestitipennis Dyar and Knab (Diptera: Culicidae) to Insecticides in Northern Belize, Central America

    Science.gov (United States)

    1999-01-01

    33:205-211. 66 Marquetti, M.C.., A. Navarro and JA Bisset. 1990. Estudio de la actividad hematofagica de Anopheles vestitipennis Dyar & Knab, 1906...Garcia. 1986. Estudio estaeional de sitios de reposo de anophelinos (Diptera: Culicidae). [Studies of the resting places ofanophelines (Diptera...Anofelinos mexicanos . Taxonomia y distribucion [Mexican anophelines. Taxonomy and distribution]. Mex.., D.F.., ecr. Salubr. Assist. CNEP/SS~ 181 pp

  3. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Govindarajan M; Mathivanan T; Elumalai K; Krishnappa K; Anandan A

    2011-01-01

    Objective: To determine the ovicidal and repellent activities of methanol leaf extract ofErvatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). Methods: The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under the laboratory conditions.Results:The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm2 provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae.aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent. Conclusions: From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

  4. Molecular identification of a myosuppressin receptor from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Schöller, Susanne; Belmont, Martin; Cazzamali, Giuseppe

    2005-01-01

    The insect myosuppressins (X1DVX2HX3FLRFamide) are neuropeptides that generally block insect muscle activities. We have used the genomic sequence information from the malaria mosquito Anopheles gambiae Genome Project to clone a G protein-coupled receptor that was closely related to the two previo...

  5. Identification of four evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae

    DEFF Research Database (Denmark)

    Belmont, Martin; Cazzamali, Giuseppe; Williamson, Michael

    2006-01-01

    The mosquito Anopheles gambiae is an important vector for malaria, which is one of the most serious human parasitic diseases in the world, causing up to 2.7 million deaths yearly. To contribute to our understanding of A. gambiae and to the transmission of malaria, we have now cloned four evolutio...

  6. Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya.

    Science.gov (United States)

    Wanjala, Christine L; Mbugi, Jernard P; Ototo, Edna; Gesuge, Maxwell; Afrane, Yaw A; Atieli, Harrysone E; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

    2015-12-01

    We conducted standard insecticide susceptibility testing across western Kenya and found that the Anopheles gambiae mosquito has acquired high resistance to pyrethroids and DDT, patchy resistance to carbamates, but no resistance to organophosphates. Use of non-pyrethroid-based vector control tools may be preferable for malaria prevention in this region.

  7. Biology and Description of the Larva and Pupa of Anopheles (Cellia) elegans James (1903),

    Science.gov (United States)

    1983-01-01

    Ramakrishnan. 1963. Experimental susceptibility of Anophe line mosquitoes to simian malaria in N the Nilgiris , Madras State, South India. Indian J...simian malaria in the Nilgiris , Madras State, India. Indian J. Malariol. 17:243-247. Colless, D.H. 1956. The Anopheles leucoph ,rus group. Trans. R

  8. Batkoa apiculata (Thaxter) Humber affecting Anopheles (Diptera: Culicidae) in the municipality of Una, Southern Bahia, Brazil

    Science.gov (United States)

    Surveys for fungal pathogens affecting adult mosquitoes from the genus Anopheles were conducted in flooded and swamp-like natural breeding sites near residences in the center and suburbs of the city of Una as well as the nearby village of Outeiro in southern Bahia. Surveys of 54 mosquito breeding si...

  9. Behavioural response of the malaria vector Anopheles gambiae to host plant volatiles and synthetic blends

    Science.gov (United States)

    Sugar feeding is critical for survival of malaria vectors and, although discriminative plant feeding previously has been shown to occur in Anopheles gambiae s.s., little is known about the cues mediating attraction to these plants. In this study, we investigated the role of olfaction in An. gambiae ...

  10. Effect of larval crowding on mating competitiveness of Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Ng'habi, K.R.; John, B.; Nkwengulila, G.; Knols, B.G.J.; Killeen, G.F.; Ferguson, H.M.

    2005-01-01

    Background: The success of sterile or transgenic Anopheles for malaria control depends on their mating competitiveness within wild populations. Current evidence suggests that transgenic mosquitoes have reduced fitness. One means of compensating for this fitness deficit would be to identify environme

  11. Egg hatching, larval movement and larval survival of the malaria vector Anopheles gambiae in desiccating habitats

    NARCIS (Netherlands)

    Koenraadt, C.J.M.; Paaijmans, K.P.; Githeko, A.K.; Knols, B.G.J.; Takken, W.

    2003-01-01

    Background - Although the effects of rainfall on the population dynamics of the malaria vector Anopheles gambiae have been studied in great detail, the effects of dry periods on its survival remain less clear. Methods - The effects of drying conditions were simulated by creating desiccated habitats,

  12. Inhibition of host-seeking response and olfactory responsiveness in Anopheles gambiae following blood feeding

    NARCIS (Netherlands)

    Takken, W.; Loon, van J.J.A.; Adam, W.

    2001-01-01

    The effect of a single blood meal on the host-seeking response of Anopheles gambiae was investigated in the laboratory using a behavioural bioassay, whereas possible changes at the chemosensory level were monitored using electroantennogram recording (EAG). To avoid the possible confounding effect of

  13. Control of pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes with chlorfenapyr in Benin

    NARCIS (Netherlands)

    N'Guessan, R.; Boko, P.; Odjo, A.; Knols, B.G.J.; Akogbeto, M.; Rowland, M.

    2009-01-01

    Objective To compare the efficacy of chlorfenapyr applied on mosquito nets and as an indoor residual spray against populations of Anopheles gambiae and Culex quinquefasciatus in an area of Benin that shows problematic levels of pyrethroid resistance. Method Eight-week trial conducted in experimental

  14. Using a near-infrared spectrometer to estimate the age of Anopheles mosquitoes exposed to pyrethroids

    Science.gov (United States)

    We report on the accuracy of using near-infrared spectroscopy (NIRS) to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as ,7 or $7 d ol...

  15. [Radiosensitivity curve of different stages of spermatogenesis of Anopheles atroparvus (Diptera:Nematocera)].

    Science.gov (United States)

    Lecis, A R; Figus, V; Santarini, C

    1975-01-01

    In order to obtain a dose-hatchability curve for irradiated spermatogenetic stages of Anopheles atroparvus, we have irradiated with the same dose "4500 r" young fourth larval stages, old fourth larval stages, nymphae and adult males. Those different stages represent different phases of spermatogenesis. The peak of radiosensitivity for embryonic mortality, was found in spermatids, lowest appeared in spermatogonies.

  16. Factors affecting the vectorial competence of Anopheles gambiae: a question of scale

    NARCIS (Netherlands)

    Takken, W.; Lindsay, S.W.

    2003-01-01

    Malaria transmission in Africa is without doubt governed by the existence of a group of highly efficient vectors, of which Anopheles gambiae Giles sensu stricto is predominant. The endophilic and anthropophagic behaviours of this mosquito create an intimate association between the human reservoir an

  17. Human skin emanations in the host-seeking behaviour of the malaria mosquito Anopheles gambiae

    NARCIS (Netherlands)

    Braks, M.A.H.

    1999-01-01

    Malaria is an infectious disease caused by a parasite ( Plasmodium spp.) that is transmitted between human individuals by mosquitoes, belonging to the order of insects, Diptera, family of Culicidae (mosquitoes) and genus of Anopheles (malaria mosquitoes). Mosquitoes feed on humans (and other animals

  18. Improvement of a synthetic lure for Anopheles gambiae using compounds produced by human skin microbiota

    NARCIS (Netherlands)

    Verhulst, N.O.; Mbadi, P.A.; Bukovinszkine-Kiss, G.; Mukabana, W.R.; Loon, van J.J.A.; Takken, W.; Smallegange, R.C.

    2011-01-01

    Background - Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addi

  19. Larvicidal effects of a neem (Azadirachta indica) oil formulation on the malaria vector Anopheles gambiae

    NARCIS (Netherlands)

    Okumu, F.O.; Knols, B.G.J.; Fillinger, U.

    2007-01-01

    Background - Larviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential of natural products as larvicides against the main African malaria vector, Anopheles gambiae s.s was evaluated. Method

  20. Sharing of antigens between Plasmodium falciparum and Anopheles albimanus Antígenos compartidos entre Plasmodium falciparum y Anopheles albimanus

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    Albina Wide

    2006-12-01

    Full Text Available The presence of common antigens between Plasmodium falciparum and Anopheles albimanus was demonstrated. Different groups of rabbits were immunized with: crude extract from female An. albimanus (EAaF, red blood cells infected with Plasmodium falciparum (EPfs, and the SPf66 synthetic malaria vaccine. The rabbit's polyclonal antibodies were evaluated by ELISA, Multiple Antigen Blot Assay (MABA, and immunoblotting. All extracts were immunogenic in rabbits according to these three techniques, when they were evaluated against the homologous antigens. Ten molecules were identified in female mosquitoes and also in P. falciparum antigens by the autologous sera. The electrophoretic pattern by SDS-PAGE was different for the three antigens evaluated. Cross-reactions between An. albimanus and P. falciparum were found by ELISA, MABA, and immunoblotting. Anti-P. falciparum and anti-SPf66 antibodies recognized ten and five components in the EAaF crude extract, respectively. Likewise, immune sera against female An. albimanus identified four molecules in the P. falciparum extract antigen. As far as we know, this is the first work that demonstrates shared antigens between anophelines and malaria parasites. This finding could be useful for diagnosis, vaccines, and the study of physiology of the immune response to malaria.Epítopes de antígenos compartidos entre Plasmodium falciparum y Anopheles albimanus fueron identificados. Diferentes grupos de conejos fueron inmunizados con: extracto crudo de mosquito hembra de An. albimanus (EAaH, glóbulos rojos infectados con P. falciparum (EPfs y la vacuna antimalárica sintética SPf66. Los anticuerpos policlonales producidos en conejos fueron evaluados por ELISA, inmunoensayo simultáneo de múltiples antígenos (MABA e Immunoblotting. Todos los extractos resultaron inmunogénicos cuando se evaluaron por ELISA, MABA e Immunoblotting. Diez moléculas fueron identificadas en los mosquitos hembras y diez en los antígenos de

  1. Prevalence of anopheles (Diptera: Culicidae) during sunset in areas of the Itaipu Hydroelectric Power Plant in Guaira County, State of Parana, Brazil; Prevalencia de anofelinos (Diptera: Culicidae) no crepusculo vespertino em areas da Usina Hidreletrica de Itaipu, no Municipio de Guaira, Estado do Parana, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Anthony Erico; Mello, Rubens Pinto de; Lopes, Catarina Macedo; Alencar, Jeronimo; Gentile, Carla [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept. de Entomologia. Lab. de Diptera

    1997-11-01

    Systematic collections of anophelines were conducted from November 1995 to August 1995 from 18:00 to 20:00 hr using Shannon traps and human-bait along the lake margin which forms the Itaipu Hydroelectric Reservoir, State of Parana, Brazil. Species prevalence was studied at 15 min intervals. Anopheles albitarsis sensu latu and An. galvaoi, were the most frequently collected mosquitoes. All Anopheles species populations peaked between 18:45 and 19:30 hr. The observations illustrate the existence of haematophagic activity cycle during the early evening hours: exogenous stimulus (the beginning of sunset) Shannon trap (light attraction) human bait (haematophagy) rest and digestion exogenous stimulus Shannon trap or surrounding vegetation. The greater abundance of An. albitarsis collected in human-bait and Shannon trap suggests it may be a potential malaria vector in the region. (author) 20 refs.

  2. Population structure and gene flow of Anopheles farauti s.s. (Diptera: Culicidae) among ten sites on five islands of Vanuatu: implications for malaria control.

    Science.gov (United States)

    Reiff, D M; Kaneko, A; Taleo, G; Amos, M; Lum, J K

    2007-07-01

    The Anopheles punctulatus (Diptera: Culicidae) group is the main vector for malaria and Bancroftian filariasis in Vanuatu. Anopheles larvae were collected from 10 localities on five islands of Vanuatu during the 2004 dry season for species identification as well as for estimating population structure and gene flow within and among islands. Species identification was determined using polymerase chain reaction-restriction fragment length polymorphism analysis of the internal transcribed spacer 2 region. Population structure and gene flow were examined by sequencing a portion of the ND4/ND5 region of the mitochondrial genome. Only one species of the An. punctulatus group, An. farauti s.s., was identified, consistent with previous studies in Vanuatu. A nonrandom distribution of An. farauti s.s. lineages was observed with one cosmopolitan lineage shared by eight sites on all five islands and a preponderance of island-specific lineages (36/40), indicating the introduction of a single main lineage into Vanuatu followed by dispersal, diversification, and limited lineage exchange between islands. Network analysis suggests a possible second introduction of An. farauti s.s. into the northern islands of Gaua and Malekula. Gene flow was high on three of the five islands, whereas Tanna and Santo have significant population structure. Among islands, gene flow was limited, indicating active mosquito dispersal only over short distances and a paucity of passive human-mediated dispersal over long distances. Minimal risk of active dispersal among these islands indicates that vector control can be effectively initiated at the island level within the archipelago of Vanuatu.

  3. Comparative analyses reveal discrepancies among results of commonly used methods for Anopheles gambiaemolecular form identification

    Directory of Open Access Journals (Sweden)

    Pinto João

    2011-08-01

    Full Text Available Abstract Background Anopheles gambiae M and S molecular forms, the major malaria vectors in the Afro-tropical region, are ongoing a process of ecological diversification and adaptive lineage splitting, which is affecting malaria transmission and vector control strategies in West Africa. These two incipient species are defined on the basis of single nucleotide differences in the IGS and ITS regions of multicopy rDNA located on the X-chromosome. A number of PCR and PCR-RFLP approaches based on form-specific SNPs in the IGS region are used for M and S identification. Moreover, a PCR-method to detect the M-specific insertion of a short interspersed transposable element (SINE200 has recently been introduced as an alternative identification approach. However, a large-scale comparative analysis of four widely used PCR or PCR-RFLP genotyping methods for M and S identification was never carried out to evaluate whether they could be used interchangeably, as commonly assumed. Results The genotyping of more than 400 A. gambiae specimens from nine African countries, and the sequencing of the IGS-amplicon of 115 of them, highlighted discrepancies among results obtained by the different approaches due to different kinds of biases, which may result in an overestimation of MS putative hybrids, as follows: i incorrect match of M and S specific primers used in the allele specific-PCR approach; ii presence of polymorphisms in the recognition sequence of restriction enzymes used in the PCR-RFLP approaches; iii incomplete cleavage during the restriction reactions; iv presence of different copy numbers of M and S-specific IGS-arrays in single individuals in areas of secondary contact between the two forms. Conclusions The results reveal that the PCR and PCR-RFLP approaches most commonly utilized to identify A. gambiae M and S forms are not fully interchangeable as usually assumed, and highlight limits of the actual definition of the two molecular forms, which might

  4. Evaluation préliminaire de l'activité larvicide des extraits aqueux des feuilles du ricin (Ricinus communis L.) et du bois de thuya (Tetraclinis articulata (Vahl) Mast.) sur les larves de quatre moustiques culicidés : Culex pipiens (Linné), Aedes caspius (Pallas), Culiseta longiareolata (Aitken) et Anopheles maculipennis (Meigen)

    OpenAIRE

    Mahari S.; Mellouki F.; Oufara S.; Aouinty B.

    2006-01-01

    Preliminary evaluation of larvicidal activity of aqueous extracts from leaves of Ricinus communis L. and from wood of Tetraclinis articulata (Vahl) Mast. on the larvae of four mosquito species: Culex pipiens (Linné), Aedes caspius (Pallas), Culiseta longiareolata (Aitken) and Anopheles maculipennis (Meigen). Aqueous extracts of Ricinus communis leaves and Tetraclinis articulata wood showed strong toxic activity against larvae of several mosquitoes. In this study, insecticide effects of these ...

  5. Potential Distribution of Two Species in the Medically Important Anopheles minimus Complex (Diptera: Culicidae)

    Science.gov (United States)

    2008-09-01

    digital geospa- tial data layers summarizing environmental variation . Georeferenced mosquito point occurrence data are available from the literature or...and Harbach et al. (2007) named An. mini- mus C as An. harrisoni Harbach and Manguin. Differ- ences in phenology between An. minimus and An. harrisoni...ation in fewer, independent dimensions. The Þrst 15 PCs explained 95% of the overall variation in the 59 original environmental parameters (Peterson

  6. Apparent Changes in the Abundance and Distribution of Anopheles Species on Grenada Island

    Science.gov (United States)

    1993-01-01

    entomolbgica en Mexico, pp. 15-40. In: Me- morias del IV Simposio Nacional Entomologia Med- ica y Veterinaria, Oaxtepec, Mor., Mexico. Sociedad...Mexicana de Entomologia . Root, F. M. and J. Andrews. 1938. Malaria and anonheline survey of Grenada, B.W.I. Am. J. H Y ~ . 27:549-579. - Shannon, R

  7. Taxonomic Study of Species Formerly Identified as Anopheles mediopunctatus and Resurrection of An. costai (Diptera: Culicidae)

    Science.gov (United States)

    1999-05-01

    quitos anofelinos ( hembras ) de Venezuela y processes idae - Culicinae). An. Corn. II-IV. Cient. Prov. Bs. Assoc. 3: simplificados para su identification...Townsend, C.H.T. 1934. Mosquitoes of the Rio Tapajos. Rev. Entomol. 4: 486-499. Vargas, L. 1942. Las hembras americanas de1 subgenero Anopheks (Dit

  8. The molecular evolution of four anti-malarial immune genes in the Anopheles gambiae species complex

    OpenAIRE

    Simard Frederic; Antonio-Nkondjio Christophe; Awono-Ambene Parfait H; Marshall Jonathon C; Slotman Michel A; Parmakelis Aristeidis; Caccone Adalgisa; Powell Jeffrey R

    2008-01-01

    Abstract Background If the insect innate immune system is to be used as a potential blocking step in transmission of malaria, then it will require targeting one or a few genes with highest relevance and ease of manipulation. The problem is to identify and manipulate those of most importance to malaria infection without the risk of decreasing the mosquito's ability to stave off infections by microbes in general. Molecular evolution methodologies and concepts can help identify such genes. Withi...

  9. "Repellent Effect of Extracts and Essential Oils of Citrus limon (Rutaceae and Melissa officinalis (Labiatae Against Main Malaria Vector, Anopheles stephensi (Diptera: Culicidae"

    Directory of Open Access Journals (Sweden)

    "MA Oshaghi

    2003-10-01

    Full Text Available Repellet effect of extracts and essential oils of Citrus limon (L. Burm.F., (lemon and Melissa officinalis, (balm were evaluated against Anopheles stephensi in laboratory on animal and human and compared with synthetic repellent, N,Ndiethyl- 3-methylbenzamide (Deet as a standard. Results of statistical analysis revealed significant differences between oils and extracts (P< 0.05 against the tested species, thus oils were more effective than extracts. There was no significant difference between Deet and lemon oil, whereas the difference between lemon and melissa oils was significant. Relative efficacy of lemon oil to Deet was 0.88 whereas it was 0.71 for melissa oil. The results were found marginally superior in repellency for animals than human. Due to advantages of botanic compounds to synthetic compounds we recommend lemon essential oil as an effective alternative to Deet with potential as a means of personal protection against mosquito vectors of disease.

  10. An analysis of some factors determining the sporozoite rates, human blood indexes, and biting rates of members of the Anopheles punctulatus complex in Papua New Guinea.

    Science.gov (United States)

    Burkot, T R; Dye, C; Graves, P M

    1989-03-01

    The degree to which Anopheles punctulatus complex members feed on humans in different Papua New Guinea villages has a significant effect on sporozoite rates. Among villages, the human blood index (HBI) of the members of the complex varied with the average number of persons sharing a bednet. Although dogs are the preferred hosts by the 3 malaria vector species, the number of dogs did not significantly affect the HBI. The HBI was dependent upon the human-biting rate, implying increased avoidance of anophelines by people relative to other hosts at times of greater mosquito numbers. Human-biting rates and HBIs were also influenced by the distribution of alternative hosts relative to people.

  11. Malaria in Kakuma refugee camp, Turkana, Kenya: facilitation of Anopheles arabiensis vector populations by installed water distribution and catchment systems

    Directory of Open Access Journals (Sweden)

    Cetron Martin S

    2011-06-01

    Full Text Available Abstract Background Malaria is a major health concern for displaced persons occupying refugee camps in sub-Saharan Africa, yet there is little information on the incidence of infection and nature of transmission in these settings. Kakuma Refugee Camp, located in a dry area of north-western Kenya, has hosted ca. 60,000 to 90,000 refugees since 1992, primarily from Sudan and Somalia. The purpose of this study was to investigate malaria prevalence and attack rate and sources of Anopheles vectors in Kakuma refugee camp, in 2005-2006, after a malaria epidemic was observed by staff at camp clinics. Methods Malaria prevalence and attack rate was estimated from cases of fever presenting to camp clinics and the hospital in August 2005, using rapid diagnostic tests and microscopy of blood smears. Larval habitats of vectors were sampled and mapped. Houses were sampled for adult vectors using the pyrethrum knockdown spray method, and mapped. Vectors were identified to species level and their infection with Plasmodium falciparum determined. Results Prevalence of febrile illness with P. falciparum was highest among the 5 to 17 year olds (62.4% while malaria attack rate was highest among the two to 4 year olds (5.2/1,000/day. Infected individuals were spatially concentrated in three of the 11 residential zones of the camp. The indoor densities of Anopheles arabiensis, the sole malaria vector, were similar during the wet and dry seasons, but were distributed in an aggregated fashion and predominantly in the same zones where malaria attack rates were high. Larval habitats and larval populations were also concentrated in these zones. Larval habitats were man-made pits of water associated with tap-stands installed as the water delivery system to residents with year round availability in the camp. Three percent of A. arabiensis adult females were infected with P. falciparum sporozoites in the rainy season. Conclusions Malaria in Kakuma refugee camp was due mainly

  12. Distribution of knock-down resistance mutations in Anopheles gambiae molecular forms in west and west-central Africa

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    Caccone Adalgisa

    2008-04-01

    Full Text Available Abstract Background Knock-down resistance (kdr to DDT and pyrethroids in the major Afrotropical vector species, Anopheles gambiae sensu stricto, is associated with two alternative point mutations at amino acid position 1014 of the voltage-gated sodium channel gene, resulting in either a leucine-phenylalanine (L1014F, or a leucine-serine (L1014S substitution. In An. gambiae S-form populations, the former mutation appears to be widespread in west Africa and has been recently reported from Uganda, while the latter, originally recorded in Kenya, has been recently found in Gabon, Cameroon and Equatorial Guinea. In M-form populations surveyed to date, only the L1014F mutation has been found, although less widespread and at lower frequencies than in sympatric S-form populations. Methods Anopheles gambiae M- and S-form specimens from 19 sites from 11 west and west-central African countries were identified to molecular form and genotyped at the kdr locus either by Hot Oligonucleotide Ligation Assay (HOLA or allele-specific PCR (AS-PCR. Results The kdr genotype was determined for about 1,000 An. gambiae specimens. The L1014F allele was found at frequencies ranging from 6% to 100% in all S-form samples (N = 628, with the exception of two samples from Angola, where it was absent, and coexisted with the L1014S allele in samples from Cameroon, Gabon and north-western Angola. The L1014F allele was present in M-form samples (N = 354 from Benin, Nigeria, and Cameroon, where both M- and S-forms were sympatric. Conclusion The results represent the most comprehensive effort to analyse the overall distribution of the L1014F and L1014S mutations in An. gambiae molecular forms, and will serve as baseline data for resistance monitoring. The overall picture shows that the emergence and spread of kdr alleles in An. gambiae is a dynamic process and that there is marked intra- and inter-form heterogeneity in resistance allele frequencies. Further studies are needed to

  13. A simplified high-throughput method for pyrethroid knock-down resistance (kdr detection in Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Walker Edward D

    2005-03-01

    Full Text Available Abstract Background A single base pair mutation in the sodium channel confers knock-down resistance to pyrethroids in many insect species. Its occurrence in Anopheles mosquitoes may have important implications for malaria vector control especially considering the current trend for large scale pyrethroid-treated bednet programmes. Screening Anopheles gambiae populations for the kdr mutation has become one of the mainstays of programmes that monitor the development of insecticide resistance. The screening is commonly performed using a multiplex Polymerase Chain Reaction (PCR which, since it is reliant on a single nucleotide polymorphism, can be unreliable. Here we present a reliable and potentially high throughput method for screening An. gambiae for the kdr mutation. Methods A Hot Ligation Oligonucleotide Assay (HOLA was developed to detect both the East and West African kdr alleles in the homozygous and heterozygous states, and was optimized for use in low-tech developing world laboratories. Results from the HOLA were compared to results from the multiplex PCR for field and laboratory mosquito specimens to provide verification of the robustness and sensitivity of the technique. Results and Discussion The HOLA assay, developed for detection of the kdr mutation, gives a bright blue colouration for a positive result whilst negative reactions remain colourless. The results are apparent within a few minutes of adding the final substrate and can be scored by eye. Heterozygotes are scored when a sample gives a positive reaction to the susceptible probe and the kdr probe. The technique uses only basic laboratory equipment and skills and can be carried out by anyone familiar with the Enzyme-linked immunosorbent assay (ELISA technique. A comparison to the multiplex PCR method showed that the HOLA assay was more reliable, and scoring of the plates was less ambiguous. Conclusion The method is capable of detecting both the East and West African kdr alleles

  14. Mosquito adulticidal and repellent activities of botanical extracts against malarial vector,Anopheles stephensi Liston (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Marimuthu Govindarajan; Rajamohan Sivakumar

    2011-01-01

    Objective:To determine the adulticidal and repellent activities of different solvent leaf extracts ofEclipta alba (E. alba) andAndrographis paniculata (A. paniculata)against malarial vector, Anopheles stephensi (An. stephensi).Methods:Adulticidal efficacy of the crude leaf extracts ofE. alba andA. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of An. stephensi. The adult mortality was observed after24 h under the laboratory conditions. The repellent efficacy was determined againstAn. stephensimosquito species at three concentrations viz.,1.0, 2.5 and 5.0 mg/cm2 under laboratory conditions.Results: Among the tested solvents the maximum efficacy was observed in the methanol extract. TheLC50 andLC90 values ofE. alba andA. paniculata against adults ofAn. stephensiwere150.36, 130.19 ppm and285.22, 244.16ppm, respectively. No mortality was observed in controls. Thechi-square values were significant at P<0.05 level. Methanol extract of E. alba andA. paniculata was produce maximum repellency againstAn. stephensi.Conclusions:From the results it can be concluded the crude extract ofE. alba andA. paniculatawas an excellent potential for controllingAn. stephensimosquitoes.

  15. Computational approach for identification of Anopheles gambiae miRNA involved in modulation of host immune response.

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    Thirugnanasambantham, Krishnaraj; Hairul-Islam, Villianur Ibrahim; Saravanan, Subramanian; Subasri, Subramaniyan; Subastri, Ariraman

    2013-05-01

    MicroRNAs (miRNAs) are small, noncoding RNAs that play key roles in regulating gene expression in animals, plants, and viruses, which involves in biological processes including development, cancer, immunity, and host-microorganism interactions. In this present study, we have used the computational approach to identify potent miRNAs involved in Anopheles gambiae immune response. Analysis of 217,261 A. gambiae ESTs and further study of RNA folding revealed six new miRNAs. The minimum free energy of the predicted miRNAs ranged from -27.2 to -62.63 kcal/mol with an average of -49.38 kcal/mol. While its A + U % ranges from 50 to 65 % with an average value of 57.37 %. Phylogenetic analysis of the predicted miRNAs revealed that aga-miR-277 was evolutionary highly conserved with more similarity with other mosquito species. Observing further the target identification of the predicted miRNA, it was noticed that the aga-miR-2304 and aga-miR-2390 are involved in modulation of immune response by targeting the gene encoding suppressin and protein prophenoloxidase. Further detailed studies of these miRNAs will help in revealing its function in modulation of A. gambiae immune response with respect to its parasite.

  16. The toxicity of angiotensin converting enzyme inhibitors to larvae of the disease vectors Aedes aegypti and Anopheles gambiae.

    Science.gov (United States)

    Abu Hasan, Zatul-'Iffah; Williams, Helen; Ismail, Nur M; Othman, Hidayatulfathi; Cozier, Gyles E; Acharya, K Ravi; Isaac, R Elwyn

    2017-03-27

    The control of mosquitoes is threatened by the appearance of insecticide resistance and therefore new control chemicals are urgently required. Here we show that inhibitors of mosquito peptidyl dipeptidase, a peptidase related to mammalian angiotensin-converting enzyme (ACE), are insecticidal to larvae of the mosquitoes, Aedes aegypti and Anopheles gambiae. ACE inhibitors (captopril, fosinopril and fosinoprilat) and two peptides (trypsin-modulating oostatic factor/TMOF and a bradykinin-potentiating peptide, BPP-12b) were all inhibitors of the larval ACE activity of both mosquitoes. Two inhibitors, captopril and fosinopril (a pro-drug ester of fosinoprilat), were tested for larvicidal activity. Within 24 h captopril had killed >90% of the early instars of both species with 3(rd) instars showing greater resistance. Mortality was also high within 24 h of exposure of 1(st), 2(nd) and 3(rd) instars of An. gambiae to fosinopril. Fosinopril was also toxic to Ae. aegypti larvae, although the 1(st) instars appeared to be less susceptible to this pro-drug even after 72 h exposure. Homology models of the larval An. gambiae ACE proteins (AnoACE2 and AnoACE3) reveal structural differences compared to human ACE, suggesting that structure-based drug design offers a fruitful approach to the development of selective inhibitors of mosquito ACE enzymes as novel larvicides.

  17. Mosquito larvicidal and ovicidal activity of puffer fish extracts against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae).

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    Samidurai, Kaliyaperumal; Mathew, Nisha

    2013-03-01

    The extracts of liver (LE), ovary (OE), skin (SE) and muscle (ME) tissues of four species of puffer fishes viz., Arothron hispidus, Lagocephalus inermis, Lagocephalus scleratus and Chelonodon patoca were evaluated against larvae and eggs of three mosquito vectors, Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The LC50 values were 1194.26, 1382.73 (LE); 1421.42, 1982.73 (OE); 7116.86, 15038.98 (ME) and 10817.8 ppm (SE) for An. stephensi and Cx. quinquefasciatus respectively for A. hispidus. In the case of L. inermis, the LC50 values were 1163.83, 1556.1 and 2426.38 (LE); 1653.53, 2734.74 (OE); 6067.47 (ME) and 10283.04 ppm (SE) for An. stephensi, Cx. quinquefasciatus and Ae. aegypti respectively. The LC50 values were 1509.98, 1608.69 (LE) and 1414.9, 2278.69 ppm (OE) for An. stephensi and Cx. quinquefasciatus respectively for the extracts of L. scleratus. In the case C. patoca extracts the LC50 values were 1182.29, 1543.00, 2441.03 (LE) and 1076.13, 2582.11 ppm (OE) for An. stephensi, Cx. quinquefasciatus and Ae. aegypti respectively. OE and LE of all puffer fishes exhibited zero percent egg hatchability from 600 to 1000 ppm against eggs of An. stephensi and Cx. quinquefasciatus. This study shows that puffer toxins are effective in killing the larvae and eggs of mosquitoes.

  18. Mosquito larvicidal and biting deterrency activity of bud of Polianthes tuberosa plants extract against Anopheles stephensi and Culex quinquefasciatus.

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    Anjali, Rawani; Atanu, Banerjee; Goutam, Chandra

    2012-06-01

    Mosquito control by phytochemicals is an alternative method to synthetic insecticides, as it is biodegradable and non resistant to vector mosquito. Polianthes tuberosa is a perennial plant distributed in many parts of India. The present study was undertaken to scientifically evaluate the larvicide and biting deterrency activity of bud of Polianthes tuberosa against Culex quinquefasciatus and Anopheles stephensi. Crude and solvent extract [ethyl acetate, chloroform: methanol (1:1, v/v), acetone] of fresh, mature, bud of P. tuberosa was tested against (ex. quinquefasciatus and An. stephensi. The repellent activity tested by chloroform: methanol (1:1, v/v) solvent extract against both mosquito species. The appropriate lethal concentrations at 24h for chloroform: methanol (1:1, v/v) extract was also studied on non target organisms such as Toxorhynchites larvae, Diplonychus annulatum and Chironomus circumdatus. In a 72 hour bioassay experiment, 0.5% crude extract showed the highest mortality and chloroform: methanol (1:1, v/v) solvent extract showed the highest mortality, the maximum (p larvicide agent. There is no changes in the activity non-target organism so, it is safe to use.

  19. In vitro larvicidal potential against Anopheles stephensi and antioxidative enzyme activities of Ginkgo biloba, Stevia rebaudiana and Parthenium hysterophorous

    Institute of Scientific and Technical Information of China (English)

    Nisar Ahmad; Hina Fazal; Bilal H Abbasi; Mazhar Iqbal

    2011-01-01

    Objective: To investigate in vitro larvicidal and antioxidant enzymes potential of the medicinal plants Ginkgo biloba (G. biloba), Stevia rebaudiana (S. rebaudiana) and Parthenium hysterophorous (P. hysterophorous) against Anopheles stephensi (An. stephensi) 4th instars larvae. Methods:For evaluation of larvicidal potential, the ethanolic, methanolic and dichloromethane leaves extracts of three different plants were used in dose-dependent experiments in two media, while the antioxidant enzymes activities were investigated using four different methods viz., superoxide dismutase, peroxidase, ascorbate and catalase. Results:An. stephensi has developed resistance to various synthetic insecticides, making its control increasingly difficult. The comparative performance of ethanolic extracts (65%-90%) was found better than the methanolic extract (70%-87%) and dichloromethane extract (60%-70%). Among the three plants extracts tested in two media, S. rebaudiana exhibited higher larvicidal activity with LC50 (24 h) in methanolic extract than P. hysterophorous and G. biloba. G. biloba and P. hysterophorous exhibited the strongest antioxidative enzymes activity and S. rebaudiana were less active and no significant difference was observed. Conclusions:These three plants exhibit larvicidal potential and can be further used for vector control alternative to synthetic insecticide due to eco-friendly and diseases control, furthermore these plant species have potent antioxidative enzyme activities, therefore, making them strong natural candidate particularly for diseases which are caused due to free radicals.

  20. Recombinant Pvs48/45 antigen expressed in E. coli generates antibodies that block malaria transmission in Anopheles albimanus mosquitoes.

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    Myriam Arévalo-Herrera

    Full Text Available Transmission of malaria parasites from humans to Anopheles mosquitoes can be inhibited by specific antibodies elicited during malaria infection, which target surface Plasmodium gametocyte/gamete proteins. Some of these proteins may have potential for vaccine development. Pvs48/45 is a P. vivax gametocyte surface antigen orthologous to Pfs48/45, which may play a role during parasite fertilization and thus has potential for transmission blocking (TB activity. Here we describe the expression of a recombinant Pvs48/45 protein expressed in Escherichia coli as a ∼60kDa construct which we tested for antigenicity using human sera and for its immunogenicity and transmission blocking activity of specific anti-mouse and anti-monkey Pvs48/45 antibodies. The protein reacted with sera of individuals from malaria-endemic areas and in addition induced specific IgG antibody responses in BALB/c mice and Aotus l. griseimembra monkeys. Sera from both immunized animal species recognized native P. vivax protein in Western blot (WB and immunofluorescence assays. Moreover, sera from immunized mice and monkeys produced significant inhibition of parasite transmission to An. Albimanus mosquitoes as shown by membrane feeding assays. Results indicate the presence of reactive epitopes in the Pvs48/45 recombinant product that induce antibodies with TB activity. Further testing of this protein is ongoing to determine its vaccine potential.

  1. STATUS OF INSECTICIDE RESISTANCE IN ANOPHELES CULICIFACIES (DIPTERA: CULICIDAE IN GHASREGHAND DISTRICT, SISTAN AND BALUCHISTAN PROVINCE, IRAN, (1997

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    H. Vatandoost

    1999-08-01

    Full Text Available Anopheles culicifacies s.l. plays an important role In transmission of malaria in Sistan and Baluchistan province, southeastern Iran. Adult susceptibility test on fieltt-collccled mosquitoes was conducted in Ohasreghand district. WHO diagnostic test procedures revealed that adult females were resistant to 0.4% dieUirin (mortality 64.5 ± 3.13, tolerant to 0.1% propoxur (mortality 88.5 ± 2.24 and susceptible to 4% DDT (mortality 98.75 ± 0.8. 5% malathion (mortality 100%, 0.1% bendiocarb (mortality 98.86 ± 0.7, 0.25% pcrmcthrin (mortality 98.4 ± 0.1, ami 0.1% lamhdacyhalothrin (mortality 100%. Malathion and lamhdacyhalothrin had the highest efficacy against this species when they were exposed at the diagnostic dose for 1 hour followed by a 24 hour recovery period. DieUirin, DDT a nil malathion had been used for malaria control as an indoor residual spraying. Tlic implication of these findings in the control programme is discussed.

  2. Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.

    Science.gov (United States)

    Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

    2013-01-01

    Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged.

  3. Comparison of the Insecticidal Characteristics of Commercially Available Plant Essential Oils Against Aedes aegypti and Anopheles gambiae (Diptera: Culicidae).

    Science.gov (United States)

    Norris, Edmund J; Gross, Aaron D; Dunphy, Brendan M; Bessette, Steven; Bartholomay, Lyric; Coats, Joel R

    2015-09-01

    Aedes aegypti and Anopheles gambiae are two mosquito species that represent significant threats to global public health as vectors of Dengue virus and malaria parasites, respectively. Although mosquito populations have been effectively controlled through the use of synthetic insecticides, the emergence of widespread insecticide-resistance in wild mosquito populations is a strong motivation to explore new insecticidal chemistries. For these studies, Ae. aegypti and An. gambiae were treated with commercially available plant essential oils via topical application. The relative toxicity of each essential oil was determined, as measured by the 24-h LD(50) and percentage knockdown at 1 h, as compared with a variety of synthetic pyrethroids. For Ae. aegypti, the most toxic essential oil (patchouli oil) was ∼1,700-times less toxic than the least toxic synthetic pyrethroid, bifenthrin. For An. gambiae, the most toxic essential oil (patchouli oil) was ∼685-times less toxic than the least toxic synthetic pyrethroid. A wide variety of toxicities were observed among the essential oils screened. Also, plant essential oils were analyzed via gas chromatography/mass spectrometry (GC/MS) to identify the major components in each of the samples screened in this study. While the toxicities of these plant essential oils were demonstrated to be lower than those of the synthetic pyrethroids tested, the large amount of GC/MS data and bioactivity data for each essential oil presented in this study will serve as a valuable resource for future studies exploring the insecticidal quality of plant essential oils.

  4. A morphological, isoenzymatic and behavioural study of ten populations of Anopheles(Nyssorhynchus albitarsis Lynch-Arribalzaga, 1878 (Diptera: culicidae including from the type-locality - Baradero, Argentina

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    Maria Goreti Rosa-Freitas

    1990-09-01

    Full Text Available Anopheles (Nyssorhynchus albitarsis Lynch-Arribalzaga, 1878 shows morphological and behavioural variations which results in it being sometimes considered as a major malaria vector and at other times as playing no important role in epidemiology. With the aim of clarifying the taxonomy of the species, comparative morphological and isoenzymatic studies were made in populations from the type-locality, Baradero, Argentina and from 9 different localities inBrazil. Morphological studies consisted of the observation of eggs in scanning electron microscopy, of complete chaetotaxy of larvae and pupae and of the detailed drawing of male and female adults. Only Guajara-Mirim and Rio Branco populations, described previously as Anopheles deaneorum sp.n., showed morphological differences. Isoenzymes were studied using 4th instar larvae homogenate and agarosegel electrophoresis. Eleven enzymatic loci were analyzed. By calculation of Nei's Genetic Distance (D, the populations could be separated into 5 groups: iBaradero, iiMarajo, iiiBoa Vista, ivAngra, Itaguai and Paraipaba and vGuajara-Mirim and Rio Branco. These groups belong to 2 major clusters called I and II, separated by D = 0.345. In the I cluster are groups i, ii and iii and in II clusteriv and v. In I, D=0.246 separates i and ii from iii, while i is separated by D =0.181 from ii. In II, D = 0.223 between iv and v. Only the population of group vcould be distinguished morphologically from the others, leading to the description of an independent species An. deaneorum.

  5. Increased proportions of outdoor feeding among residual malaria vector populations following increased use of insecticide-treated nets in rural Tanzania

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    Azizi Salum

    2011-04-01

    Full Text Available Abstract Background Insecticide-treated nets (ITNs and indoor residual spraying (IRS represent the front-line tools for malaria vector control globally, but are optimally effective where the majority of baseline transmission occurs indoors. In the surveyed area of rural southern Tanzania, bed net use steadily increased over the last decade, reducing malaria transmission intensity by 94%. Methods Starting before bed nets were introduced (1997, and then after two milestones of net use had been reached-75% community-wide use of untreated nets (2004 and then 47% use of ITNs (2009-hourly biting rates of malaria vectors from the Anopheles gambiae complex and Anopheles funestus group were surveyed. Results In 1997, An. gambiae s.l. and An. funestus mosquitoes exhibited a tendency to bite humans inside houses late at night. For An. gambiae s.l., by 2009, nocturnal activity was less (p = 0.0018. At this time, the sibling species composition of the complex had shifted from predominantly An. gambiae s.s. to predominantly An. arabiensis. For An. funestus, by 2009, nocturnal activity was less (p = 0.0054 as well as the proportion biting indoors (p An. funestus s.s. remained the predominant species within this group. As a consequence of these altered feeding patterns, the proportion (mean ± standard error of human contact with mosquitoes (bites per person per night occurring indoors dropped from 0.99 ± 0.002 in 1997 to 0.82 ± 0.008 in 2009 for the An. gambiae complex (p = 0.0143 and from 1.00 ± An. funestus complex (p = 0.0004 over the same time period. Conclusions High usage of ITNs can dramatically alter African vector populations so that intense, predominantly indoor transmission is replaced by greatly lowered residual transmission, a greater proportion of which occurs outdoors. Regardless of the underlying mechanism, the residual, self-sustaining transmission will respond poorly to further insecticidal measures within houses. Additional vector control

  6. Green synthesis of silver nanoparticles using Murraya koenigii leaf extract against Anopheles stephensi and Aedes aegypti.

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    Suganya, Ayyappan; Murugan, Kadarkarai; Kovendan, Kalimuthu; Mahesh Kumar, Palanisamy; Hwang, Jiang-Shiou

    2013-04-01

    Mosquitoes transmit serious human diseases, causing millions of deaths every year. The use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of synthesized natural products for vector control have been a priority in this area. In the present study, the activity of silver nanoparticles (AgNPs) synthesized using Murraya koenigii plant leaf extract against first to fourth instars larvae and pupae of Anopheles stephensi and Aedes aegypti was determined. Range of concentrations of synthesized AgNPs (5, 10, 20, 30, and 40 ppm) and ethanol leaf extract (50, 200, 350, 500, and 650 ppm) were tested against the larvae of A. stephensi and A. aegypti. The synthesized AgNPs from M. koenigii leaf were highly toxic than crude leaf ethanol extract in both mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis. Larvae were exposed to varying concentrations of aqueous extract of synthesized AgNPs for 24 h. The maximum mortality was observed in synthesized AgNPs, and ethanol leaf extract of M. koenigii against A. stephensi had LC50 values of 10.82, 14.67, 19.13, 24.35, and 32.09 ppm and 279.33, 334.61, 406.95, 536.11, and 700.16 ppm and LC90 values of 32.38, 42.52, 53.65, 63.51, and 75.26 ppm and 737.37, 843.84, 907.67, 1,187.62, and 1,421.13 ppm. A. aegypti had LC50 values of 13.34, 17.19, 22.03, 27.57, and 34.84 ppm and 314.29, 374.95, 461.01, 606.50, and 774.01 ppm and LC90 values of 36.98, 47.67, 55.95, 67.36, and 77.72 ppm and 777.32, 891.16, 1,021.90, 1,273.06, and 1,509.18 ppm, respectively. These results suggest that the use of M. koenigii synthesized silver nanoparticles can be a rapid, environmentally safer biopesticide which can form a novel approach to develop effective biocides for controlling the target

  7. Improvement of a synthetic lure for Anopheles gambiae using compounds produced by human skin microbiota

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    van Loon Joop JA

    2011-02-01

    Full Text Available Abstract Background Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addition, volatiles produced by human skin bacteria are attractive to this mosquito species. The purpose of the current study was to test the effect of ten compounds present in the headspace of human bacteria on the host-seeking process of A. gambiae. The effect of each of the ten compounds on the attractiveness of a basic blend of ammonia, lactic and tetradecanoic acid to A. gambiae was examined. Methods The host-seeking response of A. gambiae was evaluated in a laboratory set-up using a dual-port olfactometer and in a semi-field facility in Kenya using MM-X traps. Odorants were released from LDPE sachets and placed inside the olfactometer as well as in the MM-X traps. Carbon dioxide was added in the semi-field experiments, provided from pressurized cylinders or fermenting yeast. Results The olfactometer and semi-field set-up allowed for high-throughput testing of the compounds in blends and in multiple concentrations. Compounds with an attractive or inhibitory effect were identified in both bioassays. 3-Methyl-1-butanol was the best attractant in both set-ups and increased the attractiveness of the basic blend up to three times. 2-Phenylethanol reduced the attractiveness of the basic blend in both bioassays by more than 50%. Conclusions Identification of volatiles released by human skin bacteria led to the discovery of compounds that have an impact on the host-seeking behaviour of A. gambiae. 3-Methyl-1-butanol may be used to increase mosquito trap catches, whereas 2-phenylethanol has potential as a spatial repellent. These two compounds could be applied in push-pull strategies to reduce mosquito numbers in malaria endemic areas.

  8. Identification and expression profiling of putative odorant-binding proteins in the malaria mosquitoes, Anopheles gambiae and A.arabiensis

    Institute of Scientific and Technical Information of China (English)

    LI; Zhengxi; Jing-Jiang; ZHOU; SHEN; Zuorui; Lin; FIELD

    2004-01-01

    Olfaction plays a major role in host-seeking behaviour of mosquitoes. An informatics-based genome-wide analysis of odorant-binding protein (OBP) homologues is undertaken,and 32 putative OBP genes in total in the whole genome sequences of Anopheles gambiae are identified. Tissue-specific expression patterns of all A. gambiae OBP candidates are determined by semi-quantitative Reverse Transcription (RT)-PCR using mosquito actin gene as internal expression control standard. The results showed that 20 OBP candidates had strong expression in mosquito olfactory tissues (female antennae), which indicate that OBPs may play an important role in regulating mosquito olfactory behaviours. Species-specific expression patterns of all putative anopheline OBPs are also studied in two of the most important malaria vectors in A. gambiae complex, i.e.A. gambiae and A. arabiensis, which found 12 of the putative OBP genes examined displayed species-differential expression patterns. The cumulative relative expression intensity of the OBPs in A. arabiensis antennae was higher than that in A. gambiae (the ratio is 1441.45:1314.12), which might be due to their different host preference behaviour. While A.gambiae is a highly anthropophilic mosquito, A. arabiensis is more opportunistic (varying from anthropophilic to zoophilic). So the latter should need more OBPs to support its host selection preference. Identification of mosquito OBPs and verification of their tissue- and species-specific expression patterns represent the first step towards further molecular analysis of mosquito olfactory mechanism, such as recombinant expression and ligand identification.

  9. Effect of rice cultivation on malaria transmission in central Kenya.

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    Muturi, Ephantus J; Muriu, Simon; Shililu, Josephat; Mwangangi, Joseph; Jacob, Benjamin G; Mbogo, Charles; Githure, John; Novak, Robert J

    2008-02-01

    A 12-month field study was conducted between April 2004 and March 2005 to determine the association between irrigated rice cultivation and malaria transmission in Mwea, Kenya. Adult mosquitoes were collected indoors twice per month in three villages representing non-irrigated, planned, and unplanned rice agro-ecosystems and screened for blood meal sources and Plasmodium falciparum circumsporozoite proteins. Anopheles arabiensis Patton and An. funestus Giles comprised 98.0% and 1.9%, respectively, of the 39,609 female anophelines collected. Other species including An. pharoensis Theobald, An. maculipalpis Giles, An. pretoriensis Theobald, An. coustani Laveran, and An. rufipes Gough comprised the remaining 0.1%. The density of An. arabiensis was highest in the planned rice village and lowest in the non-irrigated village and that of An. funestus was significantly higher in the non-irrigated village than in irrigated ones. The human blood index (HBI) for An. arabiensis was significantly higher in the non-irrigated village compared with irrigated villages. For An. funestus, the HBI for each village differed significantly from the others, being highest in the non-irrigated village and lowest in the planned rice village. The sporozoite rate and annual entomologic inoculation rate (EIR) for An. arabiensis was 1.1% and 3.0 infective bites per person, respectively with no significant difference among villages. Sporozoite positive An. funestus were detected only in planned rice and non-irrigated villages. Overall, 3.0% of An. funestus samples tested positive for Plasmodium falciparum sporozoites. The annual EIR of 2.21 for this species in the non-irrigated village was significantly higher than 0.08 for the planned rice village. We conclude that at least in Mwea Kenya, irrigated rice cultivation may reduce the risk of malaria transmission by An. funestus but has no effect on malaria transmission by An. arabiensis. The zoophilic tendency of malaria vectors in irrigated areas

  10. An updated checklist of mosquito species (Diptera: Culicidae) from Madagascar.

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    Tantely, Michaël Luciano; Le Goff, Gilbert; Boyer, Sébastien; Fontenille, Didier

    2016-01-01

    An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar.

  11. An updated checklist of mosquito species (Diptera: Culicidae from Madagascar

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    Tantely Michaël Luciano

    2016-01-01

    Full Text Available An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species. This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species, Aedes (35 species, Anopheles (26 species, Coquillettidia (3 species, Culex (at least 50 species, Eretmapodites (4 species, Ficalbia (2 species, Hodgesia (at least one species, Lutzia (one species, Mansonia (2 species, Mimomyia (22 species, Orthopodomyia (8 species, Toxorhynchites (6 species, and Uranotaenia (73 species. Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%. Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27% with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar.

  12. Studies on mosquitoes (Diptera: Culicidae and anthropic environment. 12- Host-seeking behaviour of Anopheles albitarsis s.l. in South-Eastern Brazil Estudos sobre mosquitos (Diptera: Culicidae e ambiente antrópico. 12 - Atividade hematófaga de Anopheles albitarsis s.l. na região Sudeste do Brasil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1996-08-01

    Full Text Available Results obtained with Anopheles albitarsis s.l. catches mainly performed through human bait at the Ribeira Valley region, SP (Brazil, are reported. Two species of the complex were recognized, namely An. albitarsis s.s. and species B. This latter predominated both in the rice fields and in the dwelling environments. The crepuscular rhythms showed an unimodal sunset pattern with most blood-seeking females caught during dusk. The absence of differences between indoor and outdoor behavior was confirmed for both species of the complex.Relatam-se os resultados de observações sobre o complexo Anopheles albitarsis realizadas mediante o emprego de isca humana em ambiente antrópico do Vale do Ribeira, SP (Brasil, constituído pela Estação Experimental de Pariquera-Açu. Reconheceu-se a presença de duas espécies representadas por An. albitarsis s.s. e outra, designada como espécie B. As coletas foram levadas a efeito em margens de campos irrigados para cultivo de arroz e no ambiente domiciliar. Em ambas, os resultados conseguidos foram paralelos, com maior abundância ocorrendo por ocasião dos meses chuvosos (novembro-março. Quando do período do crepúsculo vespertino, o ritmo de atividade mostrou-se nitidamente unimodal, com a maioria das fêmeas ocorrendo no lusco-fusco, isto é, correspondente à segunda unidade crep, das cinco em que foi dividido aquele período. Confirmou-se a equivalência, em nível de baixa densidade, do comparecimento intra e peridomiciliar. Dos representantes do complexo, a espécie B mostrou-se francamente predominante. Os resultados obtidos em matas residuais e em outra área da mesma região mostraram-se insignificantes no que concerne a esses anofelinos.

  13. Contribution of different aquatic habitats to adult Anopheles arabiensis and Culex quinquefasciatus (Diptera: Culicidae) production in a rice agroecosystem in Mwea, Kenya.

    Science.gov (United States)

    Mwangangi, Joseph M; Muturi, Ephantus J; Shililu, Josephat; Muriu, Simon M; Jacob, Benjamin; Kabiru, Ephantus W; Mbogo, Charles M; Githure, John; Novak, Robert

    2008-06-01

    Studies were conducted to determine the contribution of diverse larval habitats to adult Anopheles arabiensis Patton and Culex quinquefasciatus Say production in a rice land agro-ecosystem in Mwea, Kenya. Two sizes of cages were placed in different habitat types to investigate the influence of non-mosquito invertebrates on larval mortalities and the contribution of each habitat type to mosquito productivities, respectively. These emergence traps had fine netting material covers to prevent adult mosquitoes from ovipositing in the area covered by the trap and immature mosquitoes from entering the cages. The emergence of Anopheles arabiensis in seeps, tire tracks, temporary pools, and paddies was 10.53%, 17.31%, 12.50%, and 2.14%, respectively, while the corresponding values for Cx. quinquefasciatus were 16.85% in tire tracks, 8.39% in temporary pools, and 5.65% in the paddies from 0.125 m3 cages during the study. Cages measuring 1 m3 were placed in different habitat types which included paddy, swamp, marsh, ditch, pool, and seep to determine larval habitat productivity. An. arabiensis was the predominant anopheline species (98.0%, n = 232), although a few Anopheles coustani Laveran (2.0%, n = 5) emerged from the habitats. The productivity for An. arabiensis larvae was 6.0 mosquitoes per m2 for the temporary pools, 5.5 for paddy, 5.4 for marsh, 2.7 for ditch, and 0.6 for seep. The Cx. quinquefasciatus larval habitat productivity was 47.8 mosquitoes per m2 for paddies, 35.7 for ditches, 11.1 for marshes, 4.2 for seeps, 2.4 for swamps, and 1.0 for temporary pools. Pools, paddy, and marsh habitat types were the most productive larval habitats for An. arabiensis while paddy, ditch, and marsh were the most productive larval habitats for Cx. quinquefasciatus. The most common non-mosquito invertebrate composition in the cages included Dytiscidae, Notonectidae, Belostomatidae, and Ephemerellidae, and their presence negatively affected the number of emergent mosquitoes from

  14. Insecticide resistance in Anopheles gambiae: data from the first year of a multi-country study highlight the extent of the problem

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    Sagnon N'Falé

    2009-12-01

    Full Text Available Abstract Background Insecticide resistance in malaria vectors is a growing concern in many countries which requires immediate attention because of the limited chemical arsenal available for vector control. The current extent and distribution of this resistance in many parts of the continent is unknown and yet such information is essential for the planning of effective malaria control interventions. Methods In 2008, a network was established, with financial support from WHO/TDR, to investigate the extent of insecticide resistance in malaria vectors in five African countries. Here, the results of bioassays on Anopheles gambiae sensu lato from two rounds of monitoring from 12 sentinel sites in three of the partner countries are reported. Results Resistance is very heterogeneous even over relatively small distances. Furthermore, in some sites, large differences in mortality rates were observed during the course of the malaria transmission season. Using WHO diagnostic doses, all populations from Burkina Faso and Chad and two of the four populations from Sudan were classified as resistant to permethrin and/or deltamethrin. Very high frequencies of DDT resistance were found in urban areas in Burkina Faso and Sudan and in a cotton-growing district in Chad. In areas where both An. gambiae s.s. and Anopheles arabiensis were present, resistance was found in both species, although generally at a higher frequency in An gambiae s.s. Anopheles gambiae s.l. remains largely susceptible to the organophosphate fenitrothion and the carbamate bendiocarb in the majority of the sentinel sites with the exception of two sites in Burkina Faso. In the cotton-growing region of Soumousso in Burkina Faso, the vector population is resistant to all four classes of insecticide available for malaria control. Conclusions Possible factors influencing the frequency of resistant individuals observed in the sentinel sites are discussed. The results of this study highlight the

  15. Evaluation préliminaire de l'activité larvicide des extraits aqueux des feuilles du ricin (Ricinus communis L. et du bois de thuya (Tetraclinis articulata (Vahl Mast. sur les larves de quatre moustiques culicidés : Culex pipiens (Linné, Aedes caspius (Pallas, Culiseta longiareolata (Aitken et Anopheles maculipennis (Meigen

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    Mahari S.

    2006-01-01

    Full Text Available Preliminary evaluation of larvicidal activity of aqueous extracts from leaves of Ricinus communis L. and from wood of Tetraclinis articulata (Vahl Mast. on the larvae of four mosquito species: Culex pipiens (Linné, Aedes caspius (Pallas, Culiseta longiareolata (Aitken and Anopheles maculipennis (Meigen. Aqueous extracts of Ricinus communis leaves and Tetraclinis articulata wood showed strong toxic activity against larvae of several mosquitoes. In this study, insecticide effects of these plant extracts have been investigated on 2nd and 4th instars larvae of Culicidae insects, Culex pipiens (Linné, Aedes caspius (Pallas, Culiseta longiareolata (Aitken and Anopheles maculipennis (Meigen. After 24 hours of exposition, bioassays revealed low lethal concentrations LC50. To control mosquitoes, these plant extracts might be used as natural biocides.

  16. Identification and characterization of the expression profile of microRNAs in Anopheles anthropophagus

    OpenAIRE

    Liu, Wenquan; Huang, Huicong; Xing, Cuicui; Li, Chunxiang; TAN, FENG; Liang, Shaohui

    2014-01-01

    Background Anopheles anthropophagus, one of the most important mosquito-borne disease vectors in Asia, mainly takes blood meals from humans and transmits both malaria and filariae. MicroRNAs (miRNAs) are small non-coding RNAs, and play a critical role in many cellular processes, including development, differentiation, apoptosis and innate immunity. Methods We investigated the global miRNA expression profile of male and female adults of A. anthropophagus using illumina Hiseq2000 sequencing com...

  17. Blood feeding induces hemocyte proliferation and activation in the African malaria mosquito, Anopheles gambiae Giles

    OpenAIRE

    Bryant, William B.; Michel, Kristin

    2014-01-01

    Malaria is a global public health problem, especially in sub-Saharan Africa, where the mosquito Anopheles gambiae Giles serves as the major vector for the protozoan Plasmodium falciparum Welch. One determinant of malaria vector competence is the mosquito's immune system. Hemocytes are a critical component as they produce soluble immune factors that either support or prevent malaria parasite development. However, despite their importance in vector competence, understanding of their basic biolo...

  18. The Brazilian Malaria Vector Anopheles (Kerteszia) Cruzii: Life Stages and Biology (Diptera: Culicidae)

    Science.gov (United States)

    1991-11-01

    Mosquitos no litoral paranaense. I - Idade fisioldgica de no Parque National da Serra dos Orgaos, Anopheles cruzii (Diptera, Culicidae). Arq. Estado do...no Parque National da Peryassii, A.G. 1908. OS culicideos do Brazil. Serra dos Grgaos, Estado do Rio de Janeiro, Inst. de Manguinhos, Rio de Janeiro...Kerteszia no litoral Guimar%es, A.E. and V.N.M. Victoria. 1986. do estado de Santa Catarina. Rev. Bras. Mosquitos no Parque National da Serra dos

  19. SNP discovery and molecular evolution in Anopheles gambiae, with special emphasis on innate immune system

    OpenAIRE

    Koutsos Anastasios; Morlais Isabelle; Simard Frédéric; Krishnakumar Sujatha; Cohuet Anna; Fontenille Didier; Mindrinos Michael; Kafatos Fotis C

    2008-01-01

    Abstract Background Anopheles innate immunity affects Plasmodium development and is a potential target of innovative malaria control strategies. The extent and distribution of nucleotide diversity in immunity genes might provide insights into the evolutionary forces that condition pathogen-vector interactions. The discovery of polymorphisms is an essential step towards association studies of susceptibility to infection. Results We sequenced coding fragments of 72 immune related genes in natur...

  20. Evidence for Population-Specific Positive Selection on Immune Genes of Anopheles gambiae

    OpenAIRE

    Crawford, Jacob E; Bischoff, Emmanuel; Garnier, Thierry; Gneme, Awa; Eiglmeier, Karin; Holm, Inge; Michelle M Riehle; Guelbeogo, Wamdaogo M.; Sagnon, N’Fale; Brian P Lazzaro; Vernick, Kenneth D

    2012-01-01

    Host-pathogen interactions can be powerful drivers of adaptive evolution, shaping the patterns of molecular variation at the genes involved. In this study, we sequenced alleles from 28 immune-related loci in wild samples of multiple genetic subpopulations of the African malaria mosquito Anopheles gambiae, obtaining unprecedented sample sizes and providing the first opportunity to contrast patterns of molecular evolution at immune-related loci in the recently discovered GOUNDRY population to t...

  1. High Genetic Differentiation between the M and S Molecular Forms of Anopheles gambiae in Africa

    OpenAIRE

    Caroline Esnault; Matthieu Boulesteix; Jean Bernard Duchemin; Koffi, Alphonsine A; Fabrice Chandre; Roch Dabiré; Vincent Robert; Frédéric Simard; Frédéric Tripet; Donnelly, Martin J.; Didier Fontenille; Christian Biémont

    2008-01-01

    BACKGROUND: Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. METHODOLOGY/PRINCI...

  2. Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

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    Read Andrew F

    2009-04-01

    Full Text Available Abstract Background Temperature is a critical determinant of the development of malaria parasites in mosquitoes, and hence the geographic distribution of malaria risk, but little is known about the thermal preferences of Anopheles. A number of other insects modify their thermal behaviour in response to infection. These alterations can be beneficial for the insect or for the infectious agent. Given current interest in developing fungal biopesticides for control of mosquitoes, Anopheles stephensi were examined to test whether mosquitoes showed thermally-mediated behaviour in response to infection with fungal entomopathogens and the rodent malaria, Plasmodium yoelii. Methods Over two experiments, groups of An. stephensi were infected with one of three entomopathogenic fungi, and/or P. yoelii. Infected and uninfected mosquitoes were released on to a thermal gradient (14 – 38°C for "snapshot" assessments of thermal preference during the first five days post-infection. Mosquito survival was monitored for eight days and, where appropriate, oocyst prevalence and intensity was assessed. Results and conclusion Both infected and uninfected An. stephensi showed a non-random distribution on the gradient, indicating some capacity to behaviourally thermoregulate. However, chosen resting temperatures were not altered by any of the infections. There is thus no evidence that thermally-mediated behaviours play a role in determining malaria prevalence or that they will influence the performance of fungal biopesticides against adult Anopheles.

  3. Larvicidal and pupicidal activity of spinosad against the malarial vector Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Kolanthasamy Prabhu; Kadarkarai Murugan; Arjunan Nareshkumar; Subramanian Bragadeeswaran

    2011-01-01

    Objective:To investigate the larvicidal and pupicidal activity of spinosad againstAnopheles stephensi Listen.Methods: Spinosad from the actinomycete,Saccharopolyspora spinosa was tested againstAnopheles stephensi at different concentrations (0.01, 0.02, 0.04, 0.06 and0.08ppm.), and against first to fourth instar larvae and pupae.Results: The larval mortality ranged from36.1±1.7 in (0.01 ppm) to 79.3±1.8 (0.08 ppm) the first instar larva. The LC50andLC90values of first, second, third and fourth instar larva were0.001, 0.031, 0.034, 0.036and0.0113, 0.102, 0.111, 0.113, respectively. The pupal mortality ranged from33.0±2.0 (0.01 ppm) to 80.0±0.9 (0.08 ppm). The LC50 andLC90values were0.028 and 0.1020, respectively. The reduction percentage ofAnopheles larvae was82.7%, 91.4% and96.0% after 24, 48, 72 hours, respectively, while more than80% reduction was observed after3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial. It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.

  4. A viral over-expression system for the major malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Suzuki, Yasutsugu; Niu, Guodong; Hughes, Grant L; Rasgon, Jason L

    2014-05-30

    Understanding pathogen/mosquito interactions is essential for developing novel strategies to control mosquito-borne diseases. Technical advances in reverse-genetics, such as RNA interference (RNAi), have facilitated elucidation of components of the mosquito immune system that are antagonistic to pathogen development, and host proteins essential for parasite development. Forward genetic approaches, however, are limited to generation of transgenic insects, and while powerful, mosquito transgenesis is a resource- and time-intensive technique that is not broadly available to most laboratories. The ability to easily "over-express" genes would enhance molecular studies in vector biology and expedite elucidation of pathogen-refractory genes without the need to make transgenic insects. We developed and characterized an efficient Anopheles gambiae densovirus (AgDNV) over-expression system for the major malaria vector Anopheles gambiae. High-levels of gene expression were detected at 3 days post-infection and increased over time, suggesting this is an effective system for gene induction. Strong expression was observed in the fat body and ovaries. We validated multiple short promoters for gene induction studies. Finally, we developed a polycistronic system to simultaneously express multiple genes of interest. This AgDNV-based toolset allows for consistent transduction of genes of interest and will be a powerful molecular tool for research in Anopheles gambiae mosquitoes.

  5. Ability of TEP1 in intestinal flora to modulate natural resistance of Anopheles dirus.

    Science.gov (United States)

    Wang, Yanyan; Wang, Ying; Zhang, Jingru; Xu, Wenyue; Zhang, Jian; Huang, Fu Sheng

    2013-08-01

    Blocking transmission of malaria is a reliable way to control and eliminate infection. However, in-depth knowledge of the interaction between Plasmodium and mosquito is needed. Studies suggest that innate immunity is the main mechanism inhibiting development of malaria parasites in the mosquito. Recent studies have found that use of antibiotics that inhibit the mosquito gut flora can reduce the immune response of Anopheles gambiae, thereby contributing to the development of malaria parasites. In our study, we used the non susceptible model of Anopheles dirus-Plasmodium yoelii to explore the effect of Anopheles intestinal flora on the natural resistance of A. dirus to P. yoelii. We found that in mosquitoes infected with Plasmodium, the intestinal flora can regulate expression of thioester-containing protein (TEP1) via an RNAi gene-silencing approach. Our results suggest that in the absence of TEP1, the natural microbiota cannot suppress the development of P. yoelii in A. dirus. This suggests that AdTEP1 plays an important role in the resistance of A. dirus to P. yoelii. The intestinal flora may modulate the development of P. yoelii in A. dirus by regulating TEP1 expression.

  6. Comparative mosquito repellency of essential oils against Aedes aegypti (Linn.), Anopheles dirus (Peyton and Harrison) and Culex quinquefasciatus (Say)

    Institute of Scientific and Technical Information of China (English)

    Siriporn Phasomkusolsil; Mayura Soonwera

    2011-01-01

    Objective: To assess the repellency to female Aedes aegypti (Ae. aegypti), Anopheles dirus (An. dirus) and Culex quinquefasciatus (Cx. quinquefasciatus) of seven essential oils using two treatment methods. Methods: Topical applications of three dose concentrations (0.02, 0.10 and 0.21 mg/cm2) were made on the forearms of volunteers. Dose-response study and protection time study were employed in the experiment. Results: In the dose-response test, Cymbopogon citratus (C. citratus), Cymbopogon nardus (C. nardus), Syzygium aromaticum (S. aromaticum) and Ocimum basilicum (O. basilicum) exhibited a high repellency against Ae. aegypti with ED50 at < 0.045 mg/cm2, whereas C. citratus, C. nardus and S. aromaticum showed repellency against An. dirus with ED50 at <0.068 mg/cm2. Furthermore, the essential oils of C. citratus, C. nardus, S. aromaticum, O.basilicum and Cananga odorata gave strong effective dose (ED 50) values at <0.003 mg/cm2 when tested against Cx. quinquefasciatus. For testing by arm in cage method, at 0.21 mg/cm2, protection time of C. citratus gave the longest lasting period against three mosquito species, 72 min for Ae. aegypti, 132 min for An. dirus and 84 min for Cx. quinquefasciatus. In addition, the two essential oils exhibited moderate repellency against Ae. aegypti, An. dirus and Cx. quinquefasciatus, at 60, 90 and 78 min with C. nardus, and 54, 96 and 72 min with S. aromaticum, respectively. Conclusions: The percentage repellency increased when the concentration of essential oils increased. In contrast, biting rates decreased when the concentration of essential oils increased.C. citratus exhibited high efficiency for the protection time and the percentage of biting deterrent against all of 3 mosquito species.

  7. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi(Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Govindarajan; M; Mathivanan; T; Elumalai; K; Krishnappa; K; Anandan; A

    2011-01-01

    Objective:To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria(E.coronaria) and Caeslpinia pulckerrima(C.pulcherrima) against Culex quinquefasciatus(Cx.quinquefasciatus),Aedes aegypti(Ae.aegypti) and Anopheles stephensi(An. stephensi).Methods:The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions.The hatch rates were assessed 48 h after treatment.The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm under the laboratory conditions. Results:The crude extract of E.coronaria exerted zero hatchability(100%mortality) at 250.200 and 150 ppm for Cx.quinqitefasciatus,Ae.aegypti and An.stephensi,respectively.The crude extract of C.pulchenima exerted zero hatchability(100%mortality) at 375.300 and 225 ppm for Cx.quinquefasciatus,Ae.aegypti and An.Stephensi,respectively.The methanol extract of E. coronaria found to be more repellenct than C.pukherrima extract.A higher concentration of 5.0 mg/cm~2 provided 100%protection up to 150.180 and 210 min against Cx.quinquefasciatus,Ae. aegypti and An.stephensi,respectively.The results clearly showed that repellent activity was dose dependent.Conclusions:From the results it can be concluded the crude extracts of E.coronaria and C.pukherrima are an excellent potential for controlling Cx.quinquefasciatus,Ae.aegypti and An.stephensi mosquitoes.

  8. Cloning and characterization of two glutathione S-transferases from a DDT-resistant strain of Anopheles gambiae.

    Science.gov (United States)

    Ranson, H; Prapanthadara, L a; Hemingway, J

    1997-05-15

    Two cDNA species, aggst1-5 and aggst1-6, comprising the entire coding region of two distinct glutathione S-transferases (GSTs) have been isolated from a 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (DDT) resistant strain (ZANDS) of Anopheles gambiae. The nucleotide sequences of these cDNA species share 80.2% identity and their derived amino acid sequences are 82.3% similar. They have been classified as insect class I GSTs on the basis of their high sequence similarity to class I GSTs from Drosophila melanogaster and Musca domestica and they are localized to a region of an An. gambiae chromosome known to contain further class I GSTs. The genes aggst1-5 and aggst1-6 were expressed at high levels in Escherichia coli and the recombinant GSTs were purified by affinity chromatography and characterized. Both agGST1-5 and agGST1-6 showed high activity with the substrates 1-chloro-2,4-dinitrobenzene and 1, 2-dichloro-4-nitrobenzene but negligible activity with the mammalian theta class substrates, 1,2-epoxy-3-(4-nitrophenoxy)propane and p-nitrophenyl bromide. Despite their high level of sequence identity, agGST1-5 and agGST1-6 displayed different kinetic properties. Both enzymes were able to metabolize DDT and were localized to a subset of GSTs that, from earlier biochemical studies, are known to be involved in insecticide resistance in An. gambiae. This subset of enzymes is one of three in which the DDT metabolism levels are elevated in resistant insects.

  9. Comparative genomic analysis of chitinase and chitinase-like genes in the African malaria mosquito (Anopheles gambiae.

    Directory of Open Access Journals (Sweden)

    Jianzhen Zhang

    Full Text Available Chitinase is an important enzyme responsible for chitin metabolism in a wide range of organisms including bacteria, yeasts and other fungi, nematodes and arthropods. However, current knowledge on chitinolytic enzymes, especially their structures, functions and regulation is very limited. In this study we have identified 20 chitinase and chitinase-like genes in the African malaria mosquito, Anopheles gambiae, through genome-wide searching and transcript profiling. We assigned these genes into eight different chitinase groupings (groups I-VIII. Domain analysis of their predicted proteins showed that all contained at least one catalytic domain. However, only seven (AgCht4, AgCht5-1, AgCht6, AgCht7, AgCht8, AgCht10 and AgCht23 displayed one or more chitin-binding domains. Analyses of stage- and tissue-specific gene expression revealed that most of these genes were expressed in larval stages. However, AgCht8 was mainly expressed in the pupal and adult stages. AgCht2 and AgCht12 were specifically expressed in the foregut, whereas AgCht13 was only expressed in the midgut. The high diversity and complexity of An. gambiae chitinase and chitinase-like genes suggest their diverse functions during different developmental stages and in different tissues of the insect. A comparative genomic analysis of these genes along with those present in Drosophila melanogaster, Tribolium castaneum and several other insect species led to a uniform classification and nomenclature of these genes. Our investigation also provided important information for conducting future studies on the functions of chitinase and chitinase-like genes in this important malaria vector and other species of arthropods.

  10. Larvicidal activity of silver nanoparticles synthesized using Plumeria rubra plant latex against Aedes aegypti and Anopheles stephensi.

    Science.gov (United States)

    Patil, Chandrashekhar D; Patil, Satish V; Borase, Hemant P; Salunke, Bipinchandra K; Salunkhe, Rahul B

    2012-05-01

    In the present study activity of silver nanoparticles (AgNPs) synthesized using Plumeria rubra plant latex against second and fourth larval instar of Aedes aegypti and Anopheles stephensi was determined. Range of concentrations of synthesized AgNps (10, 5, 2.5, 1.25, 0.625, 0.3125 ppm) and aqueous crude latex (1,000, 500, 250, 125, 62.50, 31.25 ppm) were tested against larvae of A. aegypti and A. Stephensi. The synthesized AgNps from P. rubra latex were highly toxic than crude latex extract in both mosquito species. The LC(50) values for second and fourth larval instars after 24 h of crude latex exposure were 1.49, 1.82 ppm against A. aegypti and 1.10, 1.74 ppm against A. stephensi respectively. These figures were 181.67, 287.49 ppm against A. aegypti and 143.69, 170.58 ppm against A. stephensi respectively for crude latex extract. The mortality rates were positively correlated with the concentration of AgNPs. The characterization studies of synthesized AgNPs by UV-Vis spectrophotometry, transmission electron microscopy (TEM), Particle size analysis (PSA) and zeta potential confirmed the spherical shape and size (32-200 nm) of silver nanoparticles along with stability. Toxicity studies carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of A. aegypti and A. stephensi showed no toxicity at LC(50) and LC(90) doses of the AgNPs. This is the first report on mosquito larvicidal activity of latex synthesized nanoparticles.

  11. Mosquito larvicidal activity of some common spices and vegetable waste onCulex quinquefasciatus andAnopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Someshwar Singha; Goutam Chandra

    2011-01-01

    Objective:To investigate the larvicidal activities of crude and chloroform: methanol (1:1 v/v) extracts of some common spices (Cuminum cyminum, Allium sativum, Zingiber offinale, Curcuma longa) and vegetable waste (Solanum tuberosum germinated tuber) againstAnopheles stephensiandCulex quinquefasciatus mosquito larvae.Methods:Larval mortality of above mosquito species were observed after 24, 48 and72 h of exposure to five concentrations of aqueous extract (0.1%, 0.2%, 0.3%, 0.4% and0.5%) and four concentrations (25, 50, 75 ppm) of chloroform: methanol (1:1 v/v) extract. The lethal concentration of individual spices or vegetable waste was determined by log-probit analysis (at95%confidence level) and effect of crude and chloroform: methanol (1:1 v/v) extracts were recorded on non target organisms.Results:Relative mortality rate of both larval mosquito species were recorded in the following sequences:Cuminum cyminum>Allium sativum>Zingiber offinale, Curcuma longa > Solanum tuberosum germinated tuber for crude extract, and efficacy of chloroform: methanol (1:1 v/v) extract were as follows:Curcuma longa > Zingiber offinale > Solanum tuberosum germinated tuber >Cuminum cyminum>Allium sativum.Conclusions: Crude and chloroform: methanol (1:1 v/v) extract of Cuminum cyminum, Allium sativum, Zingiber offinale, Curcuma longa andSolanum tuberosum germinated tuber can be recommended effectively in mosquito control programmes at very low concentrations. No mortality and other abnormalities were noticed on non target organisms and further studies are needed to investigate the chemical structure of active principal which are responsible for larvicidal activity.

  12. Electroantennogram, flight orientation and oviposition responses of Anopheles stephensi and Aedes aegypti to a fatty acid ester-propyl octadecanoate.

    Science.gov (United States)

    Seenivasagan, Thangaraj; Sharma, Kavita R; Prakash, Shri

    2012-10-01

    Studies were carried out to evaluate the role of a C(21)-fatty acid ester; propyl octadecanoate (PO) for olfaction-mediated behavioral responses of urban malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti mosquitoes using electroantennogram (EAG), flight orientation and oviposition experiments. Dose dependent electrophysiological responses were recorded for PO from the antenna of both mosquito species in which 10(-5) g elicited significant EAG response. An. stephensi exhibited 2.4, 4.2 and 5.5 fold increased EAG response compared to control, while Ae. aegypti showed 1.9, 4.6 and 5.8 fold EAG responses respectively at 10(-7) g, 10(-6) g and 10(-5) g doses. In the Y-tube olfactometer, 77-80% gravid females of An. stephensi, and 64-77% of Ae. aegypti were caught in the chambers releasing 10(-6) g and 10(-5) g plume of PO. The synthetic fatty acid ester loaded onto an effervescent tablet at 0.1 mg/L, 1 mg/L and 10 mg/L elicited increased ovipositional responses from gravid mosquitoes compared to control. The oviposition activity indices (OAI) of An. stephensi females were +0.40, +0.51 and +0.58, whereas the OAI for Ae. aegypti females were +0.05, +0.36 and +0.57 respectively in 0.1, 1, 10 mg/L of PO; indicated concentration dependent increased egg deposition. Similarly, in the residual activity studies, oviposition substrates treated with PO on effervescent tablet at 1mg/L and 10mg/L received significantly increased egg deposition by gravid females of both mosquito species for up to 1 week compared to control substrates. PO can potentially be used in ovitraps to monitor An. stephensi and Ae. aegypti populations in the vector surveillance programs.

  13. Is there an efficient trap or collection method for sampling Anopheles darlingi and other malaria vectors that can describe the essential parameters affecting transmission dynamics as effectively as human landing catches? - A Review

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    José Bento Pereira Lima

    2014-08-01

    Full Text Available Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species. To evaluate these parameters, mosquitoes must be collected using an appropriate method. Malaria is primarily transmitted by anthropophilic and synanthropic anophelines. Thus, collection methods must result in the identification of the anthropophilic species and efficiently evaluate the parameters involved in malaria transmission dynamics. Consequently, human landing catches would be the most appropriate method if not for their inherent risk. The choice of alternative anopheline collection methods, such as traps, must consider their effectiveness in reproducing the efficiency of human attraction. Collection methods lure mosquitoes by using a mixture of olfactory, visual and thermal cues. Here, we reviewed, classified and compared the efficiency of anopheline collection methods, with an emphasis on Neotropical anthropophilic species, especially Anopheles darlingi, in distinct malaria epidemiological conditions in Brazil.

  14. The practical importance of permanent and semipermanent habitats for controlling aquatic stages of Anopheles gambiae sensu lato mosquitoes: operational observations from a rural town in western Kenya

    NARCIS (Netherlands)

    Fillinger, U.; Sonye, G.; Killeen, G.F.; Knols, B.G.J.; Becker, N.

    2004-01-01

    Control of aquatic-stage Anopheles is one of the oldest and most historically successful interventions to prevent malaria, but it has seen little application in Africa. Consequently, the ecology of immature afrotropical Anopheles has received insufficient attention. We therefore examined the populat

  15. Pyrethroid resistance in Anopheles gambiae leads to increased susceptibility to the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

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    Knols Bart GJ

    2010-06-01

    Full Text Available Abstract Background Entomopathogenic fungi are being investigated as a new mosquito control tool because insecticide resistance is preventing successful mosquito control in many countries, and new methods are required that can target insecticide-resistant malaria vectors. Although laboratory studies have previously examined the effects of entomopathogenic fungi against adult mosquitoes, most application methods used cannot be readily deployed in the field. Because the fungi are biological organisms it is important to test potential field application methods that will not adversely affect them. The two objectives of this study were to investigate any differences in fungal susceptibility between an insecticide-resistant and insecticide-susceptible strain of Anopheles gambiae sensu stricto, and to test a potential field application method with respect to the viability and virulence of two fungal species Methods Pieces of white polyester netting were dipped in Metarhizium anisopliae ICIPE-30 or Beauveria bassiana IMI391510 mineral oil suspensions. These were kept at 27 ± 1°C, 80 ± 10% RH and the viability of the fungal conidia was recorded at different time points. Tube bioassays were used to infect insecticide-resistant (VKPER and insecticide-susceptible (SKK strains of An. gambiae s.s., and survival analysis was used to determine effects of mosquito strain, fungus species or time since fungal treatment of the net. Results The resistant VKPER strain was significantly more susceptible to fungal infection than the insecticide-susceptible SKK strain. Furthermore, B. bassiana was significantly more virulent than M. anisopliae for both mosquito strains, although this may be linked to the different viabilities of these fungal species. The viability of both fungal species decreased significantly one day after application onto polyester netting when compared to the viability of conidia remaining in suspension. Conclusions The insecticide

  16. Vector capacity of Anopheles sinensis in malaria outbreak areas of central China

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    Pan Jia-Yun

    2012-07-01

    Full Text Available Abstract Background Both falciparum and vivax malaria were historically prevalent in China with high incidence. With the control efforts, the annual incidence in the whole country has reduced to 0.0001% except in some areas in the southern borders after 2000. Despite this, the re-emergence or outbreak of malaria was unavoidable in central China during 2005–2007. In order to understand the role of the vector in the transmission of malaria during the outbreak period, the vector capacity of An. sinensis in Huanghuai valley of central China was investigated. Findings The study was undertaken in two sites, namely Huaiyuan county of Anhui province and Yongcheng county of Henan province. In each county, malaria cases were recorded for recent years, and transmission risk factors for each study village including anti-mosquito facilities and total number of livestock were recorded by visiting each household in the study sites. The specimens of mosquitoes were collected in two villages, and population density and species in each study site were recorded after the identification of different species, and the blood-fed mosquitoes were tested by ring precipitation test. Finally, various indicators were calculated to estimate vector capacity or dynamics, including mosquito biting rate (MBR, human blood index (HBI, and the parous rates (M. Finally, the vector capacity, as an important indicator of malaria transmission to predict the potential recurrence of malaria, was estimated and compared in each study site. About 93.0% of 80 households in Huaiyuan and 89.3% of 192 households in Yongcheng had anti-mosquito facilities. No cattle or pigs were found, only less than 10 sheep were found in each study village. A total of 94 and 107 Anopheles spp. mosquitos were captured in two study sites, respectively, and all of An. sinensis were morphologically identified. It was found that mosquito blood-feeding peak was between 9:00 pm and 12:00 pm. Man biting rate of

  17. Vectors and malaria transmission in deforested, rural communities in north-central Vietnam

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    Do Manh Cuong

    2010-09-01

    Full Text Available Abstract Background Malaria is still prevalent in rural communities of central Vietnam even though, due to deforestation, the primary vector Anopheles dirus is uncommon. In these situations little is known about the secondary vectors which are responsible for maintaining transmission. Basic information on the identification of the species in these rural communities is required so that transmission parameters, such as ecology, behaviour and vectorial status can be assigned to the appropriate species. Methods In two rural villages - Khe Ngang and Hang Chuon - in Truong Xuan Commune, Quang Binh Province, north central Vietnam, a series of longitudinal entomological surveys were conducted during the wet and dry seasons from 2003 - 2007. In these surveys anopheline mosquitoes were collected in human landing catches, paired human and animal bait collections, and from larval surveys. Specimens belonging to species complexes were identified by PCR and sequence analysis, incrimination of vectors was by detection of circumsporozoite protein using an enzyme-linked immunosorbent assay. Results Over 80% of the anopheline fauna was made up of Anopheles sinensis, Anopheles aconitus, Anopheles harrisoni, Anopheles maculatus, Anopheles sawadwongporni, and Anopheles philippinensis. PCR and sequence analysis resolved identification issues in the Funestus Group, Maculatus Group, Hyrcanus Group and Dirus Complex. Most species were zoophilic and while all species could be collected biting humans significantly higher densities were attracted to cattle and buffalo. Anopheles dirus was the most anthropophilic species but was uncommon making up only 1.24% of all anophelines collected. Anopheles sinensis, An. aconitus, An. harrisoni, An. maculatus, An. sawadwongporni, Anopheles peditaeniatus and An. philippinensis were all found positive for circumsporozoite protein. Heterogeneity in oviposition site preference between species enabled vector densities to be high in both

  18. Malaria vector control by indoor residual insecticide spraying on the tropical island of Bioko, Equatorial Guinea

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    Kuklinski Jaime

    2007-05-01

    Full Text Available Abstract Background A comprehensive malaria control intervention was initiated in February 2004 on Bioko Island, Equatorial Guinea. This manuscript reports on the continuous entomological monitoring of the indoor residual spray (IRS programme during the first two years of its implementation. Methods Mosquitoes were captured daily using window traps at 16 sentinel sites and analysed for species identification, sporozoite rates and knockdown resistance (kdr using polymerase chain reaction (PCR to assess the efficacy of the vector control initiative from December 2003 to December 2005. Results A total of 2,807 and 10,293 Anopheles funestus and Anopheles gambiae s.l. respectively were captured throughout the study period. Both M and S molecular forms of An. gambiae s.s. and Anopheles melas were identified. Prior to the first round of IRS, sporozoite rates were 6.0, 8.3 and 4.0 for An. gambiae s.s., An. melas and An. funestus respectively showing An. melas to be an important vector in areas in which it occurred. After the third spray round, no infective mosquitoes were identified. After the first spray round using a pyrethroid spray the number of An. gambiae s.s. were not reduced due to the presence of the kdr gene but An funestus and An. melas populations declined from 23.5 to 3.1 and 5.3 to 0.8 per trap per 100 nights respectively. After the introduction of a carbamate insecticide in the second round, An. gambiae s.s. reduced from 25.5 to 1.9 per trap per 100 nights and An. funestus and An. melas remained at very low levels. Kdr was found only in the M-form of An. gambiae s.s. with the highest frequency at Punta Europa (85%. Conclusion All three vectors that were responsible for malaria transmission before the start of the intervention were successfully controlled once an effective insecticide was used. Continuous entomological surveillance including resistance monitoring is of critical importance in any IRS based malaria vector control programme

  19. Anopheles (Kerteszia) lepidotus (Diptera: Culicidae), not the malaria vector we thought it was: Revised male and female morphology; larva, pupa, and male genitalia characters; and molecular verification

    Science.gov (United States)

    HARRISON, BRUCE A.; RUIZ-LOPEZ, FREDDY; FALERO, GUILLERMO CALDERON; SAVAGE, HARRY M.; PECOR, JAMES E.; WILKERSON, RICHARD C.

    2015-01-01

    The name Anopheles (Kerteszia) lepidotus Zavortink, commonly used for an important malaria vector in the eastern cordillera of the Andes, is here corrected to An. pholidotus Zavortink. We discovered that An. (Ker.) specimens from Peru, and reared-associated specimens from Ecuador, had unambiguous habitus characters that matched those on the male holotype of An. lepidotus. However, the specimens do not exhibit characters of the female allotype and female paratypes of An. lepidotus, which are actually An. pholidotus. Our specimens are the first correctly associated females of An. lepidotus, which allow us to provide a new morphological interpretation for the adult habitus of this species. This finding is also corroborated by molecular data from a portion of the Cytochrome Oxidase I (COI) gene and ribosomal DNA Internal Transcribed Spacer 2 (rDNA ITS2). The pupal stage of An. lepidotus is described for the first time, and additional larval characters are also noted. Diagnostic morphological characters for the adult, pupal, and larval stages of An. pholidotus are provided to separate the two species. All stages of An. lepidotus are easily separated from other currently known species in subgenus Kerteszia and a new key to the females of An. (Kerteszia) is given. Previously published distribution, bionomics, and medical significance data are corrected and enhanced. PMID:26726290

  20. Ecology and Epidemiology of Integrated Malaria Vector Management in Dar es Salaam, Tanzania

    OpenAIRE

    Geissbühler, Yvonne

    2008-01-01

    Malaria remains one of the major contributors to the global burden of disease with approximately 70% of the clinical malaria attacks occurring in sub-Saharan Africa. Sub- Saharan Africa has the highest risk as ideal climatic conditions for transmission coincide with occurrence of some of the most efficient malaria vectors, namely Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus.. Even though it is estimated that by the year 2030 more than 50% of the African p...

  1. Present habitat suitability for Anopheles atroparvus (Diptera, Culicidae and its coincidence with former malaria areas in mainland Portugal

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    César Capinha

    2009-05-01

    Full Text Available Malaria was a major health problem in the first half of the 20th Century in mainland Portugal. Nowadays, although the disease is no longer endemic, there is still the risk of future endemic infections due to the continuous occurrence of imported cases and the possibility of transmission in the country by Anopheles atroparvus Van Thiel, 1927. Since vector abundance constitute one of the foremost factors in malaria transmission, we have created several habitat suitability models to describe this vector species’ current distribution. Three different correlative models; namely (i a multilayer perceptron artificial neural network (MLP-ANN; (ii binary logistic regression (BLR; and (iii Mahalanobis distance were used to combine the species records with a set of five environmental predictors. Kappa coefficient values from k-fold cross-validation records showed that binary logistic regression produced the best predictions, while the other two models also produced acceptable results. Therefore, in order to reduce uncertainty, the three suitability models were combined. The resulting model identified high suitability for An. atroparvus in the majority of the country with exception of the northern and central coastal areas. Malaria distribution during the last endemic period in the country was also compared with the combined suitability model, and a high degree of spatial agreement was obtained (kappa = 0.62. It was concluded that habitat suitability for malaria vectors can constitute valuable information on the assessment of several spatial attributes of the disease. In addition, the results suggest that the spatial distribution of An. atroparvus in the country remains very similar to the one known about seven decades ago.

  2. Human IGF1 regulates midgut oxidative stress and epithelial homeostasis to balance lifespan and Plasmodium falciparum resistance in Anopheles stephensi.

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    Anna L Drexler

    2014-06-01

    Full Text Available Insulin and insulin-like growth factor signaling (IIS regulates cell death, repair, autophagy, and renewal in response to stress, damage, and pathogen challenge. Therefore, IIS is fundamental to lifespan and disease resistance. Previously, we showed that insulin-like growth factor 1 (IGF1 within a physiologically relevant range (0.013-0.13 µM in human blood reduced development of the human parasite Plasmodium falciparum in the Indian malaria mosquito Anopheles stephensi. Low IGF1 (0.013 µM induced FOXO and p70S6K activation in the midgut and extended mosquito lifespan, whereas high IGF1 (0.13 µM did not. In this study the physiological effects of low and high IGF1 were examined in detail to infer mechanisms for their dichotomous effects on mosquito resistance and lifespan. Following ingestion, low IGF1 induced phosphorylation of midgut c-Jun-N-terminal kinase (JNK, a critical regulator of epithelial homeostasis, but high IGF1 did not. Low and high IGF1 induced midgut mitochondrial reactive oxygen species (ROS synthesis and nitric oxide (NO synthase gene expression, responses which were necessary and sufficient to mediate IGF1 inhibition of P. falciparum development. However, increased ROS and apoptosis-associated caspase-3 activity returned to baseline levels following low IGF1 treatment, but were sustained with high IGF1 treatment and accompanied by aberrant expression of biomarkers for mitophagy, stem cell division and proliferation. Low IGF1-induced ROS are likely moderated by JNK-induced epithelial cytoprotection as well as p70S6K-mediated growth and inhibition of apoptosis over the lifetime of A. stephensi to facilitate midgut homeostasis and enhanced survivorship. Hence, mitochondrial integrity and homeostasis in the midgut, a key signaling center for IIS, can be targeted to coordinately optimize mosquito fitness and anti-pathogen resistance for improved control strategies for malaria and other vector-borne diseases.

  3. Evaluation of some aromatic plant extracts for mosquito larvicidal potential against Culex quinquefasciatus, Aedes aegypti, and Anopheles stephensi.

    Science.gov (United States)

    Jayaraman, M; Senthilkumar, A; Venkatesalu, V

    2015-04-01

    In the present investigation, larvicidal potential of hexane, choloroform, ethyl acetate, acetone, and methanol extracts of seven aromatic plants, viz., Blumea mollis, Chloroxylon swietenia, Clausena anisata, Feronia limnonia, Lantana camera, Plectranthus amboinicus, and Tagetes erecta were screened against Culex quinquefasciatus, Aedes aegypti, and Anopheles stephensi. The larval mortality was observed after 12 and 24 h of exposure period. The results revealed that all the extracts showed varied levels of larvicidal activity against the mosquito species tested. However, the ethyl acetate extract of Chloroxylon swietenia showed the remarkable larvicidal activity against C. quinquefasciatus, Ae. aegypti, and An. stephensi. After 12 h of exposure period, the larvicidal activity was LC50 = 194.22 and LC90 = 458.83 ppm (C. quinquefasciatus), LC50 = 173.04 and LC90 = 442.73 ppm (Ae. aegypti), and LC50 = 167.28 and LC90 = 433.07 ppm (An. stephensi), and the larvicidal activity after 24-h exposure period was LC50 = 94.12 and LC90 = 249.83 ppm (C. quinquefasciatus), LC50 = 80.58 and LC90 = 200.96 ppm (Ae. aegypti), and LC50 = 76.24 and LC90 = 194.51 ppm (An. stephensi). The larvicidal potential of other plant extracts were in order of ethyl acetate extract of Clausena anisata > methanol extract of P. amboinicus > acetone extract of F. limonia > methanol extract of T. erecta > methanol extract of B. mollis > and methanol extract of L. camera. The results of the present study offer a possible way for further investigations to find out the active molecule responsible for the activity.

  4. Impact of insecticide-treated nets on wild pyrethroid resistant Anopheles epiroticus population from southern Vietnam tested in experimental huts

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    Trung Ho

    2009-10-01

    Full Text Available Abstract Background In this study, the efficacy of insecticide-treated nets was evaluated in terms of deterrence, blood-feeding inhibition, induced exophily and mortality on a wild resistant population of Anopheles epiroticus in southern Vietnam, in order to gain insight into the operational consequences of the insecticide resistance observed in this malaria vector in the Mekong delta. Method An experimental station, based on the model of West Africa and adapted to the behaviour of the target species, was built in southern Vietnam. The study design was adapted from the WHO phase 2 guidelines. The study arms included a conventionally treated polyester net (CTN with deltamethrin washed just before exhaustion, the WHO recommended long-lasting insecticidal net (LLIN PermaNet 2.0® unwashed and 20 times washed and PermaNet 3.0®, designed for the control of pyrethroid resistant vectors, unwashed and 20 times washed. Results The nets still provided personal protection against the resistant An. epiroticus population. The personal protection ranged from 67% for deltamethrin CTN to 85% for unwashed PermaNet 3.0. Insecticide resistance in the An. epiroticus mosquitoes did not seem to alter the deterrent effect of pyrethroids. A significant higher mortality was still observed among the treatment arms despite the fact that the An. epiroticus population is resistant against the tested insecticides. Conclusion This study shows that CTN and LLINs still protect individuals against a pyrethroid resistant malaria vector from the Mekong region, where insecticide resistance is caused by a metabolic mechanism. In the light of a possible elimination of malaria from the Mekong region these insights in operational consequences of the insecticide resistance on control tools is of upmost importance.

  5. Studies on Anopheles (Kerteszia) homunculus Komp (Diptera: Culicidae)

    Science.gov (United States)

    2009-01-01

    records show that this species occurs on the eastern slopes of the Andes in Colombia and Bolivia, in Trinidad, Venezuela, the Guianas, Peru and...An. homunculus l.s. in Mata Atl? ica , southern Brazil, and suggest that specimens from Trinidad may belong to an unnamed morphologically similar...Trinidad especially in southern Mata Atl? ica , Brazil. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR

  6. Behavioral patterns, parity rate and natural infection analysis in anopheline species involved in the transmission of malaria in the northeastern Brazilian Amazon region.

    Science.gov (United States)

    Barbosa, Ledayane Mayana Costa; Souto, Raimundo Nonato Picanço; Dos Anjos Ferreira, Ricardo Marcelo; Scarpassa, Vera Margarete

    2016-12-01

    The characterization of behavioral patterns allows a better understanding of the transmission dynamics and the design of more effective malaria vector control strategies. This study analyzed the behavioral patterns of the Anopheles species of the Coração district situated in the northeast of the Brazilian Amazon region. The behavioral patterns of the anopheline species were measured based on the 36 collection sites of this district from December 2010 to November 2011. Collections of four hours for three consecutive nights each month and four 12-h collections, comprising two in the rainy season and two in the dry season, were performed. Furthermore, to infer the anthropophily and zoophily indexes, four additional four-hour collections were performed. The samples were also evaluated for parity rate and natural infectivity for Plasmodium spp. A total of 1689 anophelines were captured, comprising of nine species and two subgenera (Nyssorhynchus - six species, and Anopheles - three species). Anopheles darlingi was the most abundant and widely distributed species in the area, followed by A. braziliensis and A.marajoara. Anopheles darlingi and A. marajoara were the only species present in the four collections of 12-h, but only A. darlingi showed activity throughout night. Anopheles darlingi was the most anthropophilic species (AI=0.40), but the zoophily index was higher (ZI=0.60), revealing an eclectic and opportunistic behavior. Of the six most frequent species, A. nuneztovari s.l. was the most zoophilic species (ZI=1.00). All captured species showed predominance towards biting in outdoor environments. Anopheles darlingi and A. braziliensis showed multimodal biting peaks, whereas A. marajoara revealed a stable pattern, with the biting peak after sunset. Using the PCR technique, no anopheline was found infected with the malaria parasite. Since A. darlingi and A. marajoara are recognized as important vectors in this region, the district of Coração may be considered as

  7. Ecology and behavior of Anopheles arabiensis in relation to agricultural practices in central Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Mwangangi, Joseph M; Beier, John C; Blackshear, Millon; Wauna, James; Sang, Rosemary; Mukabana, Wolfgang R

    2013-09-01

    Ecological changes associated with anthropogenic ecosystem disturbances can influence human risk of exposure to malaria and other vector-borne infectious diseases. This study in Mwea, Kenya, investigated the pattern of insecticide use in irrigated and nonirrigated agroecosystems and association with the density, survival, and blood-feeding behavior of the malaria vector Anopheles arabiensis. The parity rates of adult An. arabiensis from randomly selected houses were determined by examining their ovaries for tracheal distension, and polymerase chain reaction was used to identify the host blood meals. In addition, structured questionnaires were used to generate data on insecticide use. Anopheles arabiensis densities were highest in irrigated rice agroecosystems, intermediate in irrigated French beans agroecosystems, and lowest in the nonirrigated agroecosystem. Anopheles arabiensis adult survivorship was significantly lower in irrigated rice agroecosystems than in irrigated French beans agroecosystems. The human blood index (HBI) was significantly higher in the nonirrigated agroecosystem compared to irrigated agroecosystems. Moreover, there was marked variation in HBI among villages in irrigated agroecosystems with significantly lower HBI in Kangichiri and Mathangauta compared to Kiuria, Karima, and Kangai. The proportion of mosquitoes with mixed blood meals varied among villages ranging from 0.25 in Kangichiri to 0.83 in Kiuria. Sumithion, dimethoate, and alpha cypermethrin were the most commonly used insecticides. The 1st was used mostly in irrigated rice agroecosystems, and the last 2 were used mostly in irrigated French beans agroecosystems. These findings indicate that agricultural practices may influence the ecology and behavior of malaria vectors and ultimately the risk of malaria transmission.

  8. Gal4-based enhancer-trapping in the malaria mosquito Anopheles stephensi.

    Science.gov (United States)

    O'Brochta, David A; Pilitt, Kristina L; Harrell, Robert A; Aluvihare, Channa; Alford, Robert T

    2012-11-01

    Transposon-based forward and reverse genetic technologies will contribute greatly to ongoing efforts to study mosquito functional genomics. A piggyBac transposon-based enhancer-trap system was developed that functions efficiently in the human malaria vector, Anopheles stephensi. The system consists of six transgenic lines of Anopheles stephensi, each with a single piggyBac-Gal4 element in a unique genomic location; six lines with a single piggyBac-UAStdTomato element; and two lines, each with a single Minos element containing the piggyBac-transposase gene under the regulatory control of the hsp70 promoter from Drosophila melanogaster. Enhancer detection depended upon the efficient remobilization of piggyBac-Gal4 transposons, which contain the yeast transcription factor gene Gal4 under the regulatory control of a basal promoter. Gal4 expression was detected through the expression of the fluorescent protein gene tdTomato under the regulatory control of a promoter with Gal4-binding UAS elements. From five genetic screens for larval- and adult-specific enhancers, 314 progeny were recovered from 24,250 total progeny (1.3%) with unique patterns of tdTomato expression arising from the influence of an enhancer. The frequency of piggyBac remobilization and enhancer detection was 2.5- to 3-fold higher in female germ lines compared with male germ lines. A small collection of enhancer-trap lines are described in which Gal4 expression occurred in adult female salivary glands, midgut, and fat body, either singly or in combination. These three tissues play critical roles during the infection of Anopheles stephensi by malaria-causing Plasmodium parasites. This system and the lines generated using it will be valuable resources to ongoing mosquito functional genomics efforts.

  9. Mosquito Species Composition and Plasmodium vivax Infection Rates on Baengnyeong-do (Island), Republic of Korea

    Science.gov (United States)

    2011-09-01

    313 © 2011, Korean Society for Parasitology This is an Open Access article distributed under the terms of the Creative Commons Attribution Non... parasite rates for different species have been reported [8,9], but few data of a similar nature are available for the DPRK. Anopheles belenrae...the prob­ ability of detecting DNA from parasite oocysts in the midgut. The head and thorax of a subsample of 257 mosquitoes were identified by PCR

  10. Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Malongo, Bernard B.; Simonsen, Paul E.

    2016-01-01

    Background: Ivermectin is used extensively globally for treatment of helminthic and ectoparasitic infections in animals and humans. The effect of excreted ivermectin on non-target organisms in aquatic and terrestrial environments has been increasingly reported. Due to its low water solubility...... and adsorption to sediments, the ivermectin exposure-risk to aquatic organisms dwelling in different strata of water bodies varies. This study assessed the survival of larvae of Anopheles gambiae Giles and Culex quinquefasciatus Say, when exposed to low concentrations of ivermectin under laboratory conditions...

  11. Small-scale field evaluation of the monomolecular surface film 'Arosurf MSF' against Anopheles arabiensis Patton.

    Science.gov (United States)

    Karanja, D M; Githeko, A K; Vulule, J M

    1994-04-01

    A field trial was conducted to test the insecticidal action of the monolayer surface film 'Arosurf MSF' applied by knapsack sprayers, against larvae and pupae of Anopheles arabiensis Patton in a rice irrigation scheme in Western Kenya. Larval and pupal densities and the number of emerging adults were determined by dipping and emergence cages respectively. Application of the monolayer by knapsack sprayers provided good coverage. There were high daily mortalities of the fourth instar larvae, with no adult emergence from 'Arosurf MSF' treated plots compared to lower fourth instar mortalities and continuous adult emergence from untreated control plots, indicating the potential of the monolayer for control of An. arabiensis mosquitoes in rice fields.

  12. Insecticidal activity of the essential oil of Thymus transcaspicus against Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Leila Dargahi; Kamal Razavi-Azarkhiavi; Mohammad Ramezani; Mohammad Reza Abaee; Javad Behravan

    2014-01-01

    Objective:To investigate the insecticidal activity of the essential oil of Thymus transcaspicus (T. transcaspicus) against Anopheles stephensi (An. stephensi). Methods:An. stephensi were exposed to 31, 63, 125 and 250 µg/L of essential oil of T. transcaspicus for 24 h. Results:The most toxicity was observed at 250 µg/L of essential oil with the LC50 values of 134.1 µg/L after 24 h. Conclusions:The essential oil of T. transcaspicus exhibited strong insecticidal activity against An. stephensi which can be attributed to its constituent especially carvacrol and thymol phenols.

  13. Efficacy of leaves extract of Calotropis procera Ait. (Asclepiadaceae) in controlling Anopheles arabiensis and Culex quinquefasciatus mosquitoes.

    Science.gov (United States)

    Elimam, Abdalla M; Elmalik, Khitma H; Ali, Faysal S

    2009-10-01

    The present study aimed to investigate, the larvicidal, adult emergence inhibition and oviposition deterrent activity of aqueous leaves extract of Calotropis procera against Anopheles arabiensis and Culex quinquefasciatus as natural mosquito larvicide. The larvicidal activity was monitored against 2nd, 3rd and 4th instar larvae of each mosquito species 24 h post-treatment. Adult emergence inhibition activity was tested by exposing 3rd instar larvae of each mosquito species to different concentrations of extracts (200, 400, 600, 800 and 1000 ppm for An. arabiensis and 100, 200, 300, 400, 500 and 600 ppm for Cx. quinquefasciatus). Probit analysis was used to analyze data from bioassay experiments. The oviposition deterrent activity was tested by using three different concentrations of extracts (1000, 500 and 200 for An. arabiensis, and 1000, 500 and 100 for Cx. quinquefasciatus) that caused high, moderate and low larval mortality in the larvicidal experiment against 3rd instar larvae. It was found that, LC50-LC90 values calculated were 273.53-783.43, 366.44-1018.59 and 454.99-1224.62 ppm for 2nd, 3rd and 4th larval instars, respectively, of An. arabiensis and 187.93-433.51, 218.27-538.27 and 264.85-769.13 ppm for 2nd, 3rd and 4th larval instars, respectively, of Cx. quinquefasciatus. Fifty percent of adult emergence inhibition (EI50) was shown at 277.90 and 183.65 ppm for An. arabiensis and Cx. quinquefasciatus, respectively. The pupal stage was not affected till a concentration of 5000 ppm. The extract showed oviposition deterrence and effective repellence against both mosquito species at different concentrations, with the observation on that maximal eggs were laid in low concentration of extract. These results suggest that the leaves extract of C. procera possess remarkable larvicidal, adult emergence inhibitor, repellent and oviposition deterrent effect against both An. arabiensis and Cx. quinquefasciatus, and might be used as natural biocides for mosquito

  14. Insect repellent activity of medicinal plant oils against Aedes aegypti (Linn.), Anopheles minimus (Theobald) and Culex quinquefasciatus Say based on protection time and biting rate.

    Science.gov (United States)

    Phasomkusolsil, Siriporn; Soonwera, Mayura

    2010-07-01

    This study investigated insect bite protection and length of the protection with 30 repellents which were divided into 3 categories: plant oil, essential oil and essential oil with ethyl alcohol, tested against three mosquito species, Aedes aegypti, Anopheles minimus and Culex quinquefasciatus, under laboratory conditions. The plant oil group was comprised of Phlai (Zingiber cassumunar) and Sweet basil (Ocimum basilicum). Both substances were effective as repellents and feeding deterrents against An. minimus (205 minutes protection time and a biting rate of 0.9%), Cx. quinquefasciatus (165 minutes protection time and 0.9% biting rate) and Ae. aegypti (90 minutes protection time and 0.8% biting rate). Essential oil from citronella grass (Cymbopogon nardus) exhibited protection against biting from all 3 mosquito species: for An. minimus, Cx. quinquefasciatus and Ae. aegypti, the results were 130 minutes and 0.9%, 140 minutes and 0.8%, and 115 minutes and 0.8%, respectively. The period of protection time against Ae. aegypti for all repellent candidates tested was lower than the Thai Industrial Standards Institute (TISI) determined time of greater than 2 hours.

  15. Larvicidal, adult emergence inhibition and oviposition deterrent effects of foliage extract from Ricinus communis L. against Anopheles arabiensis and Culex quinquefasciatus in Sudan.

    Science.gov (United States)

    Elimam, Abdalla M; Elmalik, Khitma H; Ali, Faysal S

    2009-08-01

    Malaria and filariases are prevalent in Sudan and their control depends largely on preventive measures against mosquito vectors. The present work aimed to investigate the larvicidal, adults emergence inhibition and oviposition deterrent effects of aqueous extracts from leaves of Ricinus communis L. against the mosquitoes, Anopheles arabiensis and Culex quinquefasciatus as a biological control means. The larval mortality was observed after 24 hours. The LC50 values calculated were 403.65, 445.66 and 498.88 ppm against 2nd, 3rd and 4th instar larvae of An. arabiensis and 1091.44, 1364.58 and 1445.44 ppm against 2nd, 3rd and 4th larval instars of Cx. quinquefasciatus. 50% of adult emergence inhibition (EI50) were 374.97 and 1180.32 ppm against 3rd instar larvae of An. arabiensis and Cx. quinquefasciatus. The extract showed oviposition deterrent effect against both species. Results reveal that the crude extract of R. communis possesses remarkable larvicidal, adult emergence inhibition and oviposition deterrent properties against both the tested species and can be used as biological control means.

  16. Toxicity of pirimiphos methyl (Actellic 25EC) on Anopheles gambiae s.s., Culex quinquefasciatus (Diptera: Culicidae), and potential biocontrol agent, Poecilia reticulata (Pisces: Poeciliidae).

    Science.gov (United States)

    Anogwih, Joy A

    2014-08-01

    The toxicity of an emulsifiable formulation of pirimiphos methyl (Actellic 25EC) on Anopheles gambiae s.s. Giles, Culex quinquefasciatus Say (Diptera: Culicidae), and predator fish Poecilia reticulata Peters (Pisces: Poeciliidae) was investigated. Acute toxicity tests were carried out to determine the effect of the larvicide on mosquito larvae and fish species. To investigate the nontarget effects on P. reticulata, fish of similar size (3.5 +/- 0.2 cm) were randomly selected and exposed for 28 d, under static renewal bioassay, to sublethal concentrations of the larvicide capable of killing 30 and 70% of Cx. quinquefasciatus. The 24 h LC50 value of pirimiphos methyl on the test organisms ranged between 20.44 and 697.30 microg liter(-1). The ultrastructural changes observed in the intestinal cells of P. reticulata were characterized by degenerating cell membranes with gradual loss of gray area in pycnotic nucleus at lower concentration. Marked damage was found at higher concentration including distinct loss of gray areas in cytosol, absence of cristae, numerous ruptures, and several dead cells. Pirimiphos methyl was toxic to a predatory fish species, and for its relevance in vector control and crop protection, warrants cumulative assessment to establish its comprehensive ecological risk, and the dosage required for field larviciding.

  17. Extent of digestion affects the success of amplifying human DNA from blood meals of Anopheles gambiae (Diptera: Culicidae)

    NARCIS (Netherlands)

    Mukabana, W.R.; Takken, W.; Seda, P.; Killeen, G.F.; Hawley, W.A.; Knols, B.G.J.

    2002-01-01

    The success of distinguishing blood meal sources of Anopheles gambiae Giles through deoxyribonucleic acid (DNA) profiling was investigated by polymerase chain reaction (PCR) amplification at the TC-11 and VWA human short tandem repeats (STR) loci. Blood meal size and locus had no significant effect

  18. First report of Metarhizium anisopliae IP 46 pathogenicity in adult Anopheles gambiae s.s. and An. arabiensis (Diptera; Culicidae)

    NARCIS (Netherlands)

    Mnyone, L.L.; Russell, T.L.; Lyimo, I.N.; Lwetoijera, D.W.; Kirby, M.J.; Luz, C.

    2009-01-01

    The entomopathogenic fungus Metarhizium anisopliae isolate IP 46, originating from a soil sample collected in 2001 in the Cerrado of Central Brazil, was tested for its ability to reduce the survival of adult male and female Anopheles gambiae s.s. and An. arabiensis mosquitoes. A 6-h exposure to the

  19. A new robust diagnostic polymerase chain reaction for determining the mating status of female Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Ng'habi, K.R.; Horton, A.; Knols, B.G.J.; Lanzaro, G.C.

    2007-01-01

    The principal malaria vector in Africa, Anopheles gambiae, contains two pairs of autosomes and one pair of sex chromosomes. The Y chromosome is only associated with males and other Y chromosome¿specific DNA sequences, which are transferred to women during mating. A reliable tool to determine the mat

  20. Differential attractiveness of humans to the African malaria vector Anopheles gambiae Giles - Effects of host characteristics and parasite infection

    NARCIS (Netherlands)

    Mukabana, W.R.

    2002-01-01

    The results of a series of studies designed to understand the principal factors that determine the differential attractiveness of humans to the malaria vector Anopheles gambiae are described in this thesis. Specific

  1. Additional selection for insecticide resistance in urban malaria vectors: DDT resistance in Anopheles arabiensis from Bobo-Dioulasso, Burkina Faso.

    Directory of Open Access Journals (Sweden)

    Christopher M Jones

    Full Text Available In the city of Bobo-Dioulasso in Burkina Faso, Anopheles arabiensis has superseded Anopheles gambiae s.s. as the major malaria vector and the larvae are found in highly polluted habitats normally considered unsuitable for Anopheles mosquitoes. Here we show that An. gambiae s.l. adults emerging from a highly polluted site in the city centre (Dioulassoba have a high prevalence of DDT resistance (percentage mortality after exposure to diagnostic dose=65.8% in the dry season and 70.4% in the rainy season, respectively. An investigation into the mechanisms responsible found an unexpectedly high frequency of the 1014S kdr mutation (allele frequency=0.4, which is found at very low frequencies in An. arabiensis in the surrounding rural areas, and an increase in transcript levels of several detoxification genes, notably from the glutathione transferase and cytochrome P450 gene families. A number of ABC transporter genes were also expressed at elevated levels in the DDT resistant An. arabiensis. Unplanned urbanisation provides numerous breeding grounds for mosquitoes. The finding that Anopheles mosquitoes adapted to these urban breeding sites have a high prevalence of insecticide resistance has important implications for our understanding of the selective forces responsible for the rapid spread of insecticide resistant populations of malaria vectors in Africa.

  2. Larvicidal and repellent activity of Vetiveria zizaniodes (Poaceae) essential oil against the malaria vector Anopheles stephensi (Liston) (Diptera: Culicidae)

    Science.gov (United States)

    Essential oil extracted by steam distillation of Vetiveria zizanioides (L.) Nash (Poaceae) was evaluated for larvicidal and adult repellent activity against the malaria vector Anopheles stephensi (Liston). Median lethal concentrations (LC50) at 24 h post treatment for instars 1-4 were, respectively,...

  3. Toxicity of six plant extracts and two pyridine alkaloids from Ricinus communis against the malaria vector Anopheles gambiae

    Science.gov (United States)

    The African malaria vector, Anopheles gambiae s.s., is known to feed selectively on certain plants for sugar sources. However, the adaptive significance of this behavior especially on how the extracts of such plants impact on the fitness of this vector has not been explored. This study determined th...

  4. Malaria in Suriname: a new era : impact of modified intervention strategies on Anopheles darlingi populations and malaria incidence

    NARCIS (Netherlands)

    Hiwat-van Laar, H.

    2011-01-01

    Malaria is an infectious disease caused by Plasmodiumblood parasites which live inside the human host and are spread by Anopheles mosquitoes.Every year an estimated 225 million new cases and near 800.000 malaria deaths are reported. Control of the disease is a formidable task involving all three liv

  5. Unassisted isolated-pair mating of Anopheles gambiae (Diptera: Culicidae) mosquitoes.

    Science.gov (United States)

    Benedict, Mark Q; Rafferty, Cristina S

    2002-11-01

    Female Anopheles mosquitoes usually mate only once, but mating is seldom seen in small containers containing only one female and male. Therefore, matings are often performed among many adults in large cages or by forced copulation. Isolated-pair mating of Anopheles gambiae G3 strain-derived mosquitoes without forced copulation in small vials is described. We observed that the experimental variables eye color and male number were significant factors in the mating frequency. Females mated more frequently when three males were present over only one male. White-eyed females were more likely to be mated than wild-eyed females, but wild males mated more frequently than did white-eyed males. Experiments were also conducted to determine when mating was occurring by using wild-eye-color mosquitoes in isolated pairs. Almost no matings were observed before day 6 rather than the frequencies typically observed after 1-2 d in standard large-cage matings among large numbers of adults.

  6. Indirect evidence that agricultural pesticides select for insecticide resistance in the malaria vector Anopheles gambiae.

    Science.gov (United States)

    Luc, Djogbénou S; Benoit, Assogba; Laurette, Djossou; Michel, Makoutode

    2016-06-01

    We investigated the possible relationship between the agricultural use of insecticides and the emergence of insecticide resistance. Bioassays were conducted using simulated mosquito larval habitats and well known Anopheles gambiae strains. Soil samples were collected from vegetable production areas in Benin, including one site with insecticide use, one site where insecticides had not been used for two months, and a third where insecticides had not been used. Pupation and emergence rates were very low in pyrethroid-susceptible strains when exposed to soil that had been recently exposed to insecticides. Pupation and emergence rates in strains with the kdr mutation alone or both the kdr and Ace-1 mutations were much higher. Overall, strains with the kdr mutation survived at higher rates compared to that without kdr mutation. Although this study is observational, we provide indirect evidence indicating that soils from agricultural areas contain insecticide residues that can play a role in the emergence of insecticide resistance in Anopheles. This aspect should be taken into account to better utilize the insecticide in the context of integrated pest management programs.

  7. Phytochemistry and larvicidal activity of Eucalyptus camaldulensisagainst malaria vector,Anopheles stephensi

    Institute of Scientific and Technical Information of China (English)

    Sedaghat Mohamad Medhi; SaneiAli Reza; Khnavi Mahnaz; Abai Mohammad Reza; Hadjiakhoondi Abbas; MohtaramiFatemeh; VatandoostHassan

    2010-01-01

    Objective:To determine phytochemistry and larvicidal activity ofEucalyptus camaldulensis againstAnopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography/mass spectrometry (GC/MS). The larvicidal activity of essential oils and extract of leaf were tested against 4th instar larvae of laboratory-rearedAnopheles stephensi.Results:GC/MS analyses identified the presence of28 compounds corresponding to 99.60%of the total oil. The main constituents in the leaf essential oil were1,8-cineole(69.46%), γ-Terpinene(15.10%), α-Pinene(5.47%)and Globulol(2%). The leaf extract and volatile oil exerted significant larvicidal activity withLC50 values of89.85 and397.75ppm, respectively. Clear dose-response relationships were established with the highest dose of320 ppm essential oil extract resulted almost100% mortality in the population.Conclusions:The larvicidal properties suggest that the essential oil of plant is a potential source of valuable larvicidal compounds against malaria vector and can be used as an alternative to synthetic insecticides.

  8. Exogenous gypsy insulator sequences modulate transgene expression in the malaria vector mosquito, Anopheles stephensi.

    Science.gov (United States)

    Carballar-Lejarazú, Rebeca; Jasinskiene, Nijole; James, Anthony A

    2013-04-30

    Malaria parasites are transmitted to humans by mosquitoes of the genus Anopheles, and these insects are the targets of innovative vector control programs. Proposed approaches include the use of genetic strategies based on transgenic mosquitoes to suppress or modify vector populations. Although substantial advances have been made in engineering resistant mosquito strains, limited efforts have been made in refining mosquito transgene expression, in particular attenuating the effects of insertions sites, which can result in variations in phenotypes and impacts on fitness due to the random integration of transposon constructs. A promising strategy to mitigate position effects is the identification of insulator or boundary DNA elements that could be used to isolate transgenes from the effects of their genomic environment. We applied quantitative approaches that show that exogenous insulator-like DNA derived from the Drosophila melanogaster gypsy retrotransposon can increase and stabilize transgene expression in transposon-mediated random insertions and recombinase-catalyzed, site-specific integrations in the malaria vector mosquito, Anopheles stephensi. These sequences can contribute to precise expression of transgenes in mosquitoes engineered for both basic and applied goals.

  9. "Comparison of Midgut Hemagglutination Activity in Three Different Geographical Populations of Anopheles stephensi"

    Directory of Open Access Journals (Sweden)

    HR Basseri

    2004-08-01

    Full Text Available Lectins that agglutinate red blood cells (RBCs were demonstrated in Anopheles stephensi mosquito midgut extracts using human (four groups: A, B, AB and O, RH+ rat, sheep and rabbit blood cells. Only rabbit RBCs showed agglutination reaction against the midgut extracts. Significant differences in hemagglutinin titers and carbohydrate specifity were detected between male and female mosquitoes as well as among three different geographical populations of Anopheles stephensi from south of Iran. Overall agglutinin levels were increased following a blood meal. The highest hemagglintination titers were due to Kazerun population. All hemagglutination assays were versus rabbit RBCS. A significant difference was detected among the number of egg-float ridges. Iranshahr population was different from Bandar-abbas and Kazerun population in egg-float ridges number. Bandr-abbas population was in the intermediate category. Iranshahr population fell between mysoransis and intermediate group and Kazerun population was between intermediate and type form. This study presents the first report on the occurrence of heterogeneous anti Rabbit RBC agglutinins in the midget extracts of the different geographical populations of An.stephensi with the sugar – binding specificities. The sugar- inhibition pattern was different between & within geographical population of An.stephensi.

  10. The effect of parental rearing conditions on offspring life history in Anopheles stephensi

    Directory of Open Access Journals (Sweden)

    Maung Liam

    2007-09-01

    Full Text Available Abstract Background The environmental conditions experienced by parents are increasingly recognized to impact the success of offspring. Little is known on the presence of such parental effects in Anopheles. If present, parental effects could influence mosquito breeding programmes, some malaria control measures and have epidemiological and evolutionary consequences. Methods The presence of parental effects on offspring emergence time, size, survival, blood meal size and fecundity in laboratory reared An. stephensi were tested. Results Parental rearing conditions did not influence the time taken for offspring to emerge, or their size or survival as adults. However, parental effects were influential in determining the fecundity of daughters. Counter-intuitively, daughters of parents reared in low food conditions produced larger egg clutches than daughters of parents reared in high food conditions. Offspring reared in low food conditions took larger blood meals if their parents had also experienced a low food environment. Conclusion So far as we are aware, this is the first evidence of parental effects on progeny in Anopheles.

  11. A natural Anopheles-associated Penicillium chrysogenum enhances mosquito susceptibility to Plasmodium infection

    Science.gov (United States)

    Angleró-Rodríguez, Yesseinia I.; Blumberg, Benjamin J.; Dong, Yuemei; Sandiford, Simone L.; Pike, Andrew; Clayton, April M.; Dimopoulos, George

    2016-01-01

    Whereas studies have extensively examined the ability of bacteria to influence Plasmodium infection in the mosquito, the tripartite interactions between non-entomopathogenic fungi, mosquitoes, and Plasmodium parasites remain largely uncharacterized. Here we report the isolation of a common mosquito-associated ascomycete fungus, Penicillium chrysogenum, from the midgut of field-caught Anopheles mosquitoes. Although the presence of Pe. chrysogenum in the Anopheles gambiae midgut does not affect mosquito survival, it renders the mosquito significantly more susceptible to Plasmodium infection through a secreted heat-stable factor. We further provide evidence that the mechanism of the fungus-mediated modulation of mosquito susceptibility to Plasmodium involves an upregulation of the insect’s ornithine decarboxylase gene, which sequesters arginine for polyamine biosynthesis. Arginine plays an important role in the mosquito’s anti-Plasmodium defense as a substrate of nitric oxide production, and its availability therefore has a direct impact on the mosquito’s susceptibility to the parasite. While this type of immunomodulatory mechanism has already been demonstrated in other host-pathogen interaction systems, this is the first report of a mosquito-associated fungus that can suppress the mosquito’s innate immune system in a way that would favor Plasmodium infection and possibly malaria transmission. PMID:27678168

  12. Human antibody response to Anopheles saliva for comparing the efficacy of three malaria vector control methods in Balombo, Angola.

    Directory of Open Access Journals (Sweden)

    Laura Brosseau

    Full Text Available Human antibody (Ab response to Anopheles whole saliva, used as biomarker of Anopheles exposure, was investigated over a period of two years (2008-2009, in children between 2 to 9 years old, before and after the introduction of three different malaria vector control methods; deltamethrin treated long lasting impregnated nets (LLIN and insecticide treated plastic sheeting (ITPS--Zero Fly® (ITPS-ZF, deltamethrin impregnated Durable (Wall Lining (ITPS-DL--Zerovector® alone, and indoor residual spraying (IRS with lambdacyhalothrin alone. These different vector control methods resulted in considerable decreases in all three entomological (82.4%, parasitological (54.8% and immunological criteria analyzed. The highest reductions in the number of Anopheles collected and number of positive blood smears, respectively 82.1% and 58.3%, were found in Capango and Canjala where LLIN and ITPS-ZF were implemented. The immunological data based on the level of anti-saliva IgG Ab in children of all villages dropped significantly from 2008 to 2009, except in Chissequele. These results indicated that these three vector control methods significantly reduced malaria infections amongst the children studied and IRS significantly reduced the human-Anopheles contact. The number of Anopheles, positive blood smears, and the levels of anti-saliva IgG Ab were most reduced when LLIN and ITPS-ZF were used in combination, compared to the use of one vector control method alone, either ITPS-DL or IRS. Therefore, as a combination of two vector control methods is significantly more effective than one control method only, this control strategy should be further developed at a more global scale.

  13. A Study of the Essential Oils of Four Sudanese Accessions of Basil (Ocimum basilicum L. Against Anopheles Mosquito Larvae

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    Azhari H. Nour

    2009-01-01

    Full Text Available Problem statement: Certain basil essential oils were claimed to have a larvicidal activity towards mosquito's larvae. To test this claim the essential oils of four accessions of basil grown in Sudan were selected and tested for Anopheles larvae. Malaria is the major health problem in the Sudan and the whole country is now considered endemic, with varying degrees, about 35,000 deaths every year due to malaria. Anopheles mosquito is the major vector of malaria disease in Sudan. Search for larvicidal active compound(s is one of several attempts to fine effective and affordable ways to control this mosquito. To determine the toxic effects of basil essential oils extracted by steam distillation against Anopheles larvae. Approach: For the larvicidal bioassay, three concentrations (100, 300, 500 ppm of essential oil solutions of four basil accessions were prepared; 1 mL of ethanol was used to solubilize the oil in water (999 mL. In each concentration of oil solution were inserted 20 larvae (third instars. A set of controls using 0.1% ethanol and untreated sets of larvae in (tap water, were also run for comparison. Data were evaluated through regression analysis, from the regression line; the LC50 values were read. The active ingredients were separated and/ or identified by TLC, IR and GC-MS. Results: Larvicidal activity of the essential oils is varied, lasted for about 9 h and thereafter decreased, LC50 values ranging from 190-300 ppm. Linalool, geraniol and eugenol are active components of basil essential oil against Anopheles larvae. Two accessions were caused 100% mortality at a concentration range 300-500 ppm for 3 h. Conclusion: These results indicated that basil essential oils have larvicidal activity towards Anopheles larvae. Therefore, could be affordable way to control this mosquito.

  14. A note on the insecticide susceptibility status of principal malaria vector Anopheles culicifacies in four states of India

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    Kamaraju Raghavendra

    2014-08-01

    Full Text Available Background & objectives: The major malaria vector, Anopheles culicifacies Giles is reported to contribute ~ 65% of the malaria cases in India. This species developed resistance to DDT and later to HCH, malathion and also to pyrethroids in some states due to their use in the national malaria control programme. In the present study, insecticide susceptibility of this species was monitored in four states of India. Methods: To determine insecticide susceptibility status of the major malaria vector An. culicifacies, adult mosquitoes were collected from different localities of 32 tribal districts in the states of Andhra Pradesh, Odisha, Jharkhand and West Bengal during October/November 2009-10. Mosquitoes were collected from stratified ecotypes comprising a group of districts in West Bengal and individual districts in three other states. Mosquitoes were exposed to papers treated with WHO diagnostic dose: 4% DDT, 5% malathion and 0.05% deltamethrin following the WHO tube method. Results: Results provided the susceptibility status of An. culicifacies to different insecticides used in the public health programme in 32 districts in four states. An. culicifacies was found resistant to DDT (mortality range 0-36% in all the 32 districts; to malathion it was resistant in 14 districts, verification required in 10 districts and susceptible in eight districts (mortality range 32.2-100%. It was resistant to deltamethrin in four districts, verification required in 11 districts and susceptible in 17 districts (mortality range 43.3-100%. Interpretation & conclusion: Development of widespread resistance to insecticides used in public health sprays for vector control including to pyrethroids in An. culicifacies in the surveyed districts is of great concern for the malaria control programme as the major interventions for vector control are heavily reliant on chemical insecticides, mainly synthetic pyrethroids used both for indoor residual spraying and for long

  15. Detection of the East and West African kdr mutation in Anopheles gambiae and Anopheles arabiensis from Uganda using a new assay based on FRET/Melt Curve analysis

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    Backeljau Thierry

    2006-02-01

    Full Text Available Abstract Background Appropriate monitoring of vector resistance to insecticides is an integral component of planning and evaluation of insecticide use in malaria control programmes. The malaria vectors Anopheles gambiae s.s. and Anopheles arabiensis have developed resistance to pyrethroid insecticides as a result of a mechanism conferring reduced nervous system sensitivity, better known as knockdown resistance (kdr. In An. gambiae s.s. and An. arabiensis, two different substitutions in the para-type sodium channel, a L1014F substitution common in West Africa and a L1014S replacement found in Kenya, are linked with kdr. Two different allele-specific polymerase chain reactions (AS-PCR are needed to detect these known kdr mutations. However, these AS-PCR assays rely on a single nucleotide polymorphism mismatch, which can result in unreliable results. Methods Here, a new assay for the detection of knockdown resistance in An. gambiae s.s. and An. arabiensis based on Fluorescence Resonance Energy Transfer/Melt Curve analysis (FRET/MCA is presented and compared with the existing assays. Results The new FRET/MCA method has the important advantage of detecting both kdr alleles in one assay. Moreover, results show that the FRET/MCA is more reliable and more sensitive than the existing AS-PCR assays and is able to detect new genotypes. By using this technique, the presence of the East African kdr mutation (L1014S is shown for the first time in An. arabiensis specimens from Uganda. In addition, a new kdr genotype is reported in An. gambiae s.s. from Uganda, where four An. gambiae s.s. mosquitoes possess both, the West (L1014F and East (L1014S African kdr allele, simultaneously. Conclusion The presence of both kdr mutations in the same geographical region shows the necessity of a reliable assay that enables to detect both mutations in one single assay. Hence, this new assay based on FRET/MCA will improve the screening of the kdr frequencies in An. gambiae s

  16. Mosquito species succession and physicochemical factors affecting their abundance in rice fields in Mwea, Kenya.

    Science.gov (United States)

    Muturi, Ephantus J; Mwangangi, Joseph; Shililu, Josephat; Muriu, Simon; Jacob, Benjamin; Kabiru, Ephantus; Gu, Weidong; Mbogo, Charles; Githure, John; Novak, Robert

    2007-03-01

    The succession of mosquito species and abiotic factors affecting their distribution and abundance in rice (Oryza spp.) fields was investigated over a 16-wk rice growing cycle covering the period between January and May 2006. Fifteen experimental rice plots were sampled for mosquito larvae and characterized based on rice height, number of tillers, floating vegetation cover, water depth, water temperature, turbidity, salinity, pH, dissolved oxygen, total dissolved solids, and conductivity. Microscopic identification of 3,025 larvae yielded nine mosquito species predominated by Anopheles arabiensis Patton (45.0%), Culex quinquefasciatus Say (35.8%), Anopheles pharoensis Theobald (9.0%) and Ficalbia splendens Theobald (7.1%). Other species, including Anopheles rufipes Gough, Anopheles coustani Laveran, Anonopheles maculipalpis Giles, Culex annulioris Theobald, and Culex poicilipes Theobald made up 3.1% of the total collection. Anopheles gambiae s.l., Cx. quinquefasciatus, and An. pharoensis occurred throughout the cycle, but they were more abundant up to 4 wk posttransplanting with peaks after fertilizer application. As rice plants became established, three groups of mosquitoes were recognized: the first groups included An. rufipes, Fl. splendens, and Cx. annulioris, which occurred throughout much of the second half of the rice cycle, whereas the second group included Cx. poicilipes, which was found in the middle of the rice cycle. An. coustani and An. maculipalpis formed the third group occurring toward the end of the cycle. Dissolved oxygen, number of tillers, and rice height were negatively associated with the abundance ofAn. arabiensis and Cx. quinquefasciatus larvae. In addition, Cx. quinquefasciatus also was associated with water depth (-ve) and turbidity (+ve). Abundance of An. pharoensis larvae was significantly associated with water temperature (+ve), the number of tillers (-ve), and rice height (-ve), whereas Fl. splendens was significantly associated with

  17. Population Structure of the Primary Malaria Vector in South America, Anopheles darlingi, Using Isozyme, Random Amplified Polymorphic DNA, Internal Transcribed Spacer 2, and Morphologic Markers

    Science.gov (United States)

    1999-01-01

    derscoring some congruence, in this case, between two dif- ferent molecular markers. Intraspecific variation in the ITS2 region of 21 members of...morphism in the salivary gland chromosomes of Anopheles darlingi. Mosq News 32: 555-565. 29. Tadei WP, Santos JMN, Rabbani MG, 1982. Biologia de ano...Contel EPB, dos Santos JMM, Tadei Wp, 1984. Biologia de Anophelinos Amazonicos. VI. Enzimatica em Anopheles dar- lingi Root (Dipt.: Culicidae). Acta

  18. Evaluation of four sampling techniques for surveillance of Culex quinquefasciatus (Diptera: Culicidae) and other mosquitoes in African rice agroecosystems.

    Science.gov (United States)

    Muturi, Ephantus J; Mwangangi, Joseph; Shililu, Josephat; Muriu, Simon; Jacob, Benjamin; Mbogo, Charles M; John, Githure; Novak, Robert

    2007-05-01

    Field studies were conducted in a rice, Oryza sativa L., agroecosystem in Mwea Kenya to compare the efficiency of CO2-baited Centers for Disease Control (CDC) light traps against nonbaited CDC light traps and gravid traps against oviposition traps in outdoor collection of Culex quinquefasciatus Say (Diptera: Culicidae) and other mosquitoes. Collectively, 21 mosquito species from the genera Culex, Anopheles, Mansonia, Ficalbia, and Aedes were captured during the 10-wk study period. Cx. quinquefasciatus was the predominant species in all trap types with proportions ranging from 57% in the nonbaited CDC light traps to 95% in the gravid traps. Significantly higher numbers of Cx. quinquefasciatus and Culex annulioris Theobald were collected in the CO2-baited CDC light traps than in the nonbaited CDC light traps, but the numbers of other mosquito species, including malaria vectors Anopheles arabiensis Patton and Anopheles funestus Giles did not differ significantly between the two trap types. More Cx. quinquefasciatus females were collected in grass infusion-baited gravid traps than egg rafts of this species in oviposition traps containing the same infusion. Although most mosquitoes captured in CO,-baited and nonbaited CDC light traps were unfed, most of those collected in gravid traps were gravid. From these findings, it is concluded that at least in the rice-growing area of Mwea Kenya, CO2-baited CDC light traps in conjunction with gravid traps can be used in monitoring of Cx. quinquefasciatus both for control and disease surveillance.

  19. Identification of one capa and two pyrokinin receptors from the malaria mosquito Anopheles gambiae.

    Science.gov (United States)

    Olsen, Stine S; Cazzamali, Giuseppe; Williamson, Michael; Grimmelikhuijzen, Cornelis J P; Hauser, Frank

    2007-10-19

    We cloned the cDNA of three evolutionarily related G protein-coupled receptors from the malaria mosquito Anopheles gambiae and functionally expressed them in Chinese hamster ovary cells. One receptor, Ang-Capa-R, was only activated by the two Anopheles capa neuropeptides Ang-capa-1 (GPTVGLFAFPRVamide) and Ang-capa-2 (pQGLVPFPRVamide) with EC(50) values of 8.6x10(-9)M and 3.3x10(-9)M, respectively, but not by any other known mosquito neuropeptide. The second receptor, Ang-PK-1-R, was selectively activated by the Anopheles pyrokinin-1 peptides Ang-PK-1-1 (AGGTGANSAMWFGPRLamide) and Ang-PK-1-2 (AAAMWFGPRLamide) with EC(50) values of 3.3x10(-8)M and 2.5x10(-8)M, respectively, but not by mosquito capa or pyrokinin-2 peptides. For the third receptor, Ang-PK-2-R, the most potent ligands were the pyrokinin-2 peptides Ang-PK-2-1 (DSVGENHQRPPFAPRLamide) and Ang-PK-2-2 (NLPFSPRLamide) with EC(50) values of 5.2x10(-9)M and 6.4x10(-9)M, respectively. However, this receptor could also be activated by the two pyrokinins-1, albeit with lower potency (EC(50): 2-5x10(-8)M). Because Ang-capa-1 and -2 and Ang-PK-1-1 are located on one preprohormone and the other peptides on another prohormone, these results imply a considerable crosstalk between the capa, pyrokinin-1 and pyrokinin-2 systems. Gene structure and phylogenetic tree analyses showed that Ang-Capa-R was the orthologue of the Drosophila capa receptor CG14575, Ang-PK-1-R the orthologue of the Drosophila pyrokinin-1 receptor CG9918, and Ang-PK-2-R the orthologue of the Drosophila pyrokinin-2 receptors CG8784 and CG8795. This is the first report on the functional characterization and crosstalk properties of capa and pyrokinin receptors in mosquitoes.

  20. Evidence that agricultural use of pesticides selects pyrethroid resistance within Anopheles gambiae s.l. populations from cotton growing areas in Burkina Faso, West Africa

    Science.gov (United States)

    Hien, Aristide Sawdetuo; Soma, Dieudonné Diloma; Hema, Omer; Bayili, Bazoma; Namountougou, Moussa; Gnankiné, Olivier; Baldet, Thierry; Diabaté, Abdoulaye; Dabiré, Kounbobr Roch

    2017-01-01

    Many studies have shown the role of agriculture in the selection and spread of resistance of Anopheles gambiae s.l. to insecticides. However, no study has directly demonstrated the presence of insecticides in breeding sources as a source of selection for this resistance. It is in this context that we investigated the presence of pesticide residues in breeding habitats and their formal involvement in vector resistance to insecticides in areas of West Africa with intensive farming. This study was carried out from June to November 2013 in Dano, southwest Burkina Faso in areas of conventional (CC) and biological cotton (BC) growing. Water and sediment samples collected from breeding sites located near BC and CC fields were submitted for chromatographic analysis to research and titrate the residual insecticide content found there. Larvae were also collected in these breeding sites and used in toxicity tests to compare their mortality to those of the susceptible strain, Anopheles gambiae Kisumu. All tested mosquitoes (living and dead) were analyzed by PCR for species identification and characterization of resistance genes. The toxicity analysis of water from breeding sites showed significantly lower mortality rates in breeding site water from biological cotton (WBC) growing sites compared to that from conventional cotton (WCC) sites respective to both An. gambiae Kisumu (WBC: 80.75% vs WCC: 92.75%) and a wild-type strain (49.75% vs 66.5%). The allele frequencies L1014F, L1014S kdr, and G116S ace -1R mutations conferring resistance, respectively, to pyrethroids and carbamates / organophosphates were 0.95, 0.4 and 0.12. Deltamethrin and lambda-cyhalothrin were identified in the water samples taken in October/November from mosquitoes breeding in the CC growing area. The concentrations obtained were respectively 0.0147ug/L and 1.49 ug/L to deltamethrin and lambdacyhalothrin. Our results provided evidence by direct analysis (biological and chromatographic tests) of the role

  1. Dynamics of multiple insecticide resistance in the malaria vector Anopheles gambiae in a rice growing area in South-Western Burkina Faso

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    Ouédraogo Jean-Bosco

    2008-09-01

    Full Text Available Abstract Background Insecticide resistance of the main malaria vector, Anopheles gambiae, has been reported in south-western Burkina Faso, West Africa. Cross-resistance to DDT and pyrethroids was conferred by alterations at site of action in the sodium channel, the Leu-Phe kdr mutation; resistance to organophosphates and carbamates resulted from a single point mutation in the oxyanion hole of the acetylcholinesterase enzyme designed as ace-1R. Methods An entomological survey was carried out during the rainy season of 2005 at Vallée du Kou, a rice growing area in south-western Burkina Faso. At the Vallée du Kou, both insecticide resistance mechanisms have been previously described in the M and S molecular forms of An. gambiae. This survey aimed i to update the temporal dynamics and the circumsporozoite infection rate of the two molecular forms M and S of An. gambiae ii to update the frequency of the Leu-Phe kdr mutation within these forms and finally iii to investigate the occurrence of the ace-1R mutation. Mosquitoes collected by indoor residual collection and by human landing catches were counted and morphologically identified. Species and molecular forms of An. gambiae, ace-1R and Leu-Phe kdr mutations were determined using PCR techniques. The presence of the circumsporozoite protein of Plasmodium falciparum was determined using ELISA. Results Anopheles gambiae populations were dominated by the M form. However the S form occurred in relative important proportion towards the end of the rainy season with a maximum peak in October at 51%. Sporozoite rates were similar in both forms. The frequency of the Leu-Phe kdr mutation in the S form reached a fixation level while it is still spreading in the M form. Furthermore, the ace-1R mutation prevailed predominately in the S form and has just started spreading in the M form. The two mutations occurred concomitantly both in M and S populations. Conclusion These results showed that the Vallée du Kou

  2. Abiotic and biotic factors associated with the presence of Anopheles arabiensis immatures and their abundance in naturally occurring and man-made aquatic habitats

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    Gouagna Louis

    2012-07-01

    Full Text Available Abstract Background Anopheles arabiensis (Diptera: Culicidae is a potential malaria vector commonly present at low altitudes in remote areas in Reunion Island. Little attention has been paid to the environmental conditions driving larval development and abundance patterns in potential habitats. Two field surveys were designed to determine whether factors that discriminate between aquatic habitats with and without An. arabiensis larvae also drive larval abundance, comparatively in man-made and naturally occurring habitats. Methods In an initial preliminary survey, a representative sample of aquatic habitats that would be amenable to an intensive long-term study were selected and divided into positive and negative sites based on the presence or absence of Anopheles arabiensis larvae. Subsequently, a second survey was prompted to gain a better understanding of biotic and abiotic drivers of larval abundance, comparatively in man-made and naturally occurring habitats in the two studied locations. In both surveys, weekly sampling was performed to record mosquito species composition and larval density within individual habitats, as well as in situ biological characteristics and physico-chemical properties. Results Whilst virtually any stagnant water body could be a potential breeding ground for An. arabiensis, habitats occupied by their immatures had different structural and biological characteristics when compared to those where larvae were absent. Larval occurrence seemed to be influenced by flow velocity, macrofauna diversity and predation pressure. Interestingly, the relative abundance of larvae in man-made habitats (average: 0.55 larvae per dip, 95%CI [0.3–0.7] was significantly lower than that recorded in naturally occurring ones (0.74, 95%CI [0.5–0.8]. Such differences may be accounted for in part by varying pressures that could be linked to a specific habitat. Conclusions If the larval ecology of An. arabiensis is in general very complex

  3. Mosquito larvicidal properties of silver nanoparticles synthesized using Heliotropium indicum (Boraginaceae) against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Rajeswary, Mohan; Muthukumaran, Udaiyan

    2014-06-01

    Mosquitoes transmit dreadful diseases to human beings wherein biological control of these vectors using plant-derived molecules would be an alternative to reduce mosquito population. In the present study activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using Helitropium indicum plant leaves against late third instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (30, 60, 90, 120, and 150 μg/mL) were tested against the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The synthesized AgNPs from H. indicum were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, transmission electron microscopy, and histogram. The synthesized AgNPs showed larvicidal effects after 24 h of exposure. Considerable mortality was evident after the treatment of H. indicum for all three important vector mosquitoes. The LC50 and LC90 values of H. indicum aqueous leaf extract appeared to be effective against A. stephensi (LC50, 68.73 μg/mL; LC90, 121.07 μg/mL) followed by A. aegypti (LC50, 72.72 μg/mL; LC90, 126.86 μg/mL) and C. quinquefasciatus (LC50, 78.74 μg/mL; LC90, 134.39 μg/mL). Synthesized AgNPs against the vector mosquitoes of A. stephensi, A. aegypti, and C. quinquefasciatus had the following LC50 and LC90 values: A. stephensi had LC50 and LC90 values of 18.40 and 32.45 μg/mL, A. aegypti had LC50 and LC90 values of 20.10 and 35.97 μg/mL, and C. quinquefasciatus had LC50 and LC90 values of 21.84 and 38.10 μg/mL. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H. indicum and green synthesis of silver nanoparticles have the

  4. Metagenomics, paratransgenesis and the Anopheles microbiome: a portrait of the geographical distribution of the anopheline microbiota based on a meta-analysis of reported taxa.

    Science.gov (United States)

    Villegas, Luis Martínez; Pimenta, Paulo Filemon Paolucci

    2014-08-01

    Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current "omics" era and the available data are mostly scattered or in "tables" that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.

  5. Green synthesis of silver nanoparticles using Cadaba indica lam leaf extract and its larvicidal and pupicidal activity against Anopheles stephensi and Culex quinquefasciatus

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    K. Kalimuthu

    2013-09-01

    Full Text Available Green nanoparticle synthesis was achieved using environmentally acceptable plant extracts and eco-friendly reducing and capping agents. In the present study, activity of silver nanoparticles (AgNPs synthesized using Cadaba indica lam plant against Anopheles stephensi and Culex quinquefasciatus was determined. A range of concentrations of synthesized AgNPs (3.125, 6.25, 12.5, 25, 50 ppm and crude extract (50, 100, 150, 200, 250 ppm were tested against A. stephensi and C. quinquefasciatus. The synthesized AgNPs from C. indica lam were much more toxic than crude extract in both mosquito species. The cured extract high mortality values were 50% lethal concentration (LC50=88.22, 90.84 ppm; 90% lethal concentration (LC90=172.94, 178.55 ppm, and the AgNPs high mortality values were LC50=3.90, 4.39 ppm; LC90=19.04, 17.35 ppm against A. stephensi and C. quinquefasciatus, respectively. The results recorded from ultraviolet-visible spectrophotometer, scanning electron microscopy, energy dispersive X-ray and Fourier transformed infrared support the biosynthesis and characterization of silver nanoparticles. These results suggest that the leaf cured extracts of C. indica lam and green synthesis of silver nanoparticles have the potential to be used as an ideal eco-friendly approach for the control of A. stephensi and C. quinquefasciatus.

  6. Mosquitocidal activity of indigenenous plants of Western Ghats, Achras sapota Linn. (Sapotaceae) and Cassia auriculata L. (Fabaceae) against a common malarial vector, Anopheles stephensi Liston (Culicidae:Diptera)

    Institute of Scientific and Technical Information of China (English)

    Kaliyamoorthy Krishnappa; Kuppusamy Elumalai

    2014-01-01

    Objective: To evaluate the mosquito larvicidal, ovicidal, pupicidal and repellent activities of hexane, diethyl ether, dichloromethane, acetone and methanol extracts of Indian medicinal plants, Achras sapota (A. sapota) and Cassia auriculata (C. auriculata) at different concentrations against Anopheles stephensi (An. stephensi), a malarial vector. Methods: Twenty five early third instar larvae of An. stephensi were exposed to various concentrations (30-210 mg/L) of plants extracts and were assayed in the laboratory by using the protocol of WHO 2005;then after 24 h LC50 values of the A. sapota and C. auriculata leaf extract was determined by probit analysis. The ovicidal activity was tested with the extracts ranging from 50-350 mg/L. The pupicidal activity was recorded after 24 h of exposure to the extract. The repellent efficacy was determined against mosquito species at two different concentrations 1.5 and 3.0 mg/cm2 under laboratory conditions. Results:Among the five different extracts tested against the An. stephensi, methanol extract of A. sapota proved to be an more effective solvent extract in almost all the parameters studied than C. auriculata. Conclusions:It is inferred that the leaf extract of A. sapota and C. auriculata could be used in vector control programme.

  7. Evaluation of larvicidal activity of the methanolic extracts of Piper alatabaccum branches and P. tuberculatum leaves and compounds isolated against Anopheles darlingi

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    Frances T. T. Trindade

    2012-10-01

    Full Text Available Piper is a notable genus among Piperaceae due to their secondary metabolites such as lignans, amides, esters and long chain fatty acids used as anti-herbivore defenses with comparable effects of pyrethroids, that holds a promise in insect control, including malaria vectors such as Anopheles darlingi, the main vector in the North of Brazil. Methanolic extracts of Piper tuberculatum Jacq., Piperaceae, and P. alatabaccum Trel. & Yunck., Piperaceae, and some isolated compounds, i.e, 3,4,5-trimetoxy-dihydrocinamic acid, dihydropiplartine; piplartine, piplartine-dihydropiplartine and 5,5',7-trimetoxy-3',4'-metilenodioxiflavone were tested as larvicides against A. darlingi. The Lethal Concentrations (LC50 and LC90 of methanolic extracts were 194 and 333 ppm for P. tuberculatum and 235 and 401 ppm for P. alatabacum, respectively. Isolated compounds had lower LC values, e.g. the LC50 and LC90 of the piplartine-dihidropiplartine isolated from both plant species was 40 and 79 ppm, respectively.

  8. Mosquitocidal activity of indigenenous plants of Western Ghats, Achras sapota Linn. (Sapotaceae and Cassia auriculata L. (Fabaceae against a common malarial vector, Anopheles stephensi Liston (Culicidae: Diptera

    Directory of Open Access Journals (Sweden)

    Kaliyamoorthy Krishnappa

    2014-05-01

    Full Text Available Objective: To evaluate the mosquito larvicidal, ovicidal, pupicidal and repellent activities of hexane, diethyl ether, dichloromethane, acetone and methanol extracts of Indian medicinal plants, Achras sapota (A. sapota and Cassia auriculata (C. auriculata at different concentrations against Anopheles stephensi (An. stephensi, a malarial vector. Methods: Twenty five early third instar larvae of An. stephensi were exposed to various concentrations (30-210 mg/L of plants extracts and were assayed in the laboratory by using the protocol of WHO 2005; then after 24 h LC50 values of the A. sapota and C. auriculata leaf extract was determined by probit analysis. The ovicidal activity was tested with the extracts ranging from 50- 350 mg/L. The pupicidal activity was recorded after 24 h of exposure to the extract. The repellent efficacy was determined against mosquito species at two different concentrations 1.5 and 3.0 mg/ cm2 under laboratory conditions. Results: Among the five different extracts tested against the An. stephensi, methanol extract of A. sapota proved to be an more effective solvent extract in almost all the parameters studied than C. auriculata. Conclusions: It is inferred that the leaf extract of A. sapota and C. auriculata could be used in vector control programme.

  9. THE BITING ACTIVITY OF ANOPHELES DTHALI IN A RURAL AREA OF MAMASANI UNDER IMPACT OF ORGANO-PHOSPHOROUS SPRAYING, SOUTHERN IRAN

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    N Eshghy

    1983-08-01

    Full Text Available Anopheles dthali Patton which is one of the 7 malaria vectors in Iran was not taken in to consideration until November 1965 when definite sporozaites were found for the first time in its salivary glands in Bandar Abbas, south of Iran. Afterwards, efforts have been made to get complete ecological and epidemiological information on this species. The areas of study were two districts of Mamasani, an agricultural area, located 200 km north of the Persian Gulf. The objective of the present paper is to summarize and discuss briefly the field investigations concerning the nocturnal biting cycle and behavior of An. dthali as well as the comparative attractiveness of man and cattle to these vectors under the impact of the organophosphouous insecticides. On the basis of the data collected, it was found that most of the bites take place between 21.00-24.00 hr. Biting pattern under local condition indicated that the number of bites per cow was much greater than the number of bites per man.

  10. Metagenomics, paratransgenesis and the Anopheles microbiome: a portrait of the geographical distribution of the anopheline microbiota based on a meta-analysis of reported taxa

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    Luis Martínez Villegas

    2014-08-01

    Full Text Available Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current “omics” era and the available data are mostly scattered or in “tables” that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.

  11. Observation of granulations in the basal body of ovarioles and follicular dilatations for the determination of physiological age ofAnopheles gambiaes.s.

    Institute of Scientific and Technical Information of China (English)

    Rodrigue Anagonou; Virgile Gnanguenon; Fiacre Agossa; Bruno Akinro; Armand Akpo; Martial Gbegbo; Albert Salako; Martin Akogbto

    2015-01-01

    Objective:To explore ovariole basal body granulations and follicular dilatations for determining physiological age inAnopheles gambiaes.s.(An. gambiaes.s.). Methods: Mosquitoes were collected by using window trap catch and identified morphologically. For the first lot ofmosquitoes, they were dissected, and ovary was left in distilled water for reading ovarian tracheoles and the second was cut and transferred to another blade in a physiological liquid for verification of ovariole basal body granulations. The same approach was followed with the second lot of mosquitoes where follicular dilatations were found after classic dilaceration of ovaries were transferred into physiological liquid. The other body parts of mosquitoes were used to identify the species of theAn. gambiaes.s. complex by PCR. Results:Among the 123An. gambiae s.s. of the first lot, the method of Detinova determined the age of 89 mosquitoes versus 114 for the observation of granulations (P > 0.05). Among the 112An. gambiae s.s. of the second lot, the method of Detinova determined the age of 84 mosquitoes versus 93 for the observation of follicular dilatations (P > 0.05). Unlike the method of Detinova, observation of follicular dilatations and basal body granulations of ovarioles were possible beyond the stage II Christophers. Conclusions: Overall, the observation of follicular dilatations and ovariole basal body granulations are reliable for the determination of the physiological age inAn. gambiaes.s. Furthermore, these two methods can be used beyond the stage II.

  12. Spinosad and neem seed kernel extract as bio-controlling agents for malarial vector,Anopheles stephensi and non-biting midge,Chironomus circumdatus

    Institute of Scientific and Technical Information of China (English)

    Kumar AN; Murugan K; Madhiyazhagan P; Prabhu K

    2011-01-01

    Objective:Midge egg masses are reported to support non-pathogenic strains of the cholera pathogen,Vibrio cholera (V. cholera). Mosquito born diseases have been reported to cause millions of death worldwide. The present research reveals the toxicity effect of spinosad and neem seed kernel extract (NSKE)against different larval stages ofAnopheles stephensi (An. stephensi) andChironomus circumdatus (Ch. circumdatus).Methods: The neem seeds were collected from Marudamalai hills, Bharathiar University, Coimbatore, India. Neem seed kernels were powdered, extracted and diluted for different concentrations (2 ppm to10 ppm). Spinosad was purchased from Kalpatharu pesticide Limited, Coimbatore, Tamil Nadu, India and thoroughly mixed with distilled water to prepare various concentrations (0.01 to0.08 ppm) and used for bioassay.Results: The results depict that spinosad is more toxic in lower concentrations when compared toNSKE and mosquitoes are more susceptible than chironomids. Lethal concentrations were evaluated using the observed mortality. The lowest LC50 value obtained from spinosad againstAn. stephensi and Ch. circumdatus were0.002 05 ppm and0.008 91 ppm. This study investigated on effect of Spinosad andNSKE on the biology of mosquito. The immature stages of both species were susceptible to Spinosad andNSKE. Spinosad andNSKE in individual as well as combined treatment provided additional days in development for mosquitoes.Conclusions:The results conclude that Spinosad andNSKE are potential larvicides against An. stephensi andCh. circumdatus.

  13. Deep sequencing revealed molecular signature of horizontal gene transfer of plant like transcripts in the mosquito Anopheles culicifacies: an evolutionary puzzle [version 1; referees: 2 approved

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    Punita Sharma

    2015-12-01

    Full Text Available In prokaryotes, horizontal gene transfer (HGT has been regarded as an important evolutionary drive to acquire and retain beneficial genes for their survival in diverse ecologies. However, in eukaryotes, the functional role of HGTs remains questionable, although current genomic tools are providing increased evidence of acquisition of novel traits within non-mating metazoan species. Here, we provide another transcriptomic evidence for the acquisition of massive plant genes in the mosquito, Anopheles culicifacies. Our multiple experimental validations including genomic PCR, RT-PCR, real-time PCR, immuno-blotting and immuno-florescence microscopy, confirmed that plant like transcripts (PLTs are of mosquito origin and may encode functional proteins. A comprehensive molecular analysis of the PLTs and ongoing metagenomic analysis of salivary microbiome provide initial clues that mosquitoes may have survival benefits through the acquisition of nuclear as well as chloroplast encoded plant genes. Our findings of PLTs further support the similar questionable observation of HGTs in other higher organisms, which is still a controversial and debatable issue in the community of evolutionists. We believe future understanding of the underlying mechanism of the feeding associated molecular responses may shed new insights in the functional role of PLTs in the mosquito.

  14. Intraspecific concerted evolution of the rDNA ITS1 in Anopheles farauti sensu stricto (Diptera: Culicidae) reveals recent patterns of population structure.

    Science.gov (United States)

    Bower, James E; Dowton, Mark; Cooper, Robert D; Beebe, Nigel W

    2008-10-01

    We examined the intraindividual variation present in the first ribosomal internal transcribed spacer (ITS1) of Anopheles farauti to determine the level of divergence among populations for this important malarial vector. We isolated 187 clones from 70 individuals and found regional variation among four internal tandem repeats. The data were partitioned prior to analysis given the presence of a paralogous ITS2 sequence, called the 5'-subrepeat, inserted in the ITS1 of most clones. A high level of homogenization and population differentiation was observed for this repeat, which indicates a higher rate of turnover relative to the adjacent 'core' region. Bayesian analysis was performed using several substitutional models on both a combined and a partitioned data set. On the whole, the ITS1 phylogeny and geographic origin of the samples appear to be congruent. Some interesting exceptions indicate the spread of variant repeats between populations and the retention of ancestral polymorphism. Our data clearly demonstrate concerted evolution at the intraspecific level despite intraindividual variation and a complex internal repeat structure from a species that occupies a continuous coastal distribution. A high rate of genomic turnover in combination with a high level of sequence divergence appears to be a major factor leading to its concerted evolution within these populations.

  15. Trapping mosquitoes using milk products as odour baits in western Kenya

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    Owino Eunice A

    2010-06-01

    Full Text Available Abstract Background Ample evidence has shown that blood seeking mosquitoes locate their hosts by following odours produced by the hosts. Odour baited traps would therefore, provide a solution in controlling diseases spread by mosquitoes. Comparative studies were undertaken to determine the relative efficacies of two odour baits i.e. Limburger cheese and African traditional milk cream in trapping mosquitoes in the field in western Kenya. Method Comparative efficacy studies were carried out in the field using Latin square experimental designs. In the first study, a counterflow geometry (CFG trap (MM-x model; American Biophysics Corp., USA. baited with Limburger cheese, man landing catches (MLC, Centres for Disease Control (CDC light trap and an entry trap were compared. In the second study, three CFG traps baited with either Limburger cheese, African traditional milk cream or with no bait were compared and in the third study four CDC traps baited with either Limburger cheese, African traditional milk cream, light or with no bait were compared. Parameters like species, catch size, abdominal status, parity status and size of the collected mosquitoes were compared. Results A total of 1,806 mosquitoes were collected (60% An. gambiae s.l and 25% An.funestus, culicines 15%. There was no significant difference in the number of An. funestus trapped by the CFG trap baited with Limburger cheese from those trapped by the MLC (P = 0.351. The Limburger cheese baited CFG trap collected significantly more gravid An. funestus than the MLC (P = 0.022. Furthermore, when the CFG trap baited with Limburger cheese and the CFG trap baited with milk cream were compared, there was no significant difference in the number of An. funestus collected (P = 0.573. The same trend was observed in the comparison of Limburger cheese baited CDC trap and milk cream baited CDC trap. Conclusions Limburger cheese and African traditional milk cream have a potential as effective odour

  16. Genetic Study of Propoxur Resistance—A Carbamate Insecticide in the Malaria Mosquito, Anopheles stephensi Liston

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    D. Sanil

    2010-01-01

    Full Text Available Anopheles stephensi Liston (Diptera: Culicidae is the urban vector of malaria in the Indian subcontinent and several countries of the Middle East. The genetics of propoxur resistance (pr in An. stephensi larvae was studied to determine its mode of inheritance. A diagnostic dose of 0.01 mg/L as recommended by WHO was used to establish homozygous resistant and susceptible strains. Reciprocal crosses between the resistant and susceptible strains showed an F1 generation of incomplete dominance. The progenies of backcrosses to susceptible parents were in 1 : 1 ratio of the same phenotypes as the parents and hybrids involved. The dosage mortality (d-m lines were constructed for each one of the crosses, and the degree of dominance was calculated. It is concluded that propoxur resistance in An. stephensi larvae is due to monofactorial inheritance with incomplete dominance and is autosomal in nature.

  17. Susceptibility of Anopheles maculipennis to different classes of insecticides in West Azarbaijan Province, Northwestern Iran

    Institute of Scientific and Technical Information of China (English)

    Ali; Reza; Chavshin; Farrokh; Dabiri; Hassan; Vatandoost; Mulood; Mohammadi; Bavani

    2015-01-01

    Objective: To determine the susceptibility status of Anopheles maculipennis(An. maculipennis) against the major insecticides used in the health sectors in West Azarbaijan Province, Northwestern Iran.Methods: Unfed 3-5 days old adult females of An. maculipennis were collected across the West Azarbaijan Province and were subjected to evaluation of their susceptibility following World Health Organization recommended protocol against six insecticides(permethrin, deltamethrin, propoxur, bendiocarb, malathion and dieldrin) belonging to four different classes. Results: In this study, 916 specimens of An. maculipennis were examined against the insecticides which indicated that An. maculipennis was tolerant to permethrin, deltamethrin and dielderin, but displayed resistance against propoxur, bendiocarb and malathion. Conclusions: The pattern of resistance in An. maculipennis could be attributed to the agricultural landscapes, agricultural pesticides used and the exposure of the mosquitoes to insecticides. Logical cooperation is needed between the agriculture and health sectors to ensure the judicious use of pesticides in each sector and the management of probable resistance.

  18. Wolbachia infections in natural Anopheles populations affect egg laying and negatively correlate with Plasmodium development

    Science.gov (United States)

    Shaw, W. Robert; Marcenac, Perrine; Childs, Lauren M.; Buckee, Caroline O.; Baldini, Francesco; Sawadogo, Simon P.; Dabiré, Roch K.; Diabaté, Abdoulaye; Catteruccia, Flaminia

    2016-01-01

    The maternally inherited alpha-proteobacterium Wolbachia has been proposed as a tool to block transmission of devastating mosquito-borne infectious diseases like dengue and malaria. Here we study the reproductive manipulations induced by a recently identified Wolbachia strain that stably infects natural mosquito populations of a major malaria vector, Anopheles coluzzii, in Burkina Faso. We determine that these infections significantly accelerate egg laying but do not induce cytoplasmic incompatibility or sex-ratio distortion, two parasitic reproductive phenotypes that facilitate the spread of other Wolbachia strains within insect hosts. Analysis of 221 blood-fed A. coluzzii females collected from houses shows a negative correlation between the presence of Plasmodium parasites and Wolbachia infection. A mathematical model incorporating these results predicts that infection with these endosymbionts may reduce malaria prevalence in human populations. These data suggest that Wolbachia may be an important player in malaria transmission dynamics in Sub-Saharan Africa. PMID:27243367

  19. HOUSE-SCALE TRIAL OF FENFLUTHRIN (OMS-2013 AGAINST DDT RESISTANT ANOPHELES ACONITUS IN CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Barodji Barodji

    2012-09-01

    Full Text Available Pengujian racun serangga fenfluthrin 5% w.d.p. dengan dosis 20 mg/m2 tingkat perumahan telah dilakukan untuk menanggulangi vektor malaria Anopheles aconitus yang sudah kebal terhadap DDT di desa Sekolo, Kecamatan Boja, Jawa Tengah. Penilaian entomologi dikerjakan dengan cara pengujian hayati kontak langsung, kontak tidak langsung dan penangkapan An. aconitus yang istirahat di dalam kandang pagi hari. Hasil pengujian hayati kontak langsung menunjukkan bahwa umur residu fenfluthrin yang disem­protkan pada permukaan dinding dengan dosis 20 mg/m2 adalah tidak lama (hanya sekitar 1 bulan. Umur residu yang efektip (kematian >70% hanya dipermukaan bambu pada 4 hari setelah penyemprot­an. Pengaruh fumigasi racun serangga ini sangat lemah, kematian hanya sebesar 14% dalam pengujian hayati kontak tidak langsung pada 4 hari setelah penyemprotan.

  20. PRELIMINARY NOTES ON THE DEVELOPMENT OF DDT RESISTANCE IN ANOPHELES CULICIFACIES

    Directory of Open Access Journals (Sweden)

    A.Zaini

    1973-09-01

    Full Text Available Anopheles culicifacies is the vector of malaria in southeastern part of Iran, India, West Pakistan and Ceylon. In 1959 the LC50 % DDT in the Panchmahal district of Gujarat state (India had increased. DDT resistant population of A. culicifacies has been reported from West Pakistan, Burma and Iran. After application of DDT in 1959, the density of A. culicifacies decreased sharply. The susceptibility test carried out in 1963 showed that the LC50 was 0.5%.After DDT spraying, followed by Dieldrin, for about 10 years the density of A. culicifacies was so negligible that it was not possible to perform susceptibility tests. By April and May of 1973 the density of A.culicifacies in Saidabad, Khairabad and Hit in Baluchesten province, Southeast of Iran, increased to about 500 per shelter. The susceptibility tests carried out showed that A. culicfacies is resistant to DDT and susceptible to Dieldrin and Malathion.

  1. Larvicidal activity of oak Quercus infectoria Oliv. (Fagaceae) gall extracts against Anopheles stephensi Liston.

    Science.gov (United States)

    Aivazi, Ali-Ashraf; Vijayan, V A

    2009-06-01

    There is a growing interest in the use of botanical insecticides to reduce the use of synthetic pesticides in order to avoid environmental side effects. Anopheles stephensi is the primary vector of urban malaria, an endemic disease in India. So, an effort to assay An. stephensi larvae with gall extracts of Quercus infectoria was made under laboratory conditions at Mysore. Ethyl-acetate extract was found to be the most effective of all the five extracts tested for larvicidal activity against the fourth instar larvae, with LC(50) of 116.92 ppm followed by gallotannin, n-butanol, acetone, and methanol with LC(50) values of 124.62, 174.76, 299.26, and 364.61 ppm, respectively. The efficacy in killing mosquito larvae may make this plant promising for the development of new botanical larvicide.

  2. Imidacloprid and Thiamethoxam Induced Mutations in Internal Transcribed Spacer 2 (ITS2) of Anopheles stephensi.

    Science.gov (United States)

    Bhinder, Preety; Chaudhry, Asha; Barna, Bhupinder; Kaur, Satvinderjeet

    2012-05-01

    The present article deals with the polymerase chain reaction (PCR)-based genotoxicity evaluation of neonicotinoid pesticides, imidacloprid and thiamethoxam, by using the genome of a mosquito Anopheles stephensi taken as an experimental model. After treatment of the second instar larvae with LC(20) of the pesticides for 24 h, the induced nucleotide sequence variations in the internal transcribed spacer 2 (ITS2) of freshly hatched unfed control and treated individuals was studied from the sequence alignment data and the mutations in the form of insertion, deletion and substitution of bases were recorded. Measurable differences, indicative of the genetic damage due to imidacloprid and thiamethoxam were observed when ITS2 sequences of control and treated individuals were compared. It was found that imidacloprid-treated individual had 8 deletions, 29 insertions, 18 transitions and 33 transversions, whereas thiamethoxam-treated individual had 10 deletions, 8 insertions, 47 transitions and 68 transversions.

  3. Differential effect of human ivermectin treatment on blood feeding Anopheles gambiae and Culex quinquefasciatus

    DEFF Research Database (Denmark)

    Derua, Yahya A.; Kisinza, William N.; Simonsen, Paul Erik

    2015-01-01

    BACKGROUND: Widespread and large scale use of ivermectin in humans and domestic animals can have unexpected effects on non-target organisms. As a search for a possible explanation for an observed longitudinal decline in density of anopheline vector mosquitoes, but not in Culex quinquefasciatus......, in an area of north-eastern Tanzania which has been exposed to ivermectin mass drug administration, this study assessed and compared the effect of human ivermectin treatment on blood feeding Anopheles gambiae and Cx. quinquefasciatus. METHODS: Consenting adult volunteers were randomized into two groups...... to receive either ivermectin or placebo. Twenty four hours after treatment, one volunteer from each group was concurrently exposed to 50 laboratory reared An. gambiae on one arm and 50 laboratory reared Cx. quinquefasciatus on the other arm for 15-30 minutes. Engorged mosquitoes were maintained on 10...

  4. Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae from Western and Northeastern Colombia

    Directory of Open Access Journals (Sweden)

    Carmen Elisa Posso

    2003-06-01

    Full Text Available Random amplified polymorphic DNA (RAPD markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8 but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8. According to molecular variance analysis, the genetic distance between populations was significant (phiST 0.1131, P < 0.001. The variation among individuals within populations (phiST 0.8869, P < 0.001was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.

  5. Anopheles culicifacies breeding in Sri Lanka and options for control through water management

    DEFF Research Database (Denmark)

    Konradsen, F; Matsuno, Y; Amerasinghe, F P

    1998-01-01

    This paper assesses the options for control of malaria vectors through different water management practices in a natural stream in Sri Lanka. The association between water level in the stream and breeding of the immature stages of the primary vector Anopheles culicifacies was investigated...... and the feasibility of using existing irrigation infrastructure to reduce the breeding potential discussed. The most feasible option would be to implement a management routine where water is released periodically from an upstream reservoir to reduce the number of breeding sites downstream. This study indicates...... that by regulating the water level above 20 cm in the stream throughout the dry season the breeding of A. culicifacies could be significantly reduced. The intervention would have only limited impact on the water lost for agriculture and the management input would be minimal. However, for the intervention to work...

  6. Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

    DEFF Research Database (Denmark)

    Mutero, C M; Blank, H; Konradsen, F

    2000-01-01

    between the 4th and 1st instar larvae in the subplots was only 0.08, indicating very low survival rates. In contrast, the 4th/1st instar ratio for subplots with other water management regimes ranged between 0.27 and 0.68, suggesting a correspondingly higher survival than observed with intermittent...... differences among subplots with different water regimes. The average yield per hectare ranged from 4.8-5.3 metric tonnes. The average daily water percolation/seepage rate was 3.6 mm and did not significantly differ among different water management regimes. Further research is necessary to, among other things......An experiment to assess the impact of intermittent irrigation on Anopheles larval populations, rice yields and water use was conducted in the Mwea rice irrigation scheme in Kenya. Four water regimes including intermittent irrigation were tested in a complete randomized block experimental design...

  7. Le système des estérases carboxyliques chez Anopheles stephensi

    OpenAIRE

    Riandey, Marie-France

    1993-01-01

    L'étude des estérases carboxyliques d'#Anopheles stephensi$ a été réalisée par électrophorèse. L'utilisation d'insecticides inhibiteurs des estérases et la modification des conditions opératoires ont permis de mettre en évidence trois classes d'estérases. Un dimorphisme sexuel est observé : dans les deux sexes, on a identifié un gène diallélique codant pour une estérase sensible aux inhibiteurs, mais, chez des mâles uniquement, il existe un autre gène, également diallélique codant pour une au...

  8. Population genetic structure of malaria vector Anopheles stephensi Liston (Diptera: Culicidae).

    Science.gov (United States)

    Gakhar, S K; Sharma, Richa; Sharma, Arvind

    2013-04-01

    Malaria is a complex disease that afflicts human today. Malaria epidemiology is associated with drug resistance in parasite and differential distribution and insecticide resistance in vector. Efforts are being made to eradicate malaria but burden of malaria is still increasing. Vector control is essential for malaria prevention strategies. Knowledge of population genetic structure is pre-requisite for determining prevention strategies particularly using transgenic mosquitoes. Population genetic study can predict level of gene flow between different populations. Anopheles stephensi Liston is urban vector of malaria in Indo-Pakistan subcontinent. About 12% of malaria cases of malaria in India are contributed by A. stephensi. Studies conducted on population genetics of A. stephensi using various markers in different parts of the world are discussed in this communication.

  9. Anopheles gambiae eicosanoids modulate Plasmodium berghei survival from oocyst to salivary gland invasion

    Directory of Open Access Journals (Sweden)

    Susana Ramos

    2014-08-01

    Full Text Available Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN, or a substrate, arachidonic acid (AA, at day 7 or day 12 post-infection (p.i.. Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.

  10. Anopheles gambiae eicosanoids modulate Plasmodium berghei survival from oocyst to salivary gland invasion.

    Science.gov (United States)

    Ramos, Susana; Custódio, Ana; Silveira, Henrique

    2014-08-01

    Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN), or a substrate, arachidonic acid (AA), at day 7 or day 12 post-infection (p.i.). Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.

  11. Suitability of monotypic and mixed diets for Anopheles hermsi larval development.

    Science.gov (United States)

    Beasley, Donald A; Walton, William E

    2016-06-01

    The developmental time and survival to eclosion of Anopheles hermsi Barr & Guptavanij fed monotypic and mixed diets of ten food types were examined in laboratory studies. Larvae fed monotypic diets containing animal detritus (freeze-dried rotifers, freeze-dried Daphnia pulicaria, and TetraMin® fish food flakes) and the mixotrophic protistan Cryptomonas ovata developed faster and survived better than larvae that were fed other monotypic diets. Survival to adulthood of larvae fed several concentrations of the diatom Planothidium (=Achnanthes) lanceolatum was poor (1% C20 polyunsaturated fatty acids as total fat, but regardless of essential fatty acid content, algae that produced mucilage and filaments that sank out of the feeding zone were poor quality diets.

  12. Genome expression analysis of Anopheles gambiae: responses to injury, bacterial challenge, and malaria infection.

    Science.gov (United States)

    Dimopoulos, George; Christophides, George K; Meister, Stephan; Schultz, Jörg; White, Kevin P; Barillas-Mury, Carolina; Kafatos, Fotis C

    2002-06-25

    The complex gene expression responses of Anopheles gambiae to microbial and malaria challenges, injury, and oxidative stress (in the mosquito and/or a cultured cell line) were surveyed by using cDNA microarrays constructed from an EST-clone collection. The expression profiles were broadly subdivided into induced and down-regulated gene clusters. Gram+ and Gram- bacteria and microbial elicitors up-regulated a diverse set of genes, many belonging to the immunity class, and the response to malaria partially overlapped with this response. Oxidative stress activated a distinctive set of genes, mainly implicated in oxidoreductive processes. Injury up- and down-regulated gene clusters also were distinctive, prominently implicating glycolysis-related genes and citric acid cycle/oxidative phosphorylation/redox-mitochondrial functions, respectively. Cross-comparison of in vivo and in vitro responses indicated the existence of tightly coregulated gene groups that may correspond to gene pathways.

  13. [The mosquitocidal efficacy of microcapsules of alpha-cypermethrin against Anopheles sinensis].

    Science.gov (United States)

    Pan, K Y; Ye, B H; Zhi, C L

    1994-01-01

    The efficacy of spraying of alpha-cypermethrin microcapsule for the control of Anopheles sinensis was investigated when alpha-cypermethrin microcapsule was sprayed at 0.5 g/m2, the KT50 was 7.9 min and