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Sample records for malarial mosquito anopheles

  1. Combining two-dimensional gel electrophoresis and metabolomic data in support of dry-season survival in the two main species of the malarial mosquito Anopheles gambiae

    Hidalgo K.

    2015-12-01

    Full Text Available In dry savannahs of West-Africa, the malarial mosquitoes of the Anopheles gambiae sensu stricto complex annually survive the harsh desiccating conditions of the dry season. However, the physiological and biochemical mechanisms underlying how these mosquitoes survive such desiccating conditions are still undefined, and controversial. In this context, we provide the first work examining both proteomic and metabolomic changes in the two molecular forms of A. gambiae s.s (M and S forms experimentally exposed to the rainy and dry season conditions as they experience in the field. Protein abundances of the mosquitoes were measured using a two-dimensional fluorescence difference gel electrophoresis (2D DIGE coupled with a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF and tandem mass spectrometry (MS for protein identification. These assays were conducted by Applied Biomics (http://www.appliedbiomics.com, Applied Biomics, Inc. Hayward, CA, USA, and the mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org via the PRIDE partner repository with the dataset identifier PXD000294. The metabolomic analysis was conducted using both Acquity UPLC® system (for amino acid identification, and a gas-chromatography-mass spectrometry platform (for sugars identification. Metabolomic fingerprintings were assessed in the University of Rennes 1, UMR CNRS 6553 EcoBio (France. A detailed interpretation of the obtained data can be found in Hidalgo et al. (2014 [1] (Journal of Insect Physiology (2014.

  2. Satellite-derived NDVI, LST, and climatic factors driving the distribution and abundance of Anopheles mosquitoes in a former malarious area in northwest Argentina.

    Dantur Juri, María Julia; Estallo, Elizabet; Almirón, Walter; Santana, Mirta; Sartor, Paolo; Lamfri, Mario; Zaidenberg, Mario

    2015-06-01

    Distribution and abundance of disease vectors are directly related to climatic conditions and environmental changes. Remote sensing data have been used for monitoring environmental conditions influencing spatial patterns of vector-borne diseases. The aim of this study was to analyze the effect of the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic factors (temperature, humidity, wind velocity, and accumulated rainfall) on the distribution and abundance of Anopheles species in northwestern Argentina using Poisson regression analyses. Samples were collected from December, 2001 to December, 2005 at three localities, Aguas Blancas, El Oculto and San Ramón de la Nueva Orán. We collected 11,206 adult Anopheles species, with the major abundance observed at El Oculto (59.11%), followed by Aguas Blancas (22.10%) and San Ramón de la Nueva Orán (18.79%). Anopheles pseudopunctipennis was the most abundant species at El Oculto, Anopheles argyritarsis predominated in Aguas Blancas, and Anopheles strodei in San Ramón de la Nueva Orán. Samples were collected throughout the sampling period, with the highest peaks during the spring seasons. LST and mean temperature appear to be the most important variables determining the distribution patterns and major abundance of An. pseudopunctipennis and An. argyritarsis within malarious areas. © 2015 The Society for Vector Ecology.

  3. Composition of Anopheles Species Collected from Selected Malarious Areas of Afghanistan and Iran

    Helen Hoosh-Deghati

    2017-10-01

    Full Text Available Background: Malarious areas in Iran are close to Afghanistan and Pakistan that urge the researchers to extend their knowledge on malaria epidemiology to the neighboring countries as well. Vectorial capacity differs at species or even at population level, the first essential step is accurate identification of vectors. This study aimed to identify Anopheles species composition in selected malarious areas of Afghanistan and Iran, providing further applied data for other research in two countries.Methods: Adults Anopheles spp. were collected from four provinces in Afghanistan (Badakhshan, Herat, Kunduz, Nangarhar by pyrethrum spray catch, hand collection methods through WHO/EMRO coordination and from Chaba­har County in Iran by pyrethrum spray catch method. Identification was performed using reliable identification key.Results: Totally, 800 female Anopheles mosquitos, 400 from each country were identified at species level. Anophe­les composition in Afghanistan was An. superpictus, An. stephensi and An. hyrcanus. Most prevalent species in Ba­dakhshan and Kunduz were An. superpictus, whereas An. stephensi and An. hyrcanus were respectively found in Nangarhar and Heart. Anopheles species in Chabahar County of Iran were An. stephensi, An. fluviatilis, An. culicifa­cies and An. sergentii. The most prevalent species was An. stephensi.Conclusion: Current study provides a basis for future research such as detection of Plasmodium infection in col­lected samples which is on process by the authors, also for effective implementation of evidence-based malaria vec­tor intervention strategies.

  4. Distribution and infectivity of anopheles mosquitoes and ...

    Malaria still remains a major public health problem in Nigeria, despite serious efforts to lessen its adverse impact. A malaria survey was conducted to determine the distribution and infectivity rate of Anopheles species, and asymptomatic malaria infections in Gboko. Mosquitoes were collected at selected sites, using ...

  5. Anopheles atroparvus density modeling using MODIS NDVI in a former malarious area in Portugal.

    Lourenço, Pedro M; Sousa, Carla A; Seixas, Júlia; Lopes, Pedro; Novo, Maria T; Almeida, A Paulo G

    2011-12-01

    Malaria is dependent on environmental factors and considered as potentially re-emerging in temperate regions. Remote sensing data have been used successfully for monitoring environmental conditions that influence the patterns of such arthropod vector-borne diseases. Anopheles atroparvus density data were collected from 2002 to 2005, on a bimonthly basis, at three sites in a former malarial area in Southern Portugal. The development of the Remote Vector Model (RVM) was based upon two main variables: temperature and the Normalized Differential Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite. Temperature influences the mosquito life cycle and affects its intra-annual prevalence, and MODIS NDVI was used as a proxy for suitable habitat conditions. Mosquito data were used for calibration and validation of the model. For areas with high mosquito density, the model validation demonstrated a Pearson correlation of 0.68 (pNDVI. RVM is a satellite data-based assimilation algorithm that uses temperature fields to predict the intra- and inter-annual densities of this mosquito species using MODIS NDVI. RVM is a relevant tool for vector density estimation, contributing to the risk assessment of transmission of mosquito-borne diseases and can be part of the early warning system and contingency plans providing support to the decision making process of relevant authorities. © 2011 The Society for Vector Ecology.

  6. Rickettsia Species in African Anopheles Mosquitoes

    Socolovschi, Cristina; Pages, Frédéric; Ndiath, Mamadou O.; Ratmanov, Pavel; Raoult, Didier

    2012-01-01

    Background There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology. Methodology/Principal Findings Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d’Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d’Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d’Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region. Conclusion R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity. PMID:23118963

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

    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.

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

    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.

  9. Susceptibility of female Anopheles mosquito to pyrethroid ...

    The detection of insecticides resistance status in a natural population of Anopheles vectors is a vital tool for malaria control intervention strategy against Anopheles gambiae sensu lato, which is the main malaria vector in Nigeria. This study was conducted to determine the susceptibility status of the female Anopheles ...

  10. Microbial Pre-exposure and Vectorial Competence of Anopheles Mosquitoes

    Constentin Dieme

    2017-12-01

    Full Text Available Anopheles female mosquitoes can transmit Plasmodium, the malaria parasite. During their aquatic life, wild Anopheles mosquito larvae are exposed to a huge diversity of microbes present in their breeding sites. Later, adult females often take successive blood meals that might also carry different micro-organisms, including parasites, bacteria, and viruses. Therefore, prior to Plasmodium ingestion, the mosquito biology could be modulated at different life stages by a suite of microbes present in larval breeding sites, as well as in the adult environment. In this article, we highlight several naturally relevant scenarios of Anopheles microbial pre-exposure that we assume might impact mosquito vectorial competence for the malaria parasite: (i larval microbial exposures; (ii protist co-infections; (iii virus co-infections; and (iv pathogenic bacteria co-infections. In addition, significant behavioral changes in African Anopheles vectors have been associated with increasing insecticide resistance. We discuss how these ethological modifications may also increase the repertoire of microbes to which mosquitoes could be exposed, and that might also influence their vectorial competence. Studying Plasmodium–Anopheles interactions in natural microbial environments would efficiently contribute to refining the transmission risks.

  11. Species\\' identification of Anopheles and Culex mosquitoes and its ...

    Indoor and outdoor bites' collections of gravid Anopheles and Culex mosquitoes were made with plastic aspirator from residential areas within Jimeta-Yola metropolis for three years (between March and May; August and October 2003 to 2005). They were identified using standard morphological keys and polymerase chain ...

  12. Highly evolvable malaria vectors : The genomes of 16 Anopheles mosquitoes

    Neafsey, D. E.; Waterhouse, R. M.; Abai, M. R.; Aganezov, S. S.; Alekseyev, M. A.; Allen, J. E.; Amon, J.; Arca, B.; Arensburger, P.; Artemov, G.; Assour, L. A.; Basseri, H.; Berlin, A.; Birren, B. W.; Blandin, S. A.; Brockman, A. I.; Burkot, T. R.; Burt, A.; Chan, C. S.; Chauve, C.; Chiu, J. C.; Christensen, M.; Costantini, C.; Davidson, V. L. M.; Deligianni, E.; Dottorini, T.; Dritsou, V.; Gabriel, S. B.; Guelbeogo, W. M.; Hall, A. B.; Han, M. V.; Hlaing, T.; Hughes, D. S. T.; Jenkins, A. M.; Jiang, X.; Jungreis, I.; Kakani, E. G.; Kamali, M.; Kemppainen, P.; Kennedy, R. C.; Kirmitzoglou, I. K.; Koekemoer, L. L.; Laban, N.; Langridge, N.; Lawniczak, M. K. N.; Lirakis, M.; Lobo, N. F.; Lowy, E.; Maccallum, R. M.; Mao, C.; Maslen, G.; Mbogo, C.; Mccarthy, J.; Michel, K.; Mitchell, S. N.; Moore, W.; Murphy, K. A.; Naumenko, A. N.; Nolan, T.; Novoa, E. M.; O'loughlin, S.; Oringanje, C.; Oshaghi, M. A.; Pakpour, N.; Papathanos, P. A.; Peery, A. N.; Povelones, M.; Prakash, A.; Price, D. P.; Rajaraman, A.; Reimer, L. J.; Rinker, D. C.; Rokas, A.; Russell, T. L.; Sagnon, N.; Sharakhova, M. V.; Shea, T.; Simao, F. A.; Simard, F.; Slotman, M. A.; Somboon, P.; Stegniy, V.; Struchiner, C. J.; Thomas, G. W. C.; Tojo, M.; Topalis, P.; Tubio, J. M. C.; Unger, M. F.; Vontas, J.; Walton, C.; Wilding, C. S.; Willis, J. H.; Wu, Y.-c.; Yan, G.; Zdobnov, E. M.; Zhou, X.; Catteruccia, F.; Christophides, G. K.; Collins, F. H.; Cornman, R. S.; Crisanti, A.; Donnelly, M. J.; Emrich, S. J.; Fontaine, M. C.; Gelbart, W.; Hahn, M. W.; Hansen, I. A.; Howell, P. I.; Kafatos, F. C.; Kellis, M.; Lawson, D.; Louis, C.; Luckhart, S.; Muskavitch, M. A. T.; Ribeiro, J. M.; Riehle, M. A.; Sharakhov, I. V.; Tu, Z.; Zwiebel, L. J.; Besansky, N. 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

  13. Abundance, composition and natural infection of Anopheles mosquitoes from two malaria-endemic regions of Colombia

    Carolina Montoya; Priscila Bascuñán; Julián Rodríguez-Zabala; Margarita M. Correa

    2017-01-01

    Introduction: In Colombia there are three Anopheles species implicated in malaria transmission as primary vectors; however, the local role of some Anopheles species must still be defined. Objective: To determine the abundance, composition and natural infection rates for Anopheles mosquitoes with Plasmodium spp. in two malaria-endemic regions of Colombia. Materials and methods: Anopheles mosquitoes were collected using the human-landing catches and while resting in livestock corrals in n...

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

    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

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

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

    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.

  16. Effect of Vetiveria zizanioides L. Root extracts on the malarial vector, Anopheles stephensi Liston

    N Aarthi

    2012-04-01

    Full Text Available Objective: To evaluate the ovicidal and oviposition deterrent potential of the ethanolic extract from Vetiveria zizanioides (V. zizanioides roots against the malarial vector, Anopheles stephensi (A. stephensi . Methods: The dried clean V. zizanioides roots were powerdered and extracted with ethanol for 8 h in a soxhlet apparatus. After evaporation, the residue was dissolved in acetone. One hundred freshly laid eggs of A. stephensi were exposed to the extract at differnt concentrations for 48 h, and the hatch rate was calculated to evaluate the ovicidal activity. Those exposed to actone aqueous solution were used as control. The egg laying behavior of gravid female A. stephensi was also observed using oviposition deterrent test. Effective repellency (ER was used to evaluate the oviposition deterrent activity. Results: Exposure to the crude ethanol extract of V. zizanioides reduced the hatchability rate of A. stephensi eggs, and zero hatchability was exerted at 375 ppm. In the oviposition deterrent test, the extract alleviated the egg laying with an ER of 78.9% at the highest concentration of 375 ppm and even 53.7% at the lowest concentration of 125 ppm. Moreover, the negative values of oviposition active index also suggests the extract was a good deterrent agent. Conclusions: The ethanolic extract of V. zizanioides roots may be used an alternative pesticide to control A. stephensi at the early stage of life history, possibly due to the presence of various active chemical compounds.

  17. Riceland mosquito management practices for Anopheles quadrimaculatus larvae.

    Allen, R A; Wilkes, W W; Lewis, C N; Meisch, M V

    2008-12-01

    Two separate but related studies were conducted regarding management of Anopheles quadrimaculatus larval populations in commercial rice fields near Cleveland, MS, in 2004. Study 1 was to evaluate the effectiveness of 2 treatments of aerially applied ultra-low volume applications of Bacillus thuringiensis var. israelensis (Bti) against An. quadrimaculatus larvae in dense, high-canopy mid- to late-season rice crop. Study 2 was to investigate the effect of preflood treatments of lambda-cyhalothrin (Karate), which is commonly used against rice water weevil (Lissorhoptrus oryzophilus), on An. quadrimaculatus larvae. Excellent initial, but short residual control (>99% control 1 day after treatment) was observed in the Bti-treated fields in both mid- and late-season rice. Little or no effect on mosquito larvae was observed in the lambda-cyhalothrin-treated fields. Results indicate that Bti can be effectively used by mosquito management personnel to control larval populations of An. quadrimaculatus in late-season rice fields; however, lambda-cyhalothrin did not effectively control larval An. quadrimaculatus when applied preflood to rice fields.

  18. Larvicidal activity of Zanthoxylum acanthopodium essential oil against the malaria mosquitoes, Anopheles anthropophagus and Anopheles sinensis.

    He, Qi; Wang, Wenxia; Zhu, Liang

    2018-05-15

    Zanthoxylum acanthopodium has insecticidal effect in Chinese traditional medicine. In this study, the essential oil from the dried Zanthoxylum plant was used as a larvicidal compound against the malaria mosquitoes, Anopheles anthropophagus and Anopheles sinensis. Compounds in the Zanthoxylum essential oil were investigated by gas chromatography and mass spectroscopy (GC-MS). The larvicidal bioassays of the whole oil, as well as the main compounds in the oil (estragole and eucalyptol) were performed using WHO method. In total, 63 main compounds (99.32%) were found in the oils, including estragole (15.46%), eucalyptol (10.94%), β-caryophyllene (5.52%), cis-linalool oxide (3.76%), cis-limonene oxide (3.06%). A dose-dependent effect on mortality was recorded with increasing concentrations of essential oil and compounds increasing mortality of the larvae. Larvicidal bioassays revealed that 24 h LC 50 of the whole essential oil was 36.00 mg/L and LC 90 was 101.49 mg/L against An. anthropophagus, while LC 50 was 49.02 mg/L and LC 90 was 125.18 mg/L against An. sinensis. Additionally, 24 h LC 50 of estragole were 38.56 and 41.67 mg/L against An. anthropophagus and An. sinensis, respectively, while the related LC 90 were 95.90 and 107.89 mg/L. LC 50 of eucalyptol were 42.41 and 45.49 mg/L against An. anthropophagus and An. sinensis, while the related LC 90 were 114.45 and 124.95 mg/L. The essential oil of Z. acanthopodium and its several major compounds may have potential for use in the control of malaria mosquitoes.

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

    Braks, M.

    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

  20. SPECIES COMPOSITION OF MALARIAL MOSQUITOES KHARKIV REGION. NATURAL FACTORS OF MALARIA TRANSMISSION

    Gazzawi - Rogozinа L. V.

    2015-05-01

    Full Text Available Introduction. This article describes the species composition of the dominant Anopheles mosquitoes in the Kharkiv region, the season of their possible effective infection, as well as ongoing anti-malaria activities . Key words: malaria , mosquitoes, p . Anopheles, epidemiology, census, hydraulic events. Material & methods. The analysis of entomological and meteorological situation in Ukraine and in the Kharkiv region according to data of the Ukrainian Center of control and monitoring of diseases of the Ministry of Health of Ukraine and Kharkiv regional laboratory center. Collection of material (imaginal and larval was carried out on the territory of natural and artificial water bodies of Kharkiv region in the period 2013 - 2014. When collecting the material used conventional accounting methods mosquito populations. On the territory of the region under study, we have found 30 species of mosquitoes three genera: Anopheles, Culex, Aedes. Results & discussion. Epidemiological role of each species of mosquitoes depends on several conditions. Dangerous vector species can only be found in large numbers, a significant percentage of individuals in a population that feeds on the blood of man, having a sufficiently long season activity and a sufficient number of females surviving to age possible maturation of sporozoites in their body. In Ukraine, the major carriers - Anopheles maculipennis, An. m. messeae, An. m. atroparvus, An. claviger, An. plumbeus, An. hyrcanus. Mosquito species registered in the territory of the Kharkiv region are susceptible to currently known types of human malaria parasites . Moreover, the dominant species in terms of urban landscapes are An.maculipennis and An.messeae . These species possess all the qualities necessary to be considered dangerous malaria vector control. They are well infected with the three main types of human parasites. In the study area , in terms of urban landscapes, gonoaktivnye females occurs within 3

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

    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...... previously cloned and characterized myosuppressin receptors from Drosophila [Proc. Natl. Acad. Sci. USA 100 (2003) 9808]. The mosquito receptor cDNA was expressed in Chinese hamster ovary cells and was found to be activated by low concentrations of Anopheles myosuppressin (TDVDHVFLRFamide; EC50, 1.6 x 10...... identification of a mosquito neuropeptide receptor....

  2. Next-generation site-directed transgenesis in the malaria vector mosquito Anopheles gambiae: self-docking strains expressing germline-specific phiC31 integrase.

    Janet M Meredith

    Full Text Available Diseases transmitted by mosquitoes have a devastating impact on global health and the situation is complicated due to difficulties with both existing control measures and the impact of climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. The Streptomyces phage phiC31 integrase system has been successfully adapted for site-directed transgene integration in a range of insects, thus overcoming many limitations due to size constraints and random integration associated with transposon-mediated transformation. Using this technology, we previously published the first site-directed transformation of Anopheles gambiae, the principal vector of human malaria. Mosquitoes were initially engineered to incorporate the phiC31 docking site at a defined genomic location. A second phase of genetic modification then achieved site-directed integration of an anti-malarial effector gene. In the current publication we report improved efficiency and utility of the phiC31 integrase system following the generation of Anopheles gambiae self-docking strains. Four independent strains, with docking sites at known locations on three different chromosome arms, were engineered to express integrase under control of the regulatory regions of the nanos gene from Anopheles gambiae. The resulting protein accumulates in the posterior oocyte to provide integrase activity at the site of germline development. Two self-docking strains, exhibiting significantly different levels of integrase expression, were assessed for site-directed transgene integration and found to demonstrate greatly improved survival and efficiency of transformation. In the fight against malaria, it is imperative to establish a broad repertoire of both anti-malarial effector genes and tissue-specific promoters to regulate their expression, enabling those offering maximum effect with minimum fitness

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

    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.

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

    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 .

  5. A highly stable blood meal alternative for rearing Aedes and Anopheles mosquitoes.

    Ted Baughman

    2017-12-01

    Full Text Available We investigated alternatives to whole blood for blood feeding of mosquitoes with a focus on improved stability and compatibility with mass rearing programs. In contrast to whole blood, an artificial blood diet of ATP-supplemented plasma was effective in maintaining mosquito populations and was compatible with storage for extended periods refrigerated, frozen, and as a lyophilized powder. The plasma ATP diet supported rearing of both Anopheles and Aedes mosquitoes. It was also effective in rearing Wolbachia-infected Aedes mosquitoes, suggesting compatibility with vector control efforts.

  6. Lack of insecticidal effect of mosquito coils containing either metofluthrin or esbiothrin on Anopheles gambiae sensu lato mosquitoes.

    Lukwa, Nzira; Chiwade, Tonderai

    2008-12-01

    Use of mosquito coils for personal protection against malaria and mosquito nuisance is advocated under mosquito and malaria control programmes. We performed field studies of mosquito coils containing either metofluthrin or esbiothrin in experimental huts situated in Kamhororo village, Gokwe district, Zimbabwe. All tests were performed on 3-5 day old reared female Anopheles gambiae sensu lato mosquitoes. The burning times were 9hr 20min for mosquito coils containing metofluthrin and 8 hr for those containing esbiothrin and the results were significantly different (p = metofluthrin was 90% and that for esbiothrin was 73.3% and the results were significantly different (p = 0.00). Mosquito coils containing metofluthrin had a mean repellence of 92.7% as compared to 85.4% for esbiothrin and the results were not significantly different (p=0.27). The protection time as required by EPA (1999) was 6 hr for mosquito coils containing metofluthrin and 5 hr for those containing esbiothrin. The mean insecticidal effect of mosquito coils containing metofluthrin was 84% as compared to 83% for those containing esbiothrin and the results were not significantly different (p = 0.56). Both mosquito formulations could not be classified as having insecticidal effect since none of them met the 95% mortality rate criteria.

  7. The effect of temperature on Anopheles mosquito population dynamics and the potential for malaria transmission.

    Lindsay M Beck-Johnson

    Full Text Available The parasites that cause malaria depend on Anopheles mosquitoes for transmission; because of this, mosquito population dynamics are a key determinant of malaria risk. Development and survival rates of both the Anopheles mosquitoes and the Plasmodium parasites that cause malaria depend on temperature, making this a potential driver of mosquito population dynamics and malaria transmission. We developed a temperature-dependent, stage-structured delayed differential equation model to better understand how climate determines risk. Including the full mosquito life cycle in the model reveals that the mosquito population abundance is more sensitive to temperature than previously thought because it is strongly influenced by the dynamics of the juvenile mosquito stages whose vital rates are also temperature-dependent. Additionally, the model predicts a peak in abundance of mosquitoes old enough to vector malaria at more accurate temperatures than previous models. Our results point to the importance of incorporating detailed vector biology into models for predicting the risk for vector borne diseases.

  8. Genetics of refractoriness to Plasmodium falciparum in the mosquito Anopheles stephensi

    Feldmann, A.M.; Gemert, Geert-Jan van; Vegte-Bolmer, Marga G. van de; Jansen, Ritsert C.

    1998-01-01

    We previously selected a line of the malaria vector mosquito Anopheles stephensi refractory (resistant) to the human malaria parasite Plasmodium falciparum, using in vitro infections with P. falciparum gametocytes. This report presents data on the genetic background of refractoriness. The results of

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

    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

  10. Blood-feeding patterns of Anopheles mosquitoes in a malaria-endemic area of Bangladesh

    Bashar Kabirul

    2012-02-01

    Full Text Available Abstract Background Blood-feeding patterns of mosquitoes are crucial for incriminating malaria vectors. However, little information is available on the host preferences of Anopheles mosquitoes in Bangladesh. Therefore, the objective of the present study was to determine the hematophagic tendencies of the anophelines inhabiting a malaria-endemic area of Bangladesh. Methods Adult Anopheles mosquitoes were collected using light traps (LTs, pyrethrum spray (PS, and human bait (HB from a malaria-endemic village (Kumari, Bandarban, Bangladesh during the peak months of malaria transmission (August-September. Enzyme-linked immunosorbent assay (ELISA and polymerase chain reaction (PCR were performed to identify the host blood meals of Anopheles mosquitoes. Results In total, 2456 female anopheline mosquitoes representing 21 species were collected from the study area. Anopheles vagus Doenitz (35.71% was the dominant species followed by An. philippinensis Ludlow (26.67% and An. minimus s.l. Theobald (5.78%. All species were collected by LTs set indoors (n = 1094, 19 species were from outdoors (n = 784, whereas, six by PS (n = 549 and four species by HB (n = 29. Anopheline species composition significantly differed between every possible combination of the three collection methods (χ2 test, P Anopheles samples belonging to 17 species. Values of the human blood index (HBI of anophelines collected from indoors and outdoors were 6.96% and 11.73%, respectively. The highest values of HBI were found in An. baimai Baimaii (80%, followed by An. minimus s.l. (43.64% and An. annularis Van den Wulp (37.50%. Anopheles baimai (Bi = 0.63 and An. minimus s.l. (Bi = 0.24 showed strong relative preferences (Bi for humans among all hosts (human, bovine, goats/sheep, and others. Anopheles annularis, An. maculatus s.l. Theobald, and An. pallidus Theobald exhibited opportunistic blood-feeding behavior, in that they fed on either humans or animals, depending on whichever was

  11. PCR detection of malaria parasites in desiccated Anopheles mosquitoes is uninhibited by storage time and temperature

    Rider Mark A

    2012-06-01

    Full Text Available Abstract Background Reliable methods to preserve mosquito vectors for malaria studies are necessary for detecting Plasmodium parasites. In field settings, however, maintaining a cold chain of storage from the time of collection until laboratory processing, or accessing other reliable means of sample preservation is often logistically impractical or cost prohibitive. As the Plasmodium infection rate of Anopheles mosquitoes is a central component of the entomological inoculation rate and other indicators of transmission intensity, storage conditions that affect pathogen detection may bias malaria surveillance indicators. This study investigated the effect of storage time and temperature on the ability to detect Plasmodium parasites in desiccated Anopheles mosquitoes by real-time polymerase chain reaction (PCR. Methods Laboratory-infected Anopheles stephensi mosquitoes were chloroform-killed and stored over desiccant for 0, 1, 3, and 6 months while being held at four different temperatures: 28, 37, -20 and -80°C. The detection of Plasmodium DNA was evaluated by real-time PCR amplification of a 111 base pair region of block 4 of the merozoite surface protein. Results Varying the storage time and temperature of desiccated mosquitoes did not impact the sensitivity of parasite detection. A two-way factorial analysis of variance suggested that storage time and temperature were not associated with a loss in the ability to detect parasites. Storage of samples at 28°C resulted in a significant increase in the ability to detect parasite DNA, though no other positive associations were observed between the experimental storage treatments and PCR amplification. Conclusions Cold chain maintenance of desiccated mosquito samples is not necessary for real-time PCR detection of parasite DNA. Though field-collected mosquitoes may be subjected to variable conditions prior to molecular processing, the storage of samples over an inexpensive and logistically

  12. Intra-specific diversity of Serratia marcescens in Anopheles mosquito midgut defines Plasmodium transmission capacity

    Bando, Hironori; Okado, Kiyoshi; Guelbeogo, Wamdaogo M.; Badolo, Athanase; Aonuma, Hiroka; Nelson, Bryce; Fukumoto, Shinya; Xuan, Xuenan; Sagnon, N'Fale; Kanuka, Hirotaka

    2013-01-01

    A critical stage in malaria transmission occurs in the Anopheles mosquito midgut, when the malaria parasite, Plasmodium, ingested with blood, first makes contact with the gut epithelial surface. To understand the response mechanisms within the midgut environment, including those influenced by resident microbiota against Plasmodium, we focus on a midgut bacteria species' intra-specific variation that confers diversity to the mosquito's competency for malaria transmission. Serratia marcescens isolated from either laboratory-reared mosquitoes or wild populations in Burkina Faso shows great phenotypic variation in its cellular and structural features. Importantly, this variation is directly correlated with its ability to inhibit Plasmodium development within the mosquito midgut. Furthermore, this anti-Plasmodium function conferred by Serratia marcescens requires increased expression of the flagellum biosynthetic pathway that is modulated by the motility master regulatory operon, flhDC. These findings point to new strategies for controlling malaria through genetic manipulation of midgut bacteria within the mosquito. PMID:23571408

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

    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

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

    Maharaj, R

    2012-09-01

    Full Text Available through effects of hor- mone regulation with subsequent disruption of instar development of Anopheles stephensi, Culex quinquefas- ciatus and Aedes aegypti [34]. Tiwari et al. [35] found that the essential oil obtained from seeds of Zanthoxy- lum.... Geerts S, Van Blerk K, Triest L: Effect of Ambrosia maritima on Anopheles stephensi and Aedes aegypti. J Ethnopharmacol 1994, 42:7?11. 20. Evans DA, Raj RK: Extracts of Indian plants as mosquito larvicides. Indian J Med Res 1988, 88:38?41. 21...

  15. Deforestation and Vectorial Capacity of Anopheles gambiae Giles Mosquitoes in Malaria Transmission, Kenya

    Afrane, Yaw A.; Little, Tom J.; Lawson, Bernard W.; Githeko, Andrew K.

    2008-01-01

    We investigated the effects of deforestation on microclimates and sporogonic development of Plasmodium falciparum parasites in Anopheles gambiae mosquitoes in an area of the western Kenyan highland prone to malaria epidemics. An. gambiae mosquitoes were fed with P. falciparum–infected blood through membrane feeders. Fed mosquitoes were placed in houses in forested and deforested areas in a highland area (1,500 m above sea level) and monitored for parasite development. Deforested sites had higher temperatures and relative humidities, and the overall infection rate of mosquitoes was increased compared with that in forested sites. Sporozoites appeared on average 1.1 days earlier in deforested areas. Vectorial capacity was estimated to be 77.7% higher in the deforested site than in the forested site. We showed that deforestation changes microclimates, leading to more rapid sporogonic development of P. falciparum and to a marked increase of malaria risk in the western Kenyan highland. PMID:18826815

  16. Infection of Laboratory-Colonized Anopheles darlingi Mosquitoes by Plasmodium vivax

    Moreno, Marta; Tong, Carlos; Guzmán, Mitchel; Chuquiyauri, Raul; Llanos-Cuentas, Alejandro; Rodriguez, Hugo; Gamboa, Dionicia; Meister, Stephan; Winzeler, Elizabeth A.; Maguina, Paula; Conn, Jan E.; Vinetz, Joseph M.

    2014-01-01

    Anopheles darlingi Root is the most important malaria vector in the Amazonia region of South America. However, continuous propagation of An. darlingi in the laboratory has been elusive, limiting entomological, genetic/genomic, and vector–pathogen interaction studies of this mosquito species. Here, we report the establishment of an An. darlingi colony derived from wild-caught mosquitoes obtained in the northeastern Peruvian Amazon region of Iquitos in the Loreto Department. We show that the numbers of eggs, larvae, pupae, and adults continue to rise at least to the F6 generation. Comparison of feeding Plasmodium vivax ex vivo of F4 and F5 to F1 generation mosquitoes showed the comparable presence of oocysts and sporozoites, with numbers that corresponded to blood-stage asexual parasitemia and gametocytemia, confirming P. vivax vectorial capacity in the colonized mosquitoes. These results provide new avenues for research on An. darlingi biology and study of An. darlingi–Plasmodium interactions. PMID:24534811

  17. Insecticide susceptibility of Anopheles mosquitoes changes in response to variations in the larval environment.

    Owusu, Henry F; Chitnis, Nakul; Müller, Pie

    2017-06-16

    Insecticide resistance threatens the success achieved through vector control in reducing the burden of malaria. An understanding of insecticide resistance mechanisms would help to develop novel tools and strategies to restore the efficacy of insecticides. Although we have substantially improved our understanding of the genetic basis of insecticide resistance over the last decade, we still know little of how environmental variations influence the mosquito phenotype. Here, we measured how variations in larval rearing conditions change the insecticide susceptibility phenotype of adult Anopheles mosquitoes. Anopheles gambiae and A. stephensi larvae were bred under different combinations of temperature, population density and nutrition, and the emerging adults were exposed to permethrin. Mosquitoes bred under different conditions showed considerable changes in mortality rates and body weight, with nutrition being the major factor. Weight is a strong predictor of insecticide susceptibility and bigger mosquitoes are more likely to survive insecticide treatment. The changes can be substantial, such that the same mosquito colony may be considered fully susceptible or highly resistant when judged by World Health Organization discriminatory concentrations. The results shown here emphasise the importance of the environmental background in developing insecticide resistance phenotypes, and caution for the interpretation of data generated by insecticide susceptibility assays.

  18. Wild Anopheles funestus mosquito genotypes are permissive for infection with the rodent malaria parasite, Plasmodium berghei.

    Jiannong Xu

    Full Text Available Malaria parasites undergo complex developmental transitions within the mosquito vector. A commonly used laboratory model for studies of mosquito-malaria interaction is the rodent parasite, P. berghei. Anopheles funestus is a major malaria vector in sub-Saharan Africa but has received less attention than the sympatric species, Anopheles gambiae. The imminent completion of the A. funestus genome sequence will provide currently lacking molecular tools to describe malaria parasite interactions in this mosquito, but previous reports suggested that A. funestus is not permissive for P. berghei development.An A. funestus population was generated in the laboratory by capturing female wild mosquitoes in Mali, allowing them to oviposit, and rearing the eggs to adults. These F1 progeny of wild mosquitoes were allowed to feed on mice infected with a fluorescent P. berghei strain. Fluorescence microscopy was used to track parasite development inside the mosquito, salivary gland sporozoites were tested for infectivity to mice, and parasite development in A. funestus was compared to A. gambiae.P. berghei oocysts were detectable on A. funestus midguts by 7 days post-infection. By 18-20 days post-infection, sporozoites had invaded the median and distal lateral lobes of the salivary glands, and hemocoel sporozoites were observed in the hemolymph. Mosquitoes were capable of infecting mice via bite, demonstrating that A. funestus supports the complete life cycle of P. berghei. In a random sample of wild mosquito genotypes, A. funestus prevalence of infection and the characteristics of parasite development were similar to that observed in A. gambiae-P. berghei infections.The data presented in this study establish an experimental laboratory model for Plasmodium infection of A. funestus, an important vector of human malaria. Studying A. funestus-Plasmodium interactions is now feasible in a laboratory setting. This information lays the groundwork for exploitation of the

  19. Disecciones de Mosquitos del género Anopheles en la Intendencia del Meta

    Renjifo-Salcedo Santiago

    1948-06-01

    Full Text Available EI esclarecimiento de los vectores de malaria reviste especial importancia para la salubridad nacional. En la presente comunicación se dan a conocer los resultados de 1048 disecciones de mosquitos del genero Anopheles (889 glándulas y 894 estómagos hechas por nosotros en el Laboratorio de Villavicencio, Instituto "Carlos Finlay", durante los meses de septiembre, octubre, noviembre y diciembre de 1946.

  20. Presence of the mosquito Anopheles hyrcanus in South Moravia, Czech Republic

    Šebesta, Oldřich; Rettich, F.; Minář, Jan; Halouzka, Jiří; Hubálek, Zdeněk; Juřicová, Zina; Rudolf, Ivo; Šikutová, Silvie; Gelbič, Ivan; Reiter, P.

    2009-01-01

    Roč. 23, č. 3 (2009), s. 284-286 ISSN 0269-283X R&D Projects: GA MŠk 2B08003 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z50070508 Keywords : Anopheles hyrcanus * mosquitoes * geographic range * Central Europe Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 2.092, year: 2009

  1. The invasive shrub Prosopis juliflora enhances the malaria parasite transmission capacity of Anopheles mosquitoes: a habitat manipulation experiment.

    Muller, Gunter C; Junnila, Amy; Traore, Mohamad M; Traore, Sekou F; Doumbia, Seydou; Sissoko, Fatoumata; Dembele, Seydou M; Schlein, Yosef; Arheart, Kristopher L; Revay, Edita E; Kravchenko, Vasiliy D; Witt, Arne; Beier, John C

    2017-07-05

    A neglected aspect of alien invasive plant species is their influence on mosquito vector ecology and malaria transmission. Invasive plants that are highly attractive to Anopheles mosquitoes provide them with sugar that is critical to their survival. The effect on Anopheles mosquito populations was examined through a habitat manipulation experiment that removed the flowering branches of highly attractive Prosopis juliflora from selected villages in Mali, West Africa. Nine villages in the Bandiagara district of Mali were selected, six with flowering Prosopis juliflora, and three without. CDC-UV light traps were used to monitor their Anopheles spp. vector populations, and recorded their species composition, population size, age structure, and sugar feeding status. After 8 days, all of the flowering branches were removed from three villages and trap catches were analysed again. Villages where flowering branches of the invasive shrub Prosopis juliflora were removed experienced a threefold drop in the older more dangerous Anopheles females. Population density dropped by 69.4% and the species composition shifted from being a mix of three species of the Anopheles gambiae complex to one dominated by Anopheles coluzzii. The proportion of sugar fed females dropped from 73 to 15% and males from 77 to 10%. This study demonstrates how an invasive plant shrub promotes the malaria parasite transmission capacity of African malaria vector mosquitoes. Proper management of invasive plants could potentially reduce mosquito populations and malaria transmission.

  2. Original Research Risk factors for Anopheles mosquitoes in rural ...

    have suggested that the strongest risk factor for malaria. Original ..... mosquitoes are adapted to urban environments characterised .... Reduction of childhood malaria by social marketing of insecticide-treated ... and ICF Macro; 2011. 22.

  3. Mediation of oviposition site selection in the African malaria mosquito Anopheles gambiae (Diptera: Culicidae) by semiochemicals of microbial origin

    Sumba, L.A.; Guda, T.O.; Deng, A.L.; Hassanali, A.; Beier, J.C.; Knols, B.G.J.

    2004-01-01

    Laboratory studies were carried out to investigate the role of larval habitat-derived microorganisms in the production of semiochemicals for oviposition site selection by Anopheles gambiae Giles sensu stricto mosquitoes. Dual-choice bioassays with gravid females were conducted in standard mosquito

  4. Limnological and botanical characterization of larval habitats for two primary malarial vectors, Anopheles albimanus and Anopheles pseudopunctipennis, in coastal areas of Chiapas State, Mexico.

    Savage, H M; Rejmankova, E; Arredondo-Jim'enez, J I; Roberts, D R; Rodr'iguez, M H

    1990-12-01

    Field surveys of mosquito breeding sites on the Pacific coastal plain and foothill regions of southern Chiapas, Mexico, were carried out in the dry and wet seasons of 1988. At each site, selected environmental variables were measured or estimated, presence and percent cover of aquatic plants recorded, a water sample collected for subsequent analyses, and 10-30 dips made for mosquito larvae. Logistic regression and discriminant analyses revealed that the occurrence of Anopheles albimanus larvae in both the wet and dry seasons was positively associated with planktonic algae and negatively associated with altitude. In the dry season, An. albimanus larvae were largely restricted to the margins of permanent water bodies and were associated with the presence of floating plants, particularly Eichhornia crassipes. During the wet season An. albimanus larvae were positively associated with emergent plants, particularly seasonally flooded Cyperaceae, and phosphorus (PO4) concentrations, and were negatively associated with abundant filamentous algae, high levels of total suspended solids (TSS) and Salvinia. In the dry season, An. pseudopunctipennis larvae were positively associated with filamentous algae, altitude and the presence of Heteranthera if encountered in a riverine setting, and were negatively associated with water depth. During the wet season, flooding eliminated typical flood plain An. pseudopunctipennis habitats, and larvae were rarely encountered.

  5. Phylogenetic study of six species of Anopheles mosquitoes in Peninsular Malaysia based on inter-transcribed spacer region 2 (ITS2) of ribosomal DNA.

    Sum, Jia-Siang; Lee, Wenn-Chyau; Amir, Amirah; Braima, Kamil A; Jeffery, John; Abdul-Aziz, Noraishah M; Fong, Mun-Yik; Lau, Yee-Ling

    2014-07-03

    Molecular techniques are invaluable for investigation on the biodiversity of Anopheles mosquitoes. This study aimed at investigating the spatial-genetic variations among Anopheles mosquitoes from different areas of Peninsular Malaysia, as well as deciphering evolutionary relationships of the local Anopheles mosquitoes with the mosquitoes from neighbouring countries using the anopheline ITS2 rDNA gene. Mosquitoes were collected, identified, dissected to check infection status, and DNA extraction was performed for PCR with primers targeting the ITS2 rDNA region. Sequencing was done and phylogenetic tree was constructed to study the evolutionary relationship among Anopheles mosquitoes within Peninsular Malaysia, as well as across the Asian region. A total of 133 Anopheles mosquitoes consisting of six different species were collected from eight different locations across Peninsular Malaysia. Of these, 65 ITS2 rDNA sequences were obtained. The ITS2 rDNA amplicons of the studied species were of different sizes. One collected species, Anopheles sinensis, shows two distinct pools of population in Peninsular Malaysia, suggesting evolvement of geographic race or allopatric speciation. Anopheles mosquitoes from Peninsular Malaysia show close evolutionary relationship with the Asian anophelines. Nevertheless, genetic differences due to geographical segregation can be seen. Meanwhile, some Anopheles mosquitoes in Peninsular Malaysia show vicariance, exemplified by the emergence of distinct cluster of An. sinensis population.

  6. Phylogenetic study of six species of Anopheles mosquitoes in Peninsular Malaysia based on inter-transcribed spacer region 2 (ITS2) of ribosomal DNA

    2014-01-01

    Background Molecular techniques are invaluable for investigation on the biodiversity of Anopheles mosquitoes. This study aimed at investigating the spatial-genetic variations among Anopheles mosquitoes from different areas of Peninsular Malaysia, as well as deciphering evolutionary relationships of the local Anopheles mosquitoes with the mosquitoes from neighbouring countries using the anopheline ITS2 rDNA gene. Methods Mosquitoes were collected, identified, dissected to check infection status, and DNA extraction was performed for PCR with primers targeting the ITS2 rDNA region. Sequencing was done and phylogenetic tree was constructed to study the evolutionary relationship among Anopheles mosquitoes within Peninsular Malaysia, as well as across the Asian region. Results A total of 133 Anopheles mosquitoes consisting of six different species were collected from eight different locations across Peninsular Malaysia. Of these, 65 ITS2 rDNA sequences were obtained. The ITS2 rDNA amplicons of the studied species were of different sizes. One collected species, Anopheles sinensis, shows two distinct pools of population in Peninsular Malaysia, suggesting evolvement of geographic race or allopatric speciation. Conclusion Anopheles mosquitoes from Peninsular Malaysia show close evolutionary relationship with the Asian anophelines. Nevertheless, genetic differences due to geographical segregation can be seen. Meanwhile, some Anopheles mosquitoes in Peninsular Malaysia show vicariance, exemplified by the emergence of distinct cluster of An. sinensis population. PMID:24993022

  7. Identification of Salivary Gland Proteins Depleted after Blood Feeding in the Malaria Vector Anopheles campestris-like Mosquitoes (Diptera: Culicidae)

    Sor-suwan, Sriwatapron; Jariyapan, Narissara; Roytrakul, Sittiruk; Paemanee, Atchara; Phumee, Atchara; Phattanawiboon, Benjarat; Intakhan, Nuchpicha; Chanmol, Wetpisit; Bates, Paul A.; Saeung, Atiporn; Choochote, Wej

    2014-01-01

    Malaria sporozoites must invade the salivary glands of mosquitoes for maturation before transmission to vertebrate hosts. The duration of the sporogonic cycle within the mosquitoes ranges from 10 to 21 days depending on the parasite species and temperature. During blood feeding salivary gland proteins are injected into the vertebrate host, along with malaria sporozoites in the case of an infected mosquito. To identify salivary gland proteins depleted after blood feeding of female Anopheles ca...

  8. Mosquito larvicidal activity of seaweeds extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus

    Mohamed Yacoob Syed Ali

    2013-06-01

    Full Text Available Objective: To identify the larvicidal activity of the seaweed extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus Methods: Seaweed extracts of Ulva lactuca, Caulerpa racemosa (C. racemosa, Sargassum microystum, Caulerpa scalpelliformis, Gracilaria corticata, Turbinaria decurrens, Turbinaria conoides and Caulerpa toxifolia were dissolved in DMSO to prepare a graded series of concentration. The test for the larvicidal effect of seaweeds against mosquitos larvae was conducted in accordance with the WHO standard method. Batches of 25 early 4th instar larvae of three mosquitoes were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (10-100 µg. Each experiment was conducted with triplicate with concurrent a control group. Results: Among the seaweeds extract, C. racemosa showed toxicity against 4th instar larvae of Aedes aegypti, Culex quinquefasciatus, Anopheles stephensi with equivalent LC 50 value (0.055 6依0.010 3 µg/mL, (0.067 5依0.136 0 µg/mL and (0.066 1 依0.007 6 µg/mL, respectively. Conclusions: The present study concluded that, the mosquito larvicidal property of C. racemosa might be the prospective alternative source to control the mosquitoes.

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

    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......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...... evolutionarily related G protein-coupled receptors (GPCRs) from this mosquito and expressed them in Chinese hamster ovary cells. After screening of a library of thirty-three insect or other invertebrate neuropeptides and eight biogenic amines, we could identify (de-orphanize) three of these GPCRs as...... relationship to the A. gambiae and other insect AKH receptors suggested that it is a receptor for an AKH-like peptide. This is the first published report on evolutionarily related AKH, corazonin, and CCAP receptors in mosquitoes....

  10. Transgenic Expression of the Anti-parasitic Factor TEP1 in the Malaria Mosquito Anopheles gambiae.

    Gloria Volohonsky

    2017-01-01

    Full Text Available Mosquitoes genetically engineered to be resistant to Plasmodium parasites represent a promising novel approach in the fight against malaria. The insect immune system itself is a source of anti-parasitic genes potentially exploitable for transgenic designs. The Anopheles gambiae thioester containing protein 1 (TEP1 is a potent anti-parasitic protein. TEP1 is secreted and circulates in the mosquito hemolymph, where its activated cleaved form binds and eliminates malaria parasites. Here we investigated whether TEP1 can be used to create malaria resistant mosquitoes. Using a GFP reporter transgene, we determined that the fat body is the main site of TEP1 expression. We generated transgenic mosquitoes that express TEP1r, a potent refractory allele of TEP1, in the fat body and examined the activity of the transgenic protein in wild-type or TEP1 mutant genetic backgrounds. Transgenic TEP1r rescued loss-of-function mutations, but did not increase parasite resistance in the presence of a wild-type susceptible allele. Consistent with previous reports, TEP1 protein expressed from the transgene in the fat body was taken up by hemocytes upon a challenge with injected bacteria. Furthermore, although maturation of transgenic TEP1 into the cleaved form was impaired in one of the TEP1 mutant lines, it was still sufficient to reduce parasite numbers and induce parasite melanization. We also report here the first use of Transcription Activator Like Effectors (TALEs in Anopheles gambiae to stimulate expression of endogenous TEP1. We found that artificial elevation of TEP1 expression remains moderate in vivo and that enhancement of endogenous TEP1 expression did not result in increased resistance to Plasmodium. Taken together, our results reveal the difficulty of artificially influencing TEP1-mediated Plasmodium resistance, and contribute to further our understanding of the molecular mechanisms underlying mosquito resistance to Plasmodium parasites.

  11. nanos-Driven expression of piggyBac transposase induces mobilization of a synthetic autonomous transposon in the malaria vector mosquito, Anopheles stephensi.

    Macias, Vanessa M; Jimenez, Alyssa J; Burini-Kojin, Bianca; Pledger, David; Jasinskiene, Nijole; Phong, Celine Hien; Chu, Karen; Fazekas, Aniko; Martin, Kelcie; Marinotti, Osvaldo; James, Anthony A

    2017-08-01

    Transposons are a class of selfish DNA elements that can mobilize within a genome. If mobilization is accompanied by an increase in copy number (replicative transposition), the transposon may sweep through a population until it is fixed in all of its interbreeding members. This introgression has been proposed as the basis for drive systems to move genes with desirable phenotypes into target species. One such application would be to use them to move a gene conferring resistance to malaria parasites throughout a population of vector mosquitos. We assessed the feasibility of using the piggyBac transposon as a gene-drive mechanism to distribute anti-malarial transgenes in populations of the malaria vector, Anopheles stephensi. We designed synthetic gene constructs that express the piggyBac transposase in the female germline using the control DNA of the An. stephensi nanos orthologous gene linked to marker genes to monitor inheritance. Two remobilization events were observed with a frequency of one every 23 generations, a rate far below what would be useful to drive anti-pathogen transgenes into wild mosquito populations. We discuss the possibility of optimizing this system and the impetus to do so. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. The ecology of Anopheles mosquitoes under climate change: case studies from the effects of deforestation in East African highlands.

    Afrane, Yaw A; Githeko, Andrew K; Yan, Guiyun

    2012-02-01

    Climate change is expected to lead to latitudinal and altitudinal temperature increases. High-elevation regions such as the highlands of Africa and those that have temperate climate are most likely to be affected. The highlands of Africa generally exhibit low ambient temperatures. This restricts the distribution of Anopheles mosquitoes, the vectors of malaria, filariasis, and O'nyong'nyong fever. The development and survival of larval and adult mosquitoes are temperature dependent, as are mosquito biting frequency and pathogen development rate. Given that various Anopheles species are adapted to different climatic conditions, changes in climate could lead to changes in species composition in an area that may change the dynamics of mosquito-borne disease transmission. It is important to consider the effect of climate change on rainfall, which is critical to the formation and persistence of mosquito breeding sites. In addition, environmental changes such as deforestation could increase local temperatures in the highlands; this could enhance the vectorial capacity of the Anopheles. These experimental data will be invaluable in facilitating the understanding of the impact of climate change on Anopheles. © 2012 New York Academy of Sciences.

  13. Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

    Weidong Gu

    Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

  14. Genomic, Physiologic, and Symbiotic Characterization of Serratia marcescens Strains Isolated from the Mosquito Anopheles stephensi

    Shicheng Chen

    2017-08-01

    Full Text Available Strains of Serratia marcescens, originally isolated from the gut lumen of adult female Anopheles stephensi mosquitoes, established persistent infection at high rates in adult A. stephensi whether fed to larvae or in the sugar meal to adults. By contrast, the congener S. fonticola originating from Aedes triseriatus had lower infection in A. stephensi, suggesting co-adaptation of Serratia strains in different species of host mosquitoes. Coinfection at high infection rate in adult A. stephensi resulted after feeding S. marcescens and Elizabethkingia anophelis in the sugar meal, but when fed together to larvae, infection rates with E. anophelis were much higher than were S. marcescens in adult A. stephensi, suggesting a suppression effect of coinfection across life stages. A primary isolate of S. marcescens was resistant to all tested antibiotics, showed high survival in the mosquito gut, and produced alpha-hemolysins which contributed to lysis of erythrocytes ingested with the blood meal. Genomes of two primary isolates from A. stephensi, designated S. marcescens ano1 and ano2, were sequenced and compared to other Serratia symbionts associated with insects, nematodes and plants. Serratia marcescens ano1 and ano2 had predicted virulence factors possibly involved in attacking parasites and/or causing opportunistic infection in mosquito hosts. S. marcescens ano1 and ano2 possessed multiple mechanisms for antagonism against other microorganisms, including production of bacteriocins and multi-antibiotic resistance determinants. These genes contributing to potential anti-malaria activity including serralysins, hemolysins and chitinases are only found in some Serratia species. It is interesting that genome sequences in S. marcescens ano1 and ano2 are distinctly different from those in Serratia sp. Ag1 and Ag2 which were isolated from Anopheles gambiae. Compared to Serratia sp. Ag1 and Ag2, S. marcescens ano1 and ano2 have more rRNAs and many important

  15. Genomic, Physiologic, and Symbiotic Characterization of Serratia marcescens Strains Isolated from the Mosquito Anopheles stephensi.

    Chen, Shicheng; Blom, Jochen; Walker, Edward D

    2017-01-01

    Strains of Serratia marcescens , originally isolated from the gut lumen of adult female Anopheles stephensi mosquitoes, established persistent infection at high rates in adult A. stephensi whether fed to larvae or in the sugar meal to adults. By contrast, the congener S. fonticola originating from Aedes triseriatus had lower infection in A. stephensi , suggesting co-adaptation of Serratia strains in different species of host mosquitoes. Coinfection at high infection rate in adult A. stephensi resulted after feeding S. marcescens and Elizabethkingia anophelis in the sugar meal, but when fed together to larvae, infection rates with E. anophelis were much higher than were S. marcescens in adult A. stephensi , suggesting a suppression effect of coinfection across life stages. A primary isolate of S. marcescens was resistant to all tested antibiotics, showed high survival in the mosquito gut, and produced alpha-hemolysins which contributed to lysis of erythrocytes ingested with the blood meal. Genomes of two primary isolates from A. stephensi , designated S. marcescens ano1 and ano2, were sequenced and compared to other Serratia symbionts associated with insects, nematodes and plants. Serratia marcescens ano1 and ano2 had predicted virulence factors possibly involved in attacking parasites and/or causing opportunistic infection in mosquito hosts. S. marcescens ano1 and ano2 possessed multiple mechanisms for antagonism against other microorganisms, including production of bacteriocins and multi-antibiotic resistance determinants. These genes contributing to potential anti-malaria activity including serralysins, hemolysins and chitinases are only found in some Serratia species. It is interesting that genome sequences in S. marcescens ano1 and ano2 are distinctly different from those in Serratia sp. Ag1 and Ag2 which were isolated from Anopheles gambiae . Compared to Serratia sp. Ag1 and Ag2, S. marcescens ano1 and ano2 have more rRNAs and many important genes involved in

  16. Light manipulation of mosquito behaviour: acute and sustained photic suppression of biting activity in the Anopheles gambiae malaria mosquito.

    Sheppard, Aaron D; Rund, Samuel S C; George, Gary F; Clark, Erin; Acri, Dominic J; Duffield, Giles E

    2017-06-16

    Host-seeking behaviours in anopheline mosquitoes are time-of-day specific, with a greater propensity for nocturnal biting. We investigated how a short exposure to light presented during the night or late day can inhibit biting activity and modulate flight activity behaviour. Anopheles gambiae (s.s.), maintained on a 12:12 LD cycle, were exposed transiently to white light for 10-min at the onset of night and the proportion taking a blood meal in a human biting assay was recorded every 2 h over an 8-h duration. The pulse significantly reduced biting propensity in mosquitoes 2 h following administration, in some trials for 4 h, and with no differences detected after 6 h. Conversely, biting levels were significantly elevated when mosquitoes were exposed to a dark treatment during the late day, suggesting that light suppresses biting behaviour even during the late daytime. These data reveal a potent effect of a discrete light pulse on biting behaviour that is both immediate and sustained. We expanded this approach to develop a method to reduce biting propensity throughout the night by exposing mosquitoes to a series of 6- or 10-min pulses presented every 2 h. We reveal both an immediate suppressive effect of light during the exposure period and 2 h after the pulse. This response was found to be effective during most times of the night: however, differential responses that were time-of-day specific suggest an underlying circadian property of the mosquito physiology that results in an altered treatment efficacy. Finally, we examined the immediate and sustained effects of light on mosquito flight activity behaviour following exposure to a 30-min pulse, and observed activity suppression during early night, and elevated activity during the late night. As mosquitoes and malaria parasites are becoming increasingly resistant to insecticide and drug treatment respectively, there is a necessity for the development of innovative control strategies beyond insecticide

  17. Protection against mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus using a novel insect repellent, ethyl anthranilate.

    Islam, Johirul; Zaman, Kamaruz; Tyagi, Varun; Duarah, Sanjukta; Dhiman, Sunil; Chattopadhyay, Pronobesh

    2017-10-01

    Growing concern on the application of synthetic mosquito repellents in the recent years has instigated the identification and development of better alternatives to control different mosquito-borne diseases. In view of above, present investigation evaluates the repellent activity of ethyl anthranilate (EA), a non-toxic, FDA approved volatile food additive against three known mosquito vectors namely, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus under laboratory conditions following standard protocols. Three concentration levels (2%, 5% and 10% w/v) of EA were tested against all the three selected mosquito species employing K & D module and arm-in-cage method to determine the effective dose (ED 50 ) and complete protection time (CPT), respectively. The repellent activity of EA was further investigated by modified arm-in-cage method to determine the protection over extended spatial ranges against all mosquito species. All behavioural situations were compared with the well-documented repellent N,N-diethylphenyl acetamide (DEPA) as a positive control. The findings demonstrated that EA exhibited significant repellent activity against all the three mosquitoes species. The ED 50 values of EA, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus were found to be 0.96%, 5.4% and 3.6% w/v, respectively. At the concentration of 10% w/v, it provided CPTs of 60, 60 and 30min, respectively, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes. Again in spatial repellency evaluation, EA was found to be extremely effective in repelling all the three tested species of mosquitoes. Ethyl anthranilate provided comparable results to standard repellent DEPA during the study. Results have concluded that the currently evaluated chemical, EA has potential repellent activity against some well established mosquito vectors. The study emphasizes that repellent activity of EA could be exploited for developing effective, eco

  18. Rapid evolution of female-biased genes among four species of Anopheles malaria mosquitoes.

    Papa, Francesco; Windbichler, Nikolai; Waterhouse, Robert M; Cagnetti, Alessia; D'Amato, Rocco; Persampieri, Tania; Lawniczak, Mara K N; Nolan, Tony; Papathanos, Philippos Aris

    2017-09-01

    Understanding how phenotypic differences between males and females arise from the sex-biased expression of nearly identical genomes can reveal important insights into the biology and evolution of a species. Among Anopheles mosquito species, these phenotypic differences include vectorial capacity, as it is only females that blood feed and thus transmit human malaria. Here, we use RNA-seq data from multiple tissues of four vector species spanning the Anopheles phylogeny to explore the genomic and evolutionary properties of sex-biased genes. We find that, in these mosquitoes, in contrast to what has been found in many other organisms, female-biased genes are more rapidly evolving in sequence, expression, and genic turnover than male-biased genes. Our results suggest that this atypical pattern may be due to the combination of sex-specific life history challenges encountered by females, such as blood feeding. Furthermore, female propensity to mate only once in nature in male swarms likely diminishes sexual selection of post-reproductive traits related to sperm competition among males. We also develop a comparative framework to systematically explore tissue- and sex-specific splicing to document its conservation throughout the genus and identify a set of candidate genes for future functional analyses of sex-specific isoform usage. Finally, our data reveal that the deficit of male-biased genes on the X Chromosomes in Anopheles is a conserved feature in this genus and can be directly attributed to chromosome-wide transcriptional regulation that de-masculinizes the X in male reproductive tissues. © 2017 Papa et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Biological differences in reproductive strategy between the mosquito sibling species Anopheles gambiae sensu stricto and An. quadriannulatus

    Takken, W.; Stuke, K.; Klowden, M.J.

    2002-01-01

    Females of the afrotropical mosquito species Anopheles gambiae Giles sensu stricto and An. quadriannulatus (Theobald) (Diptera: Culicidae) were studied for the effect of blood meal size and the frequency of blood feeding on reproductive development during the first gonotrophic cycle. To standardize

  20. The role of skin microbiota in the attractiveness of humans to the malaria mosquito Anopheles gambiae Giles

    Verhulst, N.O.

    2010-01-01

    Malaria is one of the most serious infectious diseases in the world. The African mosquito Anopheles gambiae sensu stricto (henceforth termed An. gambiae) is highly competent for malaria parasites and preferably feeds on humans inside houses, which make it one of the most effective vectors of the

  1. Human skin microbiota and their volatiles as odour baits for the malaria mosquito Anopheles gambiae s.s

    Verhulst, N.O.; Mukabana, W.R.; Takken, W.; Smallegange, R.C.

    2011-01-01

    Host seeking by the malaria mosquito Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) is mainly guided by volatile chemicals present in human odours. The skin microbiota plays an important role in the production of these volatiles, and skin bacteria grown on agar plates attract An. gambiae

  2. 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)

    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

  3. Modelling the spatial distribution of the nuisance mosquito species Anopheles plumbeus (Diptera: Culicidae) in the Netherlands.

    Ibañez-Justicia, Adolfo; Cianci, Daniela

    2015-05-01

    Landscape modifications, urbanization or changes of use of rural-agricultural areas can create more favourable conditions for certain mosquito species and therefore indirectly cause nuisance problems for humans. This could potentially result in mosquito-borne disease outbreaks when the nuisance is caused by mosquito species that can transmit pathogens. Anopheles plumbeus is a nuisance mosquito species and a potential malaria vector. It is one of the most frequently observed species in the Netherlands. Information on the distribution of this species is essential for risk assessments. The purpose of the study was to investigate the potential spatial distribution of An. plumbeus in the Netherlands. Random forest models were used to link the occurrence and the abundance of An. plumbeus with environmental features and to produce distribution maps in the Netherlands. Mosquito data were collected using a cross-sectional study design in the Netherlands, from April to October 2010-2013. The environmental data were obtained from satellite imagery and weather stations. Statistical measures (accuracy for the occurrence model and mean squared error for the abundance model) were used to evaluate the models performance. The models were externally validated. The maps show that forested areas (centre of the Netherlands) and the east of the country were predicted as suitable for An. plumbeus. In particular high suitability and high abundance was predicted in the south-eastern provinces Limburg and North Brabant. Elevation, precipitation, day and night temperature and vegetation indices were important predictors for calculating the probability of occurrence for An. plumbeus. The probability of occurrence, vegetation indices and precipitation were important for predicting its abundance. The AUC value was 0.73 and the error in the validation was 0.29; the mean squared error value was 0.12. The areas identified by the model as suitable and with high abundance of An. plumbeus, are

  4. Unraveling dual feeding associated molecular complexity of salivary glands in the mosquito Anopheles culicifacies

    Punita Sharma

    2015-08-01

    Full Text Available Mosquito salivary glands are well known to facilitate meal acquisition, however the fundamental question on how adult female salivary gland manages molecular responses during sugar versus blood meal uptake remains unanswered. To investigate these responses, we analyzed a total of 58.5 million raw reads generated from two independent RNAseq libraries of the salivary glands collected from 3–4 day-old sugar and blood fed Anopheles culicifacies mosquitoes. Comprehensive functional annotation analysis of 10,931 contigs unraveled that salivary glands may encode diverse nature of proteins in response to distinct physiological feeding status. Digital gene expression analysis and PCR validation indicated that first blood meal significantly alters the molecular architecture of the salivary glands. Comparative microscopic analysis also revealed that first blood meal uptake not only causes an alteration of at least 12–22% of morphological features of the salivary glands but also results in cellular changes e.g. apoptosis, confirming together that adult female salivary glands are specialized organs to manage meal specific responses. Unraveling the underlying mechanism of mosquito salivary gene expression, controlling dual feeding associated responses may provide a new opportunity to control vector borne diseases.

  5. Maternal environment shapes the life history and susceptibility to malaria of Anopheles gambiae mosquitoes

    Lorenz Lena M

    2011-12-01

    Full Text Available Abstract Background It is becoming generally recognized that an individual's phenotype can be shaped not only by its own genotype and environmental experience, but also by its mother's environment and condition. Maternal environmental factors can influence mosquitoes' population dynamics and susceptibility to malaria, and therefore directly and indirectly the epidemiology of malaria. Methods In a full factorial experiment, the effects of two environmental stressors - food availability and infection with the microsporidian parasite Vavraia culicis - of female mosquitoes (Anopheles gambiae sensu stricto on their offspring's development, survival and susceptibility to malaria were studied. Results The offspring of A. gambiae s.s. mothers infected with V. culicis developed into adults more slowly than those of uninfected mothers. This effect was exacerbated when mothers were reared on low food. Maternal food availability had no effect on the survival of their offspring up to emergence, and microsporidian infection decreased survival only slightly. Low food availability for mothers increased and V. culicis-infection of mothers decreased the likelihood that the offspring fed on malaria-infected blood harboured malaria parasites (but neither maternal treatment influenced their survival up to dissection. Conclusions Resource availability and infection with V. culicis of A. gambiae s.s. mosquitoes not only acted as direct environmental stimuli for changes in the success of one generation, but could also lead to maternal effects. Maternal V. culicis infection could make offspring more resistant and less likely to transmit malaria, thus enhancing the efficacy of the microsporidian for the biological control of malaria.

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

    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.

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

    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

  8. Investigation of the seasonal microbiome of Anopheles coluzzii mosquitoes in Mali.

    Benjamin J Krajacich

    Full Text Available The poorly understood mechanisms of dry season persistence of Anopheles spp. mosquitoes through the dry season in Africa remain a critical gap in our knowledge of Plasmodium disease transmission. While it is thought that adult mosquitoes remain in a dormant state throughout this seven-month dry season, the nature of this state remains unknown and has largely not been recapitulated in laboratory settings. To elucidate possible connections of this state with microbial composition, the whole body microbiomes of adult mosquitoes in the dry and wet seasons in two locations of Mali with varying water availability were compared by sequencing the 16S ribosomal RNA gene. These locations were a village near the Niger River with year-round water sources (N'Gabakoro, "riparian", and a typical Sahelian area with highly seasonal breeding sites (Thierola Area, "Sahelian". The 16S bacterial data consisted of 2057 sequence variants in 426 genera across 184 families. From these data, we found several compositional differences that were seasonally and spatially linked. Counter to our initial hypothesis, there were more pronounced seasonal differences in the bacterial microbiome of riparian, rather than Sahelian areas. These seasonal shifts were primarily in Ralstonia, Sphingorhabdus, and Duganella spp. bacteria that are usually soil and water-associated, indicating these changes may be from bacteria acquired in the larval environment, rather than adulthood. In Sahelian dry season mosquitoes, there was a unique intracellular bacteria, Anaplasma, which likely was acquired through non-human blood feeding. Cytochrome B analysis of blood meals showed greater heterogeneity in host choice of An. coluzzii independent of season in the Thierola area compared to N'Gabakoro (77.5% vs. 94.6% human-origin blood meal, respectively, indicating a relaxation of anthropophily. Overall, this exploratory study provides valuable indications of spatial and seasonal differences in

  9. Evaluation of larvicidal activity of Acalypha alnifolia Klein ex Willd. (Euphorbiaceae) leaf extract against the malarial vector, Anopheles stephensi, dengue vector, Aedes aegypti and Bancroftian filariasis vector, Culex quinquefasciatus (Diptera: Culicidae).

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Vincent, Savariar

    2012-02-01

    The leaf extract of Acalypha alnifolia with different solvents - hexane, chloroform, ethyl acetate, acetone and methanol - were tested for larvicidal activity against three important mosquitoes such as malarial vector, Anopheles stephensi, dengue vector, Aedes aegypti and Bancroftian filariasis vector, Culex quinquefasciatus. The medicinal plants were collected from the area around Kallar Hills near the Western Ghats, Coimbatore, India. A. alnifolia plant was washed with tap water and shade dried at room temperature. The dried leaves were powdered mechanically using commercial electrical stainless steel blender. The powder 800 g of the leaf material was extract with 2.5 litre of various each organic solvents such as hexane, chloroform, ethyl acetate, acetone, methanol for 8 h using Soxhlet apparatus, and filtered. The crude plant extracts were evaporated to dryness in a rotary vacuum evaporator. The yield of extracts was hexane (8.64 g), chloroform (10.74 g), ethyl acetate (9.14 g), acetone (10.02 g), and methanol (11.43 g). One gram of the each plant residue was dissolved separately in 100 ml of acetone (stock solution) from which different concentrations, i.e., 50, 150, 250, 350 and 450 ppm, was prepared. The hexane, chloroform, ethyl acetate, acetone was 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 early fourth-instar larvae of A. stephensi had values of LC(50) = 197.37, 178.75, 164.34, 149.90 and 125.73 ppm and LC(90) = 477.60, 459.21, 435.07, 416.20 and 395.50 ppm, respectively. The A. aegypti had values of LC(50) = 202.15, 182.58, 160.35, 146.07 and 128.55 ppm and LC(90) = 476.57, 460.83, 440.78, 415.38 and 381.67 ppm, respectively. The C. quinquefasciatus had values of LC(50) = 198.79, 172.48, 151.06, 140.69 and 127.98 ppm and LC(90) = 458.73, 430

  10. Extensive circadian and light regulation of the transcriptome in the malaria mosquito Anopheles gambiae

    2013-01-01

    Background Mosquitoes exhibit 24 hr rhythms in flight activity, feeding, reproduction and development. To better understand the molecular basis for these rhythms in the nocturnal malaria vector Anopheles gambiae, we have utilized microarray analysis on time-of-day specific collections of mosquitoes over 48 hr to explore the coregulation of gene expression rhythms by the circadian clock and light, and compare these with the 24 hr rhythmic gene expression in the diurnal Aedes aegypti dengue vector mosquito. Results In time courses from An. gambiae head and body collected under light:dark cycle (LD) and constant dark (DD) conditions, we applied three algorithms that detect sinusoidal patterns and an algorithm that detects spikes in expression. This revealed across four experimental conditions 393 probes newly scored as rhythmic. These genes correspond to functions such as metabolic detoxification, immunity and nutrient sensing. This includes glutathione S-transferase GSTE5, whose expression pattern and chromosomal location are shared with other genes, suggesting shared chromosomal regulation; and pulsatile expression of the gene encoding CYP6M2, a cytochrome P450 that metabolizes pyrethroid insecticides. We explored the interaction of light and the circadian clock and highlight the regulation of odorant binding proteins (OBPs), important components of the olfactory system. We reveal that OBPs have unique expression patterns as mosquitoes make the transition from LD to DD conditions. We compared rhythmic expression between An. gambiae and Ae. aegypti heads collected under LD conditions using a single cosine fitting algorithm, and report distinct similarities and differences in the temporal regulation of genes involved in tRNA priming, the vesicular-type ATPase, olfaction and vision between the two species. Conclusions These data build on our previous analyses of time-of-day specific regulation of the An. gambiae transcriptome to reveal additional rhythmic genes, an

  11. The effect of physical water quality and water level changes on the occurrence and density of Anopheles mosquito larvae around the shoreline of the Koka reservoir, central Ethiopia

    S. Kibret

    2010-12-01

    Full Text Available Entomological studies to determine the effect of the physical characteristics of mosquito larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae were conducted in two villages at Koka reservoir in central Ethiopia between August and December 2007. Of the two study villages, Ejersa is located close 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, derived from 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 An. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitat than in turbid and relatively deep aquatic habitat. The density of An. 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. There was also a positive correlation between the occurrence of Anopheles larvae with the water and daily minimum atmospheric temperature. Similarly at Ejersa, over the sampling period, there was a positive correlation between falling reservoir water levels and the number of positive breeding habitats. These results confirm that physical characteristics of the water bodies play an important role in the species composition, total Anopheles larval count, and the density of Anopheles mosquitoes. Suitable breeding habitat in the vicinity of the reservoir village was strongly associated with the reservoir. This is particularly

  12. Anthropogenic habitat disturbance and ecological divergence between incipient species of the malaria mosquito Anopheles gambiae.

    Kamdem, Colince; Tene Fossog, Billy; Simard, Frédéric; Etouna, Joachim; Ndo, Cyrille; Kengne, Pierre; Boussès, Philippe; Etoa, François-Xavier; Awono-Ambene, Parfait; Fontenille, Didier; Antonio-Nkondjio, Christophe; Besansky, Nora J; Costantini, Carlo

    2012-01-01

    Anthropogenic habitat disturbance is a prime cause in the current trend of the Earth's reduction in biodiversity. Here we show that the human footprint on the Central African rainforest, which is resulting in deforestation and growth of densely populated urban agglomerates, is associated to ecological divergence and cryptic speciation leading to adaptive radiation within the major malaria mosquito Anopheles gambiae. In southern Cameroon, the frequency of two molecular forms--M and S--among which reproductive isolation is strong but still incomplete, was correlated to an index of urbanisation extracted from remotely sensed data, expressed as the proportion of built-up surface in each sampling unit. The two forms markedly segregated along an urbanisation gradient forming a bimodal cline of ∼6-km width: the S form was exclusive to the rural habitat, whereas only the M form was present in the core of densely urbanised settings, co-occurring at times in the same polluted larval habitats of the southern house mosquito Culex quinquefasciatus--a species association that was not historically recorded before. Our results indicate that when humans create novel habitats and ecological heterogeneities, they can provide evolutionary opportunities for rapid adaptive niche shifts associated with lineage divergence, whose consequences upon malaria transmission might be significant.

  13. Artificial activation of mature unfertilized eggs in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae).

    Yamamoto, Daisuke S; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki

    2013-08-01

    In the past decade, many transgenic lines of mosquitoes have been generated and analyzed, whereas the maintenance of a large number of transgenic lines requires a great deal of effort and cost. In vitro fertilization by an injection of cryopreserved sperm into eggs has been proven to be effective for the maintenance of strains in mammals. The technique of artificial egg activation is a prerequisite for the establishment of in vitro fertilization by sperm injection. We demonstrated that artificial egg activation is feasible in the malaria vector mosquito, Anopheles stephensi (Diptera, Culicidae). Nearly 100% of eggs dissected from virgin females immersed in distilled water darkened, similar to normally oviposited fertilized eggs. It was revealed by the cytological examination of chromosomes that meiotic arrest was relieved in these eggs approximately 20 min after incubation in water. Biochemical examinations revealed that MAPK (mitogen-activated protein kinase)/ERK (extracellular signal-regulated protein kinase) and MEK (MAPK/ERK kinase) were dephosphorylated similar to that in fertilized eggs. These results indicate that dissected unfertilized eggs were activated in distilled water and started development. Injection of distilled water into body cavity of the virgin blood-fed females also induced activation of a portion of eggs in the ovaries. The technique of artificial egg activation is expected to contribute to the success of in vitro fertilization in A. stephensi.

  14. Molecular characterization of larval peripheral thermosensory responses of the malaria vector mosquito Anopheles gambiae.

    Chao Liu

    Full Text Available Thermosensation provides vital inputs for the malaria vector mosquito, Anopheles gambiae which utilizes heat-sensitivity within a broad spectrum of behaviors, most notably, the localization of human hosts for blood feeding. In this study, we examine thermosensory behaviors in larval-stage An. gambiae, which as a result of their obligate aquatic habitats and importance for vectorial capacity, represents an opportunistic target for vector control as part of the global campaign to eliminate malaria. As is the case for adults, immature mosquitoes respond differentially to a diverse array of external heat stimuli. In addition, larvae exhibit a striking phenotypic plasticity in thermal-driven behaviors that are established by temperature at which embryonic development occurs. Within this spectrum, RNAi-directed gene-silencing studies provide evidence for the essential role of the Transient Receptor Potential sub-family A1 (TRPA1 channel in mediating larval thermal-induced locomotion and thermal preference within a discrete upper range of ambient temperatures.

  15. Landscape movements of Anopheles gambiae malaria vector mosquitoes in rural Gambia.

    Thomas, Christopher J; Cross, Dónall E; Bøgh, Claus

    2013-01-01

    For malaria control in Africa it is crucial to characterise the dispersal of its most efficient vector, Anopheles gambiae, in order to target interventions and assess their impact spatially. Our study is, we believe, the first to present a statistical model of dispersal probability against distance from breeding habitat to human settlements for this important disease vector. We undertook post-hoc analyses of mosquito catches made in The Gambia to derive statistical dispersal functions for An. gambiae sensu lato collected in 48 villages at varying distances to alluvial larval habitat along the River Gambia. The proportion dispersing declined exponentially with distance, and we estimated that 90% of movements were within 1.7 km. Although a 'heavy-tailed' distribution is considered biologically more plausible due to active dispersal by mosquitoes seeking blood meals, there was no statistical basis for choosing it over a negative exponential distribution. Using a simple random walk model with daily survival and movements previously recorded in Burkina Faso, we were able to reproduce the dispersal probabilities observed in The Gambia. Our results provide an important quantification of the probability of An. gambiae s.l. dispersal in a rural African setting typical of many parts of the continent. However, dispersal will be landscape specific and in order to generalise to other spatial configurations of habitat and hosts it will be necessary to produce tractable models of mosquito movements for operational use. We show that simple random walk models have potential. Consequently, there is a pressing need for new empirical studies of An. gambiae survival and movements in different settings to drive this development.

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

    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.

  17. An Epithelial Serine Protease, AgESP, Is Required for Plasmodium Invasion in the Mosquito Anopheles gambiae

    Rodrigues, J.; Oliveira, G. A.; Kotsyfakis, Michalis; Dixit, R.; Molina-Cruz, A.; Jochim, R.; Barillas-Mury, C.

    2012-01-01

    Roč. 7, č. 4 (2012), e35210 E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : malaria * mosquito * serine protease * sporozoites * ookinetes * gene silencing * midgut * salivary glands * Plasmodium falciparum * Anopheles gambiae Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.730, year: 2012 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035210

  18. Effects of blood-feeding on olfactory sensitivity of the malaria mosquito Anopheles gambiae: application of mixed linear models to account for repeated measurements

    Qiu, Y.T.; Gort, G.; Torricelli, A.; Takken, W.; Loon, van J.J.A.

    2013-01-01

    Olfaction plays an important role in the host-seeking behavior of the malaria mosquito Anopheles gambiae. After a complete blood meal, female mosquitoes will not engage in host-seeking behavior until oviposition has occurred. We investigated if peripheral olfactory sensitivity changed after a blood

  19. Mosquito Vector Biting and Community Protection in a Malarious Area, Siahoo District, Hormozgan, Iran

    KH Shahandeh

    2010-12-01

    Conclusion: Study subjects were aware of an association between mosquito bite and malaria transmission. Health work­ers at different levels of the health care delivery system should disseminate relevant information about self-protection to help community members to be involved more in malaria control.

  20. Interventions that effectively target Anopheles funestus mosquitoes could significantly improve control of persistent malaria transmission in south-eastern Tanzania.

    Kaindoa, Emmanuel W; Matowo, Nancy S; Ngowo, Halfan S; Mkandawile, Gustav; Mmbando, Arnold; Finda, Marcelina; Okumu, Fredros O

    2017-01-01

    Malaria is transmitted by many Anopheles species whose proportionate contributions vary across settings. We re-assessed the roles of Anopheles arabiensis and Anopheles funestus, and examined potential benefits of species-specific interventions in an area in south-eastern Tanzania, where malaria transmission persists, four years after mass distribution of long-lasting insecticide-treated nets (LLINs). Monthly mosquito sampling was done in randomly selected households in three villages using CDC light traps and back-pack aspirators, between January-2015 and January-2016, four years after the last mass distribution of LLINs in 2011. Multiplex polymerase chain reaction (PCR) was used to identify members of An. funestus and Anopheles gambiae complexes. Enzyme-linked immunosorbent assay (ELISA) was used to detect Plasmodium sporozoites in mosquito salivary glands, and to identify sources of mosquito blood meals. WHO susceptibility assays were done on wild caught female An. funestus s.l, and physiological ages approximated by examining mosquito ovaries for parity. A total of 20,135 An. arabiensis and 4,759 An. funestus were collected. The An. funestus group consisted of 76.6% An. funestus s.s, 2.9% An. rivulorum, 7.1% An. leesoni, and 13.4% unamplified samples. Of all mosquitoes positive for Plasmodium, 82.6% were An. funestus s.s, 14.0% were An. arabiensis and 3.4% were An. rivulorum. An. funestus and An. arabiensis contributed 86.21% and 13.79% respectively, of annual entomological inoculation rate (EIR). An. arabiensis fed on humans (73.4%), cattle (22.0%), dogs (3.1%) and chicken (1.5%), but An. funestus fed exclusively on humans. The An. funestus populations were 100% susceptible to organophosphates, pirimiphos methyl and malathion, but resistant to permethrin (10.5% mortality), deltamethrin (18.7%), lambda-cyhalothrin (18.7%) and DDT (26.2%), and had reduced susceptibility to bendiocarb (95%) and propoxur (90.1%). Parity rate was higher in An. funestus (65.8%) than

  1. Interventions that effectively target Anopheles funestus mosquitoes could significantly improve control of persistent malaria transmission in south–eastern Tanzania

    Matowo, Nancy S.; Ngowo, Halfan S.; Mkandawile, Gustav; Mmbando, Arnold; Finda, Marcelina; Okumu, Fredros O.

    2017-01-01

    Malaria is transmitted by many Anopheles species whose proportionate contributions vary across settings. We re-assessed the roles of Anopheles arabiensis and Anopheles funestus, and examined potential benefits of species-specific interventions in an area in south-eastern Tanzania, where malaria transmission persists, four years after mass distribution of long-lasting insecticide-treated nets (LLINs). Monthly mosquito sampling was done in randomly selected households in three villages using CDC light traps and back-pack aspirators, between January-2015 and January-2016, four years after the last mass distribution of LLINs in 2011. Multiplex polymerase chain reaction (PCR) was used to identify members of An. funestus and Anopheles gambiae complexes. Enzyme-linked immunosorbent assay (ELISA) was used to detect Plasmodium sporozoites in mosquito salivary glands, and to identify sources of mosquito blood meals. WHO susceptibility assays were done on wild caught female An. funestus s.l, and physiological ages approximated by examining mosquito ovaries for parity. A total of 20,135 An. arabiensis and 4,759 An. funestus were collected. The An. funestus group consisted of 76.6% An. funestus s.s, 2.9% An. rivulorum, 7.1% An. leesoni, and 13.4% unamplified samples. Of all mosquitoes positive for Plasmodium, 82.6% were An. funestus s.s, 14.0% were An. arabiensis and 3.4% were An. rivulorum. An. funestus and An. arabiensis contributed 86.21% and 13.79% respectively, of annual entomological inoculation rate (EIR). An. arabiensis fed on humans (73.4%), cattle (22.0%), dogs (3.1%) and chicken (1.5%), but An. funestus fed exclusively on humans. The An. funestus populations were 100% susceptible to organophosphates, pirimiphos methyl and malathion, but resistant to permethrin (10.5% mortality), deltamethrin (18.7%), lambda-cyhalothrin (18.7%) and DDT (26.2%), and had reduced susceptibility to bendiocarb (95%) and propoxur (90.1%). Parity rate was higher in An. funestus (65.8%) than

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

    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.

  3. Presence of Aedes and Anopheles mosquito larvae is correlated to bacteria found in domestic water-storage containers.

    Nilsson, Louise K J; Sharma, Anil; Bhatnagar, Raj K; Bertilsson, Stefan; Terenius, Olle

    2018-06-01

    Water-storage containers are common in households where access to water is scarce and often act as breeding sites for vector mosquitoes. Bacteria in these containers may be important for attracting or repelling ovipositing mosquitoes. We hypothesized that bacterial community composition in water-storage containers would represent either inhibitory or suitable environmental conditions for mosquito larvae. To investigate this, we characterized the bacterial community composition in water-storage containers and correlated these communities to Aedes and Anopheles larval densities. Water samples were collected over two years from 13 containers in an Indian village and analyzed by high throughput 16S rRNA gene amplicon sequencing. Comparisons of bacterial community composition between water with and without mosquito larvae showed that Xanthomonadaceae, Comamonadaceae and Burkholderiaceae were more common (P < 0.05) in absence of larvae, while Lachnospiraceae, Synechococcaceae, Alcaligenaceae and Cryomorphaceae were more common (P < 0.05) in presence of larvae. Indicator analysis identified operational taxonomic units designated as CL500-29 marine group (Acidimicrobiaceae) and FukuN101 (Microbacteriaceae) for absence and presence of larvae, respectively. These results contribute to the understanding of which bacteria, directly or indirectly, can be linked to absence or presence of mosquitoes around households and set the basis for potential measures to be taken against these vector mosquitoes.

  4. Plasmodium falciparum malaria challenge by the bite of aseptic Anopheles stephensi mosquitoes: results of a randomized infectivity trial.

    Kirsten E Lyke

    2010-10-01

    Full Text Available Experimental infection of malaria-naïve volunteers by the bite of Plasmodium falciparum-infected mosquitoes is a preferred means to test the protective effect of malaria vaccines and drugs. The standard model relies on the bite of five infected mosquitoes to induce malaria. We examined the efficacy of malaria transmission using mosquitoes raised aseptically in compliance with current Good Manufacturing Practices (cGMPs.Eighteen adults aged 18-40 years were randomized to receive 1, 3 or 5 bites of Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of P. falciparum. Seventeen participants developed malaria; fourteen occurring on Day 11. The mean prepatent period was 10.9 days (9-12 days. The geometric mean parasitemia was 15.7 parasites/µL (range: 4-70 by microscopy. Polymerase chain reaction (PCR detected parasites 3.1 (range: 0-4 days prior to microscopy. The geometric mean sporozoite load was 16,753 sporozoites per infected mosquito (range: 1,000-57,500. A 1-bite participant withdrew from the study on Day 13 post-challenge and was PCR and smear negative.The use of aseptic, cGMP-compliant P. falciparum-infected mosquitoes is safe, is associated with a precise prepatent period compared to the standard model and appears more efficient than the standard approach, as it led to infection in 100% (6/6 of volunteers exposed to three mosquito bites and 83% (5/6 of volunteers exposed to one mosquito bite.ClinicalTrials.gov NCT00744133.

  5. In vivo gene expression profiling of the entomopathogenic fungus Beauveria bassiana elucidates its infection stratagems in Anopheles mosquito.

    Lai, Yiling; Chen, Huan; Wei, Ge; Wang, Guandong; Li, Fang; Wang, Sibao

    2017-08-01

    The use of entomopathogenic fungi to control mosquitoes is a promising tool for reducing vector-borne disease transmission. To better understand infection stratagems of insect pathogenic fungi, we analyzed the global gene expression profiling of Beauveria bassiana at 36, 60, 84 and 108 h after topical infection of Anopheles stephensi adult mosquitoes using RNA sequencing (RNA-Seq). A total of 5,354 differentially expressed genes (DEGs) are identified over the course of fungal infection. When the fungus grows on the mosquito cuticle, up-regulated DEGs include adhesion-related genes involved in cuticle attachment, Pth11-like GPCRs hypothesized to be involved in host recognition, and extracellular enzymes involved in the degradation and penetration of the mosquito cuticle. Once in the mosquito hemocoel, the fungus evades mosquito immune system probably through up-regulating expression of β-1,3-glucan degrading enzymes and chitin synthesis enzymes for remodeling of cell walls. Moreover, six previous unknown SSCP (small secreted cysteine-rich proteins) are significantly up-regulated, which may serve as "effectors" to suppress host defense responses. B. bassiana also induces large amounts of antioxidant genes to mitigate host-generated exogenous oxidative stress. At late stage of infection, B. bassiana activates a broad spectrum of genes including nutrient degrading enzymes, some transporters and metabolism pathway components, to exploit mosquito tissues and hemolymph as a nutrient source for hyphal growth. These findings establish an important framework of knowledge for further comprehensive elucidation of fungal pathogenesis and molecular mechanism of Beauveria-mosquito interactions.

  6. Reflections on the Anopheles gambiae genome sequence, transgenic mosquitoes and the prospect for controlling malaria and other vector borne diseases.

    Tabachnick, Walter J

    2003-09-01

    The completion of the Anopheles gambiae Giles genome sequencing project is a milestone toward developing more effective strategies in reducing the impact of malaria and other vector borne diseases. The successes in developing transgenic approaches using mosquitoes have provided another essential new tool for further progress in basic vector genetics and the goal of disease control. The use of transgenic approaches to develop refractory mosquitoes is also possible. The ability to use genome sequence to identify genes, and transgenic approaches to construct refractory mosquitoes, has provided the opportunity that with the future development of an appropriate genetic drive system, refractory transgenes can be released into vector populations leading to nontransmitting mosquitoes. An. gambiae populations incapable of transmitting malaria. This compelling strategy will be very difficult to achieve and will require a broad substantial research program for success. The fundamental information that is required on genome structure, gene function and environmental effects on genetic expression are largely unknown. The ability to predict gene effects on phenotype is rudimentary, particularly in natural populations. As a result, the release of a refractory transgene into natural mosquito populations is imprecise and there is little ability to predict unintended consequences. The new genetic tools at hand provide opportunities to address an array of important issues, many of which can have immediate impact on the effectiveness of a host of strategies to control vector borne disease. Transgenic release approaches represent only one strategy that should be pursued. A balanced research program is required.

  7. Maternal Germline-Specific Genes in the Asian Malaria Mosquito Anopheles stephensi: Characterization and Application for Disease Control

    Biedler, James K.; Qi, Yumin; Pledger, David; Macias, Vanessa M.; James, Anthony A.; Tu, Zhijian

    2014-01-01

    Anopheles stephensi is a principal vector of urban malaria on the Indian subcontinent and an emerging model for molecular and genetic studies of mosquito biology. To enhance our understanding of female mosquito reproduction, and to develop new tools for basic research and for genetic strategies to control mosquito-borne infectious diseases, we identified 79 genes that displayed previtellogenic germline-specific expression based on RNA-Seq data generated from 11 life stage–specific and sex-specific samples. Analysis of this gene set provided insights into the biology and evolution of female reproduction. Promoters from two of these candidates, vitellogenin receptor and nanos, were used in independent transgenic cassettes for the expression of artificial microRNAs against suspected mosquito maternal-effect genes, discontinuous actin hexagon and myd88. We show these promoters have early germline-specific expression and demonstrate 73% and 42% knockdown of myd88 and discontinuous actin hexagon mRNA in ovaries 48 hr after blood meal, respectively. Additionally, we demonstrate maternal-specific delivery of mRNA and protein to progeny embryos. We discuss the application of this system of maternal delivery of mRNA/miRNA/protein in research on mosquito reproduction and embryonic development, and for the development of a gene drive system based on maternal-effect dominant embryonic arrest. PMID:25480960

  8. Role of Culex and Anopheles mosquito species as potential vectors of rift valley fever virus in Sudan outbreak, 2007

    Galal Fatma H

    2010-03-01

    Full Text Available Abstract Background Rift Valley fever (RVF is an acute febrile arthropod-borne viral disease of man and animals caused by a member of the Phlebovirus genus, one of the five genera in the family Bunyaviridae. RVF virus (RVFV is transmitted between animals and human by mosquitoes, particularly those belonging to the Culex, Anopheles and Aedes genera. Methods Experiments were designed during RVF outbreak, 2007 in Sudan to provide an answer about many raised questions about the estimated role of vector in RVFV epidemiology. During this study, adult and immature mosquito species were collected from Khartoum and White Nile states, identified and species abundance was calculated. All samples were frozen individually for further virus detection. Total RNA was extracted from individual insects and RVF virus was detected from Culex, Anopheles and Aedes species using RT-PCR. In addition, data were collected about human cases up to November 24th, 2007 to asses the situation of the disease in affected states. Furthermore, a historical background of the RVF outbreaks was discussed in relation to global climatic anomalies and incriminated vector species. Results A total of 978 mosquitoes, belonging to 3 genera and 7 species, were collected during Sudan outbreak, 2007. Anopheles gambiae arabiensis was the most frequent species (80.7% in White Nile state. Meanwhile, Cx. pipiens complex was the most abundant species (91.2% in Khartoum state. RT-PCR was used and successfully amplified 551 bp within the M segment of the tripartite negative-sense single stranded RNA genome of RVFV. The virus was detected in female, male and larval stages of Culex and Anopheles species. The most affected human age interval was 15-29 years old followed by ≥ 45 years old, 30-44 years old, and then 5-14 years old. Regarding to the profession, housewives followed by farmers, students, shepherd, workers and the free were more vulnerable to the infection. Furthermore, connection between

  9. Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia

    Bogh Claus

    2008-08-01

    Full Text Available Abstract Background Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Methods Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores, and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June. Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Results Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%, with An. gambiae s.s. (10% and An. arabiensis (3% also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709 contained sporozoites. Larvae (mostly An. gambiae s.s. were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. Conclusion During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative

  10. Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia.

    Jawara, Musa; Pinder, Margaret; Drakeley, Chris J; Nwakanma, Davis C; Jallow, Ebrima; Bogh, Claus; Lindsay, Steve W; Conway, David J

    2008-08-18

    Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores), and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June). Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%), with An. gambiae s.s. (10%) and An. arabiensis (3%) also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709) contained sporozoites. Larvae (mostly An. gambiae s.s.) were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative numbers of An. gambiae s.s. adults, and with the increase in this

  11. Genetic variation associated with increased insecticide resistance in the malaria mosquito, Anopheles coluzzii.

    Main, Bradley J; Everitt, Amanda; Cornel, Anthony J; Hormozdiari, Fereydoun; Lanzaro, Gregory C

    2018-04-04

    Malaria mortality rates in sub-Saharan Africa have declined significantly in recent years as a result of increased insecticide-treated bed net (ITN) usage. A major challenge to further progress is the emergence and spread of insecticide resistance alleles in the Anopheles mosquito vectors, like An. coluzzii. A non-synonymous mutation in the para voltage-gated sodium channel gene reduces pyrethroid-binding affinity, resulting in knockdown resistance (kdr). Metabolic mechanisms of insecticide resistance involving detoxification genes like cytochrome P450 genes, carboxylesterases, and glutathione S-transferases are also important. As some gene activity is tissue-specific and/or environmentally induced, gene regulatory variation may be overlooked when comparing expression from whole mosquito bodies under standard rearing conditions. We detected complex insecticide resistance in a 2014 An. coluzzii colony from southern Mali using bottle bioassays. Additional bioassays involving recombinant genotypes from a cross with a relatively susceptible 1995 An. coluzzii colony from Mali confirmed the importance of kdr and associated increased permethrin resistance to the CYP9K1 locus on the X chromosome. Significant differential expression of CYP9K1 was not observed among these colonies in Malpighian tubules. However, the P450 gene CYP6Z1 was overexpressed in resistant individuals following sublethal permethrin exposure and the carboxylesterase gene COEAE5G was constitutively overexpressed. The significant P450-related insecticide resistance observed in the 2014 An. coluzzii colony indicates that ITNs treated with the P450 inhibitor piperonyl butoxide (PBO) would be more effective in this region. The known insecticide resistance gene CYP6Z1 was differentially expressed exclusively in the context of sublethal permethrin exposure, highlighting the importance of tissue-specificity and environmental conditions in gene expression studies. The increased activity of the carboxylesterase

  12. Tissue-specific features of the X chromosome and nucleolus spatial dynamics in a malaria mosquito, Anopheles atroparvus.

    Bondarenko, Semen M; Artemov, Gleb N; Sharakhov, Igor V; Stegniy, Vladimir N

    2017-01-01

    Spatial organization of chromosome territories is important for maintenance of genomic stability and regulation of gene expression. Recent studies have shown tissue-specific features of chromosome attachments to the nuclear envelope in various organisms including malaria mosquitoes. However, other spatial characteristics of nucleus organization, like volume and shape of chromosome territories, have not been studied in Anopheles. We conducted a thorough analysis of tissue-specific features of the X chromosome and nucleolus volume and shape in follicular epithelium and nurse cells of the Anopheles atroparvus ovaries using a modern open-source software. DNA of the polytene X chromosome from ovarian nurse cells was obtained by microdissection and was used as a template for amplification with degenerate oligo primers. A fluorescently labeled X chromosome painting probe was hybridized with formaldehyde-fixed ovaries of mosquitoes using a 3D-FISH method. The nucleolus was stained by immunostaining with an anti-fibrillarin antibody. The analysis was conducted with TANGO-a software for a chromosome spatial organization analysis. We show that the volume and position of the X chromosome have tissue-specific characteristics. Unlike nurse cell nuclei, the growth of follicular epithelium nuclei is not accompanied with the proportional growth of the X chromosome. However, the shape of the X chromosome does not differ between the tissues. The dynamics of the X chromosome attachment regions location is tissue-specific and it is correlated with the process of nucleus growth in follicular epithelium and nurse cells.

  13. Isolation of Tahyna virus (California Encephalitis Group) from Anopheles hyrcanus (Diptera, Culicidae), a mosquito species new to, and expanding in, Central Europe

    Hubálek, Zdeněk; Šebesta, Oldřich; Peško, Juraj; Betášová, Lenka; Blažejová, Hana; Venclíková, Kristýna; Rudolf, Ivo

    2014-01-01

    Roč. 51, č. 6 (2014), s. 1264-1267 ISSN 0022-2585 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Tahyna virus * Orthobunyavirus * mosquito * Anopheles hyrcanus Subject RIV: EE - Microbiology, Virology Impact factor: 1.953, year: 2014

  14. Combined effect of seaweed (Sargassum wightii) and Bacillus thuringiensis var. israelensis on the coastal mosquito,Anopheles sundaicus, in Tamil Nadu, India

    Studies were made of the extract of Sargassum wightii combined with Bacillus thuringiensis var. israelensis (Bti) for control of the malaria vector Anopheles sundaicus. Treatment of mosquito larvae with 0.001% S. wightii extract indicated median lethal concentrations (LC50) of 88, 73, 134, 156, and...

  15. The response of the malaria mosquito, Anopheles gambiae, to two components of human sweat, ammonia and L-lactic acid, in an olfactometer

    Braks, M.A.H.; Meijerink, J.; Takken, W.

    2001-01-01

    In an olfactometer study on the response of the anthropophilic malaria mosquito Anopheles gambiae s.s. (Diptera, Culicidae) to human sweat it was found that freshly collected sweat, mostly of eccrine origin, was attractive, but that incubated sweat was significantly more attractive than fresh sweat.

  16. Successful human infection with P. falciparum using three aseptic Anopheles stephensi mosquitoes: a new model for controlled human malaria infection.

    Matthew B Laurens

    Full Text Available Controlled human malaria infection (CHMI is a powerful method for assessing the efficacy of anti-malaria vaccines and drugs targeting pre-erythrocytic and erythrocytic stages of the parasite. CHMI has heretofore required the bites of 5 Plasmodium falciparum (Pf sporozoite (SPZ-infected mosquitoes to reliably induce Pf malaria. We reported that CHMI using the bites of 3 PfSPZ-infected mosquitoes reared aseptically in compliance with current good manufacturing practices (cGMP was successful in 6 participants. Here, we report results from a subsequent CHMI study using 3 PfSPZ-infected mosquitoes reared aseptically to validate the initial clinical trial. We also compare results of safety, tolerability, and transmission dynamics in participants undergoing CHMI using 3 PfSPZ-infected mosquitoes reared aseptically to published studies of CHMI using 5 mosquitoes. Nineteen adults aged 18-40 years were bitten by 3 Anopheles stephensi mosquitoes infected with the chloroquine-sensitive NF54 strain of Pf. All 19 participants developed malaria (100%; 12 of 19 (63% on Day 11. The mean pre-patent period was 258.3 hours (range 210.5-333.8. The geometric mean parasitemia at first diagnosis by microscopy was 9.5 parasites/µL (range 2-44. Quantitative polymerase chain reaction (qPCR detected parasites an average of 79.8 hours (range 43.8-116.7 before microscopy. The mosquitoes had a geometric mean of 37,894 PfSPZ/mosquito (range 3,500-152,200. Exposure to the bites of 3 aseptically-raised, PfSPZ-infected mosquitoes is a safe, effective procedure for CHMI in malaria-naïve adults. The aseptic model should be considered as a new standard for CHMI trials in non-endemic areas. Microscopy is the gold standard used for the diagnosis of Pf malaria after CHMI, but qPCR identifies parasites earlier. If qPCR continues to be shown to be highly specific, and can be made to be practical, rapid, and standardized, it should be considered as an alternative for diagnosis

  17. Salivary gland proteome analysis reveals modulation of anopheline unique proteins in insensitive acetylcholinesterase resistant Anopheles gambiae mosquitoes.

    Sylvie Cornelie

    Full Text Available Insensitive acetylcholinesterase resistance due to a mutation in the acetylcholinesterase (ace encoding ace-1 gene confers cross-resistance to organophosphate and carbamate insecticides in Anopheles gambiae populations from Central and West Africa. This mutation is associated with a strong genetic cost revealed through alterations of some life history traits but little is known about the physiological and behavioural changes in insects bearing the ace-1(R allele. Comparative analysis of the salivary gland contents between An. gambiae susceptible and ace-1(R resistant strains was carried out to charaterize factors that could be involved in modifications of blood meal process, trophic behaviour or pathogen interaction in the insecticide-resistant mosquitoes. Differential analysis of the salivary gland protein profiles revealed differences in abundance for several proteins, two of them showing major differences between the two strains. These two proteins identified as saglin and TRIO are salivary gland-1 related proteins, a family unique to anopheline mosquitoes, one of them playing a crucial role in salivary gland invasion by Plasmodium falciparum sporozoites. Differential expression of two other proteins previously identified in the Anopheles sialome was also observed. The differentially regulated proteins are involved in pathogen invasion, blood feeding process, and protection against oxidation, relevant steps in the outcome of malaria infection. Further functional studies and insect behaviour experiments would confirm the impact of the modification of the sialome composition on blood feeding and pathogen transmission abilities of the resistant mosquitoes. The data supports the hypothesis of alterations linked to insecticide resistance in the biology of the primary vector of human malaria in Africa.

  18. Identification of salivary gland proteins depleted after blood feeding in the malaria vector Anopheles campestris-like mosquitoes (Diptera: Culicidae.

    Sriwatapron Sor-suwan

    Full Text Available Malaria sporozoites must invade the salivary glands of mosquitoes for maturation before transmission to vertebrate hosts. The duration of the sporogonic cycle within the mosquitoes ranges from 10 to 21 days depending on the parasite species and temperature. During blood feeding salivary gland proteins are injected into the vertebrate host, along with malaria sporozoites in the case of an infected mosquito. To identify salivary gland proteins depleted after blood feeding of female Anopheles campestris-like, a potential malaria vector of Plasmodium vivax in Thailand, two-dimensional gel electrophoresis and nano-liquid chromatography-mass spectrometry techniques were used. Results showed that 19 major proteins were significantly depleted in three to four day-old mosquitoes fed on a first blood meal. For the mosquitoes fed the second blood meal on day 14 after the first blood meal, 14 major proteins were significantly decreased in amount. The significantly depleted proteins in both groups included apyrase, 5'-nucleotidase/apyrase, D7, D7-related 1, short form D7r1, gSG6, anti-platelet protein, serine/threonine-protein kinase rio3, putative sil1, cyclophilin A, hypothetical protein Phum_PHUM512530, AGAP007618-PA, and two non-significant hit proteins. To our knowledge, this study presents for the first time the salivary gland proteins that are involved in the second blood feeding on the day corresponding to the transmission period of the sporozoites to new mammalian hosts. This information serves as a basis for future work concerning the possible role of these proteins in the parasite transmission and the physiological processes that occur during the blood feeding.

  19. Identification of salivary gland proteins depleted after blood feeding in the malaria vector Anopheles campestris-like mosquitoes (Diptera: Culicidae).

    Sor-suwan, Sriwatapron; Jariyapan, Narissara; Roytrakul, Sittiruk; Paemanee, Atchara; Phumee, Atchara; Phattanawiboon, Benjarat; Intakhan, Nuchpicha; Chanmol, Wetpisit; Bates, Paul A; Saeung, Atiporn; Choochote, Wej

    2014-01-01

    Malaria sporozoites must invade the salivary glands of mosquitoes for maturation before transmission to vertebrate hosts. The duration of the sporogonic cycle within the mosquitoes ranges from 10 to 21 days depending on the parasite species and temperature. During blood feeding salivary gland proteins are injected into the vertebrate host, along with malaria sporozoites in the case of an infected mosquito. To identify salivary gland proteins depleted after blood feeding of female Anopheles campestris-like, a potential malaria vector of Plasmodium vivax in Thailand, two-dimensional gel electrophoresis and nano-liquid chromatography-mass spectrometry techniques were used. Results showed that 19 major proteins were significantly depleted in three to four day-old mosquitoes fed on a first blood meal. For the mosquitoes fed the second blood meal on day 14 after the first blood meal, 14 major proteins were significantly decreased in amount. The significantly depleted proteins in both groups included apyrase, 5'-nucleotidase/apyrase, D7, D7-related 1, short form D7r1, gSG6, anti-platelet protein, serine/threonine-protein kinase rio3, putative sil1, cyclophilin A, hypothetical protein Phum_PHUM512530, AGAP007618-PA, and two non-significant hit proteins. To our knowledge, this study presents for the first time the salivary gland proteins that are involved in the second blood feeding on the day corresponding to the transmission period of the sporozoites to new mammalian hosts. This information serves as a basis for future work concerning the possible role of these proteins in the parasite transmission and the physiological processes that occur during the blood feeding.

  20. Interactions between Asaia, Plasmodium and Anopheles: new insights into mosquito symbiosis and implications in malaria symbiotic control.

    Capone, Aida; Ricci, Irene; Damiani, Claudia; Mosca, Michela; Rossi, Paolo; Scuppa, Patrizia; Crotti, Elena; Epis, Sara; Angeletti, Mauro; Valzano, Matteo; Sacchi, Luciano; Bandi, Claudio; Daffonchio, Daniele; Mandrioli, Mauro; Favia, Guido

    2013-06-18

    Malaria represents one of the most devastating infectious diseases. The lack of an effective vaccine and the emergence of drug resistance make necessary the development of new effective control methods. The recent identification of bacteria of the genus Asaia, associated with larvae and adults of malaria vectors, designates them as suitable candidates for malaria paratransgenic control.To better characterize the interactions between Asaia, Plasmodium and the mosquito immune system we performed an integrated experimental approach. Quantitative PCR analysis of the amount of native Asaia was performed on individual Anopheles stephensi specimens. Mosquito infection was carried out with the strain PbGFPCON and the number of parasites in the midgut was counted by fluorescent microscopy.The colonisation of infected mosquitoes was achieved using GFP or DsRed tagged-Asaia strains.Reverse transcriptase-PCR analysis, growth and phagocytosis tests were performed using An. stephensi and Drosophila melanogaster haemocyte cultures and DsRed tagged-Asaia and Escherichia coli strains. Using quantitative PCR we have quantified the relative amount of Asaia in infected and uninfected mosquitoes, showing that the parasite does not interfere with bacterial blooming. The correlation curves have confirmed the active replication of Asaia, while at the same time, the intense decrease of the parasite.The 'in vitro' immunological studies have shown that Asaia induces the expression of antimicrobial peptides, however, the growth curves in conditioned medium as well as a phagocytosis test, indicated that the bacterium is not an immune-target.Using fluorescent strains of Asaia and Plasmodium we defined their co-localisation in the mosquito midgut and salivary glands. We have provided important information about the relationship of Asaia with both Plasmodium and Anopheles. First, physiological changes in the midgut following an infected or uninfected blood meal do not negatively affect the

  1. Anopheles plumbeus (Diptera: Culicidae) in Germany: updated geographic distribution and public health impact of a nuisance and vector mosquito.

    Heym, Eva C; Kampen, Helge; Fahle, Marcus; Hohenbrink, Tobias L; Schäfer, Mandy; Scheuch, Dorothee E; Walther, Doreen

    2017-01-01

    The aim of this study was to map the current spatial distribution of Anopheles plumbeus in Germany, a potential vector of malaria parasites and West Nile virus. Reports of mass occurrence and nuisance connected with artificial breeding site usage by this species were analysed. Distribution data were collected from 2011 to 2014 mainly through trapping and submissions of adult mosquito specimens to a citizen science project. In the framework of the latter, additional information was gathered on recent nuisance incidents caused by An. plumbeus, including a longitudinal analysis of mosquito occurrence and the impact of management measures at a nuisance site in south-western Germany. Based on the most comprehensive set of collection data obtained during the last decades, An. plumbeus is shown to be widely distributed over Germany. The data also indicate a continuing extension of the breeding site repertoire of the species from natural to artificial habitats that facilitate mass development. Increasing incidents of persistent nuisance suggest that this mosquito species is rarely diagnosed correctly and managed adequately. As An. plumbeus is both a serious nuisance pest and a potential vector species, awareness of this species and the public health problems linked to it should be raised among pest managers and public health personnel. © 2016 John Wiley & Sons Ltd.

  2. Alstonia boonei De Wild oil extract in the management of mosquito (Anopheles gambiae, a vector of malaria disease

    Kayode David Ileke

    2015-07-01

    Full Text Available Objective: To evaluate the insecticidal potential of Alstonia boonei (A. boonei oils and derivatives against different life stages of a malaria vector, Anopheles gambiae. Methods: The leaf, stem bark and root bark of A. boonei were collected from an open field and air dried before being blended to fine powder. Oils from this plant were extracted by cold extraction and were prepared at different concentrations. Contact toxicity of A. boonei was tested against the larvae and pupae of the insect while smoke toxicity of the plant materials in form of mosquito coil was tested against the adult insect. Results: Alstodine recorded the highest insect mortality rate and the order of susceptibility of the life stages of the insect to the plant was pupae alstonine > stem bark extract > leaf extract > root bark extract.

  3. Pupal habitat productivity of Anopheles gambiae complex mosquitoes in a rural village in western Kenya.

    Mutuku, Francis M; Bayoh, M Nabie; Gimnig, John E; Vulule, John M; Kamau, Luna; Walker, Edward D; Kabiru, Ephantus; Hawley, William A

    2006-01-01

    The productivity of larval habitats of the malaria vector Anopheles gambiae for pupae (the stage preceding adult metamorphosis) is poorly known, yet adult emergence from habitats is the primary determinant of vector density. To assess it, we used absolute sampling methods in four studies involving daily sampling for 25 days in 6 habitat types in a village in western Kenya. Anopheles gambiae s.s. comprised 82.5% of emergent adults and Anopheles arabiensis the remainder. Pupal production occurred from a subset of habitats, primarily soil burrow pits, and was discontinuous in time, even when larvae occupied all habitats continuously. Habitat stability was positively associated with pupal productivity. In a dry season, pupal productivity was distributed between burrow pits and pools in streambeds. Overall, these data support the notion that source reduction measures against recognizably productive habitats would be a useful component of an integrated management program for An. gambiae in villages.

  4. Analysis of expression in the Anopheles gambiae developing testes reveals rapidly evolving lineage-specific genes in mosquitoes

    Krzywinski Jaroslaw

    2009-07-01

    Full Text Available Abstract Background Male mosquitoes do not feed on blood and are not involved in delivery of pathogens to humans. Consequently, they are seldom the subjects of research, which results in a very poor understanding of their biology. To gain insights into male developmental processes we sought to identify genes transcribed exclusively in the reproductive tissues of male Anopheles gambiae pupae. Results Using a cDNA subtraction strategy, five male-specifically or highly male-biased expressed genes were isolated, four of which remain unannotated in the An. gambiae genome. Spatial and temporal expression patterns suggest that each of these genes is involved in the mid-late stages of spermatogenesis. Their sequences are rapidly evolving; however, two genes possess clear homologs in a wide range of taxa and one of these probably acts in a sperm motility control mechanism conserved in many organisms, including humans. The other three genes have no match to sequences from non-mosquito taxa, thus can be regarded as orphans. RNA in situ hybridization demonstrated that one of the orphans is transcribed in spermatids, which suggests its involvement in sperm maturation. Two other orphans have unknown functions. Expression analysis of orthologs of all five genes indicated that male-biased transcription was not conserved in the majority of cases in Aedes and Culex. Conclusion Discovery of testis-expressed orphan genes in mosquitoes opens new prospects for the development of innovative control methods. The orphan encoded proteins may represent unique targets of selective anti-mosquito sterilizing agents that will not affect non-target organisms.

  5. Analysis of expression in the Anopheles gambiae developing testes reveals rapidly evolving lineage-specific genes in mosquitoes.

    Krzywinska, Elzbieta; Krzywinski, Jaroslaw

    2009-07-06

    Male mosquitoes do not feed on blood and are not involved in delivery of pathogens to humans. Consequently, they are seldom the subjects of research, which results in a very poor understanding of their biology. To gain insights into male developmental processes we sought to identify genes transcribed exclusively in the reproductive tissues of male Anopheles gambiae pupae. Using a cDNA subtraction strategy, five male-specifically or highly male-biased expressed genes were isolated, four of which remain unannotated in the An. gambiae genome. Spatial and temporal expression patterns suggest that each of these genes is involved in the mid-late stages of spermatogenesis. Their sequences are rapidly evolving; however, two genes possess clear homologs in a wide range of taxa and one of these probably acts in a sperm motility control mechanism conserved in many organisms, including humans. The other three genes have no match to sequences from non-mosquito taxa, thus can be regarded as orphans. RNA in situ hybridization demonstrated that one of the orphans is transcribed in spermatids, which suggests its involvement in sperm maturation. Two other orphans have unknown functions. Expression analysis of orthologs of all five genes indicated that male-biased transcription was not conserved in the majority of cases in Aedes and Culex. Discovery of testis-expressed orphan genes in mosquitoes opens new prospects for the development of innovative control methods. The orphan encoded proteins may represent unique targets of selective anti-mosquito sterilizing agents that will not affect non-target organisms.

  6. Efficacy of mosquito nets treated with a pyrethroid-organophosphorous mixture against Kdr- and Kdr+ malaria vectors (Anopheles gambiae

    Darriet F.

    2003-12-01

    Full Text Available In order to prevent the resistance of Anopheles gambiae s.l. to pyrethroids from spreading too quickly and to lengthen the effectiveness of insecticide impregnated mosquito nets, it has recently been suggested to use mixtures of insecticides that have different modes of action. This study presents the results obtained with tulle mosquito nets treated with bifenthrin (a pyrethroid] and chlorpyrifos-methyl (an organophosphorous both separately and in mixture on two strains of An. gambiae, one sensitive to all insecticides, and the other resistant to pyrethroids. The values of KDt50 and KDt95 and the mortality induced with the mixture of bifenthrin (25 mg/m2 and chlorpyrifos-methyl (4.5 mg/m2 show a significant synergistic effect on the strain of An. gambiae susceptible to insecticides. However, the tested combination does not induce any synergistic effect on the VKPR strain selected with permethrin, but only enhances the effectiveness of the two insecticides taken separately.

  7. Laboratory Evaluations of the Fractions Efficacy of Annona senegalensis (Annonaceae) Leaf Extract on Immature Stage Development of Malarial and Filarial Mosquito Vectors.

    Lame, Younoussa; Nukenine, Elias Nchiwan; Pierre, Danga Yinyang Simon; Elijah, Ajaegbu Eze; Esimone, Charles Okechukwu

    2015-12-01

    Within the framework to control mosquitoes, ovicidal, larvicidal and pupicidal activity of Annona senegalensis leaf extract and its 4 fractions against Anopheles gambiae and Culex quinquefasciatus were evaluated in the laboratory conditions. Ovicidal test was performed by submitting at least 100 eggs of mosquitoes to 125, 250, 500, 1000 and 2000 ppm concentrations, while larvicidal and pupicidal effects were assessed by submitting 25 larvae or pupae to the concentrations of 2500, 1250, 625 and 312.5 ppm of plant extract or fractions of A. senegalensis. The eggs of An. gambiae were most affected by N-hexane (0.00% hatchability) and chloroform (03.67% hatchability) fractions compared to Cx. quinquefasciatus where at least 25 % hatchability were recorded at 2000 ppm. For larvicidal test, N-hexane (LC50= 298.8 ppm) and chloroform (LC50= 418.3 ppm) fractions were more effective than other fractions on An. gambiae larvae while, a moderate effectiveness was also observed with N-hexane (LC50= 2087.6 ppm), chloroform (LC50= 9010.1 ppm) fractions on Cx. quinquefasciatus larvae. The highest mortality percent of the pupae were also recorded with N-hexane and chloroform fractions on An. gambiae at 2500 ppm. As for Cx. quinquefasciatus only 50 % and 36 % mortality were recorded with N-hexane and chloroform fractions respectively. The extract of A. senegalensis was toxic on immature stage of mosquito species tested. By splitting methanolic crude extract, only N-hexane and chloroform fractions were revealed to possess a mosquitocidal effects and could be considered and utilized for future immature mosquito vectors control.

  8. Laboratory Evaluations of the Fractions Efficacy of Annona senegalensis (Annonaceae Leaf Extract on Immature Stage Development of Malarial and Filarial Mosquito Vectors

    Younoussa Lame

    2015-10-01

    Full Text Available Background: Within the framework to control mosquitoes, ovicidal, larvicidal and pupicidal activity of Annona senegalensis leaf extract and its 4 fractions against Anopheles gambiae and Culex quinquefasciatus were evaluated in the laboratory conditions.Methods: Ovicidal test was performed by submitting at least 100 eggs of mosquitoes to 125, 250, 500, 1000 and 2000 ppm concentrations, while larvicidal and pupicidal effects were assessed by submitting 25 larvae or pupae to the concentrations of 2500, 1250, 625 and 312.5 ppm of plant extract or fractions of A. senegalensis.Results: The eggs of An. gambiae were most affected by N-hexane (0.00% hatchability and chloroform (03.67% hatchability fractions compared to Cx. quinquefasciatus where at least 25 % hatchability were recorded at 2000 ppm. For larvicidal test, N-hexane (LC50= 298.8 ppm and chloroform (LC50= 418.3 ppm fractions were more effective than other fractions on An. gambiae larvae while, a moderate effectiveness was also observed with Nhexane (LC50= 2087.6 ppm, chloroform (LC50= 9010.1 ppm fractions on Cx. quinquefasciatus larvae. The highest mortality percent of the pupae were also recorded with N-hexane and chloroform fractions on An. gambiae at 2500 ppm. As for Cx. quinquefasciatus only 50 % and 36 % mortality were recorded with N-hexane and chloroform fractions respectively.Conclusion: The extract of A. senegalensis was toxic on immature stage of mosquito species tested. By splitting methanolic crude extract, only N-hexane and chloroform fractions were revealed to possess a mosquitocidal effects and could be considered and utilized for future immature mosquito vectors control.

  9. Daily oviposition patterns of the African malaria mosquito Anopheles gambiae Giles (Diptera: Culicidae on different types of aqueous substrates

    Knols Bart GJ

    2004-12-01

    Full Text Available Abstract Background Anopheles gambiae Giles is the most important vector of human malaria in sub-Saharan Africa. Knowledge of the factors that influence its daily oviposition pattern is crucial if field interventions targeting gravid females are to be successful. This laboratory study investigated the effect of oviposition substrate and time of blood feeding on daily oviposition patterns of An. gambiae mosquitoes. Methods Greenhouse-reared gravid and hypergravid (delayed oviposition onset An. gambiae sensu stricto and wild-caught An. gambiae sensu lato were exposed to three types of substrates in choice and no-choice cage bioassays: water from a predominantly anopheline colonised ground pool (anopheline habitat water, swamp water mainly colonised by culicine larvae (culicine habitat water and distilled water. The daily oviposition pattern and the number of eggs oviposited on each substrate during the entire egg-laying period were determined. The results were subjected to analysis of variance using the General Linear Model (GLM procedure. Results The main oviposition time for greenhouse-reared An. gambiae s.s. was between 19:00 and 20:00 hrs, approximately one hour after sunset. Wild-caught gravid An. gambiae s.l. displayed two distinct peak oviposition times between 19:00 and 20:00 hrs and between 22:00 and 23:00 hrs, respectively. During these times, both greenhouse-reared and wild-caught mosquitoes significantly (P P Conclusion This study shows that the peak oviposition time of An. gambiae s.l. may be regulated by the light-dark cycle rather than oviposition habitat characteristics or feeding times. However, the number of eggs laid by the female mosquito during the peak oviposition time is affected by the suitability of the habitat.

  10. Using Stable Isotopes of Carbon and Nitrogen to Mark Wild Populations of Anopheles and Aedes Mosquitoes in South-Eastern Tanzania.

    Mercy A Opiyo

    Full Text Available Marking wild mosquitoes is important for understanding their ecology, behaviours and role in disease transmission. Traditional insect marking techniques include using fluorescent dyes, protein labels, radioactive labels and tags, but such techniques have various limitations; notably low marker retention and inability to mark wild mosquitoes at source. Stable isotopes are gaining wide spread use for non-invasive marking of arthropods, permitting greater understanding of mosquito dispersal and responses to interventions. We describe here a simple technique for marking naturally-breeding malaria and dengue vectors using stable isotopes of nitrogen (15N and carbon (13C, and describe potential field applications.We created man-made aquatic mosquito habitats and added either 15N-labelled potassium nitrate or 13C-labelled glucose, leaving non-adulterated habitats as controls. We then allowed wild mosquitoes to lay eggs in these habitats and monitored their development in situ. Pupae were collected promptly as they appeared and kept in netting cages. Emergent adults (in pools of ~4 mosquitoes/pool and individually stored pupae were desiccated and analysed using Isotope Ratio Mass Spectrometry (IRMS.Anopheles gambiae s.l and Aedes spp. from enriched 13C and enriched 15N larval habitats had significantly higher isotopic levels than controls (P = 0.005, and both isotopes produced sufficient distinction between marked and unmarked mosquitoes. Mean δ15N for enriched females and males were 275.6±65.1 and 248.0±54.6, while mean δ15N in controls were 2.1±0.1 and 3.9±1.7 respectively. Similarly, mean δ13C for enriched females and males were 36.08±5.28 and 38.5±6.86, compared to -4.3±0.2 and -7.9±3.6 in controls respectively. Mean δ15N and δ13C was significantly higher in any pool containing at least one enriched mosquito compared to pools with all unenriched mosquitoes, P<0.001. In all cases, there were variations in standardized isotopic ratios

  11. Bacterial diversity analysis of larvae and adult midgut microflora using culture-dependent and culture-independent methods in lab-reared and field-collected Anopheles stephensi-an Asian malarial vector

    Adak Tridibesh

    2009-05-01

    Full Text Available Abstract Background Mosquitoes are intermediate hosts for numerous disease causing organisms. Vector control is one of the most investigated strategy for the suppression of mosquito-borne diseases. Anopheles stephensi is one of the vectors of malaria parasite Plasmodium vivax. The parasite undergoes major developmental and maturation steps within the mosquito midgut and little is known about Anopheles-associated midgut microbiota. Identification and characterization of the mosquito midgut flora is likely to contribute towards better understanding of mosquito biology including longevity, reproduction and mosquito-pathogen interactions that are important to evolve strategies for vector control mechanisms. Results Lab-reared and field-collected A. stephensi male, female and larvae were screened by "culture-dependent and culture-independent" methods. Five 16S rRNA gene library were constructed form lab and field-caught A. stephensi mosquitoes and a total of 115 culturable isolates from both samples were analyzed further. Altogether, 68 genera were identified from midgut of adult and larval A. stephensi, 53 from field-caught and 15 from lab-reared mosquitoes. A total of 171 and 44 distinct phylotypes having 85 to 99% similarity with the closest database matches were detected among field and lab-reared A. stephensi midgut, respectively. These OTUs had a Shannon diversity index value of 1.74–2.14 for lab-reared and in the range of 2.75–3.49 for field-caught A. stephensi mosquitoes. The high species evenness values of 0.93 to 0.99 in field-collected adult and larvae midgut flora indicated the vastness of microbial diversity retrieved by these approaches. The dominant bacteria in field-caught adult male A. stephensi were uncultured Paenibacillaceae while in female and in larvae it was Serratia marcescens, on the other hand in lab-reared mosquitoes, Serratia marcescens and Cryseobacterium meninqosepticum bacteria were found to be abundant. Conclusion

  12. Studies on mosquitoes (Diptera: Culicidae and anthropic environment: 1- Parity of blood seeking Anopheles (Kerteszia in South-Eastern Brazil

    Oswaldo Paulo Forattini

    1993-02-01

    Full Text Available Populations of Anopheles (Kerteszia were sampled fortnightly over a one-year period (August 1991 to July 1992 at Ribeira Valley, S. Paulo State, Brazil. Indoor and outdoor collections were made on human bait at evening crepuscular period. The Polovodova technique for age grading was applied to 3,501 females of Anopheles cruzii and to 416 females of An. bellator. That sample represented 34.4% of the total number of mosquitoes collected. The most abundant species found was An. cruzii. However, An. bellator showed an endophagy that was almost three times greater than that of An. cruzii. The overall parous rate was 25.4% and uniparity was practically dominant one. A proportion of 26.9% of An. cruzii and 12.0% of An. bellator were found to be uniparous. Only three outdoor females of the former species (0.1% showed biparity. Parity of An. cruzii was higher in females caught outdoors than in those caught indoors. Nevertheless, 497 nulliparous females examined (417 cruzii and 80 bellator had ovaries that had advanced to Christophers and Mer stages III to V. These results imply that these females had already practised hematophagy. Relating these results to those from the parous females, a high statistical significance was found, leading to the conclusion that gonothophic discordance is a common pattern among these anophelines. Further, these results obtained with human bait catches strongly suggest that nearly 38.0% of these host-seeking females had already taken at least one previous blood-meal. So it is possible that enough time could thus be available for the plasmodian development in the vectors.

  13. Ammonium sulphate fertiliser increases larval populations of Anopheles arabiensis and culicine mosquitoes in rice fields

    Mutero, C M; Ng'ang'a, P N; Wekoyela, P

    2004-01-01

    Field experiments were conducted in central Kenya, to study the effect of ammonium sulphate fertiliser ((NH(4))(2)SO(4)) on mosquito larval populations in rice fields. The experiments used a complete randomised block design having four blocks with two experimental ponds per block, and the fertili......Field experiments were conducted in central Kenya, to study the effect of ammonium sulphate fertiliser ((NH(4))(2)SO(4)) on mosquito larval populations in rice fields. The experiments used a complete randomised block design having four blocks with two experimental ponds per block...... populations of An. arabiensis (Pmosquitoes (P... in rice fields, thereby making them visually more attractive for egg-laying by An. arabiensis and culicine mosquitoes....

  14. Expression of trypsin modulating oostatic factor (TMOF in an entomopathogenic fungus increases its virulence towards Anopheles gambiae and reduces fecundity in the target mosquito

    Kamareddine Layla

    2013-01-01

    Full Text Available Abstract Background Adult and larval mosquitoes regulate food digestion in their gut with trypsin modulating oostatic factor (TMOF, a decapeptide hormone synthesized by the ovaries and the neuroendocrine system. TMOF is currently being developed as a mosquitocide, however, delivery of the peptide to the mosquito remains a significant challenge. Entomopathogenic fungi offer a means for targeting mosquitoes with TMOF. Findings The efficacy of wild type and transgenic Beauveria bassiana strains expressing Aedes aegypti TMOF (Bb-Aa1 were evaluated against larvae and sugar- and blood-fed adult Anopheles gambiae mosquitoes using insect bioassays. Bb-Aa1 displayed increased virulence against larvae, and sugar and blood fed adult A. gambiae when compared to the wild type parent strain. Median lethal dose (LD50 values decreased by ~20% for larvae, and ~40% for both sugar and blood-fed mosquitoes using Bb-Aa1 relative to the wild type parent. Median lethal time (LT50 values were lower for blood-fed compared to sugar-fed mosquitoes in infections with both wild type and Bb-Aa1. However, infection using Bb-Aa1 resulted in 15% to 25% reduction in LT50 values for sugar- and blood fed mosquitoes, and ~27% for larvae, respectively, relative to the wild type parent. In addition, infection with Bb-Aa1 resulted in a dramatic reduction in fecundity of the target mosquitoes. Conclusions B. bassiana expressing Ae. aegypti TMOF exhibited increased virulence against A. gambiae compared to the wild type strain. These data expand the range and utility of entomopathogenic fungi expressing mosquito-specific molecules to improve their biological control activities against mosquito vectors of disease.

  15. Ovicidal, larvicidal and adulticidal properties of Asparagus racemosus (Willd.) (Family: Asparagaceae) root extracts against filariasis (Culex quinquefasciatus), dengue (Aedes aegypti) and malaria (Anopheles stephensi) vector mosquitoes (Diptera: Culicidae).

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2014-04-01

    Several diseases are associated to the mosquito-human interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikungunya fever, West Nile virus and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The present investigation was undertaken to study the ovicidal, larvicidal and adulticidal activities of crude hexane, ethyl acetate, benzene, chloroform and methanol extracts of root of Asparagus racemosus were assayed for their toxicity against three important vector mosquitoes, viz., Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae). The mean percent hatchability of the eggs was observed after 48 h post-treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. All the five solvent extracts showed moderate ovicidal activity; however, the methanol extract showed the highest ovicidal activity. The methanol extract of Asparagus racemosus against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi exerted 100% mortality (zero hatchability) at 375, 300 and 225 ppm, respectively. Control eggs showed 99-100% hatchability. The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in methanol extract of root of Asparagus racemosus against the larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with the LC50 and LC90 values were 115.13, 97.71 and 90.97 ppm and 210.96, 179.92, and 168.82 ppm, respectively. The adult mortality was observed after 24 h recovery period. The plant crude extracts showed dose-dependent mortality. At higher concentrations, the adult showed restless movement for some times with abnormal wagging and then died. Among the extracts tested, the highest adulticidal activity was observed in

  16. Reduction of malaria transmission to Anopheles mosquitoes with a six-dose regimen of co-artemether.

    Colin J Sutherland

    2005-04-01

    Full Text Available Resistance of malaria parasites to chloroquine (CQ and sulphadoxine-pyrimethamine (SP is increasing in prevalence in Africa. Combination therapy can both improve treatment and provide important public health benefits if it curbs the spread of parasites harbouring resistance genes. Thus, drug combinations must be identified which minimise gametocyte emergence in treated cases, and so prevent selective transmission of parasites resistant to any of the partner drugs.In a randomised controlled trial, 497 children with uncomplicated falciparum malaria were treated with CQ and SP (three doses and one dose respectively; n = 91, or six doses of artemether in fixed combination with lumefantrine (co-artemether [Coartem, Riamet] (n = 406. Carriage rates of Plasmodium falciparum gametocytes and trophozoites were measured 7, 14, and 28 d after treatment. The infectiousness of venous blood from 29 children carrying P. falciparum gametocytes 7 d after treatment was tested by membrane-feeding of Anopheles mosquitoes. Children treated with co-artemether were significantly less likely to carry gametocytes within the 4 weeks following treatment than those receiving CQ/SP (30 of 378 [7.94%] versus 42 of 86 [48.8%]; p < 0.0001. Carriers in the co-artemether group harboured gametocytes at significantly lower densities, for shorter periods (0.3 d versus 4.2 d; p < 0.0001 and were less infectious to mosquitoes at day 7 (p < 0.001 than carriers who had received CQ/SP.Co-artemether is highly effective at preventing post-treatment transmission of P. falciparum. Our results suggest that co-artemether has specific activity against immature sequestered gametocytes, and has the capacity to minimise transmission of drug-resistant parasites.

  17. Field evaluation of synthetic lure (3-methyl-1-butanol) when compared to non odor-baited control in capturing Anopheles mosquitoes in varying land-use sites in Madagascar.

    Zohdy, Sarah; Derfus, Kristin; Andrianjafy, Mbolatiana Tovo; Wright, Patricia C; Gillespie, Thomas R

    2015-03-07

    Malaria is the 4(th) largest cause of mortality in Madagascar. To better understand malaria transmission dynamics, it is crucial to map the distribution of the malaria vectors, mosquitoes belonging to the genus Anopheles. To do so, it is important to have a strong Anopheles-specific lure to ensure the maximum number of captures. Previous studies have isolated volatiles from the human skin microbiota and found the compound 3-methyl-1-butanol to be the most attractive to the malaria mosquito, Anopheles gambiae, in a laboratory setting; and recommended 3-methyl-1-butanol as a compound to increase An. gambiae captures in the field. To date, this compound's ability to lure wild mosquitoes in differing land-use settings has not been tested. In this study, we evaluate the role of the synthetic compound, 3-methyl-1-butanol in combination with field produced CO(2) in attracting Anopheles mosquitoes in varying land-use sites in Madagascar. CDC miniature light traps in combination with field produced CO(2) were deployed in and around six villages near Ranomafana National Park, Madagascar. To test the role of 3-methyl-1-butanol in luring Anopheles mosquitoes, two traps were set in each land-use site (village, agricultural sites, and forested habitats affiliated with each village). One was baited with the synthetic odor and the other was kept as a non-baited control. While 3-methyl-1-butanol baited traps did capture An. gambiae s.l. in this study, we did not find traps baited with synthetic 3-methyl-1-butanol to be more successful in capturing Anopheles mosquitoes, (including Anopheles gambiae s.l.) than the non odor-baited control traps in any of the land-use sites examined; however, regardless of odor bait, trapping near livestock pens resulted in the capture of significantly more Anopheles specimens. A strong synthetic lure in combination with insecticide has great potential as a mosquito control. Our findings suggest that trapping mosquitoes near livestock in malaria

  18. 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

    Teklu, B. M.; Tekie, H.; McCartney, M.; Kibret, S.

    2010-08-01

    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, plevels and the number of positive breeding habitats at Ejersa during the sampling period (r=0.605, pphysical characteristics such as water temperature, turbidity, depth and vegetation cover play an important role in the species composition, total Anopheles 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 impact of water holding capacity of the soil need to be done to generate detailed baseline data which will serve as a basis

  19. Mecanismos de invasión del esporozoíto de Plasmodium en el mosquito vector Anopheles

    Lilian M. Spencer

    2016-09-01

    Full Text Available La Malaria o Paludismo es una de las enfermedades tropicales considerada un problema de salud pública a nivel mundial por la OMS. Plasmodium es un protozoario cuyo vector es la hembra del mosquito Anopheles. En este vector se cumplen dos procesos fundamentales en el ciclo de vida del parásito, como son la reproducción sexual, con la formación de un cigoto móvil llamado ooquineto como producto de la fertilización entre los gametos; y la invasión del epitelio del estómago y formación del ooquiste. El estadio producto de esta esporogonia son los esporozoítos (reproducción asexual que se dirigen a las glándulas salivales; y es el infectivo para el mamífero. El esporozoíto es el responsable de establecer la enfermedad en su hospedador vertebrado y por lo tanto los procesos de invasión de este a las glándulas salivales del mosquito es uno de los puntos fundamentales de estudio. Nosotros presentamos una revisión acerca de los mecanismos de invasión del parásito dentro del vector mosquito y las proteínas más importantes que median este proceso. Uno de los aspectos más estudiados en las investigaciones en malaria ha sido determinar la antigenicidad de dichas proteínas en esta parte del ciclo con el fin de ser usadas en el diseño de vacunas. Entre ellas, algunas de las más estudiadas son: P230, P48/45, P28, P25, CTRP, CS, TRAP, WARP y SOAP las cuales han sido consideradas en las estrategias para inhibir el desarrollo del parásito, mejor conocidas como vacunas de bloqueo de trasmisión por el vector. Por lo tanto, presentamos algunas de las estrategias en el diseño de vacunas, basado en las proteínas implicadas en los estadios desarrollados dentro del vector.

  20. Physico-chemical characteristics of Anopheles breeding sites ...

    ELO

    analysis of the physicochemical parameters of the water samples was carried out in the Nigerian ... Key words: Malaria, Anopheles mosquitoes, breeding habitat, physico-chemical properties. ... Anopheles mosquito has been found to breed in.

  1. Life on the edge: African malaria mosquito (Anopheles gambiae s. l.) larvae are amphibious.

    Miller, James R; Huang, Juan; Vulule, John; Walker, Edward D

    2007-03-01

    Anopheles gambiae s.l. is the main vector of malaria in Sub-Saharan Africa. Here, an estimated 1 million people die every year from this disease. Despite considerable research on An. gambiae that increasingly explores sub-organismal phenomena, important facets of the field biology of this deadly insect are yet being discovered. In the current study, we used simple observational tools to reveal that the habitat of larval An. gambiae is not limited within the boundaries of temporary mud puddles, as has been the accepted generalization. Thus, control tactics aimed at immatures must consider zones larger than puddles per se. In fact, eggs are more likely to be found outside than inside puddles. Eggs can develop and larvae can emerge on mud. Larvae are then capable of three distinct modes of terrestrial displacement (two active and one passive), whereby, they can reach standing water. On mud bearing a film of water, larvae actively displace backwards by sinusoidal undulations shown to be only a slight variation of the swimming motor program. On drying mud, larvae switch to a slower and forward form of active locomotion resembling that of a crawling caterpillar. During rains, small larvae may be passively displaced by flowing rainwater so as to be deposited into puddles. These capabilities for being amphibious, along with very rapid growth and development, help explain how An. gambiae thrives in a highly uncertain and often hostile larval environment.

  2. Multiple origins of knockdown resistance mutations in the Afrotropical mosquito vector Anopheles gambiae.

    João Pinto

    2007-11-01

    Full Text Available How often insecticide resistance mutations arise in natural insect populations is a fundamental question for understanding the evolution of resistance and also for modeling its spread. Moreover, the development of resistance is regarded as a favored model to study the molecular evolution of adaptive traits. In the malaria vector Anopheles gambiae two point mutations (L1014F and L1014S in the voltage-gated sodium channel gene, that confer knockdown resistance (kdr to DDT and pyrethroid insecticides, have been described. In order to determine whether resistance alleles result from single or multiple mutation events, genotyping of the kdr locus and partial sequencing of the upstream intron-1 was performed on a total of 288 A. gambiae S-form collected from 28 localities in 15 countries. Knockdown resistance alleles were found to be widespread in West Africa with co-occurrence of both 1014S and 1014F in West-Central localities. Differences in intron-1 haplotype composition suggest that kdr alleles may have arisen from at least four independent mutation events. Neutrality tests provided evidence for a selective sweep acting on this genomic region, particularly in West Africa. The frequency and distribution of these kdr haplotypes varied geographically, being influenced by an interplay between different mutational occurrences, gene flow and local selection. This has important practical implications for the management and sustainability of malaria vector control programs.

  3. Evidence of carbamate resistance in urban populations of Anopheles gambiae s.s. mosquitoes resistant to DDT and deltamethrin insecticides in Lagos, South-Western Nigeria

    Oduola Adedayo O

    2012-06-01

    Full Text Available Abstract Background Resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. This study was carried out to assess the susceptibility status of urban populations of Anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to DDT and permethrin. Methods Two – three day old adult female Anopheles mosquitoes reared from larval collections in 11 study sites from Local Government Areas of Lagos were exposed to test papers impregnated with DDT 4%, deltamethrin 0.05% and propoxur 0.1% insecticides. Additional tests were carried out to determine the susceptibility status of the Anopheles gambiae population to bendiocarb insecticide. Members of the A. gambiae complex, the molecular forms, were identified by PCR assays. The involvement of metabolic enzymes in carbamate resistance was assessed using Piperonyl butoxide (PBO synergist assays. The presence of kdr-w/e and ace-1R point mutations responsible for DDT-pyrethroid and carbamate resistance mechanisms was also investigated by PCR. Results Propoxur resistance was found in 10 out of the 11 study sites. Resistance to three classes of insecticides was observed in five urban localities. Mortality rates in mosquitoes exposed to deltamethrin and propoxur did not show any significant difference (P > 0.05 but was significantly higher (P A. gambiae s.s (M form. The kdr -w point mutation at allelic frequencies between 45%-77% was identified as one of the resistant mechanisms responsible for DDT and pyrethroid resistance. Ace-1R point mutation was absent in the carbamate resistant population. However, the possible involvement of metabolic resistance was confirmed by synergistic assays conducted. Conclusion Evidence of carbamate resistance in A. gambiae populations already harbouring resistance to DDT and permethrin is a clear indication that calls for the implementation of

  4. Evaluating the lethal and pre-lethal effects of a range of fungi against adult Anopheles stephensi mosquitoes

    Blanford Simon

    2012-11-01

    Full Text Available Abstract Background Insecticide resistance is seriously undermining efforts to eliminate malaria. In response, research on alternatives to the use of chemical insecticides against adult mosquito vectors has been increasing. Fungal entomopathogens formulated as biopesticides have received much attention and have shown considerable potential. This research has necessarily focused on relatively few fungal isolates in order to ‘prove concept’. Further, most attention has been paid to examining fungal virulence (lethality and not the other properties of fungal infection that might also contribute to reducing transmission potential. Here, a range of fungal isolates were screened to examine variation in virulence and how this relates to additional pre-lethal reductions in feeding propensity. Methods The Asian malaria vector, Anopheles stephensi was exposed to 17 different isolates of entomopathogenic fungi belonging to species of Beauveria bassiana, Metarhizium anisopliae, Metarhizium acridum and Isaria farinosus. Each isolate was applied to a test substrate at a standard dose rate of 1×109 spores ml-1 and the mosquitoes exposed for six hours. Subsequently the insects were removed to mesh cages where survival was monitored over the next 14 days. During this incubation period the mosquitoes’ propensity to feed was assayed for each isolate by offering a feeding stimulant at the side of the cage and recording the number probing. Results and conclusions Fungal isolates showed a range of virulence to A. stephensi with some causing >80% mortality within 7 days, while others caused little increase in mortality relative to controls over the study period. Similarly, some isolates had a large impact on feeding propensity, causing >50% pre-lethal reductions in feeding rate, whereas other isolates had very little impact. There was clear correlation between fungal virulence and feeding reduction with virulence explaining nearly 70% of the variation in

  5. Investigations on anopheline mosquitoes close to the nest sites of chimpanzees subject to malaria infection in Ugandan Highlands

    Krief Sabrina

    2012-04-01

    Full Text Available Abstract Background Malaria parasites (Plasmodium sp., including new species, have recently been discovered as low grade mixed infections in three wild chimpanzees (Pan troglodytes schweinfurthii sampled randomly in Kibale National Park, Uganda. This suggested a high prevalence of malaria infection in this community. The clinical course of malaria in chimpanzees and the species of the vectors that transmit their parasites are not known. The fact that these apes display a specific behaviour in which they consume plant parts of low nutritional value but that contain compounds with anti-malarial properties suggests that the apes health might be affected by the parasite. The avoidance of the night-biting anopheline mosquitoes is another potential behavioural adaptation that would lead to a decrease in the number of infectious bites and consequently malaria. Methods Mosquitoes were collected over two years using suction-light traps and yeast-generated CO2 traps at the nesting and the feeding sites of two chimpanzee communities in Kibale National Park. The species of the female Anopheles caught were then determined and the presence of Plasmodium was sought in these insects by PCR amplification. Results The mosquito catches yielded a total of 309 female Anopheles specimens, the only known vectors of malaria parasites of mammalians. These specimens belonged to 10 species, of which Anopheles implexus, Anopheles vinckei and Anopheles demeilloni dominated. Sensitive DNA amplification techniques failed to detect any Plasmodium-positive Anopheles specimens. Humidity and trap height influenced the Anopheles capture success, and there was a negative correlation between nest numbers and mosquito abundance. The anopheline mosquitoes were also less diverse and numerous in sites where chimpanzees were nesting as compared to those where they were feeding. Conclusions These observations suggest that the sites where chimpanzees build their nests every night might be

  6. Breeding of Anopheles mosquitoes in irrigated areas of South Punjab, Pakistan

    Herrel, N; Amerasinghe, F P; Ensink, J

    2001-01-01

    As part of investigations on potential linkages between irrigation and malaria transmission, all surface water bodies in and around three villages along an irrigation distributary in South Punjab, Pakistan, were surveyed for anopheline mosquito larvae (Diptera: Culicidae) from April 1999 to March.......6%), An. pulcherrimus Theobald (1.8%), An. peditaeniatus Leicester (0.3%) and An. nigerrimus Giles (0.1%). The four most abundant species were significantly associated with waterlogged fields and communal village drinking-water tanks. Habitat characteristics most correlated with occurrence of anophelines...... 2000. Samples were characterized according to exposure to sunlight, substratum, presence of vegetation, fauna, inorganic matter and physical water condition (clear/turbid/foul). Also water temperature, dissolved oxygen (DO), electroconductivity (EC) and pH of sites were recorded. A total of 37982...

  7. Potential topical natural repellent against Ae. aegypti, Culex sp. and Anopheles sp. mosquitoes

    Dewi Nur Hodijah

    2014-08-01

    Full Text Available AbstrakLatar belakang:Minyak atsiri daun sirih diketahui mempunyai daya proteksi. Dibuatkan losion berdasarkan pengantar sediaan farmasi yang ditambahkan minyak atsiri daun nilam. Sediaan losion dipilih agar dapat menempel lebih lama di permukaan kulit. Tujuan penelitian ini untuk membandingkan daya proteksi antara losion dengan penambahan minyak nilam dan losion tanpa penambahan minyak nilam dibandingkan daya proteksi dengan DEET. Metode: Penelitian ini merupakan penelitian eksperimental laboratorium. Semua nyamuk uji berasal dari insektarium laboratorium penelitian kesehatan Loka litbang P2B2 Ciamis. Konsentrasi minyak atsiri daun sirih dalam losion adalah 4%; konsentrasi minyak nilam sebagai zat pengikat adalah 0,4%. Formula yang digunakan yaitu formula dasar yang ada pada pengantar sediaan farmasi. Uji repelensi dilakukan dengan menggunakan metoda yang direkomendasikan oleh Komisi pestisida.Hasil: Dihasilkan formulasi losion yang stabil dan masih memenuhi standar formulasi sediaan. Berdasarkan hasil, diperoleh data bahwa DEET dan losion hasil modifikasi memiliki rata-rata daya proteksi di atas 90% selama 6 jam terhadap nyamuk Ae.aegypti dan Culex sp. Kesimpulan: Penambahan minyak nilam pada losion sirih dapat meningkatkan daya proteksi terhadap hinggapan nyamuk Ae. aegypti dan Culex sp. (Health Science Indones 2014;1:44-8Kata kunci:repelen alamiah, minyak atsiri, daun sirih, daun nilam, Ae. aegypti, Culex sp.AbstractBackground: Betel leaf essential oil lotion has been known to have insect repellent properties. A lotion was made based on a pharmaceutical formula from a monograph where patchouli leaf essential oil was added. A lotion preparation was intended to enhance adherence of the formula on the surface of the skin. The purpose of this study was to compare protection percentage of lotion with patchouli oil and without patchouli oil lotion compared to DEET.Methods: This study is an experimental laboratory-based research. All mosquitoes

  8. 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

    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.

  9. Identification and characterization of the fibrinogen-like domain of fibrinogen-related proteins in the mosquito, Anopheles gambiae, and the fruitfly, Drosophila melanogaster, genomes

    Zhao Qin

    2005-09-01

    Full Text Available Abstract Background The fibrinogen-like (FBG domain, which consists of approximately 200 amino acid residues, has high sequence similarity to the C-terminal halves of fibrinogen β and γ chains. Fibrinogen-related proteins (FREPs, which contain FBG domains in their C-terminal region, are found universally in vertebrates and invertebrates. In invertebrates, FREPs are involved in immune responses and other aspects of physiology. To understand the complexity of this family in insects, we analyzed FREPs in the mosquito genome and made comparisons to FREPs in the fruitfly genome. Results By using the genome data of the mosquito, Anopheles gambiae, 53 FREPs were identified, whereas only 20 members were found in the Drosophila melanogaster genome. Using sequence profile analysis, we found that FBG domains have high sequence similarity and are highly conserved throughout the FBG domain region. By secondary structure analysis and comparison, the FBG domains of FREPs are predicted to function in recognition of carbohydrates and their derivatives on the surface of microorganisms in innate immunity. Conclusion Detailed sequence and structural analysis discloses that the FREP family contains FBG domains that have high sequence similarity in the A. gambiae genome. Expansion of the FREP family in mosquitoes during evolutionary history is mainly accounted for by a major expansion of the FBG domain architecture. The characterization of the FBG domains in the FREP family is likely to aid in the experimental analysis of the ability of mosquitoes to recognize parasites in innate immunity and physiologies associated with blood feeding.

  10. Confirmation of Two Sibling Species among Anopheles fluviatilis Mosquitoes in South and Southeastern Iran by Analysis of Cytochrome Oxidase I Gene.

    Naddaf, Saied Reza; Oshaghi, Mohammad Ali; Vatandoost, Hassan

    2012-12-01

    Anopheles fluviatilis, one of the major malaria vectors in Iran, is assumed to be a complex of sibling species. The aim of this study was to evaluate Cytochrome oxidase I (COI) gene alongside 28S-D3 as a diagnostic tool for identification of An. fluviatilis sibling species in Iran. DNA sample belonging to 24 An. fluviatilis mosquitoes from different geographical areas in south and southeastern Iran were used for amplification of COI gene followed by sequencing. The 474-475 bp COI sequences obtained in this study were aligned with 59 similar sequences of An. fluviatilis and a sequence of Anopheles minimus, as out group, from GenBank database. The distances between group and individual sequences were calculated and phylogenetic tree for obtained sequences was generated by using Kimura two parameter (K2P) model of neighbor-joining method. Phylogenetic analysis using COI gene grouped members of Fars Province (central Iran) in two distinct clades separate from other Iranian members representing Hormozgan, Kerman, and Sistan va Baluchestan Provinces. The mean distance between Iranian and Indian individuals was 1.66%, whereas the value between Fars Province individuals and the group comprising individuals from other areas of Iran was 2.06%. Presence of 2.06% mean distance between individuals from Fars Province and those from other areas of Iran is indicative of at least two sibling species in An. fluviatilis mosquitoes of Iran. This finding confirms earlier results based on RAPD-PCR and 28S-D3 analysis.

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

    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.

  12. Mosquito larvicidal properties of silver nanoparticles synthesized using Heliotropium indicum (Boraginaceae) against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus (Diptera: Culicidae).

    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

  13. Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors.

    Farnesi, Luana C; Vargas, Helena C M; Valle, Denise; Rezende, Gustavo L

    2017-10-01

    Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control.

  14. Analysis of population structure and insecticide resistance in mosquitoes of the genus Culex, Anopheles and Aedes from different environments of Greece with a history of mosquito borne disease transmission.

    Fotakis, Emmanouil A; Chaskopoulou, Alexandra; Grigoraki, Linda; Tsiamantas, Alexandros; Kounadi, Stella; Georgiou, Loukas; Vontas, John

    2017-10-01

    Greece has been recently affected by several mosquito borne diseases with the West Nile Virus (WNV) outbreak in 2010 being one of the largest reported in Europe. Currently at the epicenter of an economic and refugee crisis and visited by over 16 million tourists a year the integrated management of diseases transmitted by mosquitoes is a public health and economic priority. Vector control programs rely mainly on insecticides, however data on insecticide resistance and the mosquito fauna is essential for successful applications. We determined the mosquito species composition and population dynamics in areas of increased vulnerability to vector borne disease transmission, as well as investigated the resistance status of major nuisance and disease vectors to insecticides. High mosquito densities were recorded in Thessaloniki and Evros, with Aedes caspius, a nuisance species, Culex pipiens, a known vector of WNV and Anopheles hyrcanus a potential vector of malaria being among the most prevalent species. Both vector species populations reached their peak in late summer. Aedes albopictus was recorded at high densities in Thessaloniki, but not in Evros. Notably, Cx. pipiens hybrids, which show an opportunistic biting behavior and are suspected to be involved in the transmission of the WNV, were recorded in considerable numbers in Thessaloniki and Attica. Culex pipiens and An. hyrcanus, but not Ae. caspius mosquitoes, showed moderate levels of resistance to deltamethrin. The presence of resistance in areas not exposed to vector control indicates that other factors could be selecting for resistance, i.e. pesticide applications for agriculture. Both L1014F and L101C kdr mutations were detected in Cx. pipiens populations. Anopheles hyrcanus resistance was not associated with mutations at the L1014 site. The Ace-1 mutations conferring insensitivity to organophosphates and carbamates were detected at low frequencies in all Cx. pipiens populations. Increased activity of P450s and

  15. Sex specific molecular responses of quick-to-court protein in Indian malarial vector Anopheles culicifacies: conflict of mating versus blood feeding behaviour

    Tanwee Das De

    2017-07-01

    Full Text Available Understanding the molecular basis of mosquito behavioural complexity plays a central role in designing novel molecular tools to fight against their vector-borne diseases. Although the olfactory system plays an important role in guiding and managing many behavioural responses including feeding and mating, but the sex-specific regulation of olfactory responses remain poorly investigated. From our ongoing transcriptomic data annotation of olfactory tissue of blood fed adult female An. culicifacies mosquitoes; we have identified a 383 bp long unique transcript encoding a Drosophila homolog of the quick-to-court protein. Previously this was shown to regulate courtship behaviour in adult male Drosophila. A comprehensive in silico analysis of the quick-to-court (qtc gene of An. culicifacies (Ac-qtc predicts a 1536 bp single copy gene encoding 511 amino acid protein, having a high degree of conservation with other insect homologs. The age-dependent increased expression of putative Ac-qtc correlated with the maturation of the olfactory system, necessary to meet the sex-specific conflicting demand of mating (mate finding versus host-seeking behavioural responses. Sixteen to eighteen hours of starvation did not alter Ac-qtc expression in both sexes, however, blood feeding significantly modulated its response in the adult female mosquitoes, confirming that it may not be involved in sugar feeding associated behavioural regulation. Finally, a dual behavioural and molecular assay indicated that natural dysregulation of Ac-qtc in the late evening might promote the mating events for successful insemination. We hypothesize that Ac-qtc may play a unique role to regulate the sex-specific conflicting demand of mosquito courtship behaviour versus blood feeding behaviour in the adult female mosquitoes. Further elucidation of this molecular mechanism may provide further information to evaluate Ac-qtc as a key molecular target for mosquito-borne disease management.

  16. HUBUNGAN ANOPHELES BARBIROSTRIS DENGAN MALARIA

    Krisna Iryani

    2013-03-01

    Full Text Available Malaria is a disease caused by intercellular obligate protozoa genus of Plasmodium which is a parasite carried by female Anopheles mosquito. One of them is Anopheles barbirostris. Research in several places already proved that Anopheles barbirostris acts as a vector of malaria. One case that occurred in Cineam district, Tasikmalaya regency showed that Anopheles barbirostris is suspected as vector of malaria. This is proven through a research on the relationship between Anopheles barbirostris with malaria. Data was taken from the larvae and adult mosquitoes captured around Cineam village, Tasikmalaya. The observation was done in the open field and laboratory. Data and identification by pictorial key for female Anopheles showed that the population of Anopheles barbirostris was always a dominant population compared to another Anopheles species. Because of the breeding ponds and the resting places were around the village, it is suspected that they mainly bit humans. The result of the observation in laboratory showed the life cycle of Anopheles barbirostris are around 20-27 days, and the longevity of 20 days. Morphological identification of Anopheles barbirostris by pictorial key for female Anopheles showed that there is no any significant difference. This research showed that Anopheles barbirostris was suspected as vector of malaria in Cineam village, Tasikmalaya.

  17. Estacionalidad de la densidad larval del mosquito Anopheles aquasalis (Diptera: Culicidae y otros insectos asociados a su hábitat en Sucre, Venezuela

    Jesús Berti

    2010-06-01

    Full Text Available Anopheles aquasalis es considerado como el principal vector de malaria humana en el norte de Venezuela. El estudio longitudinal se llevó a cabo en áreas costeras de la Península de Paria, estado Sucre. El hábitat de las larvas de A. aquasalis fue clasificado como: manglar salobre y pantano herbáceo. Muestreos para recolectar larvas de mosquitos e insectos asociados se realizaron mensualmente en ambos criaderos desde enero hasta diciembre de 1999 (30 muestras. Simultáneamente se midieron cinco variables seleccionadas del agua: conductividad, salinidad, oxígeno disuelto, temperatura y pH. En ambos criaderos de determinaron las variaciones estacionales y temporales de las larvas de A. aquasalis e insectos acuáticos. Para el período de estudio, la abundancia de larvas fue mayor en el manglar. El análisis de correspondencia mostró una fuerte relación entre algunos factores químicos del agua y la abundancia de las larvas. La abundancia de las larvas de A. aquasalis en ambas épocas, se correlacionó positivamente con la salinidad del agua, pH y conductividad, y negativamente con el oxígeno disuelto, en la estación seca. La presencia de larvas se correlacionó positivamente con la presencia de Avicennia germinans. En el manglar existió una asociación positiva entre la abundancia de larvas y la abundancia de la familia Scirtidae y una correlación negativa entre la abundancia de larvas y la precipitación mensual (Spearman, así como una correlación negativa significativa entre la abundancia de Gerridae y la precipitación mensual. En el pantano herbáceo, no había asociaciones significativas entre la abundancia de las larvas de A. aquasalis y la abundancia de otros insectos acuáticos asociados al hábitat.Larval seasonality of the mosquito Anopheles aquasalis (Diptera: Culicidae and other insects associated to its habitat in Sucre, Venezuela. Anopheles aquasalis Curry is considered the main vector of human malaria in Northern

  18. Confirmation of Two Sibling Species among Anopheles Fluviatilis Mosquitoes in South and Southeastern Iran by Analysis of Cytochrome Oxidase I Gene

    Saied Reza Naddaf

    2012-12-01

    Full Text Available Background: Anopheles fluviatilis, one of the major malaria vectors in Iran, is assumed to be a complex of sibling species. The aim of this study was to evaluate Cytochrome oxidase I (COI gene alongside 28S-D3 as a diagnostic tool for identification of An. fluviatilis sibling species in Iran.Methods: DNA sample belonging to 24 An. fluviatilis mosquitoes from different geographical areas in south and southeastern Iran were used for amplification of COI gene followed by sequencing. The 474–475 bp COI sequences obtained in this study were aligned with 59 similar sequences of An. fluviatilis and a sequence of Anopheles minimus, as out group, from GenBank database. The distances between group and individual sequences were calculated and phy­logenetic tree for obtained sequences was generated by using Kimura two parameter (K2P model of neighbor-join­ing method.Results: Phylogenetic analysis using COI gene grouped members of Fars Province (central Iran in two distinct clades separate from other Iranian members representing Hormozgan, Kerman, and Sistan va Baluchestan Provinces. The mean distance between Iranian and Indian individuals was 1.66%, whereas the value between Fars Province individ­uals and the group comprising individuals from other areas of Iran was 2.06%.Conclusion: Presence of 2.06% mean distance between individuals from Fars Province and those from other areas of Iran is indicative of at least two sibling species in An. fluviatilis mosquitoes of Iran. This finding confirms earlier results based on RAPD-PCR and 28S-D3 analysis.

  19. Comparative susceptibility to permethrin of two Anopheles gambiae s.l. populations from Southern Benin, regarding mosquito sex, physiological status, and mosquito age

    Nazaire Aïzoun

    2014-04-01

    Conclusions: The resistance is a hereditary and dynamic phenomenon which can be due to metabolic mechanisms like overproduction of detoxifying enzymes activity. Many factors influence vector susceptibility to insecticide. Among these factors, there are mosquito sex, mosquito age, its physiological status. Therefore, it is useful to respect the World Health Organization criteria in the assessment of insecticide susceptibility tests in malaria vectors. Otherwise, susceptibility testing is conducted using unfed female mosquitoes aged 3-5 days old. Tests should also be carried out at (25±2 °C and (80±10% relative humidity.

  20. Attractiveness of volatiles from different body parts to the malaria mosquito Anopheles coluzzii is affected by deodorant compounds

    Verhulst, Niels O.; Weldegergis, Berhane T.; Menger, David; Takken, Willem

    2016-01-01

    Mosquitoes display biting preferences among different sites of the human body. In addition to height or convection currents, body odour may play a role in the selection of these biting sites. Previous studies have shown that skin emanations are important host-finding cues for mosquitoes. In this

  1. Ultrastructure of a microsporidium brachiola gambiae n.sp.parasitising a mosquito anopheles gamblae, a malaria vector

    Weiser, Jaroslav; Žižka, Zdeněk

    - (2003), s. 35-36 ISSN 1214-021X. [Conference on Cell Biology /5./. České Budějovice, 08.09.2003-10.09.2003] Institutional research plan: CEZ:AV0Z5020903 Keywords : anopheles gambiae * malaria * vector Subject RIV: EE - Microbiology, Virology

  2. Electrophysiological responses of gustatory receptor neurons on the labella of the common malaria mosquito Anopheles quadrimaculatus Say (Diptera: Culicidae)

    We recorded electrical responses from sensory cells associated with gustatory sensilla on the labella of female Anopheles quadrimaculatus to salt, sucrose, quinine (a feeding deterrent) and the insect repellent, N,N-diethyl-3-methylbenzamide (DEET). A salt-sensitive cell responded to increasing con...

  3. morphological identification of malaria vectors within anopheles

    DR. AMIN

    Africa among the human population. Determination of risk of malaria transmission requires quick and accurate methods of identification of Anopheles mosquitoes especially when targeting vector control. (Maxwell, et al., 2003). Anopheles mosquito transmits malaria. The most important vectors of malaria are members of.

  4. The Field Practices of Lambdacyhalothrin and Deltamethrin Insecticides Against Adult Mosquitoes of Anopheles stephensi as the Main Vector of Malaria: Residual Effects

    Mousa Khosravani

    2017-04-01

    Full Text Available Background Various chemical control methods have adopted in anti-malaria interventions. Indoor residual spraying (IRS has been proven as a candidate in elimination program. On the other hand, resistance to multiple insecticides was implicated as a concern issue in these polices. Pesticides should be evaluated to identify probable resistant and make decision to choose a technique against vectors. Methods In this cross-sectional study, Bioassay test applied on lambdacyhalothrin WP 10% (0.05 mg a.i. /m2 and deltamethrin WP 5% (0.05 mg a.i./m2 on two surfaces (cement and plaster against adult mosquitoes of Anopheles stephensi according to WHO criteria to measure the residual activity in Saravan county, southern Iran. Overall, 3960 mosquitoes was used in our research. The mortality rates of An.stephensi Liston (Diptera: Culicidae measured between selected surfaces and insecticides in several times. Data analyzed by Mann-Whitney (nonparametric test using SPSS v22 statistic software. Results This paper illustrated that maximal course of residual efficacy was about 3 months. No statistically significant different was exhibited between type of surface within mortality rates of An. Stephensi (P = 0.724 but lambdacyhalothrin has more durability than deltamethrin Conclusions We established that lambdacyhalothrin can be used into control and elimination setting of malaria with two rounds of spray at an interval of 3-4 months in south of Iran.

  5. Current trends in malarial chemotherapy | Ibezim | African Journal of ...

    Malaria is a tropical disease caused by the genus Plasmodium. The sexual stage of the plasmodium is carried by mosquito while the asexual stage is carried by man. Transmission from the mosquito to man is through mosquito bite. Commonly presented symptoms of malarial attack include fever, weakness, anorexia, and ...

  6. CYP6 P450 enzymes and ACE-1 duplication produce extreme and multiple insecticide resistance in the malaria mosquito Anopheles gambiae.

    Edi, Constant V; Djogbénou, Luc; Jenkins, Adam M; Regna, Kimberly; Muskavitch, Marc A T; Poupardin, Rodolphe; Jones, Christopher M; Essandoh, John; Kétoh, Guillaume K; Paine, Mark J I; Koudou, Benjamin G; Donnelly, Martin J; Ranson, Hilary; Weetman, David

    2014-03-01

    Malaria control relies heavily on pyrethroid insecticides, to which susceptibility is declining in Anopheles mosquitoes. To combat pyrethroid resistance, application of alternative insecticides is advocated for indoor residual spraying (IRS), and carbamates are increasingly important. Emergence of a very strong carbamate resistance phenotype in Anopheles gambiae from Tiassalé, Côte d'Ivoire, West Africa, is therefore a potentially major operational challenge, particularly because these malaria vectors now exhibit resistance to multiple insecticide classes. We investigated the genetic basis of resistance to the most commonly-applied carbamate, bendiocarb, in An. gambiae from Tiassalé. Geographically-replicated whole genome microarray experiments identified elevated P450 enzyme expression as associated with bendiocarb resistance, most notably genes from the CYP6 subfamily. P450s were further implicated in resistance phenotypes by induction of significantly elevated mortality to bendiocarb by the synergist piperonyl butoxide (PBO), which also enhanced the action of pyrethroids and an organophosphate. CYP6P3 and especially CYP6M2 produced bendiocarb resistance via transgenic expression in Drosophila in addition to pyrethroid resistance for both genes, and DDT resistance for CYP6M2 expression. CYP6M2 can thus cause resistance to three distinct classes of insecticide although the biochemical mechanism for carbamates is unclear because, in contrast to CYP6P3, recombinant CYP6M2 did not metabolise bendiocarb in vitro. Strongly bendiocarb resistant mosquitoes also displayed elevated expression of the acetylcholinesterase ACE-1 gene, arising at least in part from gene duplication, which confers a survival advantage to carriers of additional copies of resistant ACE-1 G119S alleles. Our results are alarming for vector-based malaria control. Extreme carbamate resistance in Tiassalé An. gambiae results from coupling of over-expressed target site allelic variants with

  7. Video studies of passage by Anopheles gambiae mosquitoes through holes in a simulated bed net: effects of hole size, hole orientation and net environment.

    Sutcliffe, James; Colborn, Kathryn L

    2015-05-13

    Holes in netting provide potential routes for mosquitoes to enter ITNs. Despite this, there is little information on how mosquitoes respond to holes in bed nets and how their responses are affected by hole size, shape and orientation or by ambient conditions around the net. Female Anopheles gambiae (G3) were recorded in a simulated bed net consisting of two sizes of untreated netting-covered behavioural arenas placed above and beside (to simulate the bed net roof and sides respectively) the experimenter who was a source of host cues from 'inside' the net. A round hole of 9 mm or 13 mm diameter was cut into the centre of the netting of each arena. Videos of unfed female mosquitoes in arenas were analysed for time spent flying, walking and standing still and for exit through the hole. The effects of the experimenter on temperature and relative humidity around the simulated net were also measured. Mosquitoes were significantly more active in overhead arenas than in arenas to the side. Hole passage was significantly more likely in smaller arenas than larger ones and for larger holes than smaller ones. In arenas to the side, hole passage rate through small holes was about 50% less likely than what could be explained by area alone. Passage rate through holes in overhead arenas was consistent with hole area. Temperature in arenas did not strongly reflect the experimenter's presence in the simulated net. Relative humidity and absolute humidity in overhead arenas, but not in arenas to the side, were immediately affected by experimenter presence. Higher levels of activity in overhead arenas than in arenas to the side were likely due to the rising heat and humidity plume from the experimenter. Lower than expected passage rates through smaller vertically oriented holes may have been be due to an edge effect that does not apply to horizontally oriented holes. Results suggest that current methods of assessing the importance of physical damage to ITNs may not accurately reflect

  8. Contemporary evolution of resistance at the major insecticide target site gene Ace-1 by mutation and copy number variation in the malaria mosquito Anopheles gambiae

    Weetman, David; Mitchell, Sara N; Wilding, Craig S; Birks, Daniel P; Yawson, Alexander E; Essandoh, John; Mawejje, Henry D; Djogbenou, Luc S; Steen, Keith; Rippon, Emily J; Clarkson, Christopher S; Field, Stuart G; Rigden, Daniel J; Donnelly, Martin J

    2015-01-01

    Functionally constrained genes are ideal insecticide targets because disruption is often fatal, and resistance mutations are typically costly. Synaptic acetylcholinesterase (AChE) is an essential neurotransmission enzyme targeted by insecticides used increasingly in malaria control. In Anopheles and Culex mosquitoes, a glycine–serine substitution at codon 119 of the Ace-1 gene confers both resistance and fitness costs, especially for 119S/S homozygotes. G119S in Anopheles gambiae from Accra (Ghana) is strongly associated with resistance, and, despite expectations of cost, resistant 119S alleles are increasing significantly in frequency. Sequencing of Accra females detected only a single Ace-1 119S haplotype, whereas 119G diversity was high overall but very low at non-synonymous sites, evidence of strong purifying selection driven by functional constraint. Flanking microsatellites showed reduced diversity, elevated linkage disequilibrium and high differentiation of 119S, relative to 119G homozygotes across up to two megabases of the genome. Yet these signals of selection were inconsistent and sometimes weak tens of kilobases from Ace-1. This unexpected finding is attributable to apparently ubiquitous amplification of 119S alleles as part of a large copy number variant (CNV) far exceeding the size of the Ace-1 gene, whereas 119G alleles were unduplicated. Ace-1 CNV was detectable in archived samples collected when the 119S allele was rare in Ghana. Multicopy amplification of resistant alleles has not been observed previously and is likely to underpin the recent increase in 119S frequency. The large CNV compromised localization of the strong selective sweep around Ace-1, emphasizing the need to integrate CNV analysis into genome scans for selection. PMID:25865270

  9. Contemporary evolution of resistance at the major insecticide target site gene Ace-1 by mutation and copy number variation in the malaria mosquito Anopheles gambiae.

    Weetman, David; Mitchell, Sara N; Wilding, Craig S; Birks, Daniel P; Yawson, Alexander E; Essandoh, John; Mawejje, Henry D; Djogbenou, Luc S; Steen, Keith; Rippon, Emily J; Clarkson, Christopher S; Field, Stuart G; Rigden, Daniel J; Donnelly, Martin J

    2015-06-01

    Functionally constrained genes are ideal insecticide targets because disruption is often fatal, and resistance mutations are typically costly. Synaptic acetylcholinesterase (AChE) is an essential neurotransmission enzyme targeted by insecticides used increasingly in malaria control. In Anopheles and Culex mosquitoes, a glycine-serine substitution at codon 119 of the Ace-1 gene confers both resistance and fitness costs, especially for 119S/S homozygotes. G119S in Anopheles gambiae from Accra (Ghana) is strongly associated with resistance, and, despite expectations of cost, resistant 119S alleles are increasing significantly in frequency. Sequencing of Accra females detected only a single Ace-1 119S haplotype, whereas 119G diversity was high overall but very low at non-synonymous sites, evidence of strong purifying selection driven by functional constraint. Flanking microsatellites showed reduced diversity, elevated linkage disequilibrium and high differentiation of 119S, relative to 119G homozygotes across up to two megabases of the genome. Yet these signals of selection were inconsistent and sometimes weak tens of kilobases from Ace-1. This unexpected finding is attributable to apparently ubiquitous amplification of 119S alleles as part of a large copy number variant (CNV) far exceeding the size of the Ace-1 gene, whereas 119G alleles were unduplicated. Ace-1 CNV was detectable in archived samples collected when the 119S allele was rare in Ghana. Multicopy amplification of resistant alleles has not been observed previously and is likely to underpin the recent increase in 119S frequency. The large CNV compromised localization of the strong selective sweep around Ace-1, emphasizing the need to integrate CNV analysis into genome scans for selection. © 2015 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

  10. prevalence of malarial parasites in pregnant women attending sir

    DR. AMINU

    Keyword: Prevalence, Malarial Parasite, Pregnant Women, Kano. INTRODUCTION ... protective semi-immunity against plasmodium falciparum is acquired during the first 10-. 15 years of life and .... hiding place for the mosquito? It is therefore ...

  11. 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

    Okumu Fredros O

    2013-01-01

    Full Text Available Abstract Background Indoor residual insecticide spraying (IRS and long-lasting insecticide treated nets (LLINs are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. Methods A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset®, PermaNet 2.0®, Icon Life® nets with IRS (pirimiphos methyl, lambda cyhalothrin, DDT, in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Results Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset® or PermaNet 2.0® nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life® nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Conclusions Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used, but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used or even regressive (e.g. when DDT is used for the IRS. Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of

  12. Effects of bed net use, female size, and plant abundance on the first meal choice (blood vs sugar of the malaria mosquito Anopheles gambiae

    Stone Chris M

    2012-01-01

    Full Text Available Abstract Background The purpose of this study was to determine whether the sugar-or-blood meal choice of Anopheles gambiae females one day after emergence is influenced by blood-host presence and accessibility, nectariferous plant abundance, and female size. This tested the hypothesis that the initial meal of female An. gambiae is sugar, even when a blood host is available throughout the night, and, if not, whether the use of a bed net diverts mosquitoes to sugar sources. Methods Females and males Senna didymobotrya plants. Simultaneously they had access to a human blood host, either for 8 h or for only 30 min at dusk and dawn (the remainder of the night being excluded by an untreated bed net. In a third situation, the blood host was not present. All mosquitoes were collected in the morning. Their wing lengths, an indicator of pre-meal energetic state, were measured, and their meal choice was determined by the presence of midgut blood and of fructose. Results Female sugar feeding after emergence was facultative. When a blood host was accessible for 8 h per night, 92% contained blood, and only 3.7% contained sugar. Even with the use of a bed net, 78% managed to obtain a blood meal during the 30 min of accessibility at dusk or dawn, but 14% of females were now fructose-positive. In the absence of a blood host, and when either one or six plants were available, a total of 21.7% and 23.6% of females and 30.8% and 43.5% of males contained fructose, respectively. Feeding on both sugar and blood was more likely with bed net use and with greater plant abundance. Further, mosquitoes that fed on both resources were more often small and had taken a sugar meal earlier than the blood meal. The abundance of sugar hosts also affected the probability of sugar feeding by males and the amount of fructose obtained by both males and females. Conclusion Even in an abundance of potential sugar sources, female An. gambiae appear to prefer a nearby human source of blood

  13. Genes for genetic sexing in the Mediterranean fruit fly, Ceratitis capitata (Wied.), and the mosquito, Anopheles stephensi

    Robinson, A.S.

    1990-01-01

    A system was developed utilizing alcohol dehydrogenase (ADH) that produced only male medflies. High sterility in the line plus male mortality from the treatment made the system unsuitable for genetic sexing on a large scale. A strain of Anopheles stephensi was developed in which females could be killed by dieldrin, but males survived. A large field cage release of medfly sexed by colour in the pupal stage demonstrated the advantages of male-only releases. The pupal colour sexing strain broke down under mass rearing. (author). 19 refs, 1 fig., 6 tabs

  14. Identification, characterisation, and function of adipokinetic hormones and receptor in the African malaria mosquito, "Anopheles Gambiae" (Diptera)

    Kaufmann, Christian; Betschart, Bruno

    2007-01-01

    En utilisant la bioinformatique et la biologie moléculaire, nous avons pu identifier chez le principal vecteur africain de la malaria, le moustique, Anopheles gambiae deux hormones adipokinétiques (AKHs): l'octapeptide, Anoga-AKH-I (pQLTFTPAWa) et le décapeptide, Anoga-AKH-II, (pQVTFSRDWNAa). La fonction principale des AKHs est d’induire une hyperlipémie (effet d’adipokinétique), ainsi qu’une hypertrehalosémie et une hyperprolinémie. En tant que membres de la famille des AKH, les deux neurope...

  15. Phospholipid Topography of Whole-Body Sections of the Anopheles stephensi Mosquito, Characterized by High-Resolution Atmospheric-Pressure Scanning Microprobe Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

    Khalil, Saleh M; Römpp, Andreas; Pretzel, Jette; Becker, Katja; Spengler, Bernhard

    2015-11-17

    High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) has been employed to study the molecular anatomical structure of rodent malaria vector Anopheles stephensi mosquitoes. A dedicated sample preparation method was developed which suits both, the special tissue properties of the sample and the requirements of high-resolution MALDI imaging. Embedding in 5% carboxymethylcellulose (CMC) was used to maintain the tissue integrity of the whole mosquitoes, being very soft, fragile, and difficult to handle. Individual lipid compounds, specifically representing certain cell types, tissue areas, or organs, were detected and imaged in 20 μm-thick whole-body tissue sections at a spatial resolution of 12 μm per image pixel. Mass spectrometric data and information quality were based on a mass resolution of 70,000 (at m/z 200) and a mass accuracy of better than 2 ppm in positive-ion mode on an orbital trapping mass spectrometer. A total of 67 imaged lipids were assigned by database search and, in a number of cases, identified via additional MS/MS fragmentation studies directly from tissue. This is the first MSI study at 12 μm spatial resolution of the malaria vector Anopheles. The study provides insights into the molecular anatomy of Anopheles stephensi and the distribution and localization of major classes of glycerophospholipids and sphingolipids. These data can be a basis for future experiments, investigating, e.g., the metabolism of Plasmodium-infected and -uninfected Anopheles mosquitoes.

  16. A longitudinal study on Anopheles mosquito larval abundance in distinct geographical and environmental settings in western Kenya

    Imbahale, S.S.; Paaijmans, K.P.; Mukabana, W.R.; Lammeren, van R.J.A.; Githeko, A.K.; Takken, W.

    2011-01-01

    Background - As the ecology of mosquito larvae can be complex there is need to develop a rational framework for undertaking larval ecological studies. Local environmental characteristics, such as altitude, climate and land use, can significantly impact on phenology and population dynamics of

  17. Larvicidal activity and GC-MS analysis of flavonoids of Vitex negundo and Andrographis paniculata against two vector mosquitoes Anopheles stephensi and Aedes aegypti.

    Gautam, Keerti; Kumar, Padma; Poonia, Sawitri

    2013-09-01

    Development of insect resistance to synthetic pesticides, high operational cost and environmental pollution have created the need for developing alternative approaches to control vector-borne diseases. In the present study, larvicidal activity of flavonoid extracts of different parts of Vitex negundo (Linnaeus) and Andrographis paniculata (Nees) have been studied against the late III or early IV instar larvae of Aedes aegypti and Anopheles stephensi (Liston). Flavonoids were extracted from different parts of the selected plants using standard method. Bioassay test was carried out by WHO method for determination of larvicidal activity against mosquitoes. Different compounds of the most active extract were identified by the gas chromatography-mass spectrometry (GC-MS) analysis. Flavonoid extract of whole aerial part of A. paniculata was found to be inactive against the selected larvae of Ae. aegypti even at the concentration of 600 ppm, whereas it caused 70% mortality in An. stephensi at the concentration of 200 ppm. Flavonoid extract of flower-buds produced highest mortality (100%) at the concentration of 600 ppm for the late III or early IV instar larvae of Ae. aegypti and at the concentration of 200 ppm for the larvae of An. stephensi. GC-MS analysis of the most active flavonoid extract from flower-buds of Vitex showed 81 peaks. Phenol (26.83% area), naphthalene (4.95% area), 2,3-dihydrobenzofuran (6.79% area), Phenol-2,4-Bis (1,1-dimethyl) (4.49% area), flavones 4'-OH,5-OH,7-di-O-glucoside (0.25% area) and 5-hydroxy- 3,6,7,3',4'-pentamethoxy flavones (0.80% area) were present in major amount. Flavonoid extracts from different parts of two selected plants possess larvicidal activity against two selected mosquito species, hence, could be utilized for developing flavonoid-based, eco-friendly insecticide as an alternative to synthetic insecticides.

  18. The influence of late-stage pupal irradiation and increased irradiated: un-irradiated male ratio on mating competitiveness of the malaria mosquito Anopheles arabiensis Patton.

    Helinski, M E H; Knols, B G J

    2009-06-01

    Competitiveness of released males in genetic control programmes is of critical importance. In this paper, we explored two scenarios to compensate for the loss of mating competitiveness after pupal stage irradiation in males of the malaria mosquito Anopheles arabiensis. First, competition experiments with a higher ratio of irradiated versus un-irradiated males were performed. Second, pupae were irradiated just prior to emergence and male mating competitiveness was determined. Males were irradiated in the pupal stage with a partially or fully-sterilizing dose of 70 or 120 Gy, respectively. Pupae were irradiated aged 20-26 h (young) as routinely performed, or the pupal stage was artificially prolonged by cooling and pupae were irradiated aged 42-48 h (old). Irradiated males competed at a ratio of 3:1:1 to un-irradiated males for mates in a large cage design. At the 3:1 ratio, the number of females inseminated by males irradiated with 70 Gy as young pupae was similar to the number inseminated by un-irradiated males for the majority of the replicates. At 120 Gy, significantly fewer females were inseminated by irradiated than by un-irradiated males. The irradiation of older pupae did not result in a significantly improved male mating competitiveness compared to the irradiation of young pupae. Our findings indicate that the loss of competitiveness after pupal stage irradiation can be compensated for by a threefold increase of irradiated males, but only for the partially-sterilizing dose. In addition, cooling might be a useful tool to facilitate handling processes of large numbers of mosquitoes in genetic control programmes.

  19. Modelling the impact of the long-term use of insecticide-treated bed nets on Anopheles mosquito biting time.

    Ferreira, Claudia P; Lyra, Silas P; Azevedo, Franciane; Greenhalgh, David; Massad, Eduardo

    2017-09-15

    Evidence of changing in biting and resting behaviour of the main malaria vectors has been mounting up in recent years as a result of selective pressure by the widespread and long-term use of insecticide-treated bed nets (ITNs), and indoor residual spraying. The impact of resistance behaviour on malaria intervention efficacy has important implications for the epidemiology and malaria control programmes. In this context, a theoretical framework is presented to understand the mechanisms determining the evolution of feeding behaviour under the pressure of use of ITNs. An agent-based stochastic model simulates the impact of insecticide-treated bed nets on mosquito fitness by reducing the biting rates, as well as increasing mortality rates. The model also incorporates a heritability function that provides the necessary genetic plasticity upon which natural selection would act to maximize the fitness under the pressure of the control strategy. The asymptotic equilibrium distribution of mosquito population versus biting time is shown for several daily uses of ITNs, and the expected disruptive selection on this mosquito trait is observed in the simulations. The relative fitness of strains that bite at much earlier time with respect to the wild strains, when a threshold of about 50% of ITNs coverage highlights the hypothesis of a behaviour selection. A sensitivity analysis has shown that the top three parameters that play a dominant role on the mosquito fitness are the proportion of individuals using bed nets and its effectiveness, the impact of bed nets on mosquito oviposition, and the mosquito genetic plasticity related to changing in biting time. By taking the evolutionary aspect into account, the model was able to show that the long-term use of ITNs, although representing an undisputed success in reducing malaria incidence and mortality in many affected areas, is not free of undesirable side effects. From the evolutionary point of view of the parasite virulence, it

  20. Mosquito host preferences affect their response to synthetic and natural odour blends

    Busula, A.O.; Takken, W.; Loy, D.E.; Hahn, B.H.; Mukabana, W.R.; Verhulst, N.O.

    2015-01-01

    Background The anthropophilic malaria mosquito Anopheles gambiae sensu stricto (hereafter termed Anopheles gambiae) primarily takes blood meals from humans, whereas its close sibling Anopheles arabiensis is more opportunistic. Previous studies have identified several compounds that play a critical

  1. An ace-1 gene duplication resorbs the fitness cost associated with resistance in Anopheles gambiae, the main malaria mosquito.

    Assogba, Benoît S; Djogbénou, Luc S; Milesi, Pascal; Berthomieu, Arnaud; Perez, Julie; Ayala, Diego; Chandre, Fabrice; Makoutodé, Michel; Labbé, Pierrick; Weill, Mylène

    2015-10-05

    Widespread resistance to pyrethroids threatens malaria control in Africa. Consequently, several countries switched to carbamates and organophophates insecticides for indoor residual spraying. However, a mutation in the ace-1 gene conferring resistance to these compounds (ace-1(R) allele), is already present. Furthermore, a duplicated allele (ace-1(D)) recently appeared; characterizing its selective advantage is mandatory to evaluate the threat. Our data revealed that a unique duplication event, pairing a susceptible and a resistant copy of the ace-1 gene spread through West Africa. Further investigations revealed that, while ace-1(D) confers less resistance than ace-1(R), the high fitness cost associated with ace-1(R) is almost completely suppressed by the duplication for all traits studied. ace-1 duplication thus represents a permanent heterozygote phenotype, selected, and thus spreading, due to the mosaic nature of mosquito control. It provides malaria mosquito with a new evolutionary path that could hamper resistance management.

  2. Sir Ronald Ross and the Malarial Parasite

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 7. Sir Ronald Ross and the Malarial Parasite - Discovery of its Route - From Man to Mosquito and Back. Shobhona Sharma. General Article Volume 11 Issue 7 July 2006 pp 4-13 ...

  3. The genetics and ecology of male reproductive investments in the malaria mosquito Anopheles gambiae s.s

    Ekechukwu, Nkuru Esther

    2015-01-01

    Malaria continues to be a major global health problem due to high mortality and morbidity rate in endemic regions. An. gambiae s.s is the major vector in endemic African countries. About 198 million cases of malaria were recorded globally in 2013 and this have led to over 584 000 deaths. Different measures have been implemented in order to reduce and control the transmission rate. However, the drug resistant parasites and insecticide resistant mosquitoes have created problems towards achievin...

  4. Extraction of mosquitocidals from Ocimum canum leaves for the control of dengue and malarial vectors

    Pari Madhiyazhagan

    2014-09-01

    Full Text Available Objective: To assess the potentiality of Ocimum canum (O. canum (Lamiaceae in larvicidal, pupicidal, adulticidal, and repellent activities against the malarial vector, Anopheles stephensi (An. stephensi and the dengue vector, Aedes aegypti (Ae. aegypti. Methods: The mosquitocidal activity of methanol extracts from O. canum against immature and adult An. stephensi and Ae. aegypti (L. were studied. Standard WHO bioassays were used to evaluate the effectiveness of the plant extract against mosquitoes. Results: The methanol extract of O. canum was very effective against the immature stages of An. stephensi (LC50=193.280, 240.551, 303.409, 374.936 and pupa 469.547 mg/L and Ae. aegypti (LC 50=242.071, 287.277, 332.668, 394.061 and pupa 457.879 mg/L. Smoke toxicity assay showed significant mortality rate against adult An. stephensi (86.6% and Ae. aegypti (84.78%. The number of eggs laid by the females were strictly reduced after exposure to smoke. Conclusions: From the observed results we conclude that O. canum can be used as an effective larvicidal and repellent agent against the malarial and dengue vectors.

  5. Laboratory studies on the olfactory behaviour of Anopheles quadriannulatus

    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

  6. 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

    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

  7. Pilot longitudinal mosquito surveillance study in the Danube Delta Biosphere Reserve and the first reports of Anopheles algeriensis Theobald, 1903 and Aedes hungaricus Mihályi, 1955 for Romania.

    Török, Edina; Tomazatos, Alexandru; Cadar, Daniel; Horváth, Cintia; Keresztes, Lujza; Jansen, Stephanie; Becker, Norbert; Kaiser, Achim; Popescu, Octavian; Schmidt-Chanasit, Jonas; Jöst, Hanna; Lühken, Renke

    2016-04-11

    Mosquito-borne viruses (moboviruses) are of growing importance in many countries of Europe. In Romania and especially in the Danube Delta Biosphere Reserve (DDBR), mosquito and mobovirus surveillance are not performed on a regular basis. However, this type of study is crucially needed to evaluate the risk of pathogen transmission, to understand the ecology of emerging moboviruses, or to plan vector control programmes. We initiated a longitudinal mosquito surveillance study with carbon dioxide-baited Heavy Duty Encephalitis Vector Survey traps at four sampling sites to analyse the spatio-temporal pattern of the (i) mosquito species composition and diversity, (ii) functional groups of mosquitoes (oviposition sites, overwintering stage, and number of generations), and (iii) the occurrence of potential West Nile virus (WNV) vectors. During 2014, a total of 240,546 female mosquitoes were collected. All species were identified using morphological characteristics and further confirmed by mitochondrial cytochrome c oxidase subunit I (COI) gene analysis of selected specimens. The two most common taxa were Coquilettidia richiardii (40.9 %) and Anopheles hyrcanus (34.1 %), followed by Culex pipiens (sensu lato) (s.l.)/Cx. torrentium (7.7 %), Aedes caspius (5.7 %), Cx. modestus (4.0 %), An. maculipennis (s.l.) (3.9 %), and Ae. vexans (3.0 %). A further seven species were less common in the area studied, including two new records for Romania: An. algeriensis and Ae. hungaricus. Phylogenetic analysis of COI gene demonstrated the evolutionary relatedness of most species with specimens of the same species collected in other European regions, except Ae. detritus and An. algeriensis, which exhibited high genetic diversity. Due to the dominance of Cq. richiardii and An. hyrcanus (75 % of all collected specimens), the overall phenology and temporal pattern of functional groups basically followed the phenology of both species. A huge proportion of the mosquito population in the course

  8. Experimental hut evaluation of bednets treated with an organophosphate (chlorpyrifos-methyl or a pyrethroid (lambdacyhalothrin alone and in combination against insecticide-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes

    Corbel Vincent

    2005-05-01

    Full Text Available Abstract Background Pyrethroid resistant mosquitoes are becoming increasingly common in parts of Africa. It is important to identify alternative insecticides which, if necessary, could be used to replace or supplement the pyrethroids for use on treated nets. Certain compounds of an earlier generation of insecticides, the organophosphates may have potential as net treatments. Methods Comparative studies of chlorpyrifos-methyl (CM, an organophosphate with low mammalian toxicity, and lambdacyhalothrin (L, a pyrethroid, were conducted in experimental huts in Côte d'Ivoire, West Africa. Anopheles gambiae and Culex quinquefasciatus mosquitoes from the area are resistant to pyrethroids and organophosphates (kdr and insensitive acetylcholinesterase Ace.1R. Several treatments and application rates on intact or holed nets were evaluated, including single treatments, mixtures, and differential wall/ceiling treatments. Results and Conclusion All of the treatments were effective in reducing blood feeding from sleepers under the nets and in killing both species of mosquito, despite the presence of the kdr and Ace.1R genes at high frequency. In most cases, the effects of the various treatments did not differ significantly. Five washes of the nets in soap solution did not reduce the impact of the insecticides on A. gambiae mortality, but did lead to an increase in blood feeding. The three combinations performed no differently from the single insecticide treatments, but the low dose mixture performed encouragingly well indicating that such combinations might be used for controlling insecticide resistant mosquitoes. Mortality of mosquitoes that carried both Ace.1R and Ace.1S genes did not differ significantly from mosquitoes that carried only Ace.1S genes on any of the treated nets, indicating that the Ace.1R allele does not confer effective resistance to chlorpyrifos-methyl under the realistic conditions of an experimental hut.

  9. Characterization and potential role of microRNA in the Chinese dominant malaria mosquito Anopheles sinensis (Diptera: Culicidae) throughout four different life stages.

    Feng, Xinyu; Wu, Jiatong; Zhou, Shuisen; Wang, Jingwen; Hu, Wei

    2018-01-01

    microRNAs (miRNAs) are one kind of small non-coding RNAs widely distributed in insects. Many studies have shown that miRNAs play critical roles in development, differentiation, apoptosis, and innate immunity. However, there are a few reports describing miRNAs in Anopheles sinensis , the most common, and one of the dominant malaria mosquito in China. Here, we investigated the global miRNA expression profile across four different developmental stages including embryo, larval, pupal, and adult stages using Illumina Hiseq 2500 sequencing. In total, 164 miRNAs were obtained out of 107.46 million raw sequencing reads. 99 of them identified as known miRNAs, and the remaining 65 miRNAs were considered as novel. By analyzing the read counts of miRNAs in all developmental stages, 95 miRNAs showed stage-specific expression (q  1) in consecutive stages, indicating that these miRNAs may be involved in critical physiological activity during development. Sixteen miRNAs were identified to be commonly dysregulated throughout four developmental stages. Many miRNAs showed stage-specific expression, such as asi-miR-2943 was exclusively expressed in the embryo stage, and asi-miR-1891 could not be detected in larval stage. The expression of six selected differentially expressed miRNAs identified by qRT-PCR were consistent with our sequencing results. Furthermore, 5296 and 1902 target genes were identified for the dysregulated 68 known and 27 novel miRNAs respectively by combining miRanda and RNAhybrid prediction. GO annotation and KEGG pathway analysis for the predicted genes of dysregulated miRNAs revealed that they might be involved in a broad range of biological processes related with the development, such as membrane, organic substance transport and several key pathways including protein processing in endoplasmic reticulum, propanoate metabolism and folate biosynthesis. Thirty-two key miRNAs were identified by microRNA-gene network analysis. The present study represents the

  10. A Brief Survey of the Mosquitoes of South Sulawesi, Indonesia, with Special Reference to the Identity of ’Anopheles barbirostris’ (Diptera: Culicidae) from the Margolembo Area

    1977-06-20

    mosquitoes hitherto recorded from Sulawesi and adjacent islands is presented. The prevalence of malaria and filariasis in transmigration villages of...East Indian mosquitoes. Bull. Ent. Res. 25: 501-19, illus. 1939. Notes on Dutch East- Indian mosquitoes. Tij&hr. Ent. 82: 91-113, illus. Brug, S...Macdonald, W. W. 1957. Malaysian parasites. XVI. An interim review of the non-anopheline mosquitoes of Malaya. Stud. Inst. Med. Res., Malaya 28: l-34

  11. An analysis of diet quality, how it controls fatty acid profiles, isotope signatures and stoichiometry in the malaria mosquito Anopheles arabiensis.

    Rebecca Hood-Nowotny

    Full Text Available Knowing the underlying mechanisms of mosquito ecology will ensure effective vector management and contribute to the overall goal of malaria control. Mosquito populations show a high degree of population plasticity in response to environmental variability. However, the principle factors controlling population size and fecundity are for the most part unknown. Larval habitat and diet play a crucial role in subsequent mosquito fitness. Developing the most competitive insects for sterile insect technique programmes requires a "production" orientated perspective, to deduce the most effective larval diet formulation; the information gained from this process offers us some insight into the mechanisms and processes taking place in natural native mosquito habitats.Fatty acid profiles and de-novo or direct assimilation pathways, of whole-individual mosquitoes reared on a range of larval diets were determined using pyrolysis gas chromatograph/mass spectrometry. We used elemental analysis and isotope ratio mass spectrometry to measure individual-whole-body carbon, nitrogen and phosphorous values and to assess the impact of dietary quality on subsequent population stoichiometry, size, quality and isotopic signature. Diet had the greatest impact on fatty acid (FA profiles of the mosquitoes, which exhibited a high degree of dietary routing, characteristic of generalist feeders. De-novo synthesis of a number of important FAs was observed. Mosquito C:N stoichiometry was fixed in the teneral stage. Dietary N content had significant influence on mosquito size, and P was shown to be a flexible pool which limited overall population size.Direct routing of FAs was evident but there was ubiquitous de-novo synthesis suggesting mosquito larvae are competent generalist feeders capable of survival on diet with varying characteristics. It was concluded that nitrogen availability in the larval diet controlled teneral mosquito size and that teneral CN ratio is a sex- and

  12. Studies on mosquitoes (Diptera: Culicidae and anthropic environment: 1- Parity of blood seeking Anopheles (Kerteszia in South-Eastern Brazil Estudos sobre mosquitos (Diptera: Culicidae e ambiente antrópico: 1- Paridade de Anopheles (Kerteszia em atividade hematófaga, na região sudeste do Brasil

    Oswaldo Paulo Forattini

    1993-02-01

    Full Text Available Populations of Anopheles (Kerteszia were sampled fortnightly over a one-year period (August 1991 to July 1992 at Ribeira Valley, S. Paulo State, Brazil. Indoor and outdoor collections were made on human bait at evening crepuscular period. The Polovodova technique for age grading was applied to 3,501 females of Anopheles cruzii and to 416 females of An. bellator. That sample represented 34.4% of the total number of mosquitoes collected. The most abundant species found was An. cruzii. However, An. bellator showed an endophagy that was almost three times greater than that of An. cruzii. The overall parous rate was 25.4% and uniparity was practically dominant one. A proportion of 26.9% of An. cruzii and 12.0% of An. bellator were found to be uniparous. Only three outdoor females of the former species (0.1% showed biparity. Parity of An. cruzii was higher in females caught outdoors than in those caught indoors. Nevertheless, 497 nulliparous females examined (417 cruzii and 80 bellator had ovaries that had advanced to Christophers and Mer stages III to V. These results imply that these females had already practised hematophagy. Relating these results to those from the parous females, a high statistical significance was found, leading to the conclusion that gonothophic discordance is a common pattern among these anophelines. Further, these results obtained with human bait catches strongly suggest that nearly 38.0% of these host-seeking females had already taken at least one previous blood-meal. So it is possible that enough time could thus be available for the plasmodian development in the vectors.Relata-se os resultados obtidos em coletas regulares de Anopheles cruzii e An. bellator, mediante o emprego de isca humana e por ocasião do crepúsculo vespertino. Objetivou-se, precipuamente, conhecer a paridade de populações dessas espécies, quando em plena tentativa hematófaga, tanto no ambiente intra como peridomiciliar. As coletas foram levadas a

  13. Effects of a botanical larvicide derived from Azadirachta indica (the neem tree) on oviposition behaviour in Anopheles gambiae s.s. mosquitoes

    Howard, A.F.V.; Adongo, E.A.; Vulule, J.; Githure, J.

    2011-01-01

    More focus is given to mosquito larval control due to the necessity to use several control techniques together in integrated vector management programmes. Botanical products are thought to be able to provide effective, sustainable and cheap mosquito larval control tools. However, bio-larvicides like

  14. The bionomics of the malaria mosquito Anopheles gambiae sensu lato in Southeast Tanzania : adult size variation and its effect on female fecundity, survival and malaria transmission

    Lyimo, E.O.K.

    1993-01-01

    Size of adult mosquitoes is known to affect both population dynamics as well as disease transmission. Studies devoted to this topic have given different results for different species. For example in some mosquito species, large size was found to be associated with high fecundity and longer

  15. Identification of candidate volatiles that affect the behavioural response of the malaria mosquito Anopheles gambiae sensu stricto to an active kairomone blend: laboratory and semi-field assays

    Smallegange, R.C.; Bukovinszkine Kiss, G.; Otieno, B.; Mbadi, P.A.; Takken, W.; Mukabana, W.R.; Loon, van J.J.A.

    2012-01-01

    Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) is the most important vector of human malaria in sub-Saharan Africa, affecting the lives of millions of people. Existing tools such as insecticide-treated nets and indoor-residual sprays are not only effective, but also have limitations as a

  16. Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control

    Ageep, T.B.; Cox, J.; Hassan, M.M.; Knols, B.G.J.; Benedict, M.Q.; Malcolm, C.A.; Babiker, A.; Sayed, El B.B.

    2009-01-01

    Background - Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on

  17. Resolving the conflict of mating versus blood feeding: exploring role of quick-to-court gene in the mosquito Anopheles culicifacies

    Tanwee Das De

    2017-10-01

    Full Text Available Mosquitoes are the deadliest animal in the world. Mosquitoes transmit several vector borne disease (VBDs such as malaria, dengue, chikungunya, zika fever, yellow fever and responsible for a loss of millions of lives annually. Though, suppression of mosquito population by means of chemical insecticides plays a crucial role in controlling vector population. However, fast emergence of insecticide resistance limits the efforts and demanding to design alternative molecular tools to fight against these VBDs. One of the potential strategies may include interfering complex feeding and/or mating behavioural properties. Compared to female mosquito male mosquito have an indirect effect in disease transmission and thus least studied. Males induce several post-mating behavioural changes in females, including the induction of host seeking and blood feeding behavior. Although, a successful mating events are guided by non-genetic circadian rhythm, but how genetic factors manages the sequential events of swarm formation, suitable mate finding and aerial coupling remains poorly investigated. While understanding the complex feeding behaviour of adult An. culicifacies female mosquito, we identified and analyzed a unique transcript (383 bp from the olfactory system of the blood-fed mosquito, encoding the ‘quick to court’ (QTC protein. It is a homolog of Drosophila coiled-coil QTC (Q9VMU5 protein and shown to play an important role in driving the male courtship behaviour. A comprehensive in silico analysis predicted a 1536 bp long transcript encoding 511 AA long protein in the mosquito genome. Age dependent and sex specific transcriptional profiling revealed that both male female mosquitoes attain the specific age of adulteration on 5-7 days. Circadian clock dependent Ac-qtc profiling indicated that late evening natural dysregulation of Ac-qtc by unknown mechanism may promote the successful insemination event during active copulation. Together, our findings

  18. An entomopathogenic fungus for control of adult African malaria mosquitoes

    Scholte, E.J.; Ng'habi, K.R.N.; Kihonda, J.; Takken, W.; Paaijmans, K.P.; Abdulla, S.; Killeen, G.F.; Knols, B.G.J.

    2005-01-01

    Biological control of malaria mosquitoes in Africa has rarely been used in vector control programs. Recent developments in this field show that certain fungi are virulent to adult Anopheles mosquitoes. Practical delivery of an entomopathogenic fungus that infected and killed adult Anopheles gambiae,

  19. A potent series targeting the malarial cGMP-dependent protein kinase clears infection and blocks transmission.

    Baker, David A; Stewart, Lindsay B; Large, Jonathan M; Bowyer, Paul W; Ansell, Keith H; Jiménez-Díaz, María B; El Bakkouri, Majida; Birchall, Kristian; Dechering, Koen J; Bouloc, Nathalie S; Coombs, Peter J; Whalley, David; Harding, Denise J; Smiljanic-Hurley, Ela; Wheldon, Mary C; Walker, Eloise M; Dessens, Johannes T; Lafuente, María José; Sanz, Laura M; Gamo, Francisco-Javier; Ferrer, Santiago B; Hui, Raymond; Bousema, Teun; Angulo-Barturén, Iñigo; Merritt, Andy T; Croft, Simon L; Gutteridge, Winston E; Kettleborough, Catherine A; Osborne, Simon A

    2017-09-05

    To combat drug resistance, new chemical entities are urgently required for use in next generation anti-malarial combinations. We report here the results of a medicinal chemistry programme focused on an imidazopyridine series targeting the Plasmodium falciparum cyclic GMP-dependent protein kinase (PfPKG). The most potent compound (ML10) has an IC 50 of 160 pM in a PfPKG kinase assay and inhibits P. falciparum blood stage proliferation in vitro with an EC 50 of 2.1 nM. Oral dosing renders blood stage parasitaemia undetectable in vivo using a P. falciparum SCID mouse model. The series targets both merozoite egress and erythrocyte invasion, but crucially, also blocks transmission of mature P. falciparum gametocytes to Anopheles stephensi mosquitoes. A co-crystal structure of PvPKG bound to ML10, reveals intimate molecular contacts that explain the high levels of potency and selectivity we have measured. The properties of this series warrant consideration for further development to produce an antimalarial drug.Protein kinases are promising drug targets for treatment of malaria. Here, starting with a medicinal chemistry approach, Baker et al. generate an imidazopyridine that selectively targets Plasmodium falciparum PKG, inhibits blood stage parasite growth in vitro and in mice and blocks transmission to mosquitoes.

  20. Studies on mosquitoes (Diptera: Culicidae and anthropicenvironment: 5- Breeding of Anopheles albitarsis in flooded rice fields in South-Eastern Brazil

    Oswaldo Paulo Forattini

    1994-10-01

    Full Text Available Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small. That inverse correlation may give potential direction to control measures.

  1. CONTROL DEMONSTRATION OF THE RICEFIELD BREEDING MOSQUITO ANOPHELES ACONITUS DONITZ IN CENTRAL JAVA, USING; POECILIA RETICULATA THROUGH COMMUNITY PARTICIPATION : 1. EXPERIMENTAL DESIGN AND CONCEPT

    Sustriayu Nalim

    2012-09-01

    Full Text Available Penelitian dilakukan untuk menjajagi cara memberantas vektor malaria Anopheles aconitus di sawah dengan ikan pemakan jentik Poecilia reticulata. Dalam penelitian ini terlihat bahwa dalam pelaksanaan program pemberantasan ini, partisipasi petani untuk mina padi dapat digalakkan melalui rapat kelompok tani. Program mina padi menye­diakan tempat hidup bagi ikan pemakan jentik. Rencana pelaksanaan program ini serta cara penggalakan   petani dibicarakan dalam makalah ini.

  2. Molecular identification of Anopheles gambiae sensu stricto Giles ...

    User

    2016-09-28

    Sep 28, 2016 ... responsible for the transmission. The knowledge of which form, Anopheles coluzzii, A. .... National Council for Science and Technology and Health Research ..... Styer ML, Carey RJ, Wang JL, Scott TW (2007). Mosquitoes Do.

  3. CONTROL DEMONSTRATION OF THE RICEFIELD BREEDING MOSQUITO ANOPHELES ACONITUS DONITZ IN CENTRAL JAVA, USING POECILIA RETICULATA THROUGH COMMUNITY PARTICIPATION : 3. FIELD TRIAL AND EVALUATION

    Sustriayu Nalim

    2012-09-01

    Full Text Available Suatu penelitian dilakukan untuk menjajagi kemungkinan menggunakan minapadi sebagai cara pemberantasan nyamuk Anopheles aconitus. Minapadi dilakukan dengan ikan Cyprinus carpio. Dengan tersedianya air di sawah untuk ikan, ikan pemakan jentik Poecilia Reticulata yang ditebarkan dapat hidup pula. Penebaran dilakukan oleh masyarakat. Hasil Penelitian ini menunjukkan bahwa melalui minapadi yaitu dengan penebaran, ikan P. reticulata pada kepadatan 2 ekor /m2, populasi An. aconitus selama 5 tahun dapat diturunkan sebanyak 99,7% dan S.P.R. malaria sebanyak 98.8%. [1] Regency Health Service, Banjarnegara Regency, Central Java.

  4. The larvicidal effects of black pepper (Piper nigrum L.) and piperine against insecticide resistant and susceptible strains of Anopheles malaria vector mosquitoes.

    Samuel, Michael; Oliver, Shüné V; Coetzee, Maureen; Brooke, Basil D

    2016-04-26

    Insecticide resistance carries the potential to undermine the efficacy of insecticide based malaria vector control strategies. Therefore, there is an urgent need for new insecticidal compounds. Black pepper (dried fruit from the vine, Piper nigrum), used as a food additive and spice, and its principal alkaloid piperine, have previously been shown to have larvicidal properties. The aim of this study was to investigate the larvicidal effects of ground black pepper and piperine against third and fourth instar Anopheles larvae drawn from several laboratory-reared insecticide resistant and susceptible strains of Anopheles arabiensis, An. coluzzii, An. gambiae, An. quadriannulatus and An. funestus. Larvae were fed with mixtures of standard larval food and either ground black pepper or piperine in different proportions. Mortality was recorded 24 h after black pepper and 48 h after piperine were applied to the larval bowls. Black pepper and piperine mixtures caused high mortality in the An. gambiae complex strains, with black pepper proving significantly more toxic than piperine. The An. funestus strains were substantially less sensitive to black pepper and piperine which may reflect a marked difference in the feeding habits of this species compared to that of the Gambiae complex or a difference in food metabolism as a consequence of differences in breeding habitat between species. Insecticide resistant and susceptible strains by species proved equally susceptible to black pepper and piperine. It is concluded that black pepper shows potential as a larvicide for the control of certain malaria vector species.

  5. Contributions of Anopheles larval control to malaria suppression in tropical Africa: review of achievements and potential.

    Walker, K; Lynch, M

    2007-03-01

    Malaria vector control targeting the larval stages of mosquitoes was applied successfully against many species of Anopheles (Diptera: Culicidae) in malarious countries until the mid-20th Century. Since the introduction of DDT in the 1940s and the associated development of indoor residual spraying (IRS), which usually has a more powerful impact than larval control on vectorial capacity, the focus of malaria prevention programmes has shifted to the control of adult vectors. In the Afrotropical Region, where malaria is transmitted mainly by Anopheles funestus Giles and members of the Anopheles gambiae Giles complex, gaps in information on larval ecology and the ability of An. gambiae sensu lato to exploit a wide variety of larval habitats have discouraged efforts to develop and implement larval control strategies. Opportunities to complement adulticiding with other components of integrated vector management, along with concerns about insecticide resistance, environmental impacts, rising costs of IRS and logistical constraints, have stimulated renewed interest in larval control of malaria vectors. Techniques include environmental management, involving the temporary or permanent removal of anopheline larval habitats, as well as larviciding with chemical or biological agents. This present review covers large-scale trials of anopheline larval control methods, focusing on field studies in Africa conducted within the past 15 years. Although such studies are limited in number and scope, their results suggest that targeting larvae, particularly in human-made habitats, can significantly reduce malaria transmission in appropriate settings. These approaches are especially suitable for urban areas, where larval habitats are limited, particularly when applied in conjunction with IRS and other adulticidal measures, such as the use of insecticide treated bednets.

  6. EKOLOGI Anopheles spp. DI KABUPATEN LOMBOK TENGAH

    Majematang Mading

    2014-07-01

    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.Keywords: ecology, Anopheles spp., Central Lombok

  7. 1 SHORT COMMUNICATION Resting behaviour of Anopheles ...

    2011-10-04

    Oct 4, 2011 ... Resting behaviour of Anopheles gambiae s.l. and its implication on malaria .... nature) were requested to sleep under the double mosquito net trap (one ... designed from the DNA sequences of the intergenic spacer region of ...

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

    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

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

    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.

  10. Mating competitiveness of male Anopheles arabiensis mosquitoes irradiated with a partially or fully sterilizing dose in small and large laboratory cages.

    Helinski, M E H; Knols, B G J

    2008-07-01

    Male mating competitiveness is a crucial parameter in many genetic control programs including the sterile insect technique (SIT). We evaluated competitiveness of male Anopheles arabiensis Patton as a function of three experimental variables: (1) small or large cages for mating, (2) the effects of either a partially sterilizing (70 Gy) or fully sterilizing (120 Gy) dose, and (3) pupal or adult irradiation. Irradiated males competed for females with an equal number of unirradiated males. Competitiveness was determined by measuring hatch rates of individually laid egg batches. In small cages, pupal irradiation with the high dose resulted in the lowest competitiveness, whereas adult irradiation with the low dose gave the highest, with the latter males being equal in competitiveness to unirradiated males. In the large cage, reduced competitiveness of males irradiated in the pupal stage was more pronounced compared with the small cage; the males irradiated as adults at both doses performed similarly to unirradiated males. Unexpectedly, males irradiated with the high dose performed better in a large cage than in a small one. A high proportion of intermediate hatch rates was observed for eggs collected in the large cage experiments with males irradiated at the pupal stage. It is concluded that irradiation of adult An. arabiensis with the partially sterilizing dose results in the highest competitiveness for both cage designs. Cage size affected competitiveness for some treatments; therefore, competitiveness determined in laboratory experiments must be confirmed by releases into simulated field conditions. The protocols described are readily transferable to evaluate male competitiveness for other genetic control techniques.

  11. Operational note effects of fipronil and lambda-cyhalothrin against larval Anopheles quadrimaculatus and nontarget aquatic mosquito predators in Arkansas small rice plots.

    Dennett, James A; Bernhardt, John L; Meisch, Max V

    2003-06-01

    The effects of fipronil and lambda-cyhalothrin, applied at rates labeled for control of the rice water weevil, Lissorhoptrus oryzophilus, on 3 nontarget indigenous insect species in Arkansas rice are described. Three replicates of untreated control checks and fipronil- and lambda-cyhalothrin-treated plots containing 3 sentinel cages each were performed. Ten 4th-stage larvae of Anopheles quadrimaculatus, 10 adult Tropisternus lateralis, or 10 adult Notonecta indica were placed within individual cages in small rice plots treated with ICON 6.2 FS (fipronil) at 0.025 lb active ingredient (AI)/acre (0.028 kg/ha) or KARATEZ 2.08 CS (lambda-cyhalothrin) at 0.03 lb AI/acre (0.033 kg/ha) applied over vegetation and water with a single-boom sprayer. At 24 h after treatment in fipronil plots, significantly higher control of An. quadrimaculatus and T. lateralis (69 and 48% control, respectively) was achieved, compared to N. indica (18%). In lambda-cyhalothrin plots 24 h after treatment, 100% reductions of both T. lateralis and N. indica were highly significant (P lambda-cyhalothrin plots 48 h after treatment, with 93 and 53% control of T. lateralis and N. indica, respectively, compared to 7% control of An. quadrimaculatus. A marked difference in susceptibility was found between selected nontarget organisms used in this study. When using lambda-cyhalothrin to control adult L. oryzophilus, populations of nontarget beneficial insects, such as T. lateralis and N. indica, could be adversely affected, whereas nontarget pestilent species, such as An. quadrimaculatus, could proliferate. Fipronil achieved higher percentages of control against An. quadrimaculatus, compared to lambda-cyhalothrin, and was less harmful to both nontarget predators.

  12. Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control

    Malcolm Colin A

    2009-06-01

    Full Text Available Abstract Background Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on area-wide integrated pest management (AW-IPM that may include the sterile insect technique (SIT. To support the planning and implementation of future AW-IPM activities, larval surveys were carried out to provide key data on spatial and seasonal dynamics of local vector populations. Methods Monthly cross-sectional larval surveys were carried out between March 2005 and May 2007 in two localities (Dongola and Merowe adjacent to the river Nile. A stratified random sampling strategy based on the use of Remote Sensing (RS, Geographical Information Systems (GIS and the Global Positioning System (GPS was used to select survey locations. Breeding sites were mapped using GPS and data on larval density and breeding site characteristics were recorded using handheld computers. Bivariate and multivariate logistic regression models were used to identify breeding site characteristics associated with increased risk of presence of larvae. Seasonal patterns in the proportion of breeding sites positive for larvae were compared visually to contemporaneous data on climate and river height. Results Of a total of 3,349 aquatic habitats sampled, 321 (9.6% contained An. arabiensis larvae. The frequency with which larvae were found varied markedly by habitat type. Although most positive sites were associated with temporary standing water around the margins of the main Nile channel, larvae were also found at brickworks and in areas of leaking pipes and canals – often far from the river. Close to the Nile channel, a distinct seasonal pattern in larval populations was evident and appeared to be linked to the rise and fall of the river level. These patterns were not

  13. The genetics of green thorax, a new larval colour mutant, non-linked with ruby - eye locus in the malaria mosquito, Anopheles stephensi.

    Sanil, D; Shetty, N J

    2009-06-01

    Anopheles stephensi, an important vector of malaria continues to be distributed widely in the Indian subcontinent. The natural vigour of the species combined with its new tolerance, indeed resistance to insecticides has made it obligatory that we look for control methods involving genetic manipulation. Hence, there is an immediate need for greater understanding of the genetics of this vector species. One of the requirements for such genetic studies is the establishment of naturally occurring mutants, establishment of the genetic basis for the same and use of such mutants in the genetic transformation studies and other genetic control programme(s). This paper describes the isolation and genetic studies of a larval colour mutant, green thorax (gt), and linkage studies involving another autosomal recessive mutant ruby- eye (ru) in An. stephensi. After the initial discovery, the mutant green thorax was crossed inter se and pure homozygous stock of the mutant was established. The stock of the mutant ruby- eye, which has been maintained as a pure stock in the laboratory. Crosses were made between the wild type and mutant, green thorax to determine the mode of inheritance of green thorax. For linkage studies, crosses were made between the mutant green thorax and another autosomal recessive mutant ruby-eye. The percentage cross-over was calculated for the genes linkage relationship for gt and gt ru. Results of crosses between mutant and wild type showed that the inheritance of green thorax (gt) in An. stephensi is monofactorial in nature. The gt allele is recessive to wild type and is autosomal. The linkage studies showed no linkage between ru and gt. The mutant gt represents an excellent marker for An. stephensi as it is expressed in late III instar stage of larvae and is prominent in IV instar and pupal stages with complete penetrance and high viability. The said mutant could be easily identified without the aid of a microscope. This mutant can be used extensively to

  14. A reliable morphological method to assess the age of male Anopheles gambiae

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

    2006-01-01

    Background - Release of genetically-modified (GM) or sterile male mosquitoes for malaria control is hampered by inability to assess the age and mating history of free-living male Anopheles. Methods - Age and mating-related changes in the reproductive system of male Anopheles gambiae were quantified

  15. Control of pyrethroid and DDT-resistant Anopheles gambiae by application of indoor residual spraying or mosquito nets treated with a long-lasting organophosphate insecticide, chlorpyrifos-methyl

    Chabi Joseph

    2010-02-01

    Full Text Available Abstract Background Scaling up of long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS with support from the Global Fund and President's Malaria Initiative is providing increased opportunities for malaria control in Africa. The most cost-effective and longest-lasting residual insecticide DDT is also the most environmentally persistent. Alternative residual insecticides exist, but are too short-lived or too expensive to sustain. Dow Agrosciences have developed a microencapsulated formulation (CS of the organophosphate chlorpyrifos methyl as a cost-effective, long-lasting alternative to DDT. Methods Chlorpyrifos methyl CS was tested as an IRS or ITN treatment in experimental huts in an area of Benin where Anopheles gambiae and Culex quinquefasiactus are resistant to pyrethroids, but susceptible to organophosphates. Efficacy and residual activity was compared to that of DDT and the pyrethroid lambdacyalothrin. Results IRS with chlorpyrifos methyl killed 95% of An. gambiae that entered the hut as compared to 31% with lambdacyhalothrin and 50% with DDT. Control of Cx. quinquefasciatus showed a similar trend; although the level of mortality with chlorpyrifos methyl was lower (66% it was still much higher than for DDT (14% or pyrethroid (15% treatments. Nets impregnated with lambdacyhalothrin were compromized by resistance, killing only 30% of An. gambiae and 8% of Cx. quinquefasciatus. Nets impregnated with chlorpyrifos methyl killed more (45% of An gambiae and 15% of Cx. quinquefasciatus, but its activity on netting was of short duration. Contact bioassays on the sprayed cement-sand walls over the nine months of monitoring showed no loss of activity of chlorpyrifos methyl, whereas lambdacyhalothrin and DDT lost activity within a few months of spraying. Conclusion As an IRS treatment against pyrethroid resistant mosquitoes chlorpyrifos methyl CS outperformed DDT and lambdacyhalothrin. In IRS campaigns, chlorpyrifos methyl CS should

  16. Distribution of X-ray induced chromosome rearrangement breaks along the polytene chromosomes of Anopheles messeae

    Pleshkova, G.N.

    1983-01-01

    Distribution of chromosomal aberrations localization along polytene chromosomes (aoutosomes) of salivary glands of malarial mosquito. Anopheles messeae is presented. Induced aberrations in F 1 posterity from X-ray irradiated fecundated females are studied. Poipts of breaks of inversions and trapslocations are localized separately. There are no considerable dif-- ferences in the distribution character of two types of aberrations. Over the length of autosomes the breaks are more frequent in distal halves, their frequency in proximal parts anally in near centromeric regions of chromosomes is reduced. Concentration of breaks in certain ''hot points'' of the chromosomes is pointed out. Comparison of distribution of actual and expected frequencies of break points according to chi 2 criterion revealed highly fiducial discrepancies, testifying to uneven participation of different regions of chromosomes in aberration formation. Similarities and differences of the data obtained from analogous ones, demonstrated in Drosophila, as well as possible reasons for the distribution unevennes are discussed. On the basis of analysis of intrinsic and literature data a supposition is made that the ''hot points'' (break concentrations) can be considered as localizaion markers of intercalary heterochromatin

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

    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.

  18. Habitat Perkembangbiakan Spesifik Anopheles sp Di Tambang Emas Kura-Kura Banian (Perubahan Perilaku Anopheles sp

    Liestiana Indriyati, SKM

    2016-12-01

    Full Text Available The results of Health Research 2010, showed that malaria was an infectious disease that the sixth cause of death cause of the sixth of death in Indonesia. Kotabaru is a malaria endemic district, especially in Puskesmas Banian, Annual Parasite Incidence 241.19 in 2014 where the cases of malaria with occurring in illegal gold mines on the slopes of Banian Mountain. It’s needed to know the factors that affect the existence of malaria in these locations. This research was observational study doing by cross-sectional study and analyzed by descriptively. Research conducted at the Gold Mine Banian Buluh Kuning village, Sungai Durian subdistric, Kotabaru district, South Kalimantan Province in February and March, 2015. The activities were catching larva and adult mosquitoes, environmental and mosquito breeding habitats observation and Mass Blood Survey. It was found Anopheles maculatus and Anopheles leucosphyrus with very low densities in area with the number of malaria cases by 22.99%. It was found divers breeding habitats of Anopheles sp on a former gold wash, former drum and former plastic containers. This indicated a behavioral change of Anopheles breeding places because previous to this the Anopheles breed in puddles on the ground or direct contact with the ground.

  19. BIONOMY OF Anopheles punctulatus GROUP (Anopheles farauti, Anopheles koliensis, Anopheles punctulatus MALARIA VECTOR IN PAPUA PROVINCE

    Semuel Sandy

    2014-08-01

    farauti, An. punctulatus and An. koliensis. These three species were nocturnal, antrophopilic with the diferrencebionomics such as breeding habitats, biting activity, and resting places. The aim of this study was to determine the bionomicaspects of the malaria vectors (resting places, biting activity and breading habitats in the study areas. The larvae of An.farauti was reported found at coastal, area with brackish water (salinity ± 4.6 %, natural or artificial irrigation canals.Adult female mosquitoes of An. farauti were found nocturnal, eksofagik eksofilik , and antrophopilic habit. An. koliensislarvae not found in brackish, they were found in the swamp and sago forest, semipermanent or permanent ponds whichshallow and exposed to direct sunlight . Adult mosquitoes of An. koliensis were nocturnal, antrophopilic (78% human bites,eksofagik, eksofilik. The larvae of An. punctulatus was not found in brackish water, it was found in a pool with clear or turbidwater which presence or no water vegetation, the larvae of An. punctulatus also found in sago and swamp forest withexposure to direct sunlight. Adult mosquites of An. punctulatus were nocturnal, antrophopilic (98% human bites, eksofagik,endofilik. Basic data on the behaviour of Anopheles spp (bionomic is necessary in developing effective and efficientintervention pattern and control vector.Key words: malaria vector, An. punctulatus group, bionomic, Papua

  20. Increased presence of the thermophilic mosquitoes and potential vectors Anopheles hyrcanus (Pallas, 1771) and Culex modestus Ficalbi 1889 in Central Europe’s lower Dyje River basin (South Moravia, Czech Republic)

    Šebesta, O.; Gelbič, Ivan

    2015-01-01

    Roč. 51, č. 3 (2015), s. 272-280 ISSN 0037-9271 Institutional support: RVO:60077344 Keywords : Anopheles hyrcanus * Culex modestus * vector Subject RIV: EH - Ecology, Behaviour Impact factor: 0.575, year: 2015

  1. Mosquito Control

    ... Labs and Research Centers Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

  2. Relationships between anopheline mosquitoes and topography in West Timor and Java, Indonesia.

    Ndoen, Ermi; Wild, Clyde; Dale, Pat; Sipe, Neil; Dale, Mike

    2010-08-26

    Malaria is a serious health issue in Indonesia. Mosquito control is one aspect of an integrated malaria management programme. To focus resources on priority areas, information is needed about the vectors and their habitats. This research aimed to identify the relationship between anopheline mosquitoes and topography in West Timor and Java. Study areas were selected in three topographic types in West Timor and Java. These were: coastal plain, hilly (rice field) and highland. Adult mosquitoes were captured landing on humans identified to species level and counted. Eleven species were recorded, four of which were significant for malaria transmission: Anopheles aconitus, Anopheles barbirostris, Anopheles subpictus and Anopheles sundaicus. Each species occupied different topographies, but only five were significantly associated: Anopheles annularis, Anopheles vagus and Anopheles subpictus (Java only) with hilly rice fields; Anopheles barbirostris, Anopheles maculatus and Anopheles subpictus (West Timor only) with coastal areas. Information on significant malaria vectors associated with specific topography is useful for planning the mosquito control aspect of malaria management.

  3. [Hyper-reactive malarial splenomegaly].

    Maazoun, F; Deschamps, O; Barros-Kogel, E; Ngwem, E; Fauchet, N; Buffet, P; Froissart, A

    2015-11-01

    Hyper-reactive malarial splenomegaly is a rare and severe form of chronic malaria. This condition is a common cause of splenomegaly in endemic areas. The pathophysiology of hyper-reactive malarial splenomegaly involves an intense immune reaction (predominantly B cell-driven) to repeated/chronic infections with Plasmodium sp. The diagnosis may be difficult, due to a poorly specific clinical presentation (splenomegaly, fatigue, cytopenias), a long delay between residence in a malaria-endemic area and onset of symptoms, and a frequent absence of parasites on conventional thin and thick blood smears. A strongly contributive laboratory parameter is the presence of high levels of total immunoglobulin M. When the diagnostic of hyper-reactive malarial splenomegaly is considered, search for anti-Plasmodium antibodies and Plasmodium nucleic acids (genus and species) by PCR is useful. Diagnosis of hyper-reactive malarial splenomegaly relies on the simultaneous presence of epidemiological, clinical, biological and follow-up findings. Regression of both splenomegaly and hypersplenism following antimalarial therapy allows the differential diagnosis with splenic lymphoma, a common complication of hyper-reactive malarial splenomegaly. Although rare in Western countries, hyper-reactive malarial splenomegaly deserves increased medical awareness to reduce the incidence of incorrect diagnosis, to prevent progression to splenic lymphoma and to avoid splenectomy. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  4. Targeting the breeding sites of malaria mosquitoes: biological and physical control of malaria mosquito larvae

    Bukhari, S.T.

    2011-01-01

    Malaria causes an estimated 225 million cases and 781,000 deaths every year. About 85% of the deaths are in children under five years of age. Malaria is caused by the Plasmodium parasite which is transmitted by the Anopheles mosquito vector. Mainly two methods of intervention are used for vector control, i.e. insecticide-treated bed nets and indoor residual spraying. Both involve the use of insecticides and target Anopheles adults indoors. A rising increase in resistance against these insec...

  5. Ocular Manifestations of Mosquito-Transmitted Diseases.

    Karesh, James W; Mazzoli, Robert A; Heintz, Shannon K

    2018-03-01

    Of the 3,548 known mosquito species, about 100 transmit human diseases. Mosquitoes are distributed globally throughout tropical and temperate regions where standing water sources are available for egg laying and the maturation of larva. Female mosquitoes require blood meals for egg production. This is the main pathway for disease transmission. Mosquitoes carry several pathogenic organisms responsible for significant ocular pathology and vision loss including West Nile, Rift Valley, chikungunya, dengue viruses, various encephalitis viruses, malarial parasites, Francisella tularensis, microfilarial parasites, including Dirofilaria, Wuchereria, and Brugia spp., and human botfly larvae. Health care providers may not be familiar with many of these mosquito-transmitted diseases or their associated ocular findings delaying diagnosis, treatment, and recovery of visual function. This article aims to provide an overview of the ocular manifestations associated with mosquito-transmitted diseases.

  6. Factors influencing the spatial distribution of Anopheles larvae in Coimbatore District, Tamil Nadu, India.

    Arjunan, Naresh Kumar; Kadarkarai, Murugan; Kumar, Shobana; Pari, Madhiyazhagan; Thiyagarajan, Nataraj; Vincent, C Thomas; Barnard, Donald R

    2015-12-01

    Malaria causes extensive morbidity and mortality in humans and results in significant economic losses in India. The distribution of immature malaria-transmitting Anopheles mosquitoes was studied in 17 villages in Coimbatore District as a prelude to the development and implementation of vector control strategies that are intended to reduce the risk of human exposure to potentially infectious mosquitoes. Eight Anopheles species were recorded. The most numerous species were Anopheles vagus, Anopheles subpictus, and Anopheles hyrcanus. The location of mosquito development sites and the density of larvae in each village was evaluated for correlation with selected demographic, biologic, and land use parameters using remote sensing and geographic information systems (GIS) technology. We found the number of mosquito development sites in a village and the density of larvae in such sites to be positively correlated with human population density but not the surface area (km(2)) of the village. The number of mosquito development sites and the density of larvae in each site were not correlated. Data from this study are being used to construct a GIS-based mapping system that will enable the location of aquatic habitats with Anopheles larvae in the Coimbatore District, Tamil Nadu, India as target sites for the application of vector control. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Current trends in malarial chemotherapy

    SERVER

    2008-02-19

    Feb 19, 2008 ... carried by mosquito while the asexual stage is carried by man. .... Mosquitoes are also are moving, highly adaptable and ... attacks because of its slow onset of action. .... history of adverse reactions to the combination drugs. It.

  8. Spatial repellency screening in a high-throughput apparatus with Aedes aegypti and Anopheles gambiae

    Spatial repellents are essential for personal protection against mosquitoes, such as Aedes aegypti and Anopheles gambiae, to reduce annoyance biting and transmission of mosquito-borne diseases. The number of safe and effective repellents, including DEET, picaridin, and IR3535, is limited and contin...

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

    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.

  10. Biological activities of four essential oils against Anopheles gambiae ...

    The control of malaria is still a challenge partly due to mosquito's resistance to current available insecticides. The aim of this work was to evaluate the ovicidal, larvicidal and repellent activities of Lantana camara, Hyptis suaveolens, Hyptis spicigera and Ocimum canum essential oils against Anopheles gambiae s.l. ...

  11. Distribution And Seasonal Abundance Of Anopheline Mosquito ...

    The essence of this study was to identify Anopheles mosquito species in Nguru, Yobe State and to determine their distribution and relative abundance in the months of the year. Insecticide and aspirator were used to collect mosqutoes in human dwellngs and preserved in 2% formalin for identcation using dissectng ...

  12. Cultured skin microbiota attracts malaria mosquitoes

    Verhulst, N.O.; Beijleveld, H.; Knols, B.G.J.; Takken, W.; Schraa, G.; Bouwmeester, H.J.; Smallegange, R.C.

    2009-01-01

    Background - Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human

  13. Cultured skin microbiota attracts malaria mosquitoes

    Verhulst, Niels O.; Beijleveld, Hans; Knols, Bart Gj; Takken, Willem; Schraa, Gosse; Bouwmeester, Harro J.; Smallegange, Renate C.

    2009-01-01

    Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours.

  14. Cultured skin microbiota attracts malaria mosquitoes

    Verhulst, N.O.; Beijleveld, H.; Knols, B.G.J.; Takken, W.; Schraa, G.; Bouwmeester, H.J.; Smallegange, R.C.

    2009-01-01

    Background: Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human

  15. Hyperreactive malarial splenomegaly in Venezuela.

    Torres, J; Noya, O; Mondolfi, A; Peceño, C; Botto, C

    1988-07-01

    A cross-sectional seroepidemiological survey seeking hyperreactive malarial splenomegaly was carried out in isolated Yanomami hamlets in Amazonas Territory in Venezuela. All 110 inhabitants greater than 1 year of age were evaluated clinically and 98 were studied immunologically. The spleen index for individuals greater than 10 years of age was 44%. Only 3 patients had Plasmodium spp. on thick blood smears. All had serological evidence of infection with Plasmodium falciparum and P. vivax. Twenty-three patients were considered to show hyperreactive malarial splenomegaly. Clinical manifestations of the syndrome did not differ from those described in other parts of the world.

  16. Detection, isolation, and genetic characterization of Rift Valley fever virus from Anopheles (Anopheles) coustani, Anopheles (Anopheles) squamosus, and Culex (Culex) antennatus of the Haute Matsiatra region, Madagascar.

    Ratovonjato, Jocelyn; Olive, Marie-Marie; Tantely, Luciano Michael; Andrianaivolambo, Lala; Tata, Etienne; Razainirina, Josette; Jeanmaire, Elisabeth; Reynes, Jean-Marc; Elissa, Nohal

    2011-06-01

    Following veterinary alerts of Rift Valley fever (RVF) in the districts of Fianarantsoa I and II in November 2008 and in the district of Ambalavao in April 2009, entomological and virological investigations were carried out to identify the mosquito species that could act as RVF virus (RVFV) vectors in the region. A total of 12,785 adult mosquitoes belonging to 5 genera and 21 species were collected. After identification, mosquitoes were pooled by species, sex, and female status (fed or unfed) and then stored at -80°C. Of 319 pools of unfed monospecific female mosquito tested by real-time RT-polymerase chain reaction, RVFV was detected in 1 pool of Anopheles coustani, 5 pools of An. squamosus, and 2 pools of Culex antennatus mosquitoes. The virus was isolated in mosquito cell lines from two of the five Real Time-RT-polymerase chain reaction (real time-RT-PCR) positive pools of An. squamosus mosquitoes. From the eight RVFV strains detected, partial S, M, and L genome segments sequences were obtained. The phylogenetic analysis of these sequences showed that the strains circulating in mosquitoes were genetically close to those that circulated in livestock and humans during RVF outbreaks in 2008 and 2009. This study, therefore, provides strong evidence that An. squamosus, An. coustani, and Cx. antennatus could play a role as vectors of the RVFV during the disease outbreaks in 2008-2009. Bioecological, genetic, and RVF transmission studies on these three mosquito species are needed to address this question and thus improve prevention and control of future RVF outbreaks in Madagascar, where these species are present.

  17. 3D mosquito screens to create window double screen traps for mosquito control.

    Khattab, Ayman; Jylhä, Kaisa; Hakala, Tomi; Aalto, Mikko; Malima, Robert; Kisinza, William; Honkala, Markku; Nousiainen, Pertti; Meri, Seppo

    2017-08-29

    Mosquitoes are vectors for many diseases such as malaria. Insecticide-treated bed nets and indoor residual spraying of insecticides are the principal malaria vector control tools used to prevent malaria in the tropics. Other interventions aim at reducing man-vector contact. For example, house screening provides additive or synergistic effects to other implemented measures. We used commercial screen materials made of polyester, polyethylene or polypropylene to design novel mosquito screens that provide remarkable additional benefits to those commonly used in house screening. The novel design is based on a double screen setup made of a screen with 3D geometric structures parallel to a commercial mosquito screen creating a trap between the two screens. Owing to the design of the 3D screen, mosquitoes can penetrate the 3D screen from one side but cannot return through the other side, making it a unidirectional mosquito screen. Therefore, the mosquitoes are trapped inside the double screen system. The permissiveness of both sides of the 3D screens for mosquitoes to pass through was tested in a wind tunnel using the insectary strain of Anopheles stephensi. Among twenty-five tested 3D screen designs, three designs from the cone, prism, or cylinder design groups were the most efficient in acting as unidirectional mosquito screens. The three cone-, prism-, and cylinder-based screens allowed, on average, 92, 75 and 64% of Anopheles stephensi mosquitoes released into the wind tunnel to penetrate the permissive side and 0, 0 and 6% of mosquitoes to escape through the non-permissive side, respectively. A cone-based 3D screen fulfilled the study objective. It allowed capturing 92% of mosquitoes within the double screen setup inside the wind tunnel and blocked 100% from escaping. Thus, the cone-based screen effectively acted as a unidirectional mosquito screen. This 3D screen-based trap design could therefore be used in house screening as a means of avoiding infective bites and

  18. Ecology of Anopheles spp. in Central Lombok Regency

    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.

  19. Association of Climatic Variability, Vector Population and Malarial Disease in District of Visakhapatnam, India: A Modeling and Prediction Analysis.

    Srimath-Tirumula-Peddinti, Ravi Chandra Pavan Kumar; Neelapu, Nageswara Rao Reddy; Sidagam, Naresh

    2015-01-01

    Malarial incidence, severity, dynamics and distribution of malaria are strongly determined by climatic factors, i.e., temperature, precipitation, and relative humidity. The objectives of the current study were to analyse and model the relationships among climate, vector and malaria disease in district of Visakhapatnam, India to understand malaria transmission mechanism (MTM). Epidemiological, vector and climate data were analysed for the years 2005 to 2011 in Visakhapatnam to understand the magnitude, trends and seasonal patterns of the malarial disease. Statistical software MINITAB ver. 14 was used for performing correlation, linear and multiple regression analysis. Perennial malaria disease incidence and mosquito population was observed in the district of Visakhapatnam with peaks in seasons. All the climatic variables have a significant influence on disease incidence as well as on mosquito populations. Correlation coefficient analysis, seasonal index and seasonal analysis demonstrated significant relationships among climatic factors, mosquito population and malaria disease incidence in the district of Visakhapatnam, India. Multiple regression and ARIMA (I) models are best suited models for modeling and prediction of disease incidences and mosquito population. Predicted values of average temperature, mosquito population and malarial cases increased along with the year. Developed MTM algorithm observed a major MTM cycle following the June to August rains and occurring between June to September and minor MTM cycles following March to April rains and occurring between March to April in the district of Visakhapatnam. Fluctuations in climatic factors favored an increase in mosquito populations and thereby increasing the number of malarial cases. Rainfall, temperatures (20°C to 33°C) and humidity (66% to 81%) maintained a warmer, wetter climate for mosquito growth, parasite development and malaria transmission. Changes in climatic factors influence malaria directly by

  20. Targeting the breeding sites of malaria mosquitoes: biological and physical control of malaria mosquito larvae

    Bukhari, S.T.

    2011-01-01


    Malaria causes an estimated 225 million cases and 781,000 deaths every year. About 85% of the deaths are in children under five years of age. Malaria is caused by the Plasmodium parasite which is transmitted by the Anopheles mosquito vector. Mainly two methods of intervention are used for

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

    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.......5% of 151 samples analysed were mosquito-positive. Logistic regression was used for statistical analysis. RESULTS: Among physico-chemical parameters, An. culicifacies (the major malaria vector in the country) was positively related only to temperature, and An. varuna (a secondary malaria vector) to calcium...

  2. Importance of waste stabilization ponds and wastewater irrigation in the generation of vector mosquitoes in Pakistan

    Mukhtar, Muhammad; Ensink, Jeroen; Van der Hoek, Wim

    2006-01-01

    The objective of the current study was to investigate the role of waste stabilization ponds (WSP) and wastewater-irrigated sites for the production of mosquitoes of medical importance. Mosquito larvae were collected fortnightly from July 2001 to June 2002 in Faisalabad, Pakistan. In total, 3......,132 water samples from WSP and irrigated areas yielded 606,053 Culex larvae of five species. In addition, 107,113 anophelines, representing eight species were collected. Anopheles subpictus (Grassi) and Culex mosquitoes, especially Culex quinquefasciatus (Say) and Culex tritaeniorhynchus (Giles), showed...... an overwhelming preference for anaerobic ponds, which receive untreated wastewater. Facultative ponds generated lower numbers of both Anopheles and Culex mosquitoes, whereas the last ponds in the series, the maturation ponds, were the least productive for both mosquito genera. An. subpictus and Anopheles...

  3. Carbon dioxide baited trap catches do not correlate with human landing collections of Anopheles aquasalis in Suriname

    Hiwat-van Laar, H.; Andriessen, R.; Rijk, de M.; Koenraadt, C.J.M.; Takken, W.

    2011-01-01

    Three types of carbon dioxide-baited traps, i.e., the Centers for Disease Control Miniature Light Trap without light, the BioGents (BG) Sentinel Mosquito Trap (BG-Sentinel) and the Mosquito Magnet® Liberty Plus were compared with human landing collections in their efficiency in collecting Anopheles

  4. Exploring Anopheles gut bacteria for Plasmodium blocking activity

    Bahia, Ana C; Dong, Yuemei; Blumberg, Benjamin J; Mlambo, Godfree; Tripathi, Abhai; BenMarzouk-Hidalgo, Omar J; Chandra, Ramesh; Dimopoulos, George

    2014-01-01

    SUMMARY Malaria parasite transmission requires the successful development of Plasmodium gametocytes into flagellated microgametes upon mosquito blood ingestion, and the subsequent fertilization of microgametes and macrogametes for the development of motile zygotes, called ookinetes, which invade and transverse the Anopheles vector mosquito midgut at around 18-36 h after blood ingestion. Within the mosquito midgut, the malaria parasite has to withstand the mosquito's innate immune response and the detrimental effect of its commensal bacterial flora. We have assessed the midgut colonization capacity of 5 gut bacterial isolates from field-derived, and 2 from laboratory colony, mosquitoes and their effect on Plasmodium development in vivo and in vitro, along with their impact on mosquito survival. Some bacterial isolates activated the mosquito's immune system, affected the mosquito's life span, and were capable of blocking Plasmodium development. We have also shown that the ability of these bacteria to inhibit the parasites is likely to involve different mechanisms and factors. A Serratia marcescens isolate was particularly efficient in colonizing the mosquitoes’ gut, compromising mosquito survival, and inhibiting both sexual- and asexual-stage Plasmodium through secreted factors, thereby rendering it a potential candidate for the development of a malaria transmission intervention strategy. PMID:24428613

  5. The bionomics of Anopheles merus (Diptera: Culicidae along the Kenyan coast

    Kipyab Pamela C

    2013-02-01

    Full Text Available Abstract Background Anopheles merus, a sibling species of the Anopheles gambiae complex occurs along the East African coast but its biology and role in malaria transmission in this region is poorly understood. We evaluated the blood feeding pattern and the role of this species in malaria transmission in Malindi district, Coastal Kenya. Methods Adult mosquitoes were collected indoors by CDC light traps and Pyrethrum Spray Catch and outdoors by CDC light traps. Anopheles females were identified to species by morphological characteristics and sibling species of An. gambiae complex distinguished by rDNA polymerase chain reaction (PCR. Screening for host blood meal sources and presence or absence of Plasmodium falciparum circumsporozoite proteins was achieved by Enzyme Linked Immunosorbent Assays (ELISA. Results Anopheles merus comprised 77.8% of the 387 Anopheles gambiae s.l adults that were collected. Other sibling species of Anopheles gambiae s.l identified in the study site included An. arabiensis(3.6%, and An. gambiae s.s. (8%. The human blood index for An. merus was 0.12, while the sporozoite rate was 0.3%. Conclusion These findings suggest that An. merus can play a minor role in malaria transmission along the Kenyan Coast and should be a target for vector control which in turn could be applied in designing and implementing mosquito control programmes targeting marsh-breeding mosquitoes; with the ultimate goal being to reduce the transmission of malaria associated with these vectors.

  6. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

    Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo

    2014-01-01

    Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission. PMID:25185005

  7. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

    Ryan C Smith

    2014-08-01

    Full Text Available Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.

  8. Mosquito Bites

    ... virus to humans. Other mosquito-borne infections include yellow fever, malaria and some types of brain infection (encephalitis). ... certain diseases, such as West Nile virus, malaria, yellow fever and dengue fever. The mosquito obtains a virus ...

  9. Mosquito Traps: An Innovative, Environmentally Friendly Technique to Control Mosquitoes

    Brigitte Poulin

    2017-03-01

    Full Text Available We tested the use of mosquito traps as an alternative to spraying insecticide in Camargue (France following the significant impacts observed on the non-target fauna through Bti persistence and trophic perturbations. In a village of 600 inhabitants, 16 Techno Bam traps emitting CO2 and using octenol lures were set from April to November 2016. Trap performance was estimated at 70% overall based on mosquitoes landing on human bait in areas with and without traps. The reduction of Ochlerotatus caspius and Oc. detritus, the two species targeted by Bti spraying, was, respectively, 74% and 98%. Traps were less efficient against Anopheles hyrcanus (46%, which was more attracted by lactic acid than octenol lures based on previous tests. Nearly 300,000 mosquitoes from nine species were captured, with large variations among traps, emphasizing that trap performance is also influenced by surrounding factors. Environmental impact, based on the proportion of non-target insects captured, was mostly limited to small chironomids attracted by street lights. The breeding success of a house martin colony was not significantly affected by trap use, in contrast to Bti spraying. Our experiment confirms that the deployment of mosquito traps can offer a cost-effective alternative to Bti spraying for protecting local populations from mosquito nuisance in sensitive natural areas.

  10. Plasmodium falciparum ookinetes require mosquito midgut chondroitin sulfate proteoglycans for cell invasion.

    Dinglasan, R.R.; Alaganan, A.; Ghosh, A.K.; Saito, A.; Kuppevelt, A.H.M.S.M. van; Jacobs-Lorena, M.

    2007-01-01

    Malaria transmission entails development of the Plasmodium parasite in its insect vector, the Anopheles mosquito. Parasite invasion of the mosquito midgut is the critical first step and involves adhesion to host epithelial cell ligands. Partial evidence suggests that midgut oligosaccharides are

  11. Household-level and surrounding peri-domestic environmental characteristics associated with malaria vectors Anopheles arabiensis and Anopheles funestus along an urban-rural continuum in Blantyre, Malawi.

    Dear, Nicole F; Kadangwe, Chifundo; Mzilahowa, Themba; Bauleni, Andy; Mathanga, Don P; Duster, Chifundo; Walker, Edward D; Wilson, Mark L

    2018-06-08

    Malaria is increasing in some recently urbanized areas that historically were considered lower risk. Understanding what drives urban transmission is hampered by inconsistencies in how "urban" contexts are defined. A dichotomized "urban-rural" approach, based on political boundaries may misclassify environments or fail to capture local drivers of risk. Small-scale agriculture in urban or peri-urban settings has been shown to be a major risk determinant. Household-level Anopheles abundance patterns in and around Malawi's commercial capital of Blantyre (~ 1.9 M pop.) were analysed. Clusters (N = 64) of five houses each located at 2.5 km intervals along eight transects radiating out from Blantyre city centre were sampled during rainy and dry seasons of 2015 and 2016. Mosquito densities were measured inside houses using aspirators to sample resting mosquitoes, and un-baited CDC light traps to sample host seeking mosquitoes. Of 38,895 mosquitoes captured, 91% were female and 87% were Culex spp. Anopheles females (N = 5058) were primarily captured in light traps (97%). Anopheles abundance was greater during rainy seasons. Anopheles funestus was more abundant than Anopheles arabiensis, but both were found on all transects, and had similar associations with environmental risk factors. Anopheles funestus and An. arabiensis females significantly increased with distance from the urban centre, but this trend was not consistent across all transects. Presence of small-scale agriculture was predictive of greater Anopheles spp. abundance, even after controlling for urbanicity, number of nets per person, number of under-5-year olds, years of education, and season. This study revealed how small-scale agriculture along a rural-to-urban transition was associated with An. arabiensis and An. funestus indoor abundances, and that indoor Anopheles density can be high within Blantyre city limits, particularly where agriculture is present. Typical rural areas with lower house

  12. PERANAN Anopheles barbirostris VANDER WULP SEBAGAI PENULAR PENYAKIT

    Hasan Boesri

    2012-10-01

    Full Text Available An. barbirostris is one of mosquito of the genus Anopheles and was classified as 23-57 old days. It can be found at rice fields and swamps at an altitude of 2770 meters above sea level. The most preferred habitat is fresh water and pH 6-7. It is anthropolophilic and endophilic. This species in some areas, especially in East Nusa Tenggara role in transmitting malaria and filariasis.   Key words: An. barbirostris

  13. CONTROL DEMONSTRATION OF THE RICEFIELD BREEDING MOSQUITO ANOPHELES ACONITUS DONITZ IN CENTRAL JAVA, USING POECILIA RETICULATA THROUGH COMMUNITY PARTICIPATION: 2. CULTURING, DISTRIBUTION AND USE OF FISH IN THE FIELD

    Sustriayu Nalim

    2012-09-01

    Full Text Available Suatu percobaan pemberantasan vektor malaria Anopheles aconitus dengan penyebaran ikan pema­kan jentik Poecilia reticulata di sawah telah dilakukan. Untuk memacu peran serta petani, penyebaran ikan P. reticulata dilakukan bersamaan dengan minapadi di mana ikan Cyprinus carpio dipelihara di sawah. Beberapa aspek yang diteliti dalam percobaan ini adalah (1 biologi jentik An. aconitus dan ikan dan (2 cara-cara berkembangbiaknya ikan. Penelitian ini menunjukkan bahwa penyebaran An. aconitus di sawah pada umumnya 1/2 — 1 meter dari tepi pematang sawah, daya makan ikan P. reticulata rata rata adalah 119,4 jentik/hari, daya reproduksi rata-rata ikan P. reticulata adalah 109,3 ikan/bulan, daya produksi ikan C. carpio berkisar antara 5000 — 10.000 telur/3 bulan tergantung pada umur ikan betina. Kepadatan ikan P. reticulata 2 ikan/m2 dapat menanggulangi populasi jentik di sawah.

  14. Filarial worms reduce Plasmodium infectivity in mosquitoes.

    Matthew T Aliota

    2011-02-01

    Full Text Available Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG. Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness.Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections.These results could have an

  15. Larval diet affects mosquito development and permissiveness to Plasmodium infection

    Gendrin, MEM; Christophides; Linenberg, Inbar

    2016-01-01

    The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii . We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clar...

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

    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.

  17. Taxonomy Icon Data: Anopheles stephensi [Taxonomy Icon

    Full Text Available Anopheles stephensi Anopheles stephensi Arthropoda Anopheles_stephensi_L.png Anopheles_stephen...si_NL.png Anopheles_stephensi_S.png Anopheles_stephensi_NS.png http://biosciencedbc.jp/taxonomy_i...con/icon.cgi?i=Anopheles+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 ...

  18. The Brazilian Malaria Vector Anopheles (Kerteszia) Cruzii: Life Stages and Biology (Diptera: Culicidae)

    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. Repellent activity of the creams formulated from Annona senegalensis and Boswellia dalzielii leaf fractions and essential oils against Anopheles gambiae (Diptera: Culicidae

    Lame Younoussa

    2016-12-01

    Full Text Available Objective: To investigate the repellent efficacy of the creams formulated from methanol extract and n-hexane, chloroform, ethyl acetate and methanol fractions as well as essential oils of Annona senegalensis (A. senegalensis and Boswellia dalzielii (B. dalzielii leaves against the malarial vector Anopheles gambiae (An. gambiae in the laboratory. Methods: The efficacies of 25% w/w active ingredient creams formulated from the plant-based products were tested. Different concentrations of the creams, ranging from 2.0 to 12.0 mg/ cm²were applied on the exposed dorsal hand area (25 cm2 of volunteers. The treated hands were submitted to 50 caged blood-starved females of An. gambiae for 3 min after every 30 min until 180 min. Results: Total protection of up to 120 and 60 min without bites of An. gambiae were recorded with n-hexane creams applied at 12 mg/cm2 respectively for A. senegalensis and B. dalzielii. The essential oil creams of the two tested plants applied at 6 mg/cm2 protected volunteers up to 120 min without mosquito bites. The commercial Odomos cream (12% N,N-diethyl- 3-methylbenzamide tested as the positive control at 6 mg/cm2 protected volunteers from mosquito bites up to180 min. Conclusions: These results suggest that the cream formulated from the n-hexane fraction of A. senegalensis and essential oil creams of A. senegalensis and B. dalzielii leaves have the potential of a natural herbal source for the development of new, safe and eco-friendly repellent products to prevent An. gambiae bites.

  20. [New concepts in hyperactive malarial splenomegaly].

    Moraes, M F; Soares, M; Arroz, M J; Do Rosário, V E; Da Graça, J Pimenta; Abecasis, P

    2003-01-01

    Hyperreactive malarial splenomegaly is thought to represent an immunological dysfunction due to recurrent episodes of malaria. The authors present a case of hyperreactive malarial splenomegaly in a patient from São Tomé e Príncipe and discuss aspects of its differential diagnosis and treatment. A revision is made of recent concepts related to its pathogenesis and relationship with lymphoproliferative disorders. Malarial DNA was found in the absence of parasite forms in the peripheral blood. This may indicate that latent infection plays a role in its pathogenesis.

  1. Comparison of transmission parameters between Anopheles argyritarsis and Anopheles pseudopunctipennis in two ecologically different localities of Bolivia.

    Lardeux, Frédéric; Aliaga, Claudia; Tejerina, Rosenka; Torrez, Libia

    2013-08-13

    Anopheles (Anopheles) pseudopunctipennis is a recognized malaria vector in the slopes of the Andes of Bolivia. There, other species might be involved in malaria transmission and one candidate could be Anopheles argyritarsis. Although it is generally admitted that this species is not a malaria vector in the neotropical region, its potential role in transmission is still controversial and this situation has to be cleared, at least for Bolivia. Comparing the vectorial efficiency of An. pseudopunctipennis with that of An. argyritarsis could solve the question. The two species were sampled throughout Bolivia to estimate their degree of co-existence in their distribution range. Vectorial efficiencies of the two species were compared in two ecologically different localities where the species were sympatric by analysing their vectorial capacities and components (i e, human biting rates, human biting index, survival, durations of the gonotrophic cycle and extrinsic cycle), and the entomological inoculation rates (EIR). Mosquitoes were sampled monthly during more than one year in the two localities. A monthly sample consisted in hourly captures in four houses (inside and outside) in each locality, during four consecutive nights. Climatic variables (temperature, humidity, potential evapo-transpiration and precipitations) were recorded to better understand variability in the entomological parameters. Relationships were analysed using multivariate methods. Anopheles pseudopunctipennis and An. argyritarsis are "altitude" species, sharing the same geographical distribution range in the Andes of Bolivia. No Plasmodium parasite was identified in An. argyritarsis and estimates of the vectorial capacity indicated that it is not a malaria vector in the two studied localities, unlike An. pseudopunctipennis which showed positive EIRs. This latter species, although not a very good malaria vector, exhibited better life traits values and better behavioural characteristics in favour of

  2. Evaluation of Methods for Sampling the Malaria Vector Anopheles darlingi (Diptera, Culicidae) in Suriname and the Relation With Its Biting Behavior

    Hiwat-van Laar, H.; Rijk, de M.; Andriessen, R.; Koenraadt, C.J.M.; Takken, W.

    2011-01-01

    The effectiveness of CO2-baited and human-baited mosquito traps for the sampling of Anopheles darlingi Root was evaluated and compared with human landing collections in Suriname. Biting preferences of this mosquito on a human host were studied and related to trapping data. Traps used were the

  3. Trial of spatial repellency of metofluthrin-impregnated paper strip against Anopheles and Culex in shelters without walls in Lombok, Indonesia.

    Kawada, Hitoshi; Maekawa, Yoshihide; Tsuda, Yoshio; Takagi, Masahiro

    2004-12-01

    Trials of metofluthrin-impregnated multilayer paper strips against mosquitoes in shelters with no walls were carried out at 3 sites in Lombok, Indonesia. Major reductions in human biting by Culex quinquefasciatus, Anopheles balabacensis, and An. sundaicus were achieved. The device is a very practical measure of preventing outdoor mosquito biting, with no need for electricity or heating to evaporate its active ingredient.

  4. Role of Anopheles (Kerteszia bellator as malaria vector in Southeastern Brazil (Diptera: Culicidae

    Oswaldo Paulo Forattini

    1999-11-01

    Full Text Available New research concerning Anopheles bellator in the southeast of the State of São Paulo, Brazil, are reported. Adult females of this mosquito showed remarkable endophily and endophagy which was even greater than An. cruzii. The epidemiological role of this anopheline as a malaria vector is discussed.

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

    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

  6. Cryptic species Anopheles daciae (Diptera: Culicidae) found in the Czech Republic and Slovakia

    Blažejová, Hana; Šebesta, Oldřich; Rettich, F.; Mendel, Jan; Čabanová, V.; Miterpáková, M.; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk; Kampen, H.; Rudolf, Ivo

    2018-01-01

    Roč. 117, č. 1 (2018), s. 315-321 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GA16-20054S Institutional support: RVO:68081766 Keywords : Anophelinae * Maculipennis complex * Anopheles daciae * Mosquitoes * Cryptic species * Vector-borne diseases Subject RIV: EG - Zoology Impact factor: 2.329, year: 2016

  7. Effects of fungal infection on feeding and survival of Anopheles gambiae (Diptera: Culicidae) on plant sugars

    Ondiaka, S.N.; Masinde, E.W.; Koenraadt, C.J.M.; Takken, W.; Mukabana, W.R.

    2015-01-01

    Background The entomopathogenic fungus Metarhizium anisopliae shows great promise for the control of adult malaria vectors. A promising strategy for infection of mosquitoes is supplying the fungus at plant feeding sites. Methods We evaluated the survival of fungus-exposed Anopheles gambiae

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

    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

  9. Chloroquine mediated modulation of Anopheles gambiae gene expression.

    Patrícia Abrantes

    2008-07-01

    Full Text Available 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.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.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.

  10. Wolbachia-a foe for mosquitoes

    Nadipinayakanahalli Munikrishnappa Guruprasad

    2014-02-01

    Full Text Available Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

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

    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.

  12. Towards the genetic manipulation of mosquito disease vectors

    Crampton, J.M.; Lycett, G.J.; Warren, A.

    1998-01-01

    Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author)

  13. Towards the genetic manipulation of mosquito disease vectors

    Crampton, J M; Lycett, G J; Warren, A [Division of Molecular Biology and Immunology, Liverpool School of Tropical Medicine, Liverpool (United Kingdom)

    1998-01-01

    Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author). 41 refs, 2 figs.

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

    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.

  15. [Mosquitos of peri and extradomiciliary environments in the southern region of Brazil].

    Teodoro, U; Guilherme, A L; Lozovei, A L; La Salvia Filho, V; Sampaio, A A; Spinosa, R P; Ferreira, M E; Barbosa, O C; de Lima, E M

    1994-04-01

    Mosquitoes were collected on Sonho Real farm, Querência do Norte county, Paraná State, Brazil, using human bait and Falcão traps between June 1989 and May 1990. The fauna composition, monthly density, hours of major density, human attraction and presence of mosquitoes in domestic animal shelters were investigated. 5,923 mosquitoes of the genera Aedes, Aedomyia, Anopheles, Coquillettidea, Culex, Mansonia, Psorophora, Sabethes and Uranotaenia were collected. 33 species of mosquitoes were identified and among them Aedes scapularis, Anopheles albitarsis, Aedomyia squamipennis, Coquillettidea lynchi, Mansonia titillans e Coquillettidea venezuelensis were predominant. All these species were captured mainly on human bait, except Aedomyia squamipennis that was captured in domestic animal shelters. With regard to all the mosquitoes captured (5,923), their major period of activity was between 18 and 19 hours and April was the month of greatest density.

  16. [Mosquito complex (Diptera, Culicidae) in a West Nile fever focus in the Volgograd Region. II. Host-feeding patterns of mosquitoes in different habitats].

    Platonova, O V; Fedorova, M V; Lopatina, Iu V; Bezzhonova, O V; Bulgakova, T V; Platonov, A E

    2007-01-01

    Host preference of the mosquitoes collected in the urban and rural habitats of Volgograd and its suburbs was studied by the precipitation reaction test. Human and avian blood was detected in Cx. pipiens, Cx. modestus, Ae. vexans, Ae. behningi, Ae. caspius, Ae. sticticus, and females of the Anopheles maculipennis. The proportion of the mosquitoes fed on birds was similar in the urban and rural biotopes whereas that of the mosquitoes feeding on humans was significantly higher in Volgograd than in its environs. The increase in the number of human blood-fed mosquitoes in the city resulted mainly from the females collected in its multi-storied buildings.

  17. Thermal behaviour of Anopheles stephensi in response to infection with malaria and fungal entomopathogens

    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.

  18. Using green fluorescent malaria parasites to screen for permissive vector mosquitoes

    Martin Beatrice

    2006-03-01

    Full Text Available Abstract Background The Plasmodium species that infect rodents, particularly Plasmodium berghei and Plasmodium yoelii, are useful to investigate host-parasite interactions. The mosquito species that act as vectors of human plasmodia in South East Asia, Africa and South America show different susceptibilities to infection by rodent Plasmodium species. P. berghei and P. yoelii infect both Anopheles gambiae and Anopheles stephensi, which are found mainly in Africa and Asia, respectively. However, it was reported that P. yoelii can infect the South American mosquito, Anopheles albimanus, while P. berghei cannot. Methods P. berghei lines that express the green fluorescent protein were used to screen for mosquitoes that are susceptible to infection by P. berghei. Live mosquitoes were examined and screened for the presence of a fluorescent signal in the abdomen. Infected mosquitoes were then examined by time-lapse microscopy to reveal the dynamic behaviour of sporozoites in haemolymph and extracted salivary glands. Results A single fluorescent oocyst can be detected in live mosquitoes and P. berghei can infect A. albimanus. As in other mosquitoes, P. berghei sporozoites can float through the haemolymph and invade A. albimanus salivary glands and they are infectious in mice after subcutaneous injection. Conclusion Fluorescent Plasmodium parasites can be used to rapidly screen susceptible mosquitoes. These results open the way to develop a laboratory model in countries where importation of A. gambiae and A. stephensi is not allowed.

  19. (AIT) AGAINST ANOPHELES GAMBIAE

    USER

    These extracts were tested for repellence against Anopheles gambiae using the human-bait technique ... Synthetic chemicals and insecticides used for control of vectors are causing ... basil, for use as topical repellents against both diurnal and nocturnal .... The physical properties of Euphorbia balsamifera. (Table 1) reveal ...

  20. Evaluation of Insecticides Susceptibility and Malaria Vector Potential of Anopheles annularis s.l. and Anopheles vagus in Assam, India.

    Sunil Dhiman

    Full Text Available During the recent past, development of DDT resistance and reduction to pyrethroid susceptibility among the malaria vectors has posed a serious challenge in many Southeast Asian countries including India. Current study presents the insecticide susceptibility and knock-down data of field collected Anopheles annularis sensu lato and An. vagus mosquito species from endemic areas of Assam in northeast India. Anopheles annularis s.l. and An. vagus adult females were collected from four randomly selected sentinel sites in Orang primary health centre (OPHC and Balipara primary health centre (BPHC areas, and used for testing susceptibility to DDT, malathion, deltamethrin and lambda-cyhalothrin. After insecticide susceptibility tests, mosquitoes were subjected to VectorTest™ assay kits to detect the presence of malaria sporozoite in the mosquitoes. An. annularis s.l. was completely susceptible to deltamethrin, lambda-cyhalothrin and malathion in both the study areas. An. vagus was highly susceptible to deltamethrin in both the areas, but exhibited reduced susceptibility to lambda-cyhalothrin in BPHC. Both the species were resistant to DDT and showed very high KDT50 and KDT99 values for DDT. Probit model used to calculate the KDT50 and KDT99 values did not display normal distribution of percent knock-down with time for malathion in both the mosquito species in OPHC (p<0.05 and An. vagus in BPHC (χ2 = 25.3; p = 0.0, and also for deltamethrin to An. vagus in BPHC area (χ2 = 15.4; p = 0.004. Minimum infection rate (MIR of Plasmodium sporozoite for An. vagus was 0.56 in OPHC and 0.13 in BPHC, while for An. annularis MIR was found to be 0.22 in OPHC. Resistance management strategies should be identified to delay the expansion of resistance. Testing of field caught Anopheles vectors from different endemic areas for the presence of malaria sporozoite may be useful to ensure their role in malaria transmission.

  1. Mosquito Bites

    ... weeks. Some female mosquitoes can hibernate in the winter, and they can live for months. What health ... gutters, buckets, pool covers, pet water dishes, discarded tires, or birdbaths. If you plan to travel, get ...

  2. Urbanization impact on mosquito community and the transmission potential of filarial infection in central Europe

    Čabanová, V.; Miterpáková, M.; Valentová, D.; Blažejová, Hana; Rudolf, Ivo; Stloukal, E.; Hurníková, Z.; Dzidová, M.

    2018-01-01

    Roč. 11, č. 1 (2018), č. článku 261. ISSN 1756-3305 Institutional support: RVO:68081766 Keywords : Culex pipiens complex * West Nile virus * Diptera Culicidae * Anopheles hyrcanus * Dirofilaria immitis * Aedes albopictus * endemic area * 1st record * Slovakia * vector * Dirofilaria * mosquito-borne diseases * Anopheles maculipennis complex * xenomonitoring Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.080, year: 2016

  3. Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi

    Spence Philip J

    2012-12-01

    Full Text Available Abstract Background Serial blood passage of Plasmodium increases virulence, whilst mosquito transmission inherently regulates parasite virulence within the mammalian host. It is, therefore, imperative that all aspects of experimental malaria research are studied in the context of the complete Plasmodium life cycle. Methods Plasmodium chabaudi chabaudi displays many characteristics associated with human Plasmodium infection of natural mosquito vectors and the mammalian host, and thus provides a unique opportunity to study the pathogenesis of malaria in a single infection setting. An optimized protocol that permits efficient and reproducible vector transmission of P. c. chabaudi via Anopheles stephensi was developed. Results and conclusions This protocol was utilized for mosquito transmission of genetically distinct P. c. chabaudi isolates, highlighting differential parasite virulence within the mosquito vector and the spectrum of host susceptibility to infection initiated via the natural route, mosquito bite. An apposite experimental system in which to delineate the pathogenesis of malaria is described in detail.

  4. Mosquito abundance, bed net coverage and other factors associated with variations in sporozoite infectivity rates in four villages of rural Tanzania

    Kweka, Eliningaya J; Nkya, Watoky M M; Mahande, Aneth M

    2008-01-01

    . Sporozoite infectivity rates, mosquito host blood meal source, bed net coverage and mosquito abundance were assessed in this study. METHODOLOGY: A longitudinal survey was conducted in four villages in two regions of Tanzania. Malaria vectors were sampled using the CDC light trap and pyrethrum spray catch...... methods. In each village, ten paired houses were selected for mosquitoes sampling. Sampling was done in fortnight case and study was undertaken for six months in both Kilimanjaro (Northern Tanzania) and Dodoma (Central Tanzania) regions. RESULTS: A total of 6,883 mosquitoes were collected including: 5......,628 (81.8%) Anopheles arabiensis, 1,100 (15.9%) Culex quinquefasciatus, 89 (1.4%) Anopheles funestus, and 66 (0.9%) Anopheles gambiae s.s. Of the total mosquitoes collected 3,861 were captured by CDC light trap and 3,022 by the pyrethrum spray catch method. The overall light trap: spray catch ratio was 1...

  5. Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

    Ohba, S Y; Matsuo, T; Takagi, M

    2013-03-01

    Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

  6. Cryptic species Anopheles daciae (Diptera: Culicidae) found in the Czech Republic and Slovakia.

    Blažejová, Hana; Šebesta, Oldřich; Rettich, František; Mendel, Jan; Čabanová, Viktória; Miterpáková, Martina; Betášová, Lenka; Peško, Juraj; Hubálek, Zdeněk; Kampen, Helge; Rudolf, Ivo

    2018-01-01

    We report the distribution of mosquitoes of the maculipennis complex in two distinct areas of the Czech Republic (Bohemia and South Moravia) and in one locality of neighbouring Slovakia with emphasis on the detection of the newly described cryptic species Anopheles daciae (Linton, Nicolescu & Harbach, 2004). A total of 691 mosquitoes were analysed using a species-specific multiplex PCR assay to differentiate between the members of the maculipennis complex. In the Czech Republic, we found Anopheles maculipennis (with a prevalence rate of 1.4%), Anopheles messeae (49.0%) and Anopheles daciae (49.6%). In Slovakia, only An. messeae (52.1%) and An. daciae (47.9%) were detected. In this study, An. daciae was documented for the first time in the two countries where it represented a markedly higher proportion of maculipennis complex species (with an overall prevalence almost reaching 50%) in comparison to previous reports from Germany, Romania and Poland. The determination of the differential distribution of maculipennis complex species will contribute to assessing risks of mosquito-borne diseases such as malaria or dirofilariasis.

  7. Trial of spatial repellency of metofluthrin impregnated paper strip against Anopheles and Culex in shelters without walls in Lombok, Indonesia

    Kawada, Hitoshi; Maekawa, Yoshihide; Tsuda, Yoshio; Takagi, Masahiro

    2004-01-01

    TriaIs of metofluthrin-impregnated multilayer paper strips against mosquitoes in shelters with no walls were carried out at 3 sites in Lombok, Indonesia. Major reductions in human biting by Culex quinquefasciatus,Anopheles balabacensis, and An. sundaicus were achieved. The device is a very praitical measure of preventing outdoor mosquito biting, with no need for electricity or heating to evaporate its active ingredient.

  8. Disrupting Mosquito Reproduction and Parasite Development for Malaria Control.

    Lauren M Childs

    2016-12-01

    Full Text Available The control of mosquito populations with insecticide treated bed nets and indoor residual sprays remains the cornerstone of malaria reduction and elimination programs. In light of widespread insecticide resistance in mosquitoes, however, alternative strategies for reducing transmission by the mosquito vector are urgently needed, including the identification of safe compounds that affect vectorial capacity via mechanisms that differ from fast-acting insecticides. Here, we show that compounds targeting steroid hormone signaling disrupt multiple biological processes that are key to the ability of mosquitoes to transmit malaria. When an agonist of the steroid hormone 20-hydroxyecdysone (20E is applied to Anopheles gambiae females, which are the dominant malaria mosquito vector in Sub Saharan Africa, it substantially shortens lifespan, prevents insemination and egg production, and significantly blocks Plasmodium falciparum development, three components that are crucial to malaria transmission. Modeling the impact of these effects on Anopheles population dynamics and Plasmodium transmission predicts that disrupting steroid hormone signaling using 20E agonists would affect malaria transmission to a similar extent as insecticides. Manipulating 20E pathways therefore provides a powerful new approach to tackle malaria transmission by the mosquito vector, particularly in areas affected by the spread of insecticide resistance.

  9. Filling the gap 115 years after Ronald Ross: the distribution of the Anopheles coluzzii and Anopheles gambiae s.s from Freetown and Monrovia, West Africa.

    Dziedzom K de Souza

    Full Text Available It was in Freetown, Sierra Leone, that the malaria mosquito Anopheles coastalis, now known as Anopheles gambiae, was first discovered as the vector of malaria, in 1899. That discovery led to a pioneering vector research in Sierra Leone and neighbouring Liberia, where mosquito species were extensively characterized. Unfortunately, the decade long civil conflicts of the 1990s, in both countries, resulted in a stagnation of the once vibrant research on disease vectors. This paper attempts to fill in some of the gaps on what is now known of the distribution of the sibling species of the An. gambiae complex, and especially the An. coluzzii and An. gambiae s.s, formerly known as the An. gambiae molecular M and S forms respectively, in the cities of Freetown and Monrovia.

  10. Transposable elements in the Anopheles funestus transcriptome.

    Fernández-Medina, Rita D; Carareto, Claudia M A; Struchiner, Cláudio J; Ribeiro, José M C

    2017-06-01

    Transposable elements (TEs) are present in most of the eukaryotic genomes and their impact on genome evolution is increasingly recognized. Although there is extensive information on the TEs present in several eukaryotic genomes, less is known about the expression of these elements at the transcriptome level. Here we present a detailed analysis regarding the expression of TEs in Anopheles funestus, the second most important vector of human malaria in Africa. Several transcriptionally active TE families belonging both to Class I and II were identified and characterized. Interestingly, we have identified a full-length putative active element (including the presence of full length TIRs in the genomic sequence) belonging to the hAT superfamily, which presents active members in other insect genomes. This work contributes to a comprehensive understanding of the landscape of transposable elements in A. funestus transcriptome. Our results reveal that TEs are abundant and diverse in the mosquito and that most of the TE families found in the genome are represented in the mosquito transcriptome, a fact that could indicate activity of these elements.The vast diversity of TEs expressed in A. funestus suggests that there is ongoing amplification of several families in this organism.

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

    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.

  12. Ability of TEP1 in intestinal flora to modulate natural resistance of Anopheles dirus.

    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Poisoning by anti-malarial drugs

    had taken chloroquine: no other anti-malarial drugs were involved [1]. ... and angio-oedema have been described. Itching without a ... 15mg/L the risk of permanent visual damage and cardiac dysrhythmias is ... to use an alternative method.

  14. G protein-coupled receptors in Anopheles gambiae.

    Hill, Catherine A; Fox, A Nicole; Pitts, R Jason; Kent, Lauren B; Tan, Perciliz L; Chrystal, Mathew A; Cravchik, Anibal; Collins, Frank H; Robertson, Hugh M; Zwiebel, Laurence J

    2002-10-04

    We used bioinformatic approaches to identify a total of 276 G protein-coupled receptors (GPCRs) from the Anopheles gambiae genome. These include GPCRs that are likely to play roles in pathways affecting almost every aspect of the mosquito's life cycle. Seventy-nine candidate odorant receptors were characterized for tissue expression and, along with 76 putative gustatory receptors, for their molecular evolution relative to Drosophila melanogaster. Examples of lineage-specific gene expansions were observed as well as a single instance of unusually high sequence conservation.

  15. Malaria in Suriname: a new era : impact of modified intervention strategies on Anopheles darlingi populations and malaria incidence

    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

  16. Mitochondrial genomes of Anopheles arabiensis, An.gambiae and An.coluzzii show no clear species division

    Here we report the complete mitochondrial sequences of 70 individual field collected mosquito specimens from throughout Sub-Saharan Africa. We generated this dataset to identify species specific markers for the following Anopheles species and chromosomal forms: An.arabiensis, An.coluzzii (The Forest...

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

    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.

  18. Discovery of antimicrobial lipodepsipeptides produced by a Serratia sp. within mosquito microbiomes.

    Ganley, Jack; Carr, Gavin; Ioerger, Thomas; Sacchettini, James; Clardy, Jon; Derbyshire, Emily

    2018-04-26

    The Anopheles mosquito that harbors the Plasmodium parasite contains a microbiota that can influence both the vector and parasite. In recent years, insect-associated microbes have highlighted the untapped potential of exploiting interspecies interactions to discover bioactive compounds. In this study, we report the discovery of nonribosomal lipodepsipeptides that are produced by a Serratia sp. within the midgut and salivary glands of A. stephensi mosquitoes. The lipodepsipeptides, stephensiolides A-K, have antibiotic activity and facilitate bacterial surface motility. Bioinformatic analyses indicate that the stephensiolides are ubiquitous in nature and are likely important for Serratia spp. colonization within mosquitoes, humans, and other ecological niches. Our results demonstrate the usefulness of probing insect-microbiome interactions, enhance our understanding of the chemical ecology within Anopheles mosquitoes, and provide a secondary metabolite scaffold to further investigate this complex relationship. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Anopheles Midgut Epithelium Evades Human Complement Activity by Capturing Factor H from the Blood Meal

    Khattab, Ayman; Barroso, Marta; Miettinen, Tiera; Meri, Seppo

    2015-01-01

    Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood. PMID:25679788

  20. Anopheles midgut epithelium evades human complement activity by capturing factor H from the blood meal.

    Ayman Khattab

    2015-02-01

    Full Text Available Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood.

  1. Mosquitoes of the rice agroecosystem of Malaysia: species composition and their abundance in relation to rice farming

    Abu Hassan Ahmad; Che Salmah Md Rawi

    2002-01-01

    Mosquito abundance in relation to rice farming was studied in the Muda and the Kerian Irrigation Schemes. Mosquito larvae were collected using dippers for several growing seasons. Adult mosquitoes were collected by using human bait and cow bait and net trap at nights. Culex, Mansonia and Anopheles were the three genera of mosquito found in the rice agroecosystem. Four species of Mansonia were found biting on human bait. Culex mosquitoes were caught biting on human and cow baits. Culex tritaeniorhynchus, C pseudovishnui, C vishnui, C gelidus and C bitaeniorhynchus were the most common Culex mosquitoes found. Anoheles sinensis and A. peditaeniatus were the most dominant panopheline mosquitoes. High abundance of larvae and adult mosquitoes were observed during ploughing, planting, and tillering stages of rice farming. (Author)

  2. MosqTent: An individual portable protective double-chamber mosquito trap for anthropophilic mosquitoes.

    José Bento Pereira Lima

    2017-03-01

    Full Text Available Here, we describe the development of the MosqTent, an innovative double-chamber mosquito trap in which a human being attracts mosquitoes while is protected from being bitten within the inner chamber of the trap, while mosquitoes are lured to enter an outer chamber where they are trapped. The MosqTent previously collected an average of 3,000 anophelines/man-hour compared to 240 anophelines/man-hour for the human landing catch (HLC, thereby providing high numbers of human host-seeking mosquitoes while protecting the collector from mosquito bites. The MosqTent performed well by collecting a high number of specimens of Anopheles marajoara, a local vector and anthropophilic mosquito species present in high density, but not so well in collecting An. darlingi, an anthropophilic mosquito species considered the main vector in Brazil but is present in low-density conditions in the area. The HLC showed a higher efficiency in collecting An. darlingi in these low-density conditions. The MosqTent is light (<1 kg, portable (comes as a bag with two handles, flexible (can be used with other attractants, adaptable (can be deployed in a variety of environmental settings and weather conditions, and it can be used in the intra-, peri-, and in the extradomicile. Also, the MosqTent collected similar portions of parous females and anthropophilic mosquito species and collects specimens suitable for downstream analysis. Further developments may include testing for other fabric colors, different mesh sizes and dimensions for other hematophagous insects and conditions, additional chemical mosquito attractants, and even the replacement of the human attractant in favor of other attractants. MosqTent modifications that would allow the trap to be applied as a vector control tool with killing action could also be explored.

  3. Does polyandrous impede mosquito control by autocidal?

    K.Jayaprakash

    2014-03-01

    Full Text Available Vector mosquito control by releasing genetically altered males has been attempted under the presumption that the females are monandrous. The present observation was through the sex–linked inheritance pattern of eye-colour and the estimation of polyandrous in in-vitro mating. A small proportion (18.2% of the female Anopheles stephensi population exhibited polyandrous on examination of 850 F1 adults when two types of males (white and black eyed where allowed to mate with homozygous white eyed females. The above results were discussed with relation to the consequences of the polyandrous trait in sterile insect technique, genetic control programmes.

  4. [The mosquito fauna (Diptera: Culicidae) of the environs of the Sayan-Shushenskoe hydroelectric power station].

    Gornostaeva, R M

    1999-01-01

    Among females and larvae of mosquitoes collected in 1969, 1981-1984 in the area of the Sayan-Shushenskoe hydroelectric power station (140 km up the Yenisei River from the Abakan city) 5 genera and 30 species were recorded. Based on recent collections and reference data (Gornostaeva e. a., 1969; Gornostaeva, Danilov, 1986) the fauna of the region in question includes 31 species of mosquitoes (Anopheles--1, Culiseta--2, Coquillettidia--1, Aedes--22, Culex--5).

  5. Repellent Activity of TRIG (N-N Diethyl Benzamide) against Man-Biting Mosquitoes

    Msangi, Shandala; Kweka, Eliningaya; Mahande, Aneth

    2018-01-01

    A study was conducted to assess efficacy of a new repellent brand TRIG (15% N-N Diethyl Benzamide) when compared to DEET (20% N-N Methyl Toluamide). The repellents were tested in laboratory and field. In the laboratory, the repellence was tested on human volunteers, by exposing their repellent-treated arms on starved mosquitoes in cages for 3 minutes at hourly intervals, while counting the landing and probing attempts. Anopheles gambiae and Aedes aegypti mosquitoes were used. Field evaluation...

  6. Mosquito has a single multisubstrate deoxyribonucleoside kinase characterized by unique substrate specificity

    Knecht, Wolfgang; Petersen, G.E.; Sandrini, Michael

    2003-01-01

    In mammals four deoxyribonucleoside kinases, with a relatively restricted specificity, catalyze the phosphorylation of the four natural deoxyribonucleosides. When cultured mosquito cells, originating from the malaria vector Anopheles gambiae, were examined for deoxyribonucleoside kinase activities......, only a single enzyme was isolated. Subsequently, the corresponding gene was cloned and over-expressed. While the mosquito kinase (Ag-dNK) phosphorylated all four natural deoxyribonucleosides, it displayed an unexpectedly higher relative efficiency for the phosphorylation of purine versus pyrimidine...

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

    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

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

    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

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

    Chang, Mei-Chun; Teng, Hwa-Jen; Chen, Chen-Fu; Chen, Yung-Chen; Jeng, Chian-Ren

    2008-06-09

    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. 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. 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%). 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 insecticides for Anopheles at night, as well as residual spray inside

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

    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.

  11. Mosquito (Diptera: Culicidae) fauna in an area endemic for West Nile virus

    Šebesta, Oldřich; Halouzka, Jiří; Hubálek, Zdeněk; Juřicová, Zina; Rudolf, Ivo; Šikutová, Silvie; Svobodová, Petra; Reiter, P.

    2010-01-01

    Roč. 35, č. 1 (2010), s. 156-162 ISSN 1081-1710 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : mosquito es * Anopheles * Aedes * Culex * climate * ecology Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.256, year: 2010

  12. The human malaria parasite Pfs47 gene mediates evasion of the mosquito immune system

    Molina-Cruz, A.; Garver, L.S.; Alabaster, A.; Bangiolo, L.; Haile, A.; Winikor, J.; Ortega, C.; Schaijk, B.C.L. van; Sauerwein, R.W.; Taylor-Salmon, E.; Barillas-Mury, C.

    2013-01-01

    Plasmodium falciparum transmission by Anopheles gambiae mosquitoes is remarkably efficient, resulting in a very high prevalence of human malaria infection in sub-Saharan Africa. A combination of genetic mapping, linkage group selection, and functional genomics was used to identify Pfs47 as a P.

  13. Host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes

    The adaptation of two distantly related microsporidia to their mosquito hosts was investigated. Edhazardia aedis is a specialist pathogen that infects Aedes aegypti, the main vector of dengue and yellow fever arboviruses. Vavraia culicis is a generalist pathogen of several insects including Anophele...

  14. Green Nanoparticles for Mosquito Control

    Namita Soni

    2014-01-01

    Full Text Available Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag and gold (Au nanoparticles (NPs were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum (C. zyelanicum or C. verum J. Presl. Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM. The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs. The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito.

  15. A simple and affordable membrane-feeding method for Aedes aegpyti and Anopheles minimus (Diptera: Culicidae).

    Finlayson, Catherine; Saingamsook, Jassada; Somboon, Pradya

    2015-12-01

    This study developed an artificial feeding (AF) method to replace direct host feeding (DHF) for the maintenance of Aedes aegypti and Anopheles minimus mosquito colonies. The procedure can be adopted by all laboratories due to its simple and affordable materials and design. The apparatus consists of heparinized cow blood contained in a 5cm diameter glass petri dish with 5cm(2) Parafilm M (Bemis(®)) stretched thinly over the top, with a pre-heated bag of vegetable oil placed underneath to keep the blood warm. Both parts are contained within an insulated Styrofoam™ box with a hole in the lid for mosquitoes to access the membrane. Mosquitoes are fed by AF for 15min at a time. Feeding rate and fecundity of Ae. aegypti mosquitoes feeding on the AF device were compared to those feeding on a live rat (DHF(r)), and of Anopheles minimus mosquitoes feeding on the AF device compared to those feeding on a human arm (DHF(h)). Aedes aegypti mosquitoes fed by AF or DHF(r) had similar feeding rates (38.2±21.5% and 35.7±18.2%, respectively) and overall egg production (1.5% difference). Anopheles minimus mosquitoes fed by the AF method had a lower feeding rate (52.0±1.0% for AF compared to 70.7±20.2% for DHF(h)) and overall egg production (40% reduction compared to DHF(h)). However, the number of eggs produced by AF-fed mosquitoes (1808 eggs per 100 mosquitoes) was still sufficient for colony maintenance, and with increased feeding time both parameters are expected to increase. Reduced feeding rate and overall egg production was observed when Ae. aegypti mosquitoes were fed on blood refrigerated for over two weeks. In conclusion, an AF device has been developed which can replace DHF for Ae. aegypti and An. minimus colony maintenance when using blood refrigerated for a maximum of two weeks. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Monthly prevalence and diversity of mosquitoes (Diptera: Culicidae in Fars Province, Southern Iran

    Davood Keshavarzi

    2017-02-01

    Full Text Available Objective: To get new data about the ecology of mosquitoes, which would be valuable to develop programs for future provision of mosquito controls in the study area. Methods: During April to September 2012, larvae of mosquitoes were collected from six counties in south of Fars Province using dipping method. Characteristics of larval breeding places were considered based on water conditions. Species diversity was examined in terms of alpha and beta measures, with the intent of comparing mosquito diversity according to the typology of regions. Results: During this investigation, totally, 5 057 larvae of mosquitoes belonging to 5 genera and 17 different mosquito species were recognized, namely, Anopheles dthali, Anopheles fluviatilis, Anopheles stephensi, Anopheles superpictus, Culex quinquefasciatus (Cx. quinquefasciatus, Culex mimeticus, Culex perexiguus, Culex pipiens (Cx. pipiens, Culex tritaeniorhynchus, Culex theileri (Cx. theileri, Culex tritaeniorhynchus, Culex sinaiticus, Culex torrentium, Culex modestus, Ochlerotatus caspius, Culiseta longiareolata and Aedes vexans (Ae. vexans. This is the first record of Ae. vexans, Culex perexiguus and Culex modestus in the Province. Cx. pipiens (27.3%, Cx. theileri (15.9% and Cx. quinquefasciatus (9.4% were the most abundant species found respectively. Cx. pipiens reached the highest density in August and July, while Cx. theileri, Cx. quinquefasciatus and Ae. vexans were found in high numbers in June. Diversity analysis indicated the highest species diversity in the Mohr County (Margalef index of 1.41 and Shannon index of 1.7 and the lowest species diversity in the Lamerd County (Margalef index of 0.33 and Shannon index of 0.38. Conclusions: Regarding to this research, there are some potential vectors of medical and veterinary importance in Fars Province. Results of the present study may serve as a basis for risk assessment of emerging mosquito-borne diseases.

  17. Radiation biology of mosquitoes

    Knols Bart GJ

    2009-11-01

    Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

  18. Seasonal abundance and blood feeding activity of Anopheles minimus Theobald (Diptera: Culicidae) in Thailand.

    Chareonviriyaphap, Theeraphap; Prabaripai, Atchariya; Bangs, Michael J; Aum-Aung, Boonserm

    2003-11-01

    Anopheline mosquito larvae and adults were sampled at Ban Pu Teuy, Tri-Yok District, Kanchanaburi Province, western Thailand, from January 2000 to December 2001. Over the period of 2 yr, Anopheles minimus sensu lato was the most commonly collected species, followed by Anopheles swadiwongporni and Anopheles dirus sensu lato; all three species are important vectors of malaria in Thailand. Attempted blood feeding by An. minimus occurred throughout the night, with two distinct feeding peaks: strong activity immediately after sunset (1800-2100 hours), followed by a second, less pronounced, rise before sunrise (0300-0600 hours). Anopheles minimus were more abundant during the wet season compared with the dry and hot seasons, although nocturnal adult feeding patterns were similar. Anopheles minimus fed readily on humans inside and outside of houses, showing a slight preference for exophagy. The human-biting peak of An. minimus in our study area differed from other localities sampled in Thailand, indicating the possible existence of site-specific populations of An. minimus exhibiting different host-seeking behavior. These results underscore the importance of conducting site-specific studies to accurately determine vector larval habitats and adult activity patterns and linking their importance in malaria transmission in a given area.

  19. Additional selection for insecticide resistance in urban malaria vectors: DDT resistance in Anopheles arabiensis from Bobo-Dioulasso, Burkina Faso.

    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.

  20. Malaria mosquitoes attracted by fatal fungus.

    Justin George

    Full Text Available Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors.

  1. Effective autodissemination of pyriproxyfen to breeding sites by the exophilic malaria vector Anopheles arabiensis in semi-field settings in Tanzania

    Lwetoijera, Dickson; Harris, Caroline; Kiware, Samson; Dongus, Stefan; Devine, Gregor J; McCall, Philip; Majambere, Silas

    2014-01-01

    BACKGROUND\\ud Malaria vector control strategies that target adult female mosquitoes are challenged by the emergence of insecticide resistance and behavioural resilience. Conventional larviciding is restricted by high operational costs and inadequate knowledge of mosquito-breeding habitats in rural settings that might be overcome by the juvenile hormone analogue, Pyriproxyfen (PPF). This study assessed the potential for Anopheles arabiensis to pick up and transfer lethal doses of PPF from cont...

  2. Novel acetylcholinesterase target site for malaria mosquito control.

    Yuan-Ping Pang

    2006-12-01

    Full Text Available Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae AChE (AgAChE reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  3. Controlling Mosquitoes Outside

    Mosquitoes can carry viruses, like West Nile, Zika, dengue, and chikungunya. In this podcast, Mr. Hubbard will teach you and his neighbor, Laura, ways to help reduce the number of mosquitoes outside your home. Tips include eliminating areas of standing water where mosquitoes lay eggs and using larvicides to kill young mosquitoes.

  4. Identification of Blood Meals from Potential Arbovirus Mosquito Vectors in the Peruvian Amazon Basin.

    Palermo, Pedro M; Aguilar, Patricia V; Sanchez, Juan F; Zorrilla, Víctor; Flores-Mendoza, Carmen; Huayanay, Anibal; Guevara, Carolina; Lescano, Andrés G; Halsey, Eric S

    2016-11-02

    The transmission dynamics of many arboviruses in the Amazon Basin region have not been fully elucidated, including the vectors and natural reservoir hosts. Identification of blood meal sources in field-caught mosquitoes could yield information for identifying potential arbovirus vertebrate hosts. We identified blood meal sources in 131 mosquitoes collected from areas endemic for arboviruses in the Peruvian Department of Loreto by sequencing polymerase chain reaction amplicons of the cytochrome b gene. Psorophora (Janthinosoma) albigenu, Psorophora (Grabhamia) cingulata, Mansonia humeralis, Anopheles oswaldoi s.l., and Anopheles benarrochi s.l. had mainly anthropophilic feeding preferences; Aedes (Ochlerotatus) serratus, and Aedes (Ochlerotatus) fulvus had feeding preferences for peridomestic animals; and Culex (Melanoconion) spp. fed on a variety of vertebrates, mainly rodents (spiny rats), birds, and amphibians. On the basis of these feeding preferences, many mosquitoes could be considered as potential enzootic and bridge arbovirus vectors in the Amazon Basin of Peru. © The American Society of Tropical Medicine and Hygiene.

  5. Different blood and sugar feeding regimes affect the productivity of Anopheles arabiensis colonies (Diptera: Culicidae).

    Damiens, D; Soliban, S M; Balestrino, F; Alsir, R; Vreysen, M J B; Gilles, J R L

    2013-03-01

    The success of the sterile insect technique for the management of mosquito populations depends on the release of large numbers of competitive sterile male insects. Sustainable mosquito production can only be obtained when proper mass-rearing equipment and adequate methods are available, including those to feed blood to the female mosquitoes. The blood feeding apparatus Hemotek consists of a small aluminum plate to which a collagen membrane is fixed and filled with blood kept warm by an electric heating element. A larger aluminum plate was developed to feed a larger number of female mosquitoes with blood that is kept at a constant temperature. The effect of different blood feeding regimes (feeding frequency and time the blood is kept in the Hemotek) and sugar deprivation before blood feeding on egg production of female Anopheles arabiensis Patton was tested. Egg production was higher when blood was offered to the mosquitoes every day as compared with every 2 or 4 d. Sugar deprivation for 7 h before blood feeding enhanced egg production by 50% compared with female mosquitoes that had continuous access to sugar. Neither male nor female survival was impaired. Finally, we showed that the same blood could be kept warm and used over several hours to feed mosquitoes in multiple cages without any impact on egg production or hatch rate. Being able to use the same blood over extended periods would save considerable time, handling, and funds.

  6. Melanotic pathology and vertical transmission of the gut commensal Elizabethkingia meningoseptica in the major malaria vector Anopheles gambiae.

    Idir G Akhouayri

    Full Text Available The resident gut flora is known to have significant impacts on the life history of the host organism. Endosymbiotic bacterial species in the Anopheles mosquito gut are potent modulators of sexual development of the malaria parasite, Plasmodium, and thus proposed as potential control agents of malaria transmission.Here we report a melanotic pathology in the major African malaria vector Anopheles gambiae, caused by the dominant mosquito endosymbiont Elizabethkingiameningoseptica. Transfer of melanised tissues into the haemolymph of healthy adult mosquitoes or direct haemolymph inoculation with isolated E. meningoseptica bacteria were the only means for transmission and de novo formation of melanotic lesions, specifically in the fat body tissues of recipient individuals. We show that E. meningoseptica can be vertically transmitted from eggs to larvae and that E. meningoseptica-mono-associated mosquitoes display significant mortality, which is further enhanced upon Plasmodium infection, suggesting a synergistic impact of E. meningoseptica and Plasmodium on mosquito survival.The high pathogenicity and permanent association of E. meningoseptica with An. Gambiae through vertical transmission constitute attractive characteristics towards the potential design of novel mosquito/malaria biocontrol strategies.

  7. Efficacy of Advanced Odomos repellent cream (N, N-diethyl-benzamide) against mosquito vectors.

    Mittal, P K; Sreehari, U; Razdan, R K; Dash, A P; Ansari, M A

    2011-04-01

    Repellents are commonly used personal protection measures to avoid mosquito bites. In the present study, Advanced Odomos cream (12% N, N-diethyl-benzamide) was tested for its efficacy against mosquitoes in comparison to DEET (N,N-diethyl-3-methyl benzamide). Bioassays were conducted to assess the repellency of Advanced Odomos and DEET creams against Anopheles stephensi and Aedes aegypti. Their efficacy was tested on human volunteers applied with different concentrations of test creams ranging from 1 to 12 mg/cm 2 and by exposing them to mosquitoes at hourly intervals. Field evaluation was also carried out to test the duration of protection of the test creams against Anopheles and Aedes mosquitoes during whole night and day time collections, respectively on human volunteers. Mosquito collections were done using torch light and aspirator. Complete (100%) protection was achieved at 10 mg/cm 2 cream formulation of Advanced Odomos (1.2 mg a.i/cm 2 ) dose against An. stephensi and 12 mg/cm 2 (1.44 mg a.i./cm 2 ) against Ae. aegypti on human baits. There was no statistically significant differences in per cent protection against mosquito bites between Advanced Odomos and DEET cream (P>0.05) in respective doses. Complete protection up to 11 h was observed against Anopheles mosquitoes during whole night collections and up to 6 h against Ae. aegypti in day time collections. No adverse reactions such as itching, irritation, vomiting, nausea, etc. were reported by the volunteers. Advanced Odomos cream applied at 10 mg/cm 2 concentration provided 100% protection from Anopheles mosquitoes up to 11 h whereas about 6 h protection was recorded against Ae. aegypti. The laboratory and field trials indicate that for longer protection against Anopheles mosquitoes 10 mg/cm 2 will be appropriate and in case of Ae. aegypti more than 10 mg/cm 2 application is required for complete protection. In conclusion, the Advanced Odomos cream was comparable to the known repellent cream DEET for

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

    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. Diversity of mosquitoes and larval breeding preference based on physico-chemical parameters in Western Ghats, Tamilnadu, India

    Periyasamy Senthamarai Selvan

    2015-06-01

    Full Text Available Objective: To study the diversity and distribution of mosquitoes in Western Ghats of Coimbatore and Nilgiris District, Tamilnadu, India. Methods: Random collections were carried out during August-2013 to July-2014 in cesspits, animal footprints, rock holes, tree holes, drainages at study areas of Marudhamalai, Valparai, Mettupalayam in Coimbatore District and Dhottapeta, Coonoor, Gudalur in Nilgiris District of Tamilnadu, India by using suction tube and kerosene pump. Mosquitoes were identified by standard entomological procedures. Results: A total of 1 018 mosquitoes (larvae and pupae were collected from all over the study areas comprising 6 genera and 23 species. They are, Culex mimulus, Culex pseudovishnui, Culex quinquefasciatus, Culex vishnui, Culex khazani, Culex uniformis, Heizmannia chandi, Heizmannia grenii, Heizmannia indica, Oclerotatus anureostriatus, Oclerotatus albotaeniatis, Oclerotatus deccanus, Oclerotatus gubernatoris, Aedes aegypti, Aedes albopictus, Aedes edwardsi, Aedes krombeini, Toxorhynchites minimus, Toxorhynchites splendens, Anopheles aitkenii, Anopheles barbirostris, Anopheles culiciformis and Anopheles maculatus. ShannonWeaver diversity index, Margalef’s index of richness and Simpsons dominance index was also studied. From 6 sites, the highest mosquitoes were collected from Marudhamalai (309 and the least mosquitoes were collected in Mettupalayam (68. The study determined whether physicochemical characteristics differ between habitats with high and low presence of mosquito larvae. Based on Margalef’s index of richness (Dmg, the highest values were present in Mettupalayam (5.214 study area and the lowest in Marudhamalai (3.837. It can be concluded from Shanon-Weaver index of diversity that, the highest values were present in Mettupalayam (2.947 and the least value were in Gudalur (2.410 during the study period. Conclusions: In areas with reservoirs of disease, mosquito abundance information can help to identify the

  10. Evaluation of two counterflow traps for testing behaviour-mediating compounds for the malaria vector Anopheles gambiae s.s. under semi-field conditions in Tanzania

    Schmied, W.H.; Takken, W.; Killeen, G.F.; Knols, B.G.J.; Smallegange, R.C.

    2008-01-01

    Background Evaluation of mosquito responses towards different trap-bait combinations in field trials is a time-consuming process that can be shortened by experiments in contained semi-field systems. Possible use of the BG Sentinel (BGS) trap to sample Anopheles gambiae s.s. was evaluated. The

  11. Change in Anopheles richness and composition in response to artificial flooding during the creation of the Jirau hydroelectric dam in Porto Velho, Brazil.

    Rodrigures, Moreno S; Batista, Elis P; Silva, Alexandre A; Costa, Fábio M; Neto, Verissimo A S; Gil, Luiz Herman S

    2017-02-22

    Anopheles mosquitoes are the only vectors of human malaria. Anopheles species use standing water as breeding sites. Human activities, like the creation of an artificial lake during the implementation of hydroelectric power plants, lead to changes in environmental characteristics and, therefore, may changes the species richness and composition of Anopheles mosquitoes. The aim of the present study was to verify whether or not there is an association between the artificial flooding resulting from the construction of the Jirau hydroelectric power plant, and the richness and composition of anophelines. Mosquitoes samples were obtained monthly from the Jirau hydroelectric power plant area located at Porto Velho, Rondônia State, using Human Landing Catch (06:00-10:00 PM). Mosquitoes collected were transported to Laboratório de Entomologia Médica FIOCRUZ-RO where they were identified until species using dichotomous key. A total of 6347 anophelines belonging to eight different species were collected. The anophelines species richness was significantly lower during the first flooding stage. Differences in anophelines species composition were found when comparing the first flooding stage with the other stages. Furthermore, the mean number of Anopheles darlingi, the main vector of malaria in the region, increases during the first and the third flooding stages. The continual monitoring of these vectors during the late operational phase may be useful in order to understand how anophelines will behave in this area.

  12. Spatial distribution and habitat characterisation of Anopheles larvae along the Kenyan coast.

    Mwangangi, Joseph M; Mbogo, Charles M; Muturi, Ephantus J; Nzovu, Joseph G; Githure, John I; Yan, Guiyun; Minakawa, Noboru; Novak, Robert; Beier, John C

    2007-03-01

    A study was conducted to characterise larval habitats and to determine spatial heterogeneity of the Anopheles mosquito larvae. The study was conducted from May to June 1999 in nine villages along the Kenyan coast. Aquatic habitats were sampled by use of standard dipping technique. The habitats were characterised based on size, pH, distance to the nearest house, coverage of canopy, surface debris, algae and emergent plants, turbidity, substrate, and habitat type. A total of 110 aquatic habitats like stream pools (n=10); puddles (n=65); tire tracks (n=5); ponds (n=5) and swamps (n=25) were sampled in nine villages located in three districts of the Kenyan coast. A total of 7,263 Anopheles mosquito larvae were collected, 63.9% were early instars and 36.1% were late instars. Morphological identification of the III and IV instar larvae by use of microscopy yielded 90.66% (n=2377) Anopheles gambiae Complex, 0.88% (n=23) An. funestus, An. coustani 7.63% (n=200), An. rivulorum 0.42% (n=11), An. pharoensis 0.19% (n=5), An. swahilicus 0.08% (n=2), An. wilsoni 0.04% (n=1) and 0.11% (n=3) were unidentified. A subset of the An. gambiae Complex larvae identified morphologically, was further analysed using rDNA-PCR technique resulting in 68.22% (n=1290) An. gambiae s.s., 7.93% (n=150) An. arabiensis and 23.85% (n=451) An. merus. Multiple logistic regression model showed that emergent plants (p = 0.019), and floating debris (p = 0.038) were the best predictors of An. gambiae larval abundance in these habitats. Habitat type, floating debris and emergent plants were found to be the key factors determining the presence of Anopheles larvae in the habitats. For effective larval control, the type of habitat should be considered and most productive habitat type be given a priority in the mosquito abatement programme.

  13. An Algal Diet Accelerates Larval Growth of Anopheles gambiae (Diptera: Culicidae) and Anopheles arabiensis (Diptera: Culicidae).

    Tuno, N; Kohzu, A; Tayasu, I; Nakayama, T; Githeko, A; Yan, G

    2018-01-21

    The population sizes of Anopheles gambiae Giles (Diptera: Culicidae) and Anopheles arabiensis Patton (Diptera: Culicidae) increase dramatically with the onset of the rainy season in sub-Saharan Africa, but the ecological mechanisms underlying the increases are not well understood. As a first step toward to understand, we investigated the proliferation of algae, the major food of mosquito larvae, in artificial fresh water bodies exposed to sunlight for a short period, and old water bodies exposed to sunlight for a long period, and the effects thereof on the development of these anopheline larvae. We found that an epizoic green algal species of the genus Rhopalosolen (Chlorophyta: Chlorophyceae) proliferated immediately after water freshly taken from a spring was placed in sunlight. This alga proliferated only briefly (for ~10 d) even if the water was repeatedly exposed to sunlight. However, various algal species were observed in water that remained under sunlight for 40 d or longer (i.e., in old water bodies). The growth performance of larvae was higher in sunlight-exposed (alga-rich) water than in shade-stored (alga-poor) water. Stable isotope analysis suggested that these two anopheline species fed on Rhopalosolen algae in fresh water bodies but hardly at all on other algae occurring in the old water bodies. We concluded that freshly formed ground water pools facilitate high production of anopheline species because of the proliferation of Rhopalosolen algae therein, and the increase in the number of such pools in the rainy season, followed by rapid increases in A. gambiae and A. arabiensis numbers. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Emerging mosquito species in Germany-a synopsis after 6 years of mosquito monitoring (2011-2016).

    Kampen, Helge; Schuhbauer, Astrid; Walther, Doreen

    2017-12-01

    Globalisation and climate change are the main drivers of invasion of non-endemic regions by mosquitoes. Mass transportation of people, animals and goods facilitate accidental long-distance displacement while climate warming supports active spread and establishment of thermophilic species. In the framework of a mosquito-monitoring programme, eight non-indigenous culicid species have been registered in Germany since 2011, with four of them being more or less efficient vectors of disease agents and another four now considered established. The eight newly emerged species include Aedes albopictus, Ae. japonicus, Ae. aegypti, Ae. koreicus, Ae. berlandi, Ae. pulcritarsis, Anopheles petragnani and Culiseta longiareolata. We here review recent findings and at the same time present new findings of specimens of non-native mosquito species in Germany.

  15. Drinking a hot blood meal elicits a protective heat shock response in mosquitoes.

    Benoit, Joshua B; Lopez-Martinez, Giancarlo; Patrick, Kevin R; Phillips, Zachary P; Krause, Tyler B; Denlinger, David L

    2011-05-10

    The mosquito's body temperature increases dramatically when it takes a blood meal from a warm-blooded, vertebrate host. By using the yellow fever mosquito, Aedes aegypti, we demonstrate that this boost in temperature following a blood meal prompts the synthesis of heat shock protein 70 (Hsp70). This response, elicited by the temperature of the blood meal, is most robust in the mosquito's midgut. When RNA interference is used to suppress expression of hsp70, protein digestion of the blood meal is impaired, leading to production of fewer eggs. We propose that Hsp70 protects the mosquito midgut from the temperature stress incurred by drinking a hot blood meal. Similar increases in hsp70 were documented immediately after blood feeding in two other mosquitoes (Culex pipiens and Anopheles gambiae) and the bed bug, Cimex lectularius, suggesting that this is a common protective response in blood-feeding arthropods.

  16. Habitat suitability of Anopheles vector species and association with human malaria in the Atlantic Forest in south-eastern Brazil.

    Laporta, Gabriel Zorello; Ramos, Daniel Garkauskas; Ribeiro, Milton Cezar; Sallum, Maria Anice Mureb

    2011-08-01

    Every year, autochthonous cases of Plasmodium vivax malaria occur in low-endemicity areas of Vale do Ribeira in the south-eastern part of the Atlantic Forest, state of São Paulo, where Anopheles cruzii and Anopheles bellator are considered the primary vectors. However, other species in the subgenus Nyssorhynchus of Anopheles (e.g., Anopheles marajoara) are abundant and may participate in the dynamics of malarial transmission in that region. The objectives of the present study were to assess the spatial distribution of An. cruzii, An. bellator and An. marajoara and to associate the presence of these species with malaria cases in the municipalities of the Vale do Ribeira. Potential habitat suitability modelling was applied to determine both the spatial distribution of An. cruzii, An. bellator and An. marajoara and to establish the density of each species. Poisson regression was utilized to associate malaria cases with estimated vector densities. As a result, An. cruzii was correlated with the forested slopes of the Serra do Mar, An. bellator with the coastal plain and An. marajoara with the deforested areas. Moreover, both An. marajoara and An. cruzii were positively associated with malaria cases. Considering that An. marajoara was demonstrated to be a primary vector of human Plasmodium in the rural areas of the state of Amapá, more attention should be given to the species in the deforested areas of the Atlantic Forest, where it might be a secondary vector.

  17. Seasonal abundance and potential of Japanese encephalitis virus infection in mosquitoes at the nesting colony of ardeid birds, Thailand.

    Changbunjong, Tanasak; Weluwanarak, Thekhawet; Taowan, Namaoy; Suksai, Parut; Chamsai, Tatiyanuch; Sedwisai, Poonyapat

    2013-03-01

    To investigate the abundance and seasonal dynamics of mosquitoes, and to detect Japanese encephalitis virus (JEV) in these mosquitoes at the nesting colony of ardeid birds. Mosquitoes were collected bimonthly from July 2009 to May 2010 by Centers for Disease Control. Light traps and dry ice, as a source of CO2, were employed to attract mosquitoes. Mosquitoes were first identified, pooled into groups of upto 50 mosquitoes by species, and tested for JEV infection by viral isolation and reverse transcriptase polymerase chain reaction. A total of 20 370 mosquitoes comprising 14 species in five genera were collected. The five most abundant mosquito species collected were Culex tritaeniorhynchus (95.46%), Culex vishnui (2.68%), Culex gelidus (0.72%), Anopheles peditaeniatus (0.58%) and Culex quinquefasciatus (0.22%). Mosquito peak densities were observed in July. All of 416 mosquito pools were negative for JEV. This study provides new information about mosquito species and status of JEV infection in mosquitoes in Thailand. Further study should be done to continue a close survey for the presence of this virus in the ardeid birds.

  18. Eilat virus displays a narrow mosquito vector range.

    Nasar, Farooq; Haddow, Andrew D; Tesh, Robert B; Weaver, Scott C

    2014-12-17

    Most alphaviruses are arthropod-borne and utilize mosquitoes as vectors for transmission to susceptible vertebrate hosts. This ability to infect both mosquitoes and vertebrates is essential for maintenance of most alphaviruses in nature. A recently characterized alphavirus, Eilat virus (EILV), isolated from a pool of Anopheles coustani s.I. is unable to replicate in vertebrate cell lines. The EILV host range restriction occurs at both attachment/entry as well as genomic RNA replication levels. Here we investigated the mosquito vector range of EILV in species encompassing three genera that are responsible for maintenance of other alphaviruses in nature. Susceptibility studies were performed in four mosquito species: Aedes albopictus, A. aegypti, Anopheles gambiae, and Culex quinquefasciatus via intrathoracic and oral routes utilizing EILV and EILV expressing red fluorescent protein (-eRFP) clones. EILV-eRFP was injected at 10(7) PFU/mL to visualize replication in various mosquito organs at 7 days post-infection. Mosquitoes were also injected with EILV at 10(4)-10(1) PFU/mosquito and virus replication was measured via plaque assays at day 7 post-infection. Lastly, mosquitoes were provided bloodmeals containing EILV-eRFP at doses of 10(9), 10(7), 10(5) PFU/mL, and infection and dissemination rates were determined at 14 days post-infection. All four species were susceptible via the intrathoracic route; however, replication was 10-100 fold less than typical for most alphaviruses, and infection was limited to midgut-associated muscle tissue and salivary glands. A. albopictus was refractory to oral infection, while A. gambiae and C. quinquefasciatus were susceptible only at 10(9) PFU/mL dose. In contrast, A. aegypti was susceptible at both 10(9) and 10(7) PFU/mL doses, with body infection rates of 78% and 63%, and dissemination rates of 26% and 8%, respectively. The exclusion of vertebrates in its maintenance cycle may have facilitated the adaptation of EILV to a single

  19. Malpighian Tubules as Novel Targets for Mosquito Control

    Peter M. Piermarini

    2017-01-01

    Full Text Available The Malpighian tubules and hindgut are the renal excretory tissues of mosquitoes; they are essential to maintaining hemolymph water and solute homeostasis. Moreover, they make important contributions to detoxifying metabolic wastes and xenobiotics in the hemolymph. We have focused on elucidating the molecular mechanisms of Malpighian tubule function in adult female mosquitoes and developing chemical tools as prototypes for next-generation mosquitocides that would act via a novel mechanism of action (i.e., renal failure. To date, we have targeted inward rectifier potassium (Kir channels expressed in the Malpighian tubules of the yellow fever mosquito Aedes aegypti and malaria mosquito Anopheles gambiae. Inhibition of these channels with small molecules inhibits transepithelial K+ and fluid secretion in Malpighian tubules, leading to a disruption of hemolymph K+ and fluid homeostasis in adult female mosquitoes. In addition, we have used next-generation sequencing to characterize the transcriptome of Malpighian tubules in the Asian tiger mosquito Aedes albopictus, before and after blood meals, to reveal new molecular targets for potentially disrupting Malpighian tubule function. Within 24 h after a blood meal, the Malpighian tubules enhance the mRNA expression of genes encoding mechanisms involved with the detoxification of metabolic wastes produced during blood digestion (e.g., heme, NH3, reactive oxygen species. The development of chemical tools targeting these molecular mechanisms in Malpighian tubules may offer a promising avenue for the development of mosquitocides that are highly-selective against hematophagous females, which are the only life stage that transmits pathogens.

  20. Blood-feeding ecology of mosquitoes in zoos.

    Tuten, H C; Bridges, W C; Paul, K S; Adler, P H

    2012-12-01

    To determine if the unique host assemblages in zoos influence blood-feeding by mosquitoes (Diptera: Culicidae), a sampling programme was conducted in Greenville and Riverbanks Zoos, South Carolina, U.S.A., from April 2009 to October 2010. A total of 4355 female mosquitoes of 14 species were collected, of which 106 individuals of nine species were blood-fed. The most common taxa were Aedes albopictus (Skuse), Aedes triseriatus (Say), Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Culex pipiens complex (L.) and Culex restuans (Theobald). Molecular analyses (cytochrome b) of bloodmeals revealed that mosquitoes fed on captive animals, humans and wildlife, and took mixed bloodmeals. Host species included one amphibian, 16 birds, 10 mammals (including humans) and two reptiles. Minimum dispersal distances after feeding on captive hosts ranged from 15.5 m to 327.0 m. Mosquito-host associations generally conformed to previous accounts, indicating that mosquito behaviour inside zoos reflects that outside zoos. However, novel variation in host use, including new, exotic host records, warrants further investigation. Zoos, thus, can be used as experiment environments in which to study mosquito behaviour, and the findings extrapolated to non-zoo areas, while providing medical and veterinary benefits to zoo animals, employees and patrons. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

  1. Mosquitoes rely on their gut microbiota for development

    Coon, Kerri L.; Vogel, Kevin J.; Brown, Mark R.; Strand, Michael R.

    2014-01-01

    Field studies indicate adult mosquitoes (Culicidae) host low diversity communities of bacteria that vary greatly among individuals and species. In contrast, it remains unclear how adult mosquitoes acquire their microbiome, what influences community structure, and whether the microbiome is important for survival. Here we used pyrosequencing of 16S rRNA to characterize the bacterial communities of three mosquito species reared under identical conditions. Two of these species, Aedes aegypti and Anopheles gambiae, are anautogenous and must blood feed to produce eggs, while one, Georgecraigius atropalpus, is autogenous and produces eggs without blood feeding. Each mosquito species contained a low diversity community comprised primarily of aerobic bacteria acquired primarily from the aquatic habitat in which larvae developed. Our results suggested the communities in Ae. aegypti and An. gambiae larvae share more similarities with one another than with Ge. atropalpus. Studies with Ae. aegypti also strongly suggested that adults transstadially acquired several members of the larval bacterial community, but only four genera of bacteria present in blood fed females were detected on eggs. Functional assays showed that axenic larvae of each species failed to develop beyond the first instar. Experiments with Ae. aegypti indicated several members of the microbial community and Escherichia coli successfully colonized axenic larvae and rescued development. Overall, our results provide new insights about the acquisition and structure of bacterial communities in mosquitoes. They also indicate three mosquito species spanning the breadth of the Culicidae depend on their gut microbiome for development. PMID:24766707

  2. Composition of human skin microbiota affects attractiveness to malaria mosquitoes.

    Niels O Verhulst

    Full Text Available The African malaria mosquito Anopheles gambiae sensu stricto continues to play an important role in malaria transmission, which is aggravated by its high degree of anthropophily, making it among the foremost vectors of this disease. In the current study we set out to unravel the strong association between this mosquito species and human beings, as it is determined by odorant cues derived from the human skin. Microbial communities on the skin play key roles in the production of human body odour. We demonstrate that the composition of the skin microbiota affects the degree of attractiveness of human beings to this mosquito species. Bacterial plate counts and 16S rRNA sequencing revealed that individuals that are highly attractive to An. gambiae s.s. have a significantly higher abundance, but lower diversity of bacteria on their skin than individuals that are poorly attractive. Bacterial genera that are correlated with the relative degree of attractiveness to mosquitoes were identified. The discovery of the connection between skin microbial populations and attractiveness to mosquitoes may lead to the development of new mosquito attractants and personalized methods for protection against vectors of malaria and other infectious diseases.

  3. Zika virus: An updated review of competent or naturally infected mosquitoes.

    Epelboin, Yanouk; Talaga, Stanislas; Epelboin, Loïc; Dusfour, Isabelle

    2017-11-01

    Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) that recently caused outbreaks in the Americas. Over the past 60 years, this virus has been observed circulating among African, Asian, and Pacific Island populations, but little attention has been paid by the scientific community until the discovery that large-scale urban ZIKV outbreaks were associated with neurological complications such as microcephaly and several other neurological malformations in fetuses and newborns. This paper is a systematic review intended to list all mosquito species studied for ZIKV infection or for their vector competence. We discuss whether studies on ZIKV vectors have brought enough evidence to formally exclude other mosquitoes than Aedes species (and particularly Aedes aegypti) to be ZIKV vectors. From 1952 to August 15, 2017, ZIKV has been studied in 53 mosquito species, including 6 Anopheles, 26 Aedes, 11 Culex, 2 Lutzia, 3 Coquillettidia, 2 Mansonia, 2 Eretmapodites, and 1 Uranotaenia. Among those, ZIKV was isolated from 16 different Aedes species. The only species other than Aedes genus for which ZIKV was isolated were Anopheles coustani, Anopheles gambiae, Culex perfuscus, and Mansonia uniformis. Vector competence assays were performed on 22 different mosquito species, including 13 Aedes, 7 Culex, and 2 Anopheles species with, as a result, the discovery that A. aegypti and Aedes albopictus were competent for ZIKV, as well as some other Aedes species, and that there was a controversy surrounding Culex quinquefasciatus competence. Although Culex, Anopheles, and most of Aedes species were generally observed to be refractory to ZIKV infection, other potential vectors transmitting ZIKV should be explored.

  4. Zika virus: An updated review of competent or naturally infected mosquitoes

    Talaga, Stanislas; Epelboin, Loïc; Dusfour, Isabelle

    2017-01-01

    Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) that recently caused outbreaks in the Americas. Over the past 60 years, this virus has been observed circulating among African, Asian, and Pacific Island populations, but little attention has been paid by the scientific community until the discovery that large-scale urban ZIKV outbreaks were associated with neurological complications such as microcephaly and several other neurological malformations in fetuses and newborns. This paper is a systematic review intended to list all mosquito species studied for ZIKV infection or for their vector competence. We discuss whether studies on ZIKV vectors have brought enough evidence to formally exclude other mosquitoes than Aedes species (and particularly Aedes aegypti) to be ZIKV vectors. From 1952 to August 15, 2017, ZIKV has been studied in 53 mosquito species, including 6 Anopheles, 26 Aedes, 11 Culex, 2 Lutzia, 3 Coquillettidia, 2 Mansonia, 2 Eretmapodites, and 1 Uranotaenia. Among those, ZIKV was isolated from 16 different Aedes species. The only species other than Aedes genus for which ZIKV was isolated were Anopheles coustani, Anopheles gambiae, Culex perfuscus, and Mansonia uniformis. Vector competence assays were performed on 22 different mosquito species, including 13 Aedes, 7 Culex, and 2 Anopheles species with, as a result, the discovery that A. aegypti and Aedes albopictus were competent for ZIKV, as well as some other Aedes species, and that there was a controversy surrounding Culex quinquefasciatus competence. Although Culex, Anopheles, and most of Aedes species were generally observed to be refractory to ZIKV infection, other potential vectors transmitting ZIKV should be explored. PMID:29145400

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

    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

  6. Host feeding patterns and preference of Anopheles minimus (Diptera: Culicidae) in a malaria endemic area of western Thailand: baseline site description.

    Tisgratog, Rungarun; Tananchai, Chatchai; Juntarajumnong, Waraporn; Tuntakom, Siripun; Bangs, Michael J; Corbel, Vincent; Chareonviriyaphap, Theeraphap

    2012-06-07

    Host feeding patterns of Anopheles minimus in relation to ambient environmental conditions were observed during a 2-year period at Tum Sua Village, located in Mae Sot District, Tak Province, in western Thailand, where An. minimus is found in abundance and regarded as the most predominant malaria vector species. Detailed information on mosquito behavior is important for understanding the epidemiology of disease transmission and developing more effective and efficient vector control methods. Adult mosquitoes were collected every 2 months for two consecutive nights from 1800 to 0600 hrs. Three collection methods were used; indoor human-landing collections (HLC), outdoor HLC, and outdoor cattle-bait collections (CBC). A total of 7,663 female Anopheles mosquitoes were collected of which 5,392 were identified as members of 3 different species complexes, the most prevalent being Anopheles minimus complex (50.36%), followed by Anopheles maculatus complex (19.68%) and Anopheles dirus complex (0.33%). An. minimus s.s. comprised virtually all (> 99.8 percent) of Minimus Complex species captured. Blood feeding behavior of An. minimus was more pronounced during the second half of the evening, showing a slight preference to blood feed outdoors (~60%) versus inside structures. Significantly (P feeding behavior. Although a significant difference in total number of mosquitoes from the HLC was recorded between the first and second year, the mean biting frequency over the course of the evening hours remained similar. The Human landing activity of An. minimus in Tum Sua Village showed a stronger preference/attraction for humans compared to a cow-baited collection method. This study supports the incrimination of An. minimus as the primary malaria vector in the area. A better understanding of mosquito behavior related to host preference, and the temporal and spatial blood feeding activity will help facilitate the design of vector control strategies and effectiveness of vector

  7. Anti-malarial Drug Design by Targeting Apicoplasts: New Perspectives

    Avinaba Mukherjee

    2016-03-01

    Full Text Available Objectives: Malaria has been a major global health problem in recent times with increasing mortality. Current treatment methods include parasiticidal drugs and vaccinations. However, resistance among malarial parasites to the existing drugs has emerged as a significant area of concern in anti-malarial drug design. Researchers are now desperately looking for new targets to develop anti-malarials drug which is more target specific. Malarial parasites harbor a plastid-like organelle known as the ‘apicoplast’, which is thought to provide an exciting new outlook for the development of drugs to be used against the parasite. This review elaborates on the current state of development of novel compounds targeted againstemerging malaria parasites. Methods: The apicoplast, originates by an endosymbiotic process, contains a range of metabolic pathways and housekeeping processes that differ from the host body and thereby presents ideal strategies for anti-malarial drug therapy. Drugs are designed by targeting the unique mechanism of the apicoplasts genetic machinery. Several anabolic and catabolic processes, like fatty acid, isopenetyl diphosphate and heme synthess in this organelle, have also been targeted by drugs. Results: Apicoplasts offer exciting opportunities for the development of malarial treatment specific drugs have been found to act by disrupting this organelle’s function, which wouldimpede the survival of the parasite. Conclusion: Recent advanced drugs, their modes of action, and their advantages in the treatment of malaria by using apicoplasts as a target are discussed in this review which thought to be very useful in desigining anti-malarial drugs. Targetting the genetic machinery of apicoplast shows a great advantange regarding anti-malarial drug design. Critical knowledge of these new drugs would give a healthier understanding for deciphering the mechanism of action of anti-malarial drugs when targeting apicoplasts to overcome drug

  8. Molecular detection of six (endo-) symbiotic bacteria in Belgian mosquitoes: first step towards the selection of appropriate paratransgenesis candidates.

    Raharimalala, Fara Nantenaina; Boukraa, S; Bawin, T; Boyer, S; Francis, F

    2016-04-01

    Actually, the use of symbiotic bacteria is one of alternative solution to avoid vector resistance to pesticides. In Belgium, among 31 identified mosquito species, 10 were considered as potential vectors. Given to introduction risks of arbovirosis, the purpose of this study was to investigate the presence of symbiosis bacteria in potential mosquito vectors. Eleven species caught from 12 sites in Belgium were used: Culex pipiens s.l., Culex torrentium, Culex hortensis, Anopheles claviger, Anopheles maculipennis s.l., Anopheles plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Ochlerotatus dorsalis, Aedes albopictus, and Coquillettidia richiardii. Six genera of symbiotic bacteria were screened: Wolbachia sp., Comamonas sp, Delftia sp., Pseudomonas sp., Acinetobacter sp., and Asaia sp. A total of 173 mosquito individuals (144 larvae and 29 adults) were used for the polymerase chain reaction screening. Wolbachia was not found in any Anopheles species nor Cx. torrentium. A total absence of Comamonas and Delftia was observed in all species. Acinetobacter, Pseudomonas, and Asaia were found in most of species with a high prevalence for Pseudomonas. These results were discussed to develop potential strategy and exploit the variable occurrence of symbiotic bacteria to focus on them to propose biological ways of mosquito control.

  9. A simple Chelex protocol for DNA extraction from Anopheles spp.

    Musapa, Mulenga; Kumwenda, Taida; Mkulama, Mtawa; Chishimba, Sandra; Norris, Douglas E; Thuma, Philip E; Mharakurwa, Sungano

    2013-01-09

    Endemic countries are increasingly adopting molecular tools for efficient typing, identification and surveillance against malaria parasites and vector mosquitoes, as an integral part of their control programs. For sustainable establishment of these accurate approaches in operations research to strengthen malaria control and elimination efforts, simple and affordable methods, with parsimonious reagent and equipment requirements are essential. Here we present a simple Chelex-based technique for extracting malaria parasite and vector DNA from field collected mosquito specimens. We morphologically identified 72 Anopheles gambiae sl. from 156 mosquitoes captured by pyrethrum spray catches in sleeping rooms of households within a 2,000 km(2) vicinity of the Malaria Institute at Macha. After dissection to separate the head and thorax from the abdomen for all 72 Anopheles gambiae sl. mosquitoes, the two sections were individually placed in 1.5 ml microcentrifuge tubes and submerged in 20 μl of deionized water. Using a sterile pipette tip, each mosquito section was separately homogenized to a uniform suspension in the deionized water. Of the ensuing homogenate from each mosquito section, 10 μl was retained while the other 10 μl was transferred to a separate autoclaved 1.5 ml tube. The separate aliquots were subjected to DNA extraction by either the simplified Chelex or the standard salting out extraction protocol(9,10). The salting out protocol is so-called and widely used because it employs high salt concentrations in lieu of hazardous organic solvents (such as phenol and chloroform) for the protein precipitation step during DNA extraction(9). Extracts were used as templates for PCR amplification using primers targeting arthropod mitochondrial nicotinamide adenine dinucleotide dehydrogenase (NADH) subunit 4 gene (ND4) to check DNA quality, a PCR for identification of Anopheles gambiae sibling species(10) and a nested PCR for typing of Plasmodium falciparum infection

  10. Genetic evidence for malaria vectors of the Anopheles sundaicus complex in Sri Lanka with morphological characteristics attributed to Anopheles subpictus species B

    Jude Pavillupillai J

    2010-11-01

    Full Text Available Abstract Background Anopheles subpictus sensu lato, a widespread malaria vector in Asia, is reportedly composed of four sibling species A - D. Mosquitoes morphologically identified as belonging to the Subpictus complex were collected from different locations near the east coast of Sri Lanka, and specific ribosomal DNA sequences determined to validate their taxonomic status. Methods Anopheles subpictus s.l. larvae and blood-fed adults were collected from different locations in the Eastern province and their sibling species status was determined based on published morphological characteristics. DNA sequences of the D3 domain of 28 S ribosomal DNA (rDNA and the internal transcribed spacer -2 (ITS-2 of mosquitoes morphologically identified as An. subpictus sibling species A, B, C and D were determined. Results Phylogenetic analysis based on D3 domain of rDNA resulted in two clades: one clade with mosquitoes identified as An. subpictus species A, C, D and some mosquitoes identified as species B, and another clade with a majority of mosquitoes identified as species B with D3 sequences that were identical to Anopheles sundaicus cytotype D. Analysis of ITS-2 sequences confirmed a close relationship between a majority of mosquitoes identified as An. subpictus B with members of the An. sundaicus complex and others identified as An. subpictus B with An. subpictus s.l. Conclusions The study suggests that published morphological characteristics are not specific enough to identify some members of the Subpictus complex, particularly species B. The sequences of the ITS-2 and D3 domain of rDNA suggest that a majority that were identified morphologically as An. subpictus species B in the east coast of Sri Lanka, and some identified elsewhere in SE Asia as An. subpictus s.l., are in fact members of the Sundaicus complex based on genetic similarity to An. sundaicus s.l. In view of the well-known ability of An. sundaicus s.l. to breed in brackish and fresh water and

  11. Analysis of near infrared spectra for age-grading of wild populations of Anopheles gambiae

    Benjamin J. Krajacich

    2017-11-01

    Full Text Available Abstract Background Understanding the age-structure of mosquito populations, especially malaria vectors such as Anopheles gambiae, is important for assessing the risk of infectious mosquitoes, and how vector control interventions may impact this risk. The use of near-infrared spectroscopy (NIRS for age-grading has been demonstrated previously on laboratory and semi-field mosquitoes, but to date has not been utilized on wild-caught mosquitoes whose age is externally validated via parity status or parasite infection stage. In this study, we developed regression and classification models using NIRS on datasets of wild An. gambiae (s.l. reared from larvae collected from the field in Burkina Faso, and two laboratory strains. We compared the accuracy of these models for predicting the ages of wild-caught mosquitoes that had been scored for their parity status as well as for positivity for Plasmodium sporozoites. Results Regression models utilizing variable selection increased predictive accuracy over the more common full-spectrum partial least squares (PLS approach for cross-validation of the datasets, validation, and independent test sets. Models produced from datasets that included the greatest range of mosquito samples (i.e. different sampling locations and times had the highest predictive accuracy on independent testing sets, though overall accuracy on these samples was low. For classification, we found that intramodel accuracy ranged between 73.5–97.0% for grouping of mosquitoes into “early” and “late” age classes, with the highest prediction accuracy found in laboratory colonized mosquitoes. However, this accuracy was decreased on test sets, with the highest classification of an independent set of wild-caught larvae reared to set ages being 69.6%. Conclusions Variation in NIRS data, likely from dietary, genetic, and other factors limits the accuracy of this technique with wild-caught mosquitoes. Alternative algorithms may help improve

  12. Analysis of near infrared spectra for age-grading of wild populations of Anopheles gambiae.

    Krajacich, Benjamin J; Meyers, Jacob I; Alout, Haoues; Dabiré, Roch K; Dowell, Floyd E; Foy, Brian D

    2017-11-07

    Understanding the age-structure of mosquito populations, especially malaria vectors such as Anopheles gambiae, is important for assessing the risk of infectious mosquitoes, and how vector control interventions may impact this risk. The use of near-infrared spectroscopy (NIRS) for age-grading has been demonstrated previously on laboratory and semi-field mosquitoes, but to date has not been utilized on wild-caught mosquitoes whose age is externally validated via parity status or parasite infection stage. In this study, we developed regression and classification models using NIRS on datasets of wild An. gambiae (s.l.) reared from larvae collected from the field in Burkina Faso, and two laboratory strains. We compared the accuracy of these models for predicting the ages of wild-caught mosquitoes that had been scored for their parity status as well as for positivity for Plasmodium sporozoites. Regression models utilizing variable selection increased predictive accuracy over the more common full-spectrum partial least squares (PLS) approach for cross-validation of the datasets, validation, and independent test sets. Models produced from datasets that included the greatest range of mosquito samples (i.e. different sampling locations and times) had the highest predictive accuracy on independent testing sets, though overall accuracy on these samples was low. For classification, we found that intramodel accuracy ranged between 73.5-97.0% for grouping of mosquitoes into "early" and "late" age classes, with the highest prediction accuracy found in laboratory colonized mosquitoes. However, this accuracy was decreased on test sets, with the highest classification of an independent set of wild-caught larvae reared to set ages being 69.6%. Variation in NIRS data, likely from dietary, genetic, and other factors limits the accuracy of this technique with wild-caught mosquitoes. Alternative algorithms may help improve prediction accuracy, but care should be taken to either maximize

  13. First record of Anopheles stephensi in Sri Lanka: a potential challenge for prevention of malaria reintroduction.

    Gayan Dharmasiri, A G; Perera, A Yashan; Harishchandra, Jeevanie; Herath, Hemantha; Aravindan, Kandasamy; Jayasooriya, H T R; Ranawaka, Gaya R; Hewavitharane, Mihirini

    2017-08-10

    The major malaria vector in Sri Lanka is reported to be Anopheles culicifacies with Anopheles subpictus, Anopheles annularis, and Anopheles varuna considered as potential vectors. The occurrence of Anopheles stephensi, which is the key vector of urban malaria in India and the Middle East, had never been reported from Sri Lanka. A series of entomological investigations were carried out by the Anti Malaria Campaign, Ministry of Health, Sri Lanka during December 2016 to April 2017 in two localities of the Mannar District in the Northern Province of the country. Adult mosquito collections were done through indoor and outdoor resting collections, animal and human biting collections and emergence traps. Potential mosquito breeding sites were investigated through larval surveys. The larvae and adults of An. stephensi were initially identified using morphological keys, and subsequently confirmed by sequencing the barcode region of the cytochrome c oxidase I (COI) gene. This is the first report of the presence of An. stephensi in the island of Mannar in the Northern Province of Sri Lanka. Anopheles stephensi (36.65%) was the most abundant anopheline species in the larval habitats in Mannar. It was found breeding together with An. culicifacies (20.7%), An. subpictus (13.5%) and An. varuna (28.13%). Anopheles stephensi was found to be abundantly breeding in built wells used for domestic purposes. Adult females of An. stephensi were observed in emergence trap collections (93.9%), human landing catches all night (79.2%), pyrethrum spray sheet collections (38.6%), outdoor collections (8.3%), donkey-baited trap collections (14.3), and cattle-baited net trap collections (0.7%). Sri Lanka was certified as malaria-free by the WHO in September 2016, however, this new finding may pose a serious challenge to the efforts of the Ministry of Health to prevent the re-introduction of malaria transmission in the country, considering the role that An. stephensi could play in urban and high

  14. Explaining variation in adult Anopheles indoor resting abundance: the relative effects of larval habitat proximity and insecticide-treated bed net use.

    McCann, Robert S; Messina, Joseph P; MacFarlane, David W; Bayoh, M Nabie; Gimnig, John E; Giorgi, Emanuele; Walker, Edward D

    2017-07-17

    Spatial determinants of malaria risk within communities are associated with heterogeneity of exposure to vector mosquitoes. The abundance of adult malaria vectors inside people's houses, where most transmission takes place, should be associated with several factors: proximity of houses to larval habitats, structural characteristics of houses, indoor use of vector control tools containing insecticides, and human behavioural and environmental factors in and near houses. While most previous studies have assessed the association of larval habitat proximity in landscapes with relatively low densities of larval habitats, in this study these relationships were analysed in a region of rural, lowland western Kenya with high larval habitat density. 525 houses were sampled for indoor-resting mosquitoes across an 8 by 8 km study area using the pyrethrum spray catch method. A predictive model of larval habitat location in this landscape, previously verified, provided derivations of indices of larval habitat proximity to houses. Using geostatistical regression models, the association of larval habitat proximity, long-lasting insecticidal nets (LLIN) use, house structural characteristics (wall type, roof type), and peridomestic variables (cooking in the house, cattle near the house, number of people sleeping in the house) with mosquito abundance in houses was quantified. Vector abundance was low (mean, 1.1 adult Anopheles per house). Proximity of larval habitats was a strong predictor of Anopheles abundance. Houses without an LLIN had more female Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus than houses where some people used an LLIN (rate ratios, 95% CI 0.87, 0.85-0.89; 0.84, 0.82-0.86; 0.38, 0.37-0.40) and houses where everyone used an LLIN (RR, 95% CI 0.49, 0.48-0.50; 0.39, 0.39-0.40; 0.60, 0.58-0.61). Cooking in the house also reduced Anopheles abundance across all species. The number of people sleeping in the house, presence of cattle near the house

  15. Vessel discoloration detection in malarial retinopathy

    Agurto, C.; Nemeth, S.; Barriga, S.; Soliz, P.; MacCormick, I.; Taylor, T.; Harding, S.; Lewallen, S.; Joshi, V.

    2016-03-01

    Cerebral malaria (CM) is a life-threatening clinical syndrome associated with malarial infection. It affects approximately 200 million people, mostly sub-Saharan African children under five years of age. Malarial retinopathy (MR) is a condition in which lesions such as whitening and vessel discoloration that are highly specific to CM appear in the retina. Other unrelated diseases can present with symptoms similar to CM, therefore the exact nature of the clinical symptoms must be ascertained in order to avoid misdiagnosis, which can lead to inappropriate treatment and, potentially, death. In this paper we outline the first system to detect the presence of discolored vessels associated with MR as a means to improve the CM diagnosis. We modified and improved our previous vessel segmentation algorithm by incorporating the `a' channel of the CIELab color space and noise reduction. We then divided the segmented vasculature into vessel segments and extracted features at the wall and in the centerline of the segment. Finally, we used a regression classifier to sort the segments into discolored and not-discolored vessel classes. By counting the abnormal vessel segments in each image, we were able to divide the analyzed images into two groups: normal and presence of vessel discoloration due to MR. We achieved an accuracy of 85% with sensitivity of 94% and specificity of 67%. In clinical practice, this algorithm would be combined with other MR retinal pathology detection algorithms. Therefore, a high specificity can be achieved. By choosing a different operating point in the ROC curve, our system achieved sensitivity of 67% with specificity of 100%.

  16. The origin of malarial parasites in orangutans.

    M Andreína Pacheco

    Full Text Available BACKGROUND: Recent findings of Plasmodium in African apes have changed our perspectives on the evolution of malarial parasites in hominids. However, phylogenetic analyses of primate malarias are still missing information from Southeast Asian apes. In this study, we report molecular data for a malaria parasite lineage found in orangutans. METHODOLOGY/PRINCIPAL FINDINGS: We screened twenty-four blood samples from Pongo pygmaeus (Kalimantan, Indonesia for Plasmodium parasites by PCR. For all the malaria positive orangutan samples, parasite mitochondrial genomes (mtDNA and two antigens: merozoite surface protein 1 42 kDa (MSP-1(42 and circumsporozoite protein gene (CSP were amplified, cloned, and sequenced. Fifteen orangutans tested positive and yielded 5 distinct mitochondrial haplotypes not previously found. The haplotypes detected exhibited low genetic divergence among them, indicating that they belong to one species. We report phylogenetic analyses using mitochondrial genomes, MSP-1(42 and CSP. We found that the orangutan malaria parasite lineage was part of a monophyletic group that includes all the known non-human primate malaria parasites found in Southeast Asia; specifically, it shares a recent common ancestor with P. inui (a macaque parasite and P. hylobati (a gibbon parasite suggesting that this lineage originated as a result of a host switch. The genetic diversity of MSP-1(42 in orangutans seems to be under negative selection. This result is similar to previous findings in non-human primate malarias closely related to P. vivax. As has been previously observed in the other Plasmodium species found in non-human primates, the CSP shows high polymorphism in the number of repeats. However, it has clearly distinctive motifs from those previously found in other malarial parasites. CONCLUSION: The evidence available from Asian apes indicates that these parasites originated independently from those found in Africa, likely as the result of host

  17. Visualization of house-entry behaviour of malaria mosquitoes.

    Spitzen, Jeroen; Koelewijn, Teun; Mukabana, W Richard; Takken, Willem

    2016-04-25

    Malaria mosquitoes often blood feed indoors on human hosts. The mosquitoes predominantly enter houses via open eaves. Host-seeking is odour-driven, and finding a host depends on the quality of the odour plume and whether the route towards the host is free of obstructions. Little is known about in-flight behaviour of mosquitoes during house entry. This semi-field study visualizes mosquito house entry in three dimensions (3D) and offers new insights for optimizing vector control interventions. The approach and house entry of Anopheles gambiae sensu stricto was studied in a semi-field set-up using video-recorded flight tracks and 3D analysis. Behavioural parameters of host-seeking female mosquitoes were visualized with respect to their position relative to the eave as well as whether a mosquito would enter or not. Host odour was standardized using an attractive synthetic blend in addition to CO2. The study was conducted in western Kenya at the Thomas Odhiambo Campus of the International Centre of Insect Physiology and Ecology, Mbita. The majority of host-seeking An. gambiae approached a house with a flight altitude at eave level, arriving within a horizontal arc of 180°. Fifty-five per cent of mosquitoes approaching a house did not enter or made multiple attempts before passing through the eave. During approach, mosquitoes greatly reduced their speed and the flight paths became more convoluted. As a result, mosquitoes that passed through the eave spent more than 80 % of the observed time within 30 cm of the eave. Mosquitoes that exited the eave departed at eave level and followed the edge of the roof (12.5 %) or quickly re-entered after exiting (9.6 %). The study shows that host-seeking mosquitoes, when entering a house, approach the eave in a wide angle to the house at eave level. Less than 25 % of approaching mosquitoes entered the house without interruption, whereas 12.5 % of mosquitoes that had entered left the house again within the time of observation

  18. Controlling Mosquitoes Outside

    2016-08-09

    Mosquitoes can carry viruses, like West Nile, Zika, dengue, and chikungunya. In this podcast, Mr. Hubbard will teach you and his neighbor, Laura, ways to help reduce the number of mosquitoes outside your home. Tips include eliminating areas of standing water where mosquitoes lay eggs and using larvicides to kill young mosquitoes.  Created: 8/9/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/9/2016.

  19. Field evaluation of spatial repellency of metofluthrin-impregnated plastic strips against Anopheles gambiae complex in Bagamoyo, coastal Tanzania.

    Kawada, Hitoshi; Temu, Emmanuel A.; Minjas, Japhet N.; Matsumoto, Osamu; Iwasaki, Tomonori; Takagi, Masahiro

    2008-01-01

    Metofluthrin is a newly synthesized pyrethroid possessing high knockdown and lethal activity against mosquitoes. Studies of metofluthrin-impregnated plastic strips have been performed with dengue vectors. This study reports the efficacy of the new prototypes of metofluthrin-impregnated plastic strips against malaria vectors, Anopheles gambiae complex, in the Kongo villages of Bagamoyo district in coastal Tanzania. The study, using 20 houses, half intervention, half control, was conducted for ...

  20. Larvicidal & ovicidal efficacy of Pithecellobium dulce (Roxb.) Benth. (Fabaceae) against Anopheles stephensi Liston & Aedes aegypti Linn. (Diptera: Culicidae)

    Govindarajan, M.; Rajeswary, M.; Sivakumar, R.

    2013-01-01

    Background & objectives: In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude hexane, benzene, chloroform, ethyl acetate and methanol solvent extracts from the medicinal plant Pithecellobium dulce against the mosquito vectors, Anopheles stephensi and Aedes aegypti (Diptera: Culicidae). Methods: Larvicidal activity of P. dulce plant...

  1. El doctor Moreno Pérez y el anopheles crucians

    Facultad de Medicina Revista

    1943-03-01

    Full Text Available En el año de 1933, con ocasión del conflicto del Amazonas, el doctor Ignacio Moreno·Pérez trabajó como médico de sanidad en la hoya del río Caquetá. Prosiguiendo sus estudios sobre paludismo y mosquitos transmisores a que dedicó gran parte de su meritoria vida, practicó una inspección entomológica de las cercanías de Florencia, capital de la comisaria del Caquetá, y encontró una raza en aguas salobres de Anopheles crucians. El hallazgo comunicado por él en el informe de 1934 de la comisión de paludismo del valle del Magdalena, (Estudios de Paludismo en el Valle del Magdalena, Departamento Nacional de Higiene, Sección de Sanidad Rural, Bogotá editorial de "Cromos", 1934, despertó mucho interés y fué objeto de controversias, porque conforme a los estudios de Howard, Dyar y Knab (1917, la localización del Anopheles crucians era casi hiperbórea, por encima del paralelo 25 en la América del Norte y solamente se había logrado ver además en Cuba y Jamaica.

  2. Pathogenicity, serological responses, and diagnosis of experimental and natural malarial infections in native Hawaiian thrushes

    Atkinson, C.T.; Lease, J.K.; Drake, B.M.; Shema, N.P.

    2001-01-01

    Omao (Myadestes obscurus) from the Hawaiian Islands typically have very low prevalences of infection with avian malaria (Plasmodium relictum) and it is not clear whether they share the same high susceptibility to this parasite that has been documented in native Hawaiian honeycreepers. We exposed four captive Omao to single infective mosquito bites and measured parasitemia, serological responses, and mortality over time. All four birds experienced transient infections with low parasitemias and were immune when rechallenged with multiple infective mosquito bites. By contrast, three of four honeycreepers (Maui Alauahio, Paroreomyza montana) that were exposed to the same dose and parasite isolate succumbed to infection. All four Omao developed antibodies to a common suite of malarial antigens that were detectable on immunoblots of a crude red blood cell extract of P. relictum. We used this technique to screen plasma samples from wild Omao and endangered Puaiohi (Myadestes palmeri) that were captured at elevations between 900 and 1300 m on the islands of Hawaii and Kauai. We found that the true prevalence of infection at elevations where active malaria transmission occurs is much higher than estimates based on blood smears alone. Hawaiian thrushes appear to have a high tolerance for malaria, with most individuals developing chronic, low-level infections after exposure that cannot be diagnosed accurately by blood smears.

  3. Mosquito Life Cycle

    Knowing the stages of the mosquito's life will help you prevent mosquitoes around your home and help you choose the right pesticides for your needs, if you decide to use them. All mosquito species go through four distinct stages during their live cycle.

  4. Indoor application of attractive toxic sugar bait (ATSB in combination with mosquito nets for control of pyrethroid-resistant mosquitoes.

    Zachary P Stewart

    Full Text Available BACKGROUND: Attractive toxic sugar bait (ATSB sprayed onto vegetation has been successful in controlling Anopheles mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking mosquitoes and constitute a new approach to control of mosquito-borne diseases. METHODS: Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental huts in Moshi, Tanzania. ATSB stations were hung in huts next to untreated mosquito nets occupied by human volunteers. The proportions of mosquitoes killed in huts with ATSB treatments relative to huts with non-insecticide control treatments huts were recorded, noting evidence of dye in mosquito abdomens. RESULTS: In feeding bioassays, chlorfenapyr 0.5% v/v, boric acid 2% w/v, and tolfenpyrad 1% v/v, mixed in a guava juice-based bait, each killed more than 90% of pyrethroid-susceptible An. Gambiae s.s. and pyrethroid-resistant An. arabiensis and Cx. quinquefasciatus. In the hut trial, mortality rates of the three ATSB treatments ranged from 41-48% against An. arabiensis and 36-43% against Cx. quinquefasciatus and all were significantly greater than the control mortalities: 18% for An. arabiensis, 7% for Cx. quinquefasciatus (p<0.05. Mortality rates with ATSB were comparable to those with long lasting insecticidal nets previously tested against the same species in this area. CONCLUSIONS: Indoor ATSB shows promise as a supplement to mosquito nets for controlling mosquitoes. Indoor ATSB constitute a novel application method for insecticide classes that act as stomach poisons and have not hitherto been exploited for mosquito control. Combined with LLIN, indoor

  5. Intravenous ferric carboxymaltose accelerates erythropoietic recovery from experimental malarial anemia

    Maretty, Lasse; Sharp, Rebecca Emilie; Andersson, Mikael

    2012-01-01

    Iron restriction has been proposed as a cause of erythropoietic suppression in malarial anemia; however, the role of iron in malaria remains controversial, because it may increase parasitemia. To investigate the role of iron-restricted erythropoiesis, A/J mice were infected with Plasmodium chabaudi...... use of iron therapy in malaria and show the need for trials of intravenous ferric carboxymaltose as an adjunctive treatment for severe malarial anemia....

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

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

    Christophe Paupy

    Full Text Available 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.

  8. Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon

    Chouaibou Mouhamadou

    2006-09-01

    Full Text Available Abstract Background Recent field studies indicated that insecticide-treated bednets (ITNs maintain their efficacy despite a high frequency of the knock-down resistance (kdr gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. Methods Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m2, a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m2, a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. Results Bifenthrin at 50 mg/m2 significantly reduced anophelines' entry rate (>80%. This was not observed at 5 mg/m2. Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. Conclusion Bifenthrin-impregnated bednets at 50 mg/m2 were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations.

  9. Efficacy of bifenthrin-impregnated bednets against Anopheles funestus and pyrethroid-resistant Anopheles gambiae in North Cameroon

    Chouaibou, Mouhamadou; Simard, Frédéric; Chandre, Fabrice; Etang, Josiane; Darriet, Frédéric; Hougard, Jean-Marc

    2006-01-01

    Background Recent field studies indicated that insecticide-treated bednets (ITNs) maintain their efficacy despite a high frequency of the knock-down resistance (kdr) gene in Anopheles gambiae populations. It was essential to evaluate ITNs efficacy in areas with metabolic-based resistance. Methods Bifenthrin was used in this experiment because it is considered a promising candidate for bednets impregnation. Nets were treated at 50 mg/m2, a dose that has high insecticidal activity on kdr mosquitoes and at 5 mg/m2, a dose that kills 95% of susceptible mosquitoes under laboratory conditions with 3 minutes exposure. Bednets were holed to mimic physical damage. The trial was conducted in three experimental huts from Pitoa, North-Cameroon where Anopheles gambiae displays metabolic resistance and cohabits with An. funestus. Results Bifenthrin at 50 mg/m2 significantly reduced anophelines' entry rate (>80%). This was not observed at 5 mg/m2. Both treatments increased exophily in An. gambiae, and to a lesser extent in An. funestus. With bifenthrin at high dosage, over 60% reduction in blood feeding and 75–90% mortality rates were observed in both vectors. Despite presence of holes, only a single An. gambiae and two An. funestus females were collected inside the treated net, and all were found dead. The same trends were observed with low dosage bifenthrin though in most cases, no significant difference was found with the untreated control net. Conclusion Bifenthrin-impregnated bednets at 50 mg/m2 were efficient in the reduction of human-vector contact in Pitoa. Considerable personal protection was gained against An. funestus and metabolic pyrethroid resistant An. gambiae populations. PMID:16961938

  10. The physicochemical and environmental factors affecting the distribution of Anopheles merus along the Kenyan coast.

    Kipyab, Pamela C; Khaemba, Battan M; Mwangangi, Joseph M; Mbogo, Charles M

    2015-04-11

    Members of the Anopheles gambiae complex are the main transmitters of malaria. Anopheles merus is a member of the complex found along the Kenyan coast because it breeds in saline waters. An entomological study was conducted in Garithe Malindi District, to investigate the physicochemical and environmental factors affecting the distribution of An. merus. Field and laboratory studies were used to investigate the breeding habitats of the subspecies. Mosquito larvae were sampled using standard dipping technique from small pockets of pools, ponds, hoof prints, road drain, wells and mangrove swamps found in Garithe. All 3(rd) and 4(th) instars of Anopheles larvae sampled were identified microscopically into species. A representative of Anopheles gambiae complex was then identified to specific sibling species using r-DNA PCR technique. The habitats were characterized based on temperature, conductivity, salinity, dissolved oxygen, total dissolved solids, pH, size, distance to nearest house, canopy coverage, surface debris, presence of algae, emergent plants, turbidity and habitat types. A total of 159 morphologically identified late stage instar Anopheles gambiae s.l larvae were selected for r-DNA analysis by PCR. Out of these, 60.4% (n = 96) were Anopheles merus, 8.8% (n = 14) were Anopheles arabiensis, 18.2% (n = 29) were Anopheles gambiae s.s and 12.6% (n = 20) were unknown. Using paired t-test (t (121) = -3.331, P = 0.001) a significantly high proportion of An. merus was observed in all habitats compared to An. arabiensis, and An. gambiae s. s. In habitat characterization, Pearson's correlation analysis test showed different parameters being associated with the occurrence of An. merus larvae in the different habitats sampled. Six out of the 55 correlation coefficients (10.9%) were statistically significant, suggesting non-random association between some pairs of variables. Those that had a significantly high positive correlation with An. merus

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

    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.

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

    Pimenta, Paulo FP; Orfano, Alessandra S; Bahia, Ana C; Duarte, Ana PM; Ríos-Velásquez, Claudia M; Melo, Fabrício F; Pessoa, Felipe AC; Oliveira, Giselle A; Campos, Keillen MM; Villegas, Luis Martínez; Rodrigues, Nilton Barnabé; Nacif-Pimenta, Rafael; Simões, Rejane C; Monteiro, Wuelton M; Amino, Rogerio; Traub-Cseko, Yara M; Lima, José BP; Barbosa, Maria GV; Lacerda, Marcus VG; Tadei, Wanderli P; Secundino, Nágila FC

    2015-01-01

    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. PMID:25742262

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

    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.

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

    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

  15. Quantification of the efficiency of treatment of Anopheles gambiae breeding sites with petroleum products by local communities in areas of insecticide resistance in the Republic of Benin

    Doannio Julien MC MC

    2007-05-01

    Full Text Available Abstract Background The emergence of Anopheles populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for developing new insecticidal molecules or, improving the efficacy of existing insecticides or abandoning those to which resistance has emerged. The use of petroleum products (PP against mosquito larvae had an immense success during early programmes of malaria control, but these compounds were abandoned and replaced in the 1950s by synthetic insecticides probably because of the high performances given by these new products. In the current context of vector resistance, it is important to elucidate the empirical use of PP by quantifying their efficiencies on resistant strains of Anopheles. Methods Larvae of Anopheles Ladji a local resistant strain were exposed to increasing concentrations of various PP (kerosene, petrol and engine oils for 24 hours and the lethal activities recorded. The highest concentration (HiC having no lethal activity (also referred as the NOEL or no effect level and the lowest concentration (LoC100 yielding 100% mortality were rated for each PP on the Ladji strain. Prior to laboratory analysis, KAP studies were conducted in three traditional communities were insecticide resistance is clearly established to confirm the use of PP against mosquitoes. Results Laboratory analysis of petrol, kerosene and engine oils, clearly established their lethal activities on resistant strains of Anopheles larvae. Contrary to existing references, this research revealed that exposed larvae of Anopheles were mostly killed by direct contact toxicity and not by suffocation as indicated in some earlier reports. Conclusion This research could serve as scientific basis to backup the empirical utilisation of PP on mosquito larvae and to envisage possibilities of using PP in some traditional settings where Anopheles have developed

  16. Larval diet affects mosquito development and permissiveness to Plasmodium infection.

    Linenberg, Inbar; Christophides, George K; Gendrin, Mathilde

    2016-12-02

    The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii. We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clarke's Pool Pellets and Nishikoi Fish Pellets, and one flaked diet, Tetramin Fish-Flakes. Larvae grow and develop faster and produce bigger adults when feeding on both types of pellets compared with flakes. This correlates with a higher microbiota load in pellet-fed larvae, in agreement with the known positive effect of the microbiota on mosquito development. Larval diet also significantly influences the prevalence and intensity of Plasmodium berghei infection in adults, whereby Nishikoi Fish Pellets-fed larvae develop into adults that are highly permissive to parasites and survive longer after infection. This correlates with a lower amount of Enterobacteriaceae in the midgut microbiota. Together, our results shed light on the influence of larval feeding on mosquito development, microbiota and vector competence; they also provide useful data for mosquito rearing.

  17. West Nile Virus in Mosquitoes of Iranian Wetlands.

    Bagheri, Masoomeh; Terenius, Olle; Oshaghi, Mohammad Ali; Motazakker, Morteza; Asgari, Sassan; Dabiri, Farrokh; Vatandoost, Hassan; Mohammadi Bavani, Mulood; Chavshin, Ali Reza

    2015-12-01

    The West Nile virus (WNV) transmission cycle includes a wide range of migratory wetland birds as reservoirs, mosquitoes as biological vectors, and equines and humans as dead-end hosts. Despite the presence of potential vector species, there is no information about the existence of WNV in mosquito vectors in Iran. The Iranian West Azerbaijan Province is located in the northwestern part of Iran and has borders with Turkey, Iraq, Armenia, and the Republic of Azerbaijan. The current study was conducted to identify the wetland mosquitoes of the West Azerbaijan Province and their infection with WNV. In this study, 2143 specimens were collected, comprising 1541 adults and 602 larvae. Six species belonging to four genera were collected and identified: Anopheles maculipennis sensu lato (s.l.), Culex (Cx.) hortensis, Cx. pipiens s.l., Cx. theileri, Culiseta longiareolata, and Aedes (Ae.) (Ochlerotatus) caspius. In total, 45 pools of mosquitoes were examined. Two of the adult pools collected from the same location showed the presence of WNV in Ae. (Och.) caspius, from Sangar, Makoo County, as confirmed by PCR and sequencing. Due to the discovery of WNV in the mosquito population of the region, and the presence of wetlands and significant populations of migratory birds, the health sector should carefully monitor the factors involved in the cycle of this disease.

  18. Malaria case in Madagascar, probable implication of a new vector, Anopheles coustani.

    Nepomichene, Thiery N J J; Tata, Etienne; Boyer, Sébastien

    2015-12-01

    Indoor spraying of insecticides and the use of insecticide-treated bed nets are key strategies for national malaria vector control in the central highlands of Madagascar. During the year 2013, malaria outbreaks were reported by the National Malaria Control Programme in the highlands, including the district of Ankazobe. Entomological trapping was carried out in April and May 2013 and in March 2014, using human landing catches, collection of mosquitoes resting in stables and in houses by oral aspirators, and Centers for Disease Control and Prevention light traps. Detection of Plasmodium in mosquitoes was carried out on head and thorax of anopheline females by ELISA, CSP and PCR (Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, or Plasmodium ovale). Human biting rate (HBR), sporozoite index and entomological infection rate (EIR) were calculated for Anopheles funestus, Anopheles arabiensis, Anopheles mascarensis, and Anopheles coustani. In Ankazobe district, the presence of malaria vectors such as An. funestus, An. arabiensis and An. mascarensis was confirmed, and a new and abundant potential vector, An. coustani was detected. Indeed, one individual of An. funestus and two An. coustani were detected positive with P. falciparum while one An. mascarensis and four An. coustani were positive with P. vivax. For An. coustani, in March 2014, the EIR varied from 0.01 infectious bites/person/month (ipm) outdoors to 0.11 ipm indoors. For An. funestus, in April 2013, the EIR was 0.13 ipm. The highest HBR value was observed for An. coustani, 86.13 ipm outdoors. The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive. The implication of An. coustani in malaria transmission was not previously mentioned in Madagascar. Its very high abundance and the detection of Plasmodium coupled with an opportunistic feeding behaviour in villages with malaria cases supports its role in malaria transmission in Madagascar.

  19. Visualizing non infectious and infectious Anopheles gambiae blood feedings in naive and saliva-immunized mice.

    Valerie Choumet

    Full Text Available BACKGROUND: Anopheles gambiae is a major vector of malaria and lymphatic filariasis. The arthropod-host interactions occurring at the skin interface are complex and dynamic. We used a global approach to describe the interaction between the mosquito (infected or uninfected and the skin of mammals during blood feeding. METHODS: Intravital video microscopy was used to characterize several features during blood feeding. The deposition and movement of Plasmodium berghei sporozoites in the dermis were also observed. We also used histological techniques to analyze the impact of infected and uninfected feedings on the skin cell response in naive mice. RESULTS: The mouthparts were highly mobile within the skin during the probing phase. Probing time increased with mosquito age, with possible effects on pathogen transmission. Repletion was achieved by capillary feeding. The presence of sporozoites in the salivary glands modified the behavior of the mosquitoes, with infected females tending to probe more than uninfected females (86% versus 44%. A white area around the tip of the proboscis was observed when the mosquitoes fed on blood from the vessels of mice immunized with saliva. Mosquito feedings elicited an acute inflammatory response in naive mice that peaked three hours after the bite. Polynuclear and mast cells were associated with saliva deposits. We describe the first visualization of saliva in the skin by immunohistochemistry (IHC with antibodies directed against saliva. Both saliva deposits and sporozoites were detected in the skin for up to 18 h after the bite. CONCLUSION: This study, in which we visualized the probing and engorgement phases of Anopheles gambiae blood meals, provides precise information about the behavior of the insect as a function of its infection status and the presence or absence of anti-saliva antibodies. It also provides insight into the possible consequences of the inflammatory reaction for blood feeding and pathogen

  20. Visualizing non infectious and infectious Anopheles gambiae blood feedings in naive and saliva-immunized mice.

    Choumet, Valerie; Attout, Tarik; Chartier, Loïc; Khun, Huot; Sautereau, Jean; Robbe-Vincent, Annie; Brey, Paul; Huerre, Michel; Bain, Odile

    2012-01-01

    Anopheles gambiae is a major vector of malaria and lymphatic filariasis. The arthropod-host interactions occurring at the skin interface are complex and dynamic. We used a global approach to describe the interaction between the mosquito (infected or uninfected) and the skin of mammals during blood feeding. Intravital video microscopy was used to characterize several features during blood feeding. The deposition and movement of Plasmodium berghei sporozoites in the dermis were also observed. We also used histological techniques to analyze the impact of infected and uninfected feedings on the skin cell response in naive mice. The mouthparts were highly mobile within the skin during the probing phase. Probing time increased with mosquito age, with possible effects on pathogen transmission. Repletion was achieved by capillary feeding. The presence of sporozoites in the salivary glands modified the behavior of the mosquitoes, with infected females tending to probe more than uninfected females (86% versus 44%). A white area around the tip of the proboscis was observed when the mosquitoes fed on blood from the vessels of mice immunized with saliva. Mosquito feedings elicited an acute inflammatory response in naive mice that peaked three hours after the bite. Polynuclear and mast cells were associated with saliva deposits. We describe the first visualization of saliva in the skin by immunohistochemistry (IHC) with antibodies directed against saliva. Both saliva deposits and sporozoites were detected in the skin for up to 18 h after the bite. This study, in which we visualized the probing and engorgement phases of Anopheles gambiae blood meals, provides precise information about the behavior of the insect as a function of its infection status and the presence or absence of anti-saliva antibodies. It also provides insight into the possible consequences of the inflammatory reaction for blood feeding and pathogen transmission.

  1. Survivorship of Anopheles darlingi (Diptera: Culicidae in relation with malaria incidence in the Brazilian Amazon.

    Fábio Saito Monteiro de Barros

    Full Text Available We performed a longitudinal study of adult survival of Anopheles darlingi, the most important vector in the Amazon, in a malarigenous frontier zone of Brazil. Survival rates were determined from both parous rates and multiparous dissections. Anopheles darlingi human biting rates, daily survival rates and expectation of life where higher in the dry season, as compared to the rainy season, and were correlated with malaria incidence. The biting density of mosquitoes that had survived long enough for completing at least one sporogonic cycle was related with the number of malaria cases by linear regression. Survival rates were the limiting factor explaining longitudinal variations in Plasmodium vivax malaria incidence and the association between adult mosquito survival and malaria was statistically significant by logistic regression (P<0.05. Survival rates were better correlated with malaria incidence than adult mosquito biting density. Mathematical modeling showed that P. falciparum and P. malariae were more vulnerable to changes in mosquito survival rates because of longer sporogonic cycle duration, as compared to P. vivax, which could account for the low prevalence of the former parasites observed in the study area. Population modeling also showed that the observed decreases in human biting rates in the wet season could be entirely explained by decreases in survival rates, suggesting that decreased breeding did not occur in the wet season, at the sites where adult mosquitoes were collected. For the first time in the literature, multivariate methods detected a statistically significant inverse relation (P<0.05 between the number of rainy days per month and daily survival rates, suggesting that rainfall may cause adult mortality.

  2. A(maize)ing attraction: gravid Anopheles arabiensis are attracted and oviposit in response to maize pollen odours.

    Wondwosen, Betelehem; Hill, Sharon R; Birgersson, Göran; Seyoum, Emiru; Tekie, Habte; Ignell, Rickard

    2017-01-23

    Maize cultivation contributes to the prevalence of malaria mosquitoes and exacerbates malaria transmission in sub-Saharan Africa. The pollen from maize serves as an important larval food source for Anopheles mosquitoes, and females that are able to detect breeding sites where maize pollen is abundant may provide their offspring with selective advantages. Anopheles mosquitoes are hypothesized to locate, discriminate among, and select such sites using olfactory cues, and that synthetic volatile blends can mimic these olfactory-guided behaviours. Two-port olfactometer and two-choice oviposition assays were used to assess the attraction and oviposition preference of gravid Anopheles arabiensis to the headspace of the pollen from two maize cultivars (BH-660 and ZM-521). Bioactive compounds were identified using combined gas chromatography and electroantennographic detection from the headspace of the cultivar found to be most attractive (BH-660). Synthetic blends of the volatile compounds were then assessed for attraction and oviposition preference of gravid An. arabiensis, as above. Here the collected headspace volatiles from the pollen of two maize cultivars was shown to differentially attract and stimulate oviposition in gravid An. arabiensis. Furthermore, a five-component synthetic maize pollen odour blend was identified, which elicited the full oviposition behavioural repertoire of the gravid mosquitoes. The cues identified from maize pollen provide important substrates for the development of novel control measures that modulate gravid female behaviour. Such measures are irrespective of indoor or outdoor feeding and resting patterns, thus providing a much-needed addition to the arsenal of tools that currently target indoor biting mosquitoes.

  3. Insecticide resistance of Anopheles sinensis and An. vagus in Hainan Island, a malaria-endemic area of China.

    Qin, Qian; Li, Yiji; Zhong, Daibin; Zhou, Ning; Chang, Xuelian; Li, Chunyuan; Cui, Liwang; Yan, Guiyun; Chen, Xiao-Guang

    2014-03-03

    Malaria is one of the most important public health problems in Southeast Asia, including Hainan Island, China. Vector control is the main malaria control measure, and insecticide resistance is a major concern for the effectiveness of chemical insecticide control programs. The objective of this study is to determine the resistance status of the main malaria vector species to pyrethroids and other insecticides recommended by the World Health Organization (WHO) for indoor residual sprays. The larvae and pupae of Anopheles mosquitoes were sampled from multiple sites in Hainan Island, and five sites yielded sufficient mosquitoes for insecticide susceptibility bioassays. Bioassays of female adult mosquitoes three days after emergence were conducted in the two most abundant species, Anopheles sinensis and An. vagus, using three insecticides (0.05% deltamethrin, 4% DDT, and 5% malathion) and following the WHO standard tube assay procedure. P450 monooxygenase, glutathione S-transferase and carboxylesterase activities were measured. Mutations at the knockdown resistance (kdr) gene and the ace-1 gene were detected by DNA sequencing and PCR-RFLP analysis, respectively. An. sinensis and An. vagus were the predominant Anopheles mosquito species. An. sinensis was found to be resistant to DDT and deltamethrin. An. vagus was susceptible to deltamethrin but resistant to DDT and malathion. Low kdr mutation (L1014F) frequency (P450 monooxygenase and carboxylesterase activities were detected in deltamethrin-resistant An. sinensis, and significantly higher P450 monooxygenase, glutathione S-transferase and carboxylesterase activities were found in malathion-resistant An. vagus mosquitoes. Multiple insecticide resistance was found in An. sinensis and An. vagus in Hainan Island, a malaria-endemic area of China. Cost-effective integrated vector control programs that go beyond synthetic insecticides are urgently needed.

  4. Impact of rapid urbanization on mosquitoes and their disease transmission potential in Accra and Tema, Ghana.

    Chinery, W A

    1995-06-01

    The total of 75 mosquito species recorded in Accra have declined to 28 species. Contributing factors to this decline and the reduction in prevalence of malaria and bancroftian filariasis in Accra presently include extensive water pollution and a fairly high daily mosquito mortality due to several factors including loss of natural adult resting places, use of mosquito repellents and the probable increase of Anopheles arabiensis population. Presently low yellow fever incidence is due inter alia to loss of its feral vectors and reduced intradomiciliary breeding of Aedes aegypti (L) although more common species like A. gambiae s.l., A. aegypti and C. p. quinquefasciatus could between them transmit many other arboviruses. However because of ready availability of human blood, spill-over of viruses from reservoir hosts to man will be rare. Ipso factor, malaria is the most common mosquito-borne disease with centripetal distribution of prevalence.

  5. Enkapsulasi B. bassiana menggunakan maizena dan daya infeksinya terhadap larva Aedes aegypti, Anopheles sp., Culex sp.

    Mutiara Widawati

    2015-12-01

    Full Text Available Abstract. Encapsulation formulae of mycoinsecticide have to be able to maintain fungus viability and pathogenicity. This mycoinsecticide was developed as an alternative way to control mosquito borne disease. The aim of this study was to encapsulate Beauveria bassiana as viable storage and have the capability to kill larvae of Aedes aegypti, Anopheles sp. and Culex sp. Mosquito larvae obtained from laboratory reared at health research laboratory; Loka Litbang P2B2 Ciamis. The treatments made in this study were the formu-lation of cornstarch and controls for comparison. This study showed potential formulation of cornstarch encapsulation as a biolarvacidal. Cornstarch formulations proven to be succeed in maintaining fungus viability, however, the pathogenicity of the microcapsule still not effective to kill Aedes, Culex and Anopheles larvae. Keywords: encapsulation, Beauveria bassiana, Ae.aegypti, Anopheles sp., Culex sp. Abstrak. Pembuatan formula bioinsektisida yang optimal sebagai salah satu alternatif untuk pengen-dalian nyamuk vektor perlu di kembangkan. Sediaan mikoinsektisida yang dibuat harus dapat memper-tahankan viabilitas jamur B. bassiana sehingga masih efektif pada saat penggunaannya. Salah satu cara yang digunakan untuk menjaga kestabilan sediaan mikoinsektisida yang berdampak langsung pada via-bilitas jamur adalah dengan menerapkan metode enkapsulasi. Penelitian ini bertujuan untuk meng-hasilkan sediaan mikokapsul dari Beauvaria bassiana melalui proses enkapsulasi menggunakan maizena yang memiliki kapabilitas tinggi sebagai penyimpan B. bassiana dan efektif dalam membunuh larva dan telur Aedes aegypti, Anopheles sp. dan Culex sp. Semua larva uji berasal dari insektarium laboratorium penelitian kesehatan Loka litbang P2B2 Ciamis. Pembuatan enkapsulasi dimulai dengan kultur dan pema-nenan B. bassiana, uji viabilitas, proses enkapsulasi serta uji larvasida di laboratorium. Uji dilakukan dengan satu perlakuan dan satu kontrol untuk

  6. Malaria infectivity of xanthurenic acid-deficient anopheline mosquitoes produced by TALEN-mediated targeted mutagenesis.

    Yamamoto, Daisuke S; Sumitani, Megumi; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki

    2018-02-01

    Anopheline mosquitoes are major vectors of malaria parasites. When the gametocytes of the malaria parasite are transferred from a vertebrate to mosquitoes, they differentiate into gametes, and are fertilized in the midguts of mosquitoes. Xanthurenic acid (XA), a waste product of the ommochrome synthesis pathway, has been shown to induce exflagellation during microgametogenesis in vitro; however, it currently remains unclear whether endogenous XA affects the infectivity of anopheline mosquitoes to malaria parasites in vivo due to the lack of appropriate experimental systems such as a XA-deficient line. In the present study, we produced a XA-deficient line in Anopheles stephensi using transcription activator-like effector nuclease (TALEN)-mediated gene targeting (knockout) of the kynurenine 3-monooxygenase (kmo) gene, which encodes an enzyme that participates in the ommochrome synthesis pathway. The knockout of kmo resulted in the absence of XA, and oocyst formation was inhibited in the midguts of these XA-deficient mosquitoes, which, in turn, reduced sporozoite numbers in their salivary glands. These results suggest that endogenous XA stimulates exflagellation, and enhances the infectivity of anopheline mosquitoes to malaria parasites in vivo. The XA-deficient line of the anopheline mosquito provides a useful system for analyzing and understanding the associated factors of malaria gametogenesis in the mosquito midgut.

  7. British Container Breeding Mosquitoes: The Impact of Urbanisation and Climate Change on Community Composition and Phenology

    Townroe, Susannah; Callaghan, Amanda

    2014-01-01

    The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK. PMID:24759617

  8. Multiple blood meals in Anopheles darlingi (Diptera: Culicidae).

    de Oliveira, Caroline Dantas; Tadei, Wanderli Pedro; Abdalla, Fábio Camargo; Paolucci Pimenta, Paulo Filemon; Marinotti, Osvaldo

    2012-12-01

    Anopheles darlingi is an important vector of human malaria in the Amazon. Adult females of this mosquito species require a blood meal to develop eggs, preferring humans to other blood sources. Although gonotrophic concordance has been described as the norm for An. darlingi, here we report An. darlingi female mosquitoes taking two or more blood meals within their first gonotrophic cycle. Only half of field-captured adult females fed one blood meal developed follicles to Christophers' stage V. This outcome is dependent on larval nutrition, as 88% of laboratory-raised well-nourished females completed the first gonotrophic cycle with only one blood meal, while less nourished females needed additional blood meals. Half of the field-captured blood-seeking An. darlingi females had follicles in intermediate (IIIa and IIIb) and final (V) stages of the gonotrophic cycle, supporting the conclusion that An. darlingi blood feed more than once during a gonotrophic cycle. Additionally, we observed females attempting to blood feed a second time during the same day. Additional studies of An. darlingi biting behavior are necessary to accurately estimate Plasmodium sp. entomologic inoculation rates throughout the An. darlingi vast geographical distribution. © 2012 The Society for Vector Ecology.

  9. Almendravirus: A Proposed New Genus of Rhabdoviruses Isolated from Mosquitoes in Tropical Regions of the Americas.

    Contreras, Maria Angelica; Eastwood, Gillian; Guzman, Hilda; Popov, Vsevolod; Savit, Chelsea; Uribe, Sandra; Kramer, Laura D; Wood, Thomas G; Widen, Steven G; Fish, Durland; Tesh, Robert B; Vasilakis, Nikos; Walker, Peter J

    2017-01-11

    The Rhabdoviridae is a diverse family of negative-sense single-stranded RNA viruses, many of which infect vertebrate hosts and are transmitted by hematophagous arthropods. Others appear to be arthropod specific, circulating only within arthropod populations. Herein, we report the isolation and characterization of three novel viruses from mosquitoes collected from the Americas. Coot Bay virus was isolated from Anopheles quadrimaculatus mosquitoes collected in the Everglades National Park, Florida; Rio Chico virus was isolated from Anopheles triannulatus mosquitoes collected in Panama; and Balsa virus was isolated from two pools of Culex erraticus mosquitoes collected in Colombia. Sequence analysis indicated that the viruses share a similar genome organization to Arboretum virus and Puerto Almendras virus that had previously been isolated from mosquitoes collected in Peru. Each genome features the five canonical rhabdovirus structural protein genes as well as a gene encoding a class 1A viroporin-like protein (U1) located between the G and L genes (3'-N-P-M-G-U1-L-5'). Phylogenetic analysis of complete L protein sequences indicated that all five viruses cluster in a unique clade that is relatively deeply rooted in the ancestry of animal rhabdoviruses. The failure of all viruses in this clade to grow in newborn mice or vertebrate cells in culture suggests that they may be poorly adapted to replication in vertebrates. © The American Society of Tropical Medicine and Hygiene.

  10. Almendravirus: A Proposed New Genus of Rhabdoviruses Isolated from Mosquitoes in Tropical Regions of the Americas

    Contreras, Maria Angelica; Eastwood, Gillian; Guzman, Hilda; Popov, Vsevolod; Savit, Chelsea; Uribe, Sandra; Kramer, Laura D.; Wood, Thomas G.; Widen, Steven G.; Fish, Durland; Tesh, Robert B.; Vasilakis, Nikos; Walker, Peter J.

    2017-01-01

    The Rhabdoviridae is a diverse family of negative-sense single-stranded RNA viruses, many of which infect vertebrate hosts and are transmitted by hematophagous arthropods. Others appear to be arthropod specific, circulating only within arthropod populations. Herein, we report the isolation and characterization of three novel viruses from mosquitoes collected from the Americas. Coot Bay virus was isolated from Anopheles quadrimaculatus mosquitoes collected in the Everglades National Park, Florida; Rio Chico virus was isolated from Anopheles triannulatus mosquitoes collected in Panama; and Balsa virus was isolated from two pools of Culex erraticus mosquitoes collected in Colombia. Sequence analysis indicated that the viruses share a similar genome organization to Arboretum virus and Puerto Almendras virus that had previously been isolated from mosquitoes collected in Peru. Each genome features the five canonical rhabdovirus structural protein genes as well as a gene encoding a class 1A viroporin-like protein (U1) located between the G and L genes (3′-N-P-M-G-U1-L-5′). Phylogenetic analysis of complete L protein sequences indicated that all five viruses cluster in a unique clade that is relatively deeply rooted in the ancestry of animal rhabdoviruses. The failure of all viruses in this clade to grow in newborn mice or vertebrate cells in culture suggests that they may be poorly adapted to replication in vertebrates. PMID:27799634

  11. Repellent Activity of TRIG (N-N Diethyl Benzamide against Man-Biting Mosquitoes

    Shandala Msangi

    2018-01-01

    Full Text Available A study was conducted to assess efficacy of a new repellent brand TRIG (15% N-N Diethyl Benzamide when compared to DEET (20% N-N Methyl Toluamide. The repellents were tested in laboratory and field. In the laboratory, the repellence was tested on human volunteers, by exposing their repellent-treated arms on starved mosquitoes in cages for 3 minutes at hourly intervals, while counting the landing and probing attempts. Anopheles gambiae and Aedes aegypti mosquitoes were used. Field evaluation was conducted by Human Landing Catch technique. During the night, the repellents were applied on arms and legs and mosquitoes landing on these areas were collected. In laboratory tests, TRIG provided complete protection (100% against Anopheles gambiae when applied at 1.25 g, while DEET provided this at 0.75 g. When tested on Aedes aegypti, TRIG provided complete protection when applied at 1 g, compared to 0.5 g for DEET. In the field, when applied at a recommended dose, both TRIG and DEET achieved above 90% protection against both An. arabiensis and Culex quinquefasciatus and a Complete Protection Time of about 6 hrs against both species of mosquitoes. The performances of the two products were found to be comparable and TRIG was recommended for use as repellent against mosquito bites.

  12. Repellent Activity of TRIG (N-N Diethyl Benzamide) against Man-Biting Mosquitoes.

    Msangi, Shandala; Kweka, Eliningaya; Mahande, Aneth

    2018-01-01

    A study was conducted to assess efficacy of a new repellent brand TRIG (15% N-N Diethyl Benzamide) when compared to DEET (20% N-N Methyl Toluamide). The repellents were tested in laboratory and field. In the laboratory, the repellence was tested on human volunteers, by exposing their repellent-treated arms on starved mosquitoes in cages for 3 minutes at hourly intervals, while counting the landing and probing attempts. Anopheles gambiae and Aedes aegypti mosquitoes were used. Field evaluation was conducted by Human Landing Catch technique. During the night, the repellents were applied on arms and legs and mosquitoes landing on these areas were collected. In laboratory tests, TRIG provided complete protection (100%) against Anopheles gambiae when applied at 1.25 g, while DEET provided this at 0.75 g. When tested on Aedes aegypti, TRIG provided complete protection when applied at 1 g, compared to 0.5 g for DEET. In the field, when applied at a recommended dose, both TRIG and DEET achieved above 90% protection against both An. arabiensis and Culex quinquefasciatus and a Complete Protection Time of about 6 hrs against both species of mosquitoes. The performances of the two products were found to be comparable and TRIG was recommended for use as repellent against mosquito bites.

  13. Assessment of Clarias gariepinus as a biological control agent against mosquito larvae.

    Chala, Buze; Erko, Berhanu; Animut, Abebe; Degarege, Abraham; Petros, Beyene

    2016-05-31

    The emergence and spread of insecticide resistant mosquitoes renewed interest in investigating the use of larvivorous fish as a biological control agent. The potential of Clarias gariepinus fish in controlling Anopheles arabiensis and culicine larvae was assessed under laboratory and semi-field conditions. Small size (15-20 cm) C. gariepinus fish consumed greater number of mosquito larvae than the large size fish (25-40 cm) in the multivariate regression model (β = 13.36, 95 % CI = 4.57, 22.15). The Anopheles larvae consumed was greater in number than the culicines larvae consumed by the fish (β = 12.10, 95 % CI = 3.31, 20.89). The number of larvae consumed was greater during the night hours than during the light hours (β = 30.06, 95 % CI = 21.27, 38.85). Amount of supplementary fish food did not cause significant differences in the number of mosquito larvae consumed by the fish among different groups. C. gariepinus was observed to feed on mosquito larvae under laboratory and semi-field conditions. C. gariepinus fed on the larvae of An. arabiensis and culicines readily. Hence, it can be used as an alternative mosquito control agent in Ethiopia where the breeding habitats are small and localized.

  14. Resistance Level of Mosquito Species (Diptera: Culicidae from Shandong Province, China

    Hong-Mei Liu

    2015-01-01

    Full Text Available This study describes the aquatic habitats, species composition, and the insecticide resistance level of the mosquito Culex pipiens pallens in Shandong Province, China. A cross-sectional survey of mosquito larval habitats was conducted from May to November 2014 to determine the species composition and larval abundance. Larvae were collected using the standard dipping technique, and a total of four habitat types were sampled. The fourth instar larvae of Cx. pipiens pallens collected in each habitat type were tested for resistance to five insecticides according to a WHO bioassay. A total of 7,281 mosquito larvae were collected, of which 399 (5.48% were categorized as Anopheles mosquito larvae ( An. sinensis , 6636 (91.14% as culicine larvae ( Cx. pipiens pallens, Cx. tritaeniorhynchus, Cx. halifaxii, and Cx. bitaeniorhynchus , 213 (2.93% as Armigeres larvae, and 33 (0.45% as Aedes larvae ( Aedes albopictus . In addition, a total of 1,149 mosquito pupae were collected. Culex larvae were distributed in all habitats investigated. Tukeys HSD analysis showed that roadside drainages were the most productive habitat type for Culex larvae. Armigeres species were found only in drains, Aedes only in water tanks, and Anopheles in water that was comparatively clear and rich in emergent plants. Bioassay showed that the maximum resistance level of Cx. pipiens pallens was to deltamethrin, while it was lowest to plifenate. The productivity of various mosquitoes in different habitat types is very heterogeneous. It is particularly important to modify human activity and the environment to achieve effective mosquito vector control. For effective larval control, the type of habitat should be considered, and the most productive habitat type should be given priority in mosquito abatement programs.

  15. Efectividad y supervivencia de Romanomermis culicivorax en criaderos naturales de larvas de mosquitos

    Pérez-Pacheco, Rafael; Santamarina-Mijares, Alberto; Vásquez-López, Alfonso; Martínez-Tomás, Sabino H.; Suárez-Espinosa, Javier

    2009-01-01

    Los mosquitos (Díptera: Culicidae) son transmisores de agentes causales de paludismo, dengue y encefalitis del Nilo occidental y causan fuertes molestias a los humanos. El objetivo del presente estudio fue determinar el efecto de aplicar 500 y 1000 nemátodos, Romanomermis culicivorax Ross y Smith, por metro cuadrado en poblaciones de larvas de Anopheles albimanus Wiedeman, Culex nigipalpus Theobald y Uranotaenia sapphirina Oster-Sacken, para su control en 13 criaderos naturales. El diseño exp...

  16. Analyzing mosquito (Diptera: culicidae diversity in Pakistan by DNA barcoding.

    Muhammad Ashfaq

    Full Text Available Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications.Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 2010-2013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection. The genus Aedes (Stegomyia comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 0-2.4%, while congeneric species showed from 2.3-17.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments.As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations.

  17. Species composition, co-occurrence, association and affinity indices of mosquito larvae (Diptera: Culicidae) in Mazandaran Province, northern Iran.

    Nikookar, Seyed Hassan; Azari-Hamidian, Shahyad; Fazeli-Dinan, Mahmoud; Nasab, Seyed Nouraddin Mousavi; Aarabi, Mohsen; Ziapour, Seyyed Payman; Enayati, Ahmadali

    2016-05-01

    Although considerable progress has been made in the past years in management of mosquito borne diseases such as malaria, dengue, yellow fever and West Nile fever through research in biology and ecology of the vectors, these diseases are still major threats to human health. Therefore, more research is required for better management of the diseases. This investigation provides information on the composition, co-occurrence, association and affinity indices of mosquito larvae in Mazandaran Province, northern Iran. In a large scale field study, mosquito larvae were collected from 120 sentinel sites in 16 counties in Mazandaran Province, using standard 350 ml dipper. Sampling took place monthly from May to December 2014. Collected larvae were mounted on glass slides using de Faure's medium and were diagnosed using morphological characters. Totally, 19,840 larvae were collected including three genera and 16 species from 120 larval habitats, as follows: Anopheles claviger, Anopheles hyrcanus, Anopheles maculipennis s.l., Anopheles marteri, Anopheles plumbeus, Anopheles pseudopictus, Culex pipiens, Culex tritaeniorhynchus, Culex torrentium, Culex perexiguus, Culex territans, Culex mimeticus, Culex hortensis, Culiseta annulata, Culiseta longiareolata, and Culiseta morsitans. Predominant species were Cx. pipiens and An. maculipennis s.l. which show the highest co-occurrence. The pair of species An. hyrcanus/An. pseudopictus showed significant affinity and association. High co-occurrence of the predominant species Cx. pipiens and An. maculipennis s.l. in the study area is of considerable importance in terms of vector ecology. It was also revealed that An. pseudopictus/An. hyrcanus often occur sympatrically indicating their common habitat requirements. The information may be equally important when vector control measures are considered. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Artificial Diets for Mosquitoes

    Kristina K. Gonzales

    2016-12-01

    Full Text Available Mosquito-borne diseases are responsible for more than a million human deaths every year. Modern mosquito control strategies such as sterile insect technique (SIT, release of insects carrying a dominant lethal (RIDL, population replacement strategies (PR, and Wolbachia-based strategies require the rearing of large numbers of mosquitoes in culture for continuous release over an extended period of time. Anautogenous mosquitoes require essential nutrients for egg production, which they obtain through the acquisition and digestion of a protein-rich blood meal. Therefore, mosquito mass production in laboratories and other facilities relies on vertebrate blood from live animal hosts. However, vertebrate blood is expensive to acquire and hard to store for longer times especially under field conditions. This review discusses older and recent studies that were aimed at the development of artificial diets for mosquitoes in order to replace vertebrate blood.

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

    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.

  20. Implications for changes in Anopheles darlingi biting behaviour in three communities in the peri-Iquitos region of Amazonian Peru.

    Moreno, Marta; Saavedra, Marlon P; Bickersmith, Sara A; Lainhart, William; Tong, Carlos; Alava, Freddy; Vinetz, Joseph M; Conn, Jan E

    2015-07-30

    Malaria transmission in the peri-Iquitos region of Amazonian Peru has been designated as seasonal and hypo-endemic with recently described hyper-endemic hotspots. Despite relatively recent distribution of long-lasting insecticidal bed nets (LLINs), malaria in Amazonian Peru persists and increased substantially in 2014 compared to previous years. Anopheles darlingi, identified as the main malaria vector, is known for its variable behaviour depending on locality and environment. To evaluate vector biology metrics in relation to seasonality and malaria transmission, mosquito collections were carried out in three localities in the peri-Iquitos region, Loreto, Peru in 2011-2012. Human landing catch (HLC) collection method, Shannon (SHA) and CDC trap types were compared for effectiveness in a neotropical setting. Abundance, human biting rate and entomological inoculation rate (EIR) were measured to provide an updated view of transmission patterns post-LLIN distribution. HLC collected significantly more anopheline mosquitoes than SHA and CDC light traps. Anopheles darlingi was the most prevalent species in all three villages (84% overall). Biting patterns varied depending on trap type, season and village. EIR varied temporally (monthly) and spatially and the highest (2.52) occurred during the 2012 malaria outbreak in Cahuide. Unexpectedly there was a high infection rate (1.47 and 1.75) outside the normal malaria transmission season, coincident with a second local outbreak in Cahuide. The first identification of Anopheles dunhami and Anopheles oswaldoi C in Peru, using molecular markers, is also reported in this study. These data underscore the importance of HLC as the most meaningful collection method for measuring vector biology indices in this region. The highest monthly EIR provides additional evidence of seasonal transmission in riverine localities correlated with high river levels, and An. darlingi as the only contributor to transmission. The trend of an increase in

  1. Postpartum Aplastic Anemia Presenting as Pancytopenia Due to Malarial Infection

    Shah, M. U.; Sundhu, M. A.; Hussain, M. Z.

    2013-01-01

    Pancytopenia is a condition with decreased numbers of all cell lines. Aplastic anemia is a common cause although malarial infection causing lysis of RBCs may also partly mimic this condition. The infection may also damage the patient's bone marrow resulting in pancytopenia as well. We present the case of a post-partum female patient who reported with fever, body aches and shortness of breath one month after the delivery of her baby. All blood cell counts were decreased and peripheral blood smear showed malarial parasites. Anti-malarial treatment was initiated following which the fever subsided but, despite regular transfusions, the blood counts remained low. Bone marrow biopsy report revealed P. falciparum pigments along with hypocellularity characteristic of severe aplastic anemia. Consequently, bone marrow transplantation was advised as a therapeutic measure. This case report highlights the increased susceptibility of pregnant women to malaria in endemic areas and subsequent aplastic anemia. (author)

  2. Laboratory evaluation of the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae.

    Evans, R G

    1993-09-01

    In a laboratory study, the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae was evaluated at field, 1/3 field and 1/10 field rates using WHO conical exposure chambers and excito-repellency test boxes. Bendiocarb was the least irritant insecticide at all rates, inducing levels of takeoff, flight and exiting behavior similar to those of a distilled water control treatment. Of those mosquitoes introduced to the bendiocarb-treated boxes, not more than 1% exited and survived at any dose rate. Lambda-cyhalothrin and DDT were highly irritant to An. gambiae, inducing a strong stimulation to take off and fly and also a high level of exiting. Exiting-survival rates associated with lambda-cyhalothrin and DDT were between 15 and 51%. The relevance of these findings to the control of mosquito populations and the prevention of malaria transmission is discussed.

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

    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.

  4. Effects of the anti-malarial compound cryptolepine and its analogues in human lymphocytes and sperm in the Comet assay.

    Gopalan, Rajendran C; Emerce, Esra; Wright, Colin W; Karahalil, Bensu; Karakaya, Ali E; Anderson, Diana

    2011-12-15

    Malaria is a mosquito-borne infectious disease caused by the genus Plasmodium. It causes one million deaths per year in African children under the age of 5 years. There is an increasing development of resistance of malarial parasites to chloroquine and other currently used anti-malarial drugs. Some plant products such as the indoloquinoline alkaloid cryptolepine have been shown to have potent activity against P. falciparum in vitro. On account of its toxicity, cryptolepine is not suitable for use as an antimalarial drug but a number of analogues of cryptolepine have been synthesised in an attempt to find compounds that have reduced cytotoxicity and these have been investigated in the present study in human sperm and lymphocytes using the Comet assay. The results suggest that cryptolepine and the analogues cause DNA damage in lymphocytes, but appear to have no effect on human sperm at the assessed doses. In the context of antimalarial drug development, the data suggest that all cryptolepine compounds and in particular 2,7-dibromocryptolepine cause DNA damage and therefore may not be suitable for pre clinical development as antimalarial agents. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. The Romanomermis iyengari parasite for Anopheles pseudopunctipennis suppression in natural habitats in Oaxaca State, Mexico

    Santamarina Mijares Alberto

    1999-01-01

    Full Text Available In September and November 1996 Romanomermis iyengari Welch, a parasite of larval mosquitoes, was released in 44 natural larval habitat sites of Anopheles pseudopunctipennis Theobald in an attempt to reduce the larval populations of this important malaria vector. The selected treatment sites ranged in size from 5 to 500 m². The study was carried out in Pochutla District of Oaxaca State, on the Pacific coast of Mexico. Chemical pesticides to reduce vector populations have been the principal tool in malaria suppression campaigns. However, the excessive use of these chemicals has created pesticide resistance and other serious collateral problems. Therefore, a biological control project using agents that are pathogens of Anopheles larvae was initiated in 1996. The principal objective was to establish mass rearing capacities for R. iyengari. Detailed methodology for rearing and introducing these nematodes into mosquito larval habitats was established at the National Polytechnic Institute of Oaxaca State. Before application of the parasites to larval habitats, site characteristics were determined, including size, depth, aquatic vegetation, salinity, pH, conductivity, temperature, and pretreatment larval density. With a compressed air sprayer, infective mermithid parasites were released at rates of either 2000 or 3000/m², and the parasites produced high levels of infection. Anopheles populations were sampled 72 h posttreatment, and the larvae obtained were taken to the laboratory and examined through microscopic dissection to determine infection levels and mean parasitism. Nematode parasitism ranged from 85 to 100% at all the treatment sites, even though no previous information concerning field parasitism of An. pseudopunctipennis by R. iyengari has been reported. In addition, a significant reduction of mosquito larval density at the treatment sites was found five days after the nematode application. Levels of parasitism were indicative of the number

  6. Bioactivity of sea grass against the malarial fever mosquito Culex quinquefasciatus

    Suburamaniyan Vijayakumar

    2014-08-01

    Full Text Available Objective: To identify the larvicidal activity of the seagrass extracts against Culex quinquefasciatus (Cx. quinquefasciatus Methods: Seagrass extracts, Halodule pinifolia (H. pinifolia, Cymodocea serrulata (C. serrulata and Thalasia testudinum (T. testudinum were dissolved in dimethylsulfoxide to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Cx. quinquefasciatus were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01 mg-0.1 mg. After 24 h the mortality rate was identified with the formulae [(% of test mortality - % of control mortality/(100 - % of control mortality]伊100. Each experiment was conducted with three replicates and a concurrent control group. A control group consisted of 1 mL of dimethylsulfoxide and 199 mL of distilled water only. Results: The root extract of H. pinifolia showed maximum larvicidal activity with minimum concentration of extract of LC 50 value of (0.614依0.006 µg/mL with lower confidence limit-upper confidence limit value of (0.052-0.072 and LC90 value of 0.9120 µg/mL followed by leaf extract of C. serrulata LC 50 value of (0.074依0.008 µg/mL and LC90 value of 0.1487 µg/mL. T. testudinum leaf extract showed LC 50 value of (0.082依0.006 µg/mL. The regression equation of root and leaf extract of H. pinifolia for 4 th instar larvae of Cx. quinquefasciatus were Y=5.229+1.36x (R2=0.993 and Y=2.369+1.21x (R2=0.878 respectively and analysis of variation was significant at P<0.05 level. The result of the preliminary phytochemical constituents showed the presence of saponin, steroids, terpenoid, phenols, protein and sugars. Conclusions: From the present study the ethanolic extracts of seagrass of H. pinifolia possess lead compound for development of larvicidal activity.

  7. Desiccation tolerance in Anopheles coluzzii: the effects of spiracle size and cuticular hydrocarbons

    Arcaz, Arthur C.; Huestis, Diana L.; Dao, Adama; Yaro, Alpha S.; Diallo, Moussa; Andersen, John; Blomquist, Gary J.; Lehmann, Tovi

    2016-01-01

    ABSTRACT The African malaria mosquitoes Anopheles gambiae and Anopheles coluzzii range over forests and arid areas, where they withstand dry spells and months-long dry seasons, suggesting variation in their desiccation tolerance. We subjected a laboratory colony (G3) and wild Sahelian mosquitoes during the rainy and dry seasons to desiccation assays. The thoracic spiracles and amount and composition of cuticular hydrocarbons (CHCs) of individual mosquitoes were measured to determine the effects of these traits on desiccation tolerance. The relative humidity of the assay, body water available, rate of water loss and water content at death accounted for 88% of the variation in desiccation tolerance. Spiracle size did not affect the rate of water loss or desiccation tolerance of the colony mosquitoes, as was the case for the total CHCs. However, six CHCs accounted for 71% of the variation in desiccation tolerance and three accounted for 72% of the variation in the rate of water loss. Wild A. coluzzii exhibited elevated desiccation tolerance during the dry season. During that time, relative thorax and spiracle sizes were smaller than during the rainy season. A smaller spiracle size appeared to increase A. coluzzii's desiccation tolerance, but was not statistically significant. Seasonal changes in CHC composition were detected in Sahelian A. coluzzii. Stepwise regression models suggested the effect of particular CHCs on desiccation tolerance. In conclusion, the combination of particular CHCs along with the total amount of CHCs is a primary mechanism conferring desiccation tolerance in A. coluzzii, while variation in spiracle size might be a secondary mechanism. PMID:27207644

  8. Spatial and sex-specific dissection of the Anopheles gambiae midgut transcriptome

    Mahairaki Vassiliki

    2007-01-01

    Full Text Available Abstract Background The midgut of hematophagous insects, such as disease transmitting mosquitoes, carries out a variety of essential functions that mostly relate to blood feeding. The midgut of the female malaria vector mosquito Anopheles gambiae is a major site of interactions between the parasite and the vector. Distinct compartments and cell types of the midgut tissue carry out specific functions and vector borne pathogens interact and infect different parts of the midgut. Results A microarray based global gene expression approach was used to compare transcript abundance in the four major female midgut compartments (cardia, anterior, anterior part of posterior and posterior part of posterior midgut and between the male and female Anopheles gambiae midgut. Major differences between the female and male midgut gene expression relate to digestive processes and immunity. Each compartment has a distinct gene function profile with the posterior midgut expressing digestive enzyme genes and the cardia and anterior midgut expressing high levels of antimicrobial peptide and other immune gene transcripts. Interestingly, the cardia expressed several known anti-Plasmodium factors. A parallel peptidomic analysis of the cardia identified known mosquito antimicrobial peptides as well as several putative short secreted peptides that are likely to represent novel antimicrobial factors. Conclusion The A. gambiae sex specific midgut and female midgut compartment specific transcriptomes correlates with their known functions. The significantly greater functional diversity of the female midgut relate to hematophagy that is associated with digestion and nutrition uptake as well as exposes it to a variety of pathogens, and promotes growth of its endogenous microbial flora. The strikingly high proportion of immunity related factors in the cardia tissue most likely serves the function to increase sterility of ingested sugar and blood. A detailed characterization of the

  9. Molecular characterization of novel mosquito-borne Rickettsia spp. from mosquitoes collected at the Demilitarized Zone of the Republic of Korea.

    Maina, Alice N; Klein, Terry A; Kim, Heung-Chul; Chong, Sung-Tae; Yang, Yu; Mullins, Kristin; Jiang, Ju; St John, Heidi; Jarman, Richard G; Hang, Jun; Richards, Allen L

    2017-01-01

    Rickettsiae are associated with a diverse range of invertebrate hosts. Of these, mosquitoes could emerge as one of the most important vectors because of their ability to transmit significant numbers of pathogens and parasites throughout the world. Recent studies have implicated Anopheles gambiae as a potential vector of Rickettsia felis. Herein we report that a metagenome sequencing study identified rickettsial sequence reads in culicine mosquitoes from the Republic of Korea. The detected rickettsiae were characterized by a genus-specific quantitative real-time PCR assay and sequencing of rrs, gltA, 17kDa, ompB, and sca4 genes. Three novel rickettsial genotypes were detected (Rickettsia sp. A12.2646, Rickettsia sp. A12.2638 and Rickettsia sp. A12.3271), from Mansonia uniformis, Culex pipiens, and Aedes esoensis, respectively. The results underscore the need to determine the Rickettsia species diversity associated with mosquitoes, their evolution, distribution and pathogenic potential.

  10. Human biting activity, spatial-temporal distribution and malaria vector role of Anopheles calderoni in the southwest of Colombia.

    Orjuela, Lorena I; Ahumada, Martha L; Avila, Ivonni; Herrera, Sócrates; Beier, John C; Quiñones, Martha L

    2015-06-24

    Anopheles calderoni was first recognized in Colombia in 2010 as this species had been misidentified as Anopheles punctimacula due to morphological similarities. An. calderoni is considered a malaria vector in Peru and has been found naturally infected with Plasmodium falciparum in Colombia. However, its biting behaviour, population dynamics and epidemiological importance have not been well described for Colombia. To assess the contribution of An. calderoni to malaria transmission and its human biting behaviour and spatial/temporal distribution in the southwest of Colombia, human landing catches (HLC) and larval collections were carried out in a cross-sectional, entomological study in 22 localities between 2011 and 2012, and a longitudinal study was performed in the Boca de Prieta locality in Olaya Herrera municipality between July 2012 and June 2013. All mosquitoes determined as An. calderoni were tested by ELISA to establish infection with Plasmodium spp. Larvae of An. calderoni were found in four localities in 12 out of 244 breeding sites inspected. An. calderoni adults were collected in 14 out of 22 localities during the cross-sectional study and represented 41.3% (459 of 1,111) of the collected adult specimens. Other species found were Anopheles albimanus (54.7%), Anopheles apicimacula (2.1%), Anopheles neivai (1.7%), and Anopheles argyritarsis (0.2%). In the localities that reported the highest malaria Annual Parasite Index (>10/1,000 inhabitants) during the year of sampling, An. calderoni was the predominant species (>90% of the specimens collected). In the longitudinal study, 1,528 An. calderoni were collected by HLC with highest biting rates in February, May and June 2013, periods of high precipitation. In general, the species showed a preference to bite outdoors (p Colombia. Its observed preference for outdoor biting is a major challenge for malaria control.

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

    Marta Moreno

    2017-02-01

    Full Text Available 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.

  12. Host preferences and feeding patterns of Anopheles sinensis Wiedemann in three sites of Shandong province, China.

    Zhang, Chongxing; Shi, Guihong; Cheng, Peng; Liu, Lijuan; Gong, Maoqing

    2017-01-01

    Anopheles sinensis Wiedemann is a major vector of malaria and is among the dominant species in Shandong province of China. Knowledge of the blood-feeding patterns of mosquitoes is crucial for elimination of malaria vectors. However, little information is available on the blood-feeding behaviour of An. sinensis mosquitoes in Shandong province. This study was carried out to compare the blood-feeding behaviour of An. sinensis in malaria-endemic areas of Shandong province China. Adult Anopheles mosquitoes were collected from three malaria-endemic areas (Jimo, Yinan and Shanxian), during the peak months of mosquito population (August and September) from 2014 to 2015. Indoor-resting mosquitoes and outdoor-resting blood-fed females were sampled in the morning hours (0600 to 0900 hrs) from 10 randomly selected houses using pyrethrum spray catch method, and sweeping with an insect net. ELISA was used for the identification of blood meal. The blood meal of each mosquito was tested against antisera specific to human, pig, dog, cow, goat, horse (mule) and fowl. At all indoor study locations of Jimo, Yinan and Shanxian, 59.4, 68.1 and 98.8% blood-engorged female An. sinensis collected from cattle sheds fed almost exclusively on bovines, respectively. For outdoor locations, at Jimo site, 27.27 and 49.55% An. sinensis fed on cattle and pigs; at Yinan, 30.42% fed on cattle and 36.88% fed both on cattle and goats, while no pig antibodies were detected. At Shanxian, percent of An. sinensis that fed on cattle, pigs and cattle-goat was 20.72, 27.62 and 21.78%, respectively. The analysis of An. sinensis blood meals in all the three studied areas from human houses, cattle sheds, pig sheds and mixed dwellings revealed that An. sinensis prefers cattle hosts, and can feed on other available animal hosts if the cattle hosts are absent, and the mosquitoes readily feed on humans when domestic animals (cattle and pigs) are not nearby for feeding. The analysis of blood meal revealed that An

  13. Insecticide mixtures for mosquito net impregnation against malaria vectors

    Corbel V.

    2002-09-01

    Full Text Available Insecticides belonging to the pyrethroid family are the only compounds currently available for the treatment of mosquito nets. Unfortunately, some malaria vector species have developed resistance to pyrethroids and the lack of alternative chemical categories is a great concern. One strategy for resistance management would be to treat mosquito nets with a mixture associating two insecticides having different modes of action. This study presents the results obtained with insecticide mixtures containing several proportions of bifenthrin (a pyrethroid insecticide and carbosulfan (a carbamate insecticide. The mixtures were sprayed on mosquito net samples and their efficacy were tested against a susceptible strain of Anopheles gambiae, the major malaria vector in Africa. A significant synergism was observed with a mixture containing 25 mg/m2 of bifenthrin (half the recommended dosage for treated nets and 6.25 mg/m2 of carbosulfan (about 2 % of the recommended dosage. The observed mortality was significantly more than expected in the absence of any interaction (80 % vs 41 % and the knock-down effect was maintained, providing an effective barrier against susceptible mosquitoes.

  14. Controlling Mosquitoes Indoors

    2016-08-23

    Mosquitoes can carry viruses, like West Nile and Zika. In this podcast, Mr. Hubbard teaches his neighbors, the Smith family, ways to help reduce the number of mosquitoes inside their home.  Created: 8/23/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/23/2016.

  15. Plasmodium evasion of mosquito immunity and global malaria transmission: The lock-and-key theory.

    Molina-Cruz, Alvaro; Canepa, Gaspar E; Kamath, Nitin; Pavlovic, Noelle V; Mu, Jianbing; Ramphul, Urvashi N; Ramirez, Jose Luis; Barillas-Mury, Carolina

    2015-12-08

    Plasmodium falciparum malaria originated in Africa and became global as humans migrated to other continents. During this journey, parasites encountered new mosquito species, some of them evolutionarily distant from African vectors. We have previously shown that the Pfs47 protein allows the parasite to evade the mosquito immune system of Anopheles gambiae mosquitoes. Here, we investigated the role of Pfs47-mediated immune evasion in the adaptation of P. falciparum to evolutionarily distant mosquito species. We found that P. falciparum isolates from Africa, Asia, or the Americas have low compatibility to malaria vectors from a different continent, an effect that is mediated by the mosquito immune system. We identified 42 different haplotypes of Pfs47 that have a strong geographic population structure and much lower haplotype diversity outside Africa. Replacement of the Pfs47 haplotypes in a P. falciparum isolate is sufficient to make it compatible to a different mosquito species. Those parasites that express a Pfs47 haplotype compatible with a given vector evade antiplasmodial immunity and survive. We propose that Pfs47-mediated immune evasion has been critical for the globalization of P. falciparum malaria as parasites adapted to new vector species. Our findings predict that this ongoing selective force by the mosquito immune system could influence the dispersal of Plasmodium genetic traits and point to Pfs47 as a potential target to block malaria transmission. A new model, the "lock-and-key theory" of P. falciparum globalization, is proposed, and its implications are discussed.

  16. Dusk to dawn activity patterns of anopheline mosquitoes in West Timor and Java, Indonesia.

    Ndoen, Ermi; Wild, Clyde; Dale, Pat; Sipe, Neil; Dale, Mike

    2011-05-01

    Malaria is a serious health issue in Indonesia. We investigated the dusk to dawn anopheline mosquito activity patterns, host-seeking and resting locations in coastal plain, hilly and highland areas in West Timor and Java. Adult mosquitoes were captured landing on humans or resting in houses or animal barns. Data analyzed were: mosquito night-time activities; period of peak activity; night-time activity in specific periods of time and for mosquito resting locations. Eleven species were recorded; data were sparse for some species therefore detailed analyses were performed for four species only. In Java Anopheles vagus was common, with a bimodal pattern of high activity. In West Timor, its activity peaked around midnight. Other species with peak activity around the middle of the night were An. barbirostris and An. subpictus. Most species showed no biting and resting preference for indoors or outdoors, although An. barbirostris preferred indoors in West Timor, but outdoors in Java. An. aconitus and An. annularis preferred resting in human dwellings; An. subpictus and An. vagus preferred resting in animal barns. An. barbirostris preferred resting in human dwellings in West Timor and in animal barns in Java. The information is useful for planning the mosquito control aspect of malaria management. For example, where mosquito species have peak activity at night indoors, bednets and indoor residual spraying should reduce malaria risk, but where mosquitoes are most active outdoors, other options may be more effective.

  17. Comparative genomic analysis of Drosophila melanogaster and vector mosquito developmental genes.

    Susanta K Behura

    Full Text Available Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1 are components of developmental signaling pathways, 2 regulate fundamental developmental processes, 3 are critical for the development of tissues of vector importance, 4 function in developmental processes known to have diverged within insects, and 5 encode microRNAs (miRNAs that regulate developmental transcripts in Drosophila. While most fruit fly developmental genes are conserved in the three vector mosquito species, several genes known to be critical for Drosophila development were not identified in one or more mosquito genomes. In other cases, mosquito lineage-specific gene gains with respect to D. melanogaster were noted. Sequence analyses also revealed that numerous repetitive sequences are a common structural feature of Drosophila and mosquito developmental genes. Finally, analysis of predicted miRNA binding sites in fruit fly and mosquito developmental genes suggests that the repertoire of developmental genes targeted by miRNAs is species-specific. The results of this study provide insight into the evolution of developmental genes and processes in dipterans and other arthropods, serve as a resource for those pursuing analysis of mosquito development, and will promote the design and refinement of functional analysis experiments.

  18. Fauna and Larval Habitats of Mosquitoes (Diptera: Culicidae of West Azerbaijan Province, Northwestern Iran.

    Farahnaz Khoshdel-Nezamiha

    2014-12-01

    Full Text Available Several important diseases are transmitted by mosquitoes. Despite of the potential of the occurrence of some mosquito-borne diseases such as West Nile, dirofilariasis and malaria in the region, there is no recent study of mosquitoes in West Azerbaijan Province. The aim of this investigation was to study the fauna, composition and distribution of mosquitoes and the characteristics of their larval habitats in this province.Larvae and adult collections were carried out from different habitats using the standard methods in twenty five localities of seven counties across West Azerbaijan Province.Overall, 1569 mosquitoes including 1336 larvae and 233 adults were collected from 25 localities. The details of geographical properties were recorded. Five genera along with 12 species were collected and identified including: Anopheles claviger, An. maculipennis s.l., An. superpictus, Culex pipiens, Cx. theileri, Cx. modestus, Cx. hortensis, Cx. mimeticus, Culiseta Longiareolata, Ochlerotatus caspius s.l., Oc. geniculatus and Uranotaenia unguiculata. This is the first record of Oc. geniculatus in the province.Due to the geographical location of the West Azerbaijan Province, it comprises different climatic condition which provides suitable environment for the establishment of various species of mosquitoes. The solidarity geographical, cultural and territorial exchanges complicate the situation of the province and its vectors as a threat for future and probable epidemics of mosquito-borne diseases.

  19. Regulation of anti-Plasmodium immunity by a LITAF-like transcription factor in the malaria vector Anopheles gambiae.

    Ryan C Smith

    Full Text Available The mosquito is the obligate vector for malaria transmission. To complete its development within the mosquito, the malaria parasite Plasmodium must overcome the protective action of the mosquito innate immune system. Here we report on the involvement of the Anopheles gambiae orthologue of a conserved component of the vertebrate immune system, LPS-induced TNFα transcription factor (LITAF, and its role in mosquito anti-Plasmodium immunity. An. gambiae LITAF-like 3 (LL3 expression is up-regulated in response to midgut invasion by both rodent and human malaria parasites. Silencing of LL3 expression greatly increases parasite survival, indicating that LL3 is part of an anti-Plasmodium defense mechanism. Electrophoretic mobility shift assays identified specific LL3 DNA-binding motifs within the promoter of SRPN6, a gene that also mediates mosquito defense against Plasmodium. Further experiments indicated that these motifs play a direct role in LL3 regulation of SRPN6 expression. We conclude that LL3 is a transcription factor capable of modulating SRPN6 expression as part of the mosquito anti-Plasmodium immune response.

  20. Laboratory evaluation of three commercial coil products for protection efficacy against Anopheles gambiae from southern Ghana: a preliminary study.

    Avicor, S W; Wajidi M, F F; Jaal, Z

    2015-06-01

    Residents in irrigated urban agricultural sites face numerous mosquito problems such as increased mosquito populations and reduced insecticides susceptibility due to the creation of mosquito breeding sites and agricultural use of insecticides and hence require effective protective products against them. In this study, the protection effectiveness of three pyrethroid formulated mosquito coils of Malaysian origin against Anopheles gambiae sensu lato from an irrigated urban agricultural site in Ghana were evaluated for their potential use. Sucrose fed An. gambiae s.l. were exposed to insecticide-containing coils in a 70 cm x 70 cm x 70 cm glass chamber to assess the insecticidal effect of the coils. The 0.005% metofluthrin coil caused the most rapid knockdown of 50% of the test mosquitoes. The mean lethal effect of the coils on An. gambiae s.l. were as follows; 0.005% metofluthrin (86%), 0.3% d-allethrin (74.33%), 0.15% d-trans allethrin (72%) and the 0.25% d-allethrin reference coil (69%). The 0.005% metofluthrin coil achieved the highest insecticidal effect on An. gambiae s.l. compared to the other coils and hence performed better than the others as an anti-mosquito product. All the three test coils were effective against An. gambaie s.l. from the irrigated agricultural site compared to the reference coil.

  1. Species composition and natural infectivity of anthropophilic Anopheles (Diptera: Culicidae) in Córdoba and Antioquia states in northwestern Colombia

    Gutiérrez, Lina A; González, John J; Gómez, Giovan F; Castro, Martha I; Rosero, Doris A; Luckhart, Shirley; Conn, Jan E; Correa, Margarita M

    2011-01-01

    Malaria is a serious health problem in Córdoba and Antioquia states in northwestern Colombia, where 64.4% of the total Colombian cases were reported in 2007. Because little entomological information is available in this region, the aim of this work was to identify the Anopheles species composition and natural infectivity of mosquitoes distributed in seven localities with the highest malaria transmission. A total of 1,768 Anopheles mosquitoes were collected using human landing catches from March 2007 to July 2008. Ten species were identified; overall, An. nuneztovari s.l. was the most widespread (62%) and showed the highest average human biting rates. There were six other species of the Nyssorhynchus subgenus: An. albimanus (11.6%), An. darlingi (9.8%), An. braziliensis (6.6%), An. triannulatus s.l. (3.5%), An. albitarsis s.l. and An. oswaldoi s.l. at <1%; and three of the Anopheles subgenus: An. punctimacula, An. pseudopunctipennis s.l. and An. neomaculipalpus at <1% each. Two species from Córdoba, An. nuneztovari and An. darlingi, were detected naturally infected by Plasmodium vivax VK247 using ELISA and confirmed by nested PCR. All species were active indoors and outdoors. These results provide basic information for targeted vector control strategies in these localities. PMID:20140372

  2. The vertical dispersión of Anopheles (Kerteszia cruzi in a forest in southern Brazil suggests that human cases of malaria of simian origin might be expected

    Leonidas M. Deane

    1984-12-01

    Full Text Available By staining females of Anopheles cruzi with fluorescent coloured powders in a forest in the State of Santa Catarina, we showed that they move from canopy to ground and vice-versa to feed. This suggests that in areas where this mosquito is a vector of human and simian malarias sporadic infections of man with monkey plasmodia might be expected.Pintando fêmeas de Anopheles cruzi com pós fluorescentes coloridos, numa floresta de Santa Catarina, mostramos que elas movimentam-se da copa ao solo e vice-versa para se alimentar de sangue. Isso sugere que em áreas onde esse mosquito for tansmissor das malárias humana e simiana pode-se esperar que ocorram infecções humanas esporádicas por plasmódios de macacos.

  3. Chemical Composition and Repellent Activity of Achillea vermiculata and Satureja hortensis against Anopheles stephensi

    Masoumeh Pirmohammadi

    2016-01-01

    Full Text Available Background: One of the best ways to control the malaria disease and to be protected human against Anopheles mos­quito biting is the use of repellents. Throughout repellents, herbal ones may be an appropriate and safe source for protection.Methods: Chemical constituents of Achillea vermiculata and Satoreja hortensis were determined by using gas chromatography-mass spectrometry. Efficacy and the protection time of these plants were assessed on Anopheles stephensi under the laboratory condition.Results: The mean assessed protection time and efficacy for A. vermiculata was 2.16 and 3.16 hours respectively and the obtained ED50 and ED90 for this plant was 5.67 and 63 µl/cm2 respectively. The figured for S. hortensis was 4.16 and 5 hours respectively.  ED50 and ED90 for this plant were 5.63 and 45.75µl/cm2 respectively.Conclusion: Results of investigation showed that S. hortensis plant has an acceptable protection time, therefore, this plant could be considered as a good herbal repellent against anopheles mosquitoes.

  4. Diversity and transmission competence in lymphatic filariasis vectors in West Africa, and the implications for accelerated elimination of Anopheles-transmitted filariasis

    de Souza Dziedzom K

    2012-11-01

    Full Text Available Abstract Lymphatic Filariasis (LF is targeted for elimination by the Global Programme for the Elimination of Lymphatic Filariasis (GPELF. The strategy adopted is based on the density dependent phenomenon of Facilitation, which hypothesizes that in an area where the vector species transmitting Wuchereria bancrofti are Anopheles mosquitoes, it is feasible to eliminate LF using Mass Drug Administration (MDA because of the inability of Anopheles species to transmit low-density microfilaraemia. Even though earlier studies have shown Anopheles species can exhibit the process of Facilitation in West Africa, observations point towards the process of Limitation in certain areas, in which case vector control is recommended. Studies on Anopheles species in West Africa have also shown genetic differentiation, cryptic taxa and speciation, insecticide resistance and the existence of molecular and chromosomal forms, all of which could influence the vectorial capacity of the mosquitoes and ultimately the elimination goal. This paper outlines the uniqueness of LF vectors in West Africa and the challenges it poses to the 2020 elimination goal, based on the current MDA strategies.

  5. Changing distribution and abundance of the malaria vector Anopheles merus in Mpumalanga Province, South Africa.

    Mbokazi, F; Coetzee, M; Brooke, B; Govere, J; Reid, A; Owiti, P; Kosgei, R; Zhou, S; Magagula, R; Kok, G; Namboze, J; Tweya, H; Mabuza, A

    2018-04-25

    Background: The malaria vector Anopheles merus occurs in the Mpumalanga Province of South Africa. As its contribution to malaria transmission in South Africa has yet to be ascertained, an intensification of surveillance is necessary to provide baseline information on this species. The aim of this study was therefore to map An. merus breeding sites in the Ehlanzeni District of Mpumalanga Province and to assess qualitative trends in the distribution and relative abundance of this species over a 9-year period. Methods: The study was carried out during the period 2005-2014 in the four high-risk municipalities of Ehlanzeni District. Fifty-two breeding sites were chosen from all water bodies that produced anopheline mosquitoes. The study data were extracted from historical entomological records that are captured monthly. Results: Of the 15 058 Anopheles mosquitoes collected, 64% were An. merus. The abundance and distribution of An. merus increased throughout the four municipalities in Ehlanzeni District during the study period. Conclusion: The expanded distribution and increased abundance of An. merus in the Ehlanzeni District may contribute significantly to locally acquired malaria in Mpumalanga Province, likely necessitating the incorporation of additional vector control methods specifically directed against populations of this species.

  6. A reliable morphological method to assess the age of male Anopheles gambiae

    Killeen Gerry F

    2006-07-01

    Full Text Available Abstract Background Release of genetically-modified (GM or sterile male mosquitoes for malaria control is hampered by inability to assess the age and mating history of free-living male Anopheles. Methods Age and mating-related changes in the reproductive system of male Anopheles gambiae were quantified and used to fit predictive statistical models. These models, based on numbers of spermatocysts, relative size of sperm reservoir and presence/absence of a clear area around the accessory gland, were evaluated using an independent sample of mosquitoes whose status was blinded during the experiment. Results The number of spermatocysts in male testes decreased with age, and the relative size of their sperm reservoir increased. The presence of a clear area around accessory glands was also linked to age and mating status. A quantitative model was able to categorize males from the blind trial into age groups of young (≤ 4 days and old (> 4 days with an overall efficiency of 89%. Using the parameters of this model, a simple table was compiled that can be used to predict male age. In contrast, mating history could not be reliably assessed as virgins could not be distinguished from mated males. Conclusion Simple assessment of a few morphological traits which are easily collected in the field allows accurate age-grading of male An. gambiae. This simple, yet robust, model enables evaluation of demographic patterns and mortality in wild and released males in populations targeted by GM or sterile male-based control programmes.

  7. A rodent malarial model of Plasmodium berghei for the development ...

    A rodent malarial model of Plasmodium berghei for the development of pyrimethamine and sulphadoxine-pyrimethamine resistant malaria in mice. ... course approach with 125/6.25mg/kg S/P. The stability of resistance phenotypes, parasite pathogenic disposition and host leukocyte response were also investigated.

  8. Hyper-reactive Malarial Splenomegaly: A Case Report and Review ...

    Hyper-reactive malarial splenomegaly is thought to represent a dysfunctional immune response to recurrent malaria infection. A 14 year old male child with hms, hypersplenism, ascites and peripheral lymphadenopathy is reported. There was initial poor response to proguanil aggravated by non compliance. He was started ...

  9. QSAR models for anti-malarial activity of 4-aminoquinolines.

    Masand, Vijay H; Toropov, Andrey A; Toropova, Alla P; Mahajan, Devidas T

    2014-03-01

    In the present study, predictive quantitative structure - activity relationship (QSAR) models for anti-malarial activity of 4-aminoquinolines have been developed. CORAL, which is freely available on internet (http://www.insilico.eu/coral), has been used as a tool of QSAR analysis to establish statistically robust QSAR model of anti-malarial activity of 4-aminoquinolines. Six random splits into the visible sub-system of the training and invisible subsystem of validation were examined. Statistical qualities for these splits vary, but in all these cases, statistical quality of prediction for anti-malarial activity was quite good. The optimal SMILES-based descriptor was used to derive the single descriptor based QSAR model for a data set of 112 aminoquinolones. All the splits had r(2)> 0.85 and r(2)> 0.78 for subtraining and validation sets, respectively. The three parametric multilinear regression (MLR) QSAR model has Q(2) = 0.83, R(2) = 0.84 and F = 190.39. The anti-malarial activity has strong correlation with presence/absence of nitrogen and oxygen at a topological distance of six.

  10. Management of severe malarial anaemia in Gambian children

    Bojang, K. A.; Palmer, A.; Boele van Hensbroek, M.; Banya, W. A.; Greenwood, B. M.

    1997-01-01

    The optimum management of children with severe malarial anaemia is still uncertain. Hence, we have undertaken a study to determine whether iron treatment is as effective at restoring haemoglobin levels one month after presentation as blood transfusion without iron treatment in children with

  11. Malarial infection among HIV Patients on Antiretroviral Therapy (ART)

    Malarial infection among patients on antiretroviral therapy (ART) attending Federal Medical Centre, Makurdi, Benue State was investigated between April and August 2008 to determine the level of malaria infection in HIV/AIDS patients on ART and those not on ART with respect to CD4+ counts, age and gender. A total of ...

  12. Zur Verbreitung von Phaethornis malaris (Nordmann) (Aves, Trochilidae)

    Mees, G.F.

    1977-01-01

    Obwohl der Kolibri Phaethornis malaris (Nordmann) der Wissenschaft wahrscheinlich schon vor Ausgang des XVIII. Jahrhunderts bekannt war (eine Abbildung findet sich in Audebert & Vieillot, 1802: 37, T. 17) und 1835 die wissenschaftliche Benennung erfolgte (Nordmann, 1835), war er nur aus einem

  13. The effect of metal pollution on the life history and insecticide resistance phenotype of the major malaria vector Anopheles arabiensis (Diptera: Culicidae)

    Oliver, Shüné V.; Brooke, Basil D.

    2018-01-01

    Metal exposure is one of the commonest anthropogenic pollutants mosquito larvae are exposed to, both in agricultural and urban settings. As members of the Anopheles gambiae complex, which contains several major malaria vector species including An. arabiensis, are increasingly adapting to polluted environments, this study examined the effects of larval metal exposure on various life history traits of epidemiological importance. Two laboratory strains of An. arabiensis, SENN (insecticide suscep...

  14. Bionomics of Anopheles fluviatilis and Anopheles culicifacies (Diptera: Culicidae) in Relation to Malaria Transmission in East-Central India.

    Sahu, S S; Gunasekaran, K; Krishnamoorthy, N; Vanamail, P; Mathivanan, A; Manonmani, A; Jambulingam, P

    2017-07-01

    The southern districts of Odisha State in east-central India have been highly endemic for falciparum malaria for many decades. However, there is no adequate information on the abundance of the vector species or their bionomics in relation to space and time in these districts. Therefore, a study was carried out on the entomological aspects of malaria transmission to generate such information. Collections of mosquitoes were made once during each of the three seasons in 128 villages selected from eight districts. Villages within the foot-hill ecotype had a significantly greater abundance of Anopheles fluviatilis James s. l., whereas the abundance of Anopheles culicifacies Giles s. l. was significantly greater in the plain ecotype. The abundance of An. fluviatilis was maximum during the cold season, whereas An. culicifacies abundance was highest during summer and rainy seasons. The maximum likelihood estimation of the malaria infection rate in An. fluviatilis was 1.78%, 6.05%, and 2.6% in Ganjam, Kalahandi, and Rayagada districts, respectively. The infection rate of An. culicifacies was 1.39% only in Kandhamal district; infected females were not detected elsewhere. Concurrently, the annual malaria parasite incidence (MPI) was significantly higher in hill-top (17.6) and foot-hill (14.4) villages compared to plain villages (4.1). The districts with more villages in hill-top and foot-hill ecotypes also had a greater abundance of An. fluviatilis, the major malaria vector, and exhibited a higher incidence of malaria than villages within the plain ecotype, where An. culicifacies was the most abundant vector. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  15. Hemozoin (malarial pigment directly promotes apoptosis of erythroid precursors.

    Abigail A Lamikanra

    2009-12-01

    Full Text Available Severe malarial anemia is the most common syndrome of severe malaria in endemic areas. The pathophysiology of chronic malaria is characterised by a striking degree of abnormal development of erythroid precursors (dyserythropoiesis and an inadequate erythropoietic response in spite of elevated levels of erythropoietin. The cause of dyserythropoiesis is unclear although it has been suggested that bone-marrow macrophages release cytokines, chemokines or lipo-peroxides after exposure to hemozoin, a crystalloid form of undigested heme moieties from malarial infected erythrocytes, and so inhibit erythropoiesis. However, we have previously shown that hemozoin may directly inhibit erythroid development in vitro and the levels of hemozoin in plasma from patients with malarial anemia and hemozoin within the bone marrow was associated with reduced reticulocyte response. We hypothesized that macrophages may reduce, not enhance, the inhibitory effect of hemozoin on erythropoiesis. In an in vitro model of erythropoiesis, we now show that inhibition of erythroid cell development by hemozoin isolated from P. falciparum is characterised by delayed expression of the erythroid markers and increased apoptosis of progenitor cells. Crucially, macrophages appear to protect erythroid cells from hemozoin, consistent with a direct contribution of hemozoin to the depression of reticulocyte output from the bone marrow in children with malarial anemia. Moreover, hemozoin isolated from P. falciparum in vitro inhibits erythroid development independently of inflammatory mediators by inducing apoptotic pathways that not only involve activation of caspase 8 and cleavage of caspase 3 but also loss of mitochondrial potential. Taken together these data are consistent with a direct effect of hemozoin in inducing apoptosis in developing erythroid cells in malarial anemia. Accumulation of hemozoin in the bone marrow could therefore result in inadequate reticulocytosis in children that

  16. Larvicidal activity of neem oil (Azadirachta indica formulation against mosquitoes

    Dua Virendra K

    2009-06-01

    Full Text Available Abstract Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae and its derived products have shown a variety of insecticidal properties. The present paper discusses the larvicidal activity of neem-based biopesticide for the control of mosquitoes. Methods Larvicidal efficacy of an emulsified concentrate of neem oil formulation (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin developed by BMR & Company, Pune, India, was evaluated against late 3rd and early 4th instar larvae of different genera of mosquitoes. The larvae were exposed to different concentrations (0.5–5.0 ppm of the formulation along with untreated control. Larvicidal activity of the formulation was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The formulation was diluted with equal volumes of water and applied @ 140 mg a.i./m2 to different mosquito breeding sites with the help of pre calibrated knapsack sprayer. Larval density was determined at pre and post application of the formulation using a standard dipper. Results Median lethal concentration (LC50 of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the formulation stored at 26°C, 40°C and 45°C for 48 hours against Ae. aegypti were 1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively. Further no significant difference in LC50 and LC90 values of the formulation was observed against Ae. aegypti during 18 months storage period at room temperature. An application of the formulation at the rate of 140 mg a.i./m2 in different breeding

  17. Pyrethroids and DDT tolerance of Anopheles gambiae s.l. from Sengerema District, an area of intensive pesticide usage in north-western Tanzania.

    Philbert, Anitha; Lyantagaye, Sylvester Leonard; Pradel, Gabriele; Ngwa, Che Julius; Nkwengulila, Gamba

    2017-04-01

    To assess the susceptibility status of malaria vectors to pyrethroids and dichlorodiphenyltrichloroethane (DDT), characterise the mechanisms underlying resistance and evaluate the role of agro-chemical use in resistance selection among malaria vectors in Sengerema agro-ecosystem zone, Tanzania. Mosquito larvae were collected from farms and reared to obtain adults. The susceptibility status of An. gambiae s.l. was assessed using WHO bioassay tests to permethrin, deltamethrin, lambdacyhalothrin, etofenprox, cyfluthrin and DDT. Resistant specimens were screened for knock-down resistance gene (kdr), followed by sequencing both Western and Eastern African variants. A gas chromatography-mass spectrophotometer (GC-MS) was used to determine pesticide residues in soil and sediments from mosquitoes' breeding habitats. Anopheles gambiae s.l. was resistant to all the insecticides tested. The population of Anopheles gambiae s.l was composed of Anopheles arabiensis by 91%. The East African kdr (L1014S) allele was found in 13 of 305 specimens that survived insecticide exposure, with an allele frequency from 0.9% to 50%. DDTs residues were found in soils at a concentration up to 9.90 ng/g (dry weight). The observed high resistance levels of An. gambiae s.l., the detection of kdr mutations and pesticide residues in mosquito breeding habitats demonstrate vector resistance mediated by pesticide usage. An integrated intervention through collaboration of agricultural, livestock and vector control units is vital. © 2017 John Wiley & Sons Ltd.

  18. Sequencing and analysis of the complete mitochondrial genome in Anopheles sinensis (Diptera: Culicidae).

    Chen, Kai; Wang, Yan; Li, Xiang-Yu; Peng, Heng; Ma, Ya-Jun

    2017-10-02

    Anopheles sinensis (Diptera: Culicidae) is a primary vector of Plasmodium vivax and Brugia malayi in most regions of China. In addition, its phylogenetic relationship with the cryptic species of the Hyrcanus Group is complex and remains unresolved. Mitochondrial genome sequences are widely used as molecular markers for phylogenetic studies of mosquito species complexes, of which mitochondrial genome data of An. sinensis is not available. An. sinensis samples was collected from Shandong, China, and identified by molecular marker. Genomic DNA was extracted, followed by the Illumina sequencing. Two complete mitochondrial genomes were assembled and annotated using the mitochondrial genome of An. gambiae as reference. The mitochondrial genomes sequences of the 28 known Anopheles species were aligned and reconstructed phylogenetic tree by Maximum Likelihood (ML) method. The length of complete mitochondrial genomes of An. sinensis was 15,076 bp and 15,138 bp, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and an AT-rich control region. As in other insects, most mitochondrial genes are encoded on the J strand, except for ND5, ND4, ND4L, ND1, two rRNA and eight tRNA genes, which are encoded on the N strand. The bootstrap value was set as 1000 in ML analyses. The topologies restored phylogenetic affinity within subfamily Anophelinae. The ML tree showed four major clades, corresponding to the subgenera Cellia, Anopheles, Nyssorhynchus and Kerteszia of the genus Anopheles. The complete mitochondrial genomes of An. sinensis were obtained. The number, order and transcription direction of An. sinensis mitochondrial genes were the same as in other species of family Culicidae.

  19. Laboratory evolution of the entomopathogenic fungus Beauveria bassiana against Anopheles stephensi larvae (Diptera: Culicidae

    Rahele Veys-Behbahani

    2014-09-01

    Full Text Available Objective: To examine Beauveria bassiana (B. bassiana fungus bioassay against the larval stages of Anopheles stephensi in Iran. Methods: The fungal suspension by the concentrations of 1伊1 09, 5伊1 08, 1 08, 5伊1 07 and 1伊 107 conidia per milliliter have been prepared in different volumes (2, 4 and 6 mL and each concentration were added to containers containing 25 Anopheles larva instars 1 and 2. The mortality of the dead larvae with abnormal symptoms was recorded as a result of the fungal infection after 24, 48 and 72 h. Results: Comparison between the mean mortality rate of Anopheles stephensi larva at different concentrations of B. bassiana strain Iran 429C at 2, 4 and 6 mL showed that there was no significant relation of the mean mortality rate of larvae at concentrations of 1伊109 and 5伊108, and after 48 h resulted in 100% mortality rate of the larvae populations. In addition, there is no significant differences in the amounts of lethal times (LT (LT50 and LT90 as LT90 values calculated at a concentration of 5伊108 and in volumes 2, 4 and 6 mL were 1.46, 1.36 and 1.08 d, respectively. Conclusions: B. bassiana strain Iran 429C in 2 mL of 5伊108 concentration or the concentration of a 1伊109 mL per 100 mL of water is recommended as the optimal concentration for the control of Anopheles larvae. The development of suitable formulations of entomopathogenic fungi may be a promising prospect in the mosquito control programs.

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

    Kloke, R Graham; Nhamahanga, Eduardo; Hunt, Richard H; Coetzee, Maureen

    2011-02-09

    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. 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. 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 bendiocarb within the estate for seven years and the

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

    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

  2. Quantitative real-time PCR analysis of Anopheles dirus TEP1 and NOS during Plasmodium berghei infection, using three reference genes

    Jonathan W.K. Liew

    2017-07-01

    Full Text Available Quantitative reverse transcription PCR (qRT-PCR has been an integral part of characterizing the immunity of Anopheles mosquitoes towards Plasmodium invasion. Two anti-Plasmodium factors of Anopheles, thioester-containing protein 1 (TEP1 and nitric oxide synthase (NOS, play a role in the refractoriness of Anopheles towards Plasmodium infection and are generally expressed during infection. However, these are less studied in Anopheles dirus, a dominant malaria vector in Southeast Asia. Furthermore, most studies used a single reference gene for normalization during gene expression analysis without proper validation. This may lead to erroneous quantification of expression levels. Therefore, the present study characterized and investigated the expression profiles of TEP1 and NOS of Anopheles dirus during P. berghei infection. Prior to that, the elongation factor 1-alpha (EF1, actin 1 (Act and ribosomal protein S7 (S7 genes were validated for their suitability as a set of reference genes. TEP1 and NOS expressions in An. dirus were found to be significantly induced after P. berghei infection.

  3. Mapping insecticide resistance and characterization of resistance mechanisms in Anopheles arabiensis (Diptera: Culicidae) in Ethiopia.

    Alemayehu, Eba; Asale, Abebe; Eba, Kasahun; Getahun, Kefelegn; Tushune, Kora; Bryon, Astrid; Morou, Evangelia; Vontas, John; Van Leeuwen, Thomas; Duchateau, Luc; Yewhalaw, Delenasaw

    2017-09-02

    The emergence and spread of insecticide resistance in the major African malaria vectors Anopheles gambiae (s.s.) and An. arabiensis may compromise the current vector control interventions and threatens the global malaria control and elimination efforts. Insecticide resistance was monitored in several study sites in Ethiopia from 2013 to 2015 using papers impregnated with discriminating concentrations of DDT, deltamethrin, bendiocarb, propoxur, malathion, fenitrothion and pirimiphos-methyl, following the WHO insecticide susceptibility test procedure. Mosquitoes sampled from different localities for WHO bioassay were morphologically identified as An. gambiae (s.l.) using standard taxonomic keys. Samples were identified to species using species-specific polymerase chain reaction (PCR) and screened for the presence of target site mutations L1014F, L1014S and N1575Y in the voltage gated sodium channel (VGSC) gene and G119S in the acethylcholinesterase (AChE) gene using allele-specific PCR. Biochemical assays were performed to assess elevated levels of acetylcholinesterases, carboxylcholinesterases, glutathione-S-transferases (GSTs) and cytochrome P450s monooxygenases in wild populations of An. arabiensis, compared to the fully susceptible Sekoru An. arabiensis laboratory strain. Populations of An. arabiensis were resistant to DDT and deltamethrin but were susceptible to fenitrothion in all the study sites. Reduced susceptibility to malathion, pirimiphos-methyl, propoxur and bendiocarb was observed in some of the study sites. Knockdown resistance (kdr L1014F) was detected in all mosquito populations with allele frequency ranging from 42 to 91%. Elevated levels of glutathione-S-transferases (GSTs) were detected in some of the mosquito populations. However, no elevated levels of monooxygenases and esterases were detected in any of the populations assessed. Anopheles arabiensis populations from all surveyed sites in Ethiopia exhibited resistance against DDT and pyrethroids

  4. Multiple insecticide resistance mechanisms in Anopheles gambiae s.l. populations from Cameroon, Central Africa.

    Nwane, Philippe; Etang, Josiane; Chouaїbou, Mouhamadou; Toto, Jean Claude; Koffi, Alphonsine; Mimpfoundi, Rémy; Simard, Frédéric

    2013-02-22

    Increasing incidence of DDT and pyrethroid resistance in Anopheles mosquitoes is seen as a limiting factor for malaria vector control. The current study aimed at an in-depth characterization of An. gambiae s.l. resistance to insecticides in Cameroon, in order to guide malaria vector control interventions. Anopheles gambiae s.l. mosquitoes were collected as larvae and pupae from six localities spread throughout the four main biogeographical domains of Cameroon and reared to adults in insectaries. Standard WHO insecticide susceptibility tests were carried out with 4% DDT, 0.75% permethrin and 0.05% deltamethrin. Mortality rates and knockdown times (kdt50 and kdt95) were determined and the effect of pre-exposure to the synergists DEF, DEM and PBO was assessed. Tested mosquitoes were identified to species and molecular forms (M or S) using PCR-RFLP. The hot ligation method was used to depict kdr mutations and biochemical assays were conducted to assess detoxifying enzyme activities. The An. arabiensis population from Pitoa was fully susceptible to DDT and permethrin (mortality rates>98%) and showed reduced susceptibility to deltamethrin. Resistance to DDT was widespread in An. gambiae s.s. populations and heterogeneous levels of susceptibility to permethrin and deltamethrin were observed. In many cases, prior exposure to synergists partially restored insecticide knockdown effect and increased mortality rates, suggesting a role of detoxifying enzymes in increasing mosquito survival upon challenge by pyrethroids and, to a lower extent DDT. The distribution of kdr alleles suggested a major role of kdr-based resistance in the S form of An. gambiae. In biochemical tests, all but one mosquito population overexpressed P450 activity, whereas baseline GST activity was low and similar in all field mosquito populations and in the control. In Cameroon, multiple resistance mechanisms segregate in the S form of An. gambiae resulting in heterogeneous resistance profiles, whereas in

  5. A survey of mosquitoes breeding in used tires in Spain for the detection of imported potential vector species.

    Roiz, D; Eritja, R; Escosa, R; Lucientes, J; Marquès, E; Melero-Alcíbar, R; Ruiz, S; Molina, R

    2007-06-01

    The used tire trade has facilitated the introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, and other mosquito species in several countries of America, Africa, Oceania, and Europe. A strategy for detecting these imported mosquito vectors was developed in Spain during 2003-2004 by EVITAR (multidisciplinary network for the study of viruses transmitted by arthropods and rodents). A survey in 45 locations found no invasive species. Eight autochthonous species of mosquitoes were detected in used tires, including Culex pipiens, Cx. hortensis, Cx. modestus, Anopheles atroparvus, An. claviger, Culiseta longiareolata, Cs. annulata, and Aedes caspius. Dominant species were Cx. pipiens and Cs. longiareolata. Aedes caspius was found in only once, near its natural breeding habitat. Considering the recent discovery of an established population of Ae. albopictus in Catalonia, the increasing commerce of used tires in Spain for recycling, storage, and recapping might greatly contribute to the rapid spread of this species across the Iberian Peninsula.

  6. Development of a gravid trap for collecting live malaria vectors Anopheles gambiae s.l.

    Sisay Dugassa

    Full Text Available Effective malaria vector control targeting indoor host-seeking mosquitoes has resulted in fewer vectors entering houses in many areas of sub-Saharan Africa, with the proportion of vectors outdoors becoming more important in the transmission of this disease. This study aimed to develop a gravid trap for the outdoor collection of the malaria vector Anopheles gambiae s.l. based on evaluation and modification of commercially available gravid traps.Experiments were implemented in an 80 m(2 semi-field system where 200 gravid Anopheles gambiae s.s. were released nightly. The efficacy of the Box, CDC and Frommer updraft gravid traps was compared. The Box gravid trap was tested to determine if the presence of the trap over water and the trap's sound affected catch size. Mosquitoes approaching the treatment were evaluated using electrocuting nets or detergents added to the water in the trap. Based on the results, a new gravid trap (OviART trap that provided an open, unobstructed oviposition site was developed and evaluated.Box and CDC gravid traps collected similar numbers (relative rate (RR 0.8, 95% confidence interval (CI 0.6-1.2; p = 0.284, whereas the Frommer trap caught 70% fewer mosquitoes (RR 0.3, 95% CI 0.2-0.5; p < 0.001. The number of mosquitoes approaching the Box trap was significantly reduced when the trap was positioned over a water-filled basin compared to an open pond (RR 0.7 95% CI 0.6-0.7; p < 0.001. This effect was not due to the sound of the trap. Catch size increased by 60% (RR 1.6, 1.2-2.2; p = 0.001 with the new OviART trap.Gravid An. Gambiae s.s. females were visually deterred by the presence of the trapping device directly over the oviposition medium. Based on these investigations, an effective gravid trap was developed that provides open landing space for egg-laying Anopheles.

  7. The efficacy of repellents against Aedes, Anopheles, Culex and Ixodes spp. - a literature review.

    Lupi, Eleonora; Hatz, Christoph; Schlagenhauf, Patricia

    2013-01-01

    Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the literature, up to December 31st, 2012, regarding repellent efficacy. We searched PubMed for relevant papers. Repellents of interest were DEET, Icaridin as well as other piperidine-derived products (SS220), Insect Repellent (IR) 3535 (ethyl-butylacetyl-amino-propionat, EBAAP) and plant-derived products, including Citriodora (para-menthane-3,8-diol). As vectors, we considered the mosquito species Anopheles, Aedes and Culex as well as the tick species Ixodes. We selected only studies evaluating the protective efficacy of repellents on human skin. We reviewed a total of 102 publications. Repellents were evaluated regarding complete protection time or as percentage efficacy [%] in a time interval. We found no standardized study for tick bite prevention. Regarding Aedes, DEET at concentration of 20% or more, showed the best efficacy providing up to 10 h protection. Citriodora repellency against this mosquito genus was lower compared to the other products. Also between subspecies a difference could be observed: Ae. aegypti proved more difficult to repel than Ae. Albopictus. Fewer studies have been conducted on mosquito species Anopheles and Culex. The repellency profile against Anopheles species was similar for the four principal repellents of interest, providing on average 4-10 h of protection. Culex mosquitoes are easier to repel and all four repellents provided good protection. Few studies have been conducted on the tick species Ixodes. According to our results, the longest protection against Ixodes scapularis was provided by repellents containing IR3535, while DEET and commercial products containing Icaridin or PMD showed a better response than IR3535 against Ixodes ricinus. Many plant-based repellents provide only short duration protection. Adding vanillin 5% to plant-based repellents and to DEET

  8. Susceptibility of Anopheles gambiae to insecticides used for malaria vector control in Rwanda.

    Hakizimana, Emmanuel; Karema, Corine; Munyakanage, Dunia; Iranzi, Gad; Githure, John; Tongren, Jon Eric; Takken, Willem; Binagwaho, Agnes; Koenraadt, Constantianus J M

    2016-12-01

    The widespread emergence of resistance to pyrethroids is a major threat to the gains made in malaria control. To monitor the presence and possible emergence of resistance against a variety of insecticides used for malaria control in Rwanda, nationwide insecticide resistance surveys were conducted in 2011 and 2013. Larvae of Anopheles gambiae sensu lato mosquitoes were collected in 12 sentinel sites throughout Rwanda. These were reared to adults and analysed for knock-down and mortality using WHO insecticide test papers with standard diagnostic doses of the recommended insecticides. A sub-sample of tested specimens was analysed for the presence of knockdown resistance (kdr) mutations. A total of 14,311 mosquitoes were tested and from a sample of 1406 specimens, 1165 (82.9%) were identified as Anopheles arabiensis and 241 (17.1%) as Anopheles gambiae sensu stricto. Mortality results indicated a significant increase in resistance to lambda-cyhalothrin from 2011 to 2013 in 83% of the sites, permethrin in 25% of the sites, deltamethrin in 25% of the sites and DDT in 50% of the sites. Mosquitoes from 83% of the sites showed full susceptibility to bendiocarb and 17% of sites were suspected to harbour resistance that requires further confirmation. No resistance was observed to fenitrothion in all study sites during the entire survey. The kdr genotype results in An. gambiae s.s. showed that 67 (50%) possessed susceptibility (SS) alleles, while 35 (26.1%) and 32 (23.9%) mosquitoes had heterozygous (RS) and homozygous (RR) alleles, respectively. Of the 591 An. arabiensis genotyped, 425 (71.9%) possessed homozygous (SS) alleles while 158 (26.7%) and 8 (1.4%) had heterozygous (RS) and homozygous (RR) alleles, respectively. Metabolic resistance involving oxidase enzymes was also detected using the synergist PBO. This is the first nationwide study of insecticide resistance in malaria vectors in Rwanda. It shows the gradual increase of insecticide resistance to pyrethroids (lambda

  9. Population dynamics, structure and behavior of Anopheles darlingi in a rural settlement in the Amazon rainforest of Acre, Brazil.

    Moutinho, Paulo Rufalco; Gil, Luis Herman Soares; Cruz, Rafael Bastos; Ribolla, Paulo Eduardo Martins

    2011-06-24

    Anopheles darlingi is the major vector of malaria in South America, and its behavior and distribution has epidemiological importance to biomedical research. In Brazil, An. darlingi is found in the northern area of the Amazon basin, where 99.5% of the disease is reported. The study area, known as Ramal do Granada, is a rural settlement inside the Amazon basin in the state of Acre. Population variations and density have been analysed by species behaviour, and molecular analysis has been measured by ND4 mitochondrial gene sequencing. The results show higher density in collections near a recent settlement, suggesting that a high level of colonization decreases the vector presence. The biting activity showed higher activity at twilight and major numbers of mosquitos in the remaining hours of the night in months of high density. From a sample of 110 individual mosquitoes, 18 different haplotypes were presented with a diversity index of 0.895, which is higher than that found in other Anopheles studies. An. darlingi depends on forested regions for their larval and adult survival. In months with higher population density, the presence of mosquitoes persisted in the second part of the night, increasing the vector capacity of the species. Despite the intra-population variation in the transition to rainy season, the seasonal distribution of haplotypes shows no change in the structure population of An. darlingi.

  10. Avoid Mosquito Bites

    ... visiting CDC Travelers’ Health website . Pack a travel health kit . Remember to pack insect repellent and use it as directed to prevent mosquito bites. See a healthcare provider familiar with travel medicine, ideally 4 to 6 weeks ...

  11. Mosquito inspired medical needles

    Lenau, Torben Anker; Hesselberg, Thomas; Drakidis, Alexandros Dimitrios

    2017-01-01

    The stinging proboscis in mosquitos have diameters of only 40-100 μm which is much less than the thinnest medical needles and the mechanics of these natural stinging mechanisms have therefore attracted attention amongst developers of injection devises. The mosquito use a range of different...... strategies to lower the required penetration force hence allowing a thinner and less stiff proboscis structure. Earlier studies of the mosquito proboscis insertion strategies have shown how each of the single strategies reduces the required penetration force. The present paper gives an overview...... of the advanced set of mechanisms that allow the mosquito to penetrate human skin and also presents other biological mechanisms that facilitate skin penetration. Results from experiments in a skin mimic using biomimetic equivalents to the natural mechanisms are presented. This includes skin stretching, insertion...

  12. Ecology of Culiseta Melanura and Other Mosquitoes (Diptera: Culicidae) from Walton County, FL, During Winter Period 2013-2014.

    Burkett-Cadena, Nathan D; Bingham, Andrea M; Hunt, Brenda; Morse, Gary; Unnasch, Thomas R

    2015-09-01

    Winter ecology of putative vectors of eastern equine encephalomyelitis virus (EEEV) in northern Florida was investigated at field locations with evidence of historic EEEV winter transmission. Light traps and resting shelters were used to sample the mosquito community in the vicinity of eight sentinel flocks throughout the winter period (November-April) of 2013 and 2014 in Walton County, FL. Overall mosquito activity was relatively low, although mosquitoes were captured during each week of the study period. Mosquito activity was linked to morning temperature, and females were captured when ambient morning temperatures were quite low (1-5°C). Anopheles crucians Wiedemann, Culex erraticus (Dyar and Knab), Culex territans Walker, and Culiseta melanura (Coquillett) were the most commonly collected mosquito species (of 20 total species). Analysis of blood-engorged mosquitoes revealed a number of mosquito species feeding upon chickens, other birds, amphibians, and domestic and wild mammals. Cs. melanura fed primarily upon chickens and songbirds (Passeriformes), suggesting that this mosquito species is the likely winter vector of EEEV to sentinel chickens in northern Florida. Both resident and nonresident songbird species were fed upon, constituting 63.9 and 36.1% of total songbird meals, respectively. Our results suggest important roles for Cs. melanura and songbird hosts for the winter transmission of EEEV in northern Florida. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. The mode of action of spatial repellents and their impact on vectorial capacity of Anopheles gambiae sensu stricto.

    Sheila B Ogoma

    Full Text Available Malaria vector control relies on toxicity of insecticides used in long lasting insecticide treated nets and indoor residual spraying. This is despite evidence that sub-lethal insecticides reduce human-vector contact and malaria transmission. The impact of sub-lethal insecticides on host seeking and blood feeding of mosquitoes was measured. Taxis boxes distinguished between repellency and attraction inhibition of mosquitoes by measuring response of mosquitoes towards or away from Transfluthrin coils and humans. Protective effective distance of coils and long-term effects on blood feeding were measured in the semi-field tunnel and in a Peet Grady chamber. Laboratory reared pyrethroid susceptible Anopheles gambiae sensu stricto mosquitoes were used. In the taxis boxes, a higher proportion of mosquitoes (67%-82% were activated and flew towards the human in the presence of Transfluthrin coils. Coils did not hinder attraction of mosquitoes to the human. In the semi-field Tunnel, coils placed 0.3 m from the human reduced feeding by 86% (95% CI [0.66; 0.95] when used as a "bubble" compared to 65% (95% CI [0.51; 0.76] when used as a "point source". Mosquitoes exposed to coils inside a Peet Grady chamber were delayed from feeding normally for 12 hours but there was no effect on free flying and caged mosquitoes exposed in the semi-field tunnel. These findings indicate that airborne pyrethroids minimize human-vector contact through reduced and delayed blood feeding. This information is useful for the development of target product profiles of spatial repellent products that can be used to complement mainstream malaria vector control tools.

  14. The mode of action of spatial repellents and their impact on vectorial capacity of Anopheles gambiae sensu stricto.

    Ogoma, Sheila B; Ngonyani, Hassan; Simfukwe, Emmanuel T; Mseka, Antony; Moore, Jason; Maia, Marta F; Moore, Sarah J; Lorenz, Lena M

    2014-01-01

    Malaria vector control relies on toxicity of insecticides used in long lasting insecticide treated nets and indoor residual spraying. This is despite evidence that sub-lethal insecticides reduce human-vector contact and malaria transmission. The impact of sub-lethal insecticides on host seeking and blood feeding of mosquitoes was measured. Taxis boxes distinguished between repellency and attraction inhibition of mosquitoes by measuring response of mosquitoes towards or away from Transfluthrin coils and humans. Protective effective distance of coils and long-term effects on blood feeding were measured in the semi-field tunnel and in a Peet Grady chamber. Laboratory reared pyrethroid susceptible Anopheles gambiae sensu stricto mosquitoes were used. In the taxis boxes, a higher proportion of mosquitoes (67%-82%) were activated and flew towards the human in the presence of Transfluthrin coils. Coils did not hinder attraction of mosquitoes to the human. In the semi-field Tunnel, coils placed 0.3 m from the human reduced feeding by 86% (95% CI [0.66; 0.95]) when used as a "bubble" compared to 65% (95% CI [0.51; 0.76]) when used as a "point source". Mosquitoes exposed to coils inside a Peet Grady chamber were delayed from feeding normally for 12 hours but there was no effect on free flying and caged mosquitoes exposed in the semi-field tunnel. These findings indicate that airborne pyrethroids minimize human-vector contact through reduced and delayed blood feeding. This information is useful for the development of target product profiles of spatial repellent products that can be used to complement mainstream malaria vector control tools.

  15. Mosquitoes of Middle America.

    1976-09-30

    data on bionomics and disease relations. 0. P. Forattini’s treatment of the Culicidae in “ Entomologia Medica” (Sao Paulo , Faculdade de Higiene e Saude...Canal Zone and U.S.A. Casal. Osvaldo H., Depart amento de Entomologia Sanitaria , Instituto de Microbio logi a, Buenos Aires, Argen tina.— Mosquitoes...976 17 Garcia , M iguel, Departamento de Entomologia Sanitaria , Instituto de Microbiologia , Buenos Aires, Argentina . — Mosquitoes from Argentina

  16. Adulticidal effect of fungal pathogen, Metarhizium anisopliae on ...

    The entomopathogenic fungus, Metarhizium anisopliae is being considered as a biocontrol agent for the adult mosquito of Anopheles stephensi (Malarial vector). In the present experiment was carried out in the laboratory of 30-50 male and female adult mosquitoes were exposed to M. anisopliae (exposed to 1 x 106 ...

  17. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania.

    Mweya, Clement N; Kimera, Sharadhuli I; Mellau, Lesakit S B; Mboera, Leonard E G

    2015-01-01

    Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  18. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

    Clement N. Mweya

    2015-01-01

    Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

  19. Fauna of mosquito larvae (Diptera: Culicida) in Asir Provence, Kingdom of Saudi Arabia.

    Al Ashry, Hamdy A; Kenawy, Mohamed A; Shobrak, Mohammed

    2014-04-01

    An entomological survey was undertaken for one year to update the mosquito fauna of Asir Region, Kingdom of Saudi Arabia. A total of 31 species of 8 genera were reported of which genus Culex (55%) was the most common. Most of collected larvae (59%) belonged to genus Culex (+ Lutzia) followed by Culiseta (26%), Anopheles (13%) and Aedine spp. (2%). Cx. pipiens (39%) and Cs. longiareolata (26.%) were generally the most abundant of all collected larvae. Of the Anopheles spp., An. dthali was common (40%), of Culex spp., Cx. pipiens was predominating (66%) and of Aedine spp., St. aegypti was predominating (71%). Four species: An. fluviatilis, Cx. mattinglyi, Cx. arbieeni and Cx. mimeticus were new reports in Asir Region and Cx. wigglesworthi recorded for the first time from the kingdom. Larvae were more common in low- and highlands than in the moderately altitude areas. In general all species prefer stagnant water but with the exception of Aedine larvae (altogether), the other species prefer presence of algae, vegetation and shade and absence of turbidity (except Culex spp.). A total of 98 different forms of association were reported of which 9 forms were common. All genera breed year round with peaks of abundance during spring for Anopheles spp. and Culex spp. and during winter for Aedine spp. and Cs. longiareolata. A complete list of mosquito fauna of Asir Region comprising 45 spp. was presented based on the present and previous surveys. The study concluded that the occurrence and prevalence of mosquito species mainly the disease vectors in Asir carry the thread of maintaining and transmission of several mosquito-borne diseases.

  20. Microsporidia parásitos de larvas de mosquito de la Costa Pacífica del Chocó

    Zuluaga Juan S.

    1993-12-01

    Full Text Available Two genera of Microsporidia were found infecting mosquito larvae in three localities on the Pacific coast of Choco. Vavraia sp. (Microsporida: Pleistophoridae was found in larvae of Wyeomyia circumcincta, W. simmsi and Anopheles albimanus collected from plants of the Bromeliacea family in Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae was found parasitizingAedes angustivittatuslarvae COllectedfrom a terrestrial breeding pond in the locality of Nuqur. Morphology of the spores of the two parasites under light microscopy is described, as well as preliminary data on host range when exposed to laboratory rearad Aedes aegypti, Culex quinquefasciatus and Anopheles albimanus. Their rola in mosquito control is discussed.Se reportan dos géneros de microsporidia que parasitan larvas de mosquitos en criaderos naturales de tres localidades en la costa Pacffica Chocoana. Vavraia sp. (Microsporida: Pleistophoridae parásita larvas de Wyeomyia circumcincta, de Wyeomya simmsi y de Anopheles neivai, recolectadas en las rosetas de especies de la familia Bromeliaceae en las localidades de Arusí y Joví. Amblyospora sp. (Microsporida: Amblyosporidae parásita larvas deAedes angustivittatusde criaderos terrestres semipermanentes en la localidad de Nuquí. Se describe la morfología de estos dos microsporidia al microscopio óptico. Estudios preliminares de infección en larvas de Aedes aegypti, Culex quinquefasciatus yAnopheles albimanus, criadas en laboratorio, indican que Vavraia sp. infecta las tres especies, con preferencia a Culex quinquefasciatus. Las larvas expuestas a esporas de Amblyospora sp. no presentaron infección. Se discute el posible papel de estos dos géneros en el control de las poblaciones de mosquitos.

  1. Molecular species identification, host preference and detection of myxoma virus in the Anopheles maculipennis complex (Diptera: Culicidae) in southern England, UK.

    Brugman, Victor A; Hernández-Triana, Luis M; Prosser, Sean W J; Weland, Chris; Westcott, David G; Fooks, Anthony R; Johnson, Nicholas

    2015-08-15

    Determining the host feeding patterns of mosquitoes by identifying the origin of their blood-meals is an important part of understanding the role of vector species in current and future disease transmission cycles. Collecting large numbers of blood-fed mosquitoes from the field is difficult, therefore it is important to maximise the information obtained from each specimen. This study aimed to use mosquito genome sequence to identify the species within Anopheles maculipennis sensu lato (An. maculipennis s.l.), identify the vertebrate hosts of field-caught blood-fed An. maculipennis s.l. , and to test for the presence of myxoma virus (Poxviridae, genus Leporipoxvirus) in specimens found to have fed on the European rabbit (Oryctolagus cuniculus). Blood-fed An. maculipennis s.l. were collected from resting sites at Elmley Nature Reserve, Kent, between June and September 2013. Hosts that An. maculipennis s.l. had fed on were determined by a PCR-sequencing approach based on the partial amplification of the mitochondrial cytochrome C oxidase subunit I gene. Mosquitoes were then identified to species by sequencing a region of the internal transcribed spacer-2. DNA extracts from all mosquitoes identified as having fed on rabbits were subsequently screened using PCR for the presence of myxoma virus. A total of 94 blood-fed Anopheles maculipennis s.l. were collected, of which 43 (46%) provided positive blood-meal identification results. Thirty-six of these specimens were identified as Anopheles atroparvus, which had fed on rabbit (n = 33, 92%) and cattle (n = 3, 8%). Seven mosquitoes were identified as Anopheles messeae, which had fed on cattle (n = 6, 86%) and dog (n = 1, 14%). Of the 33 An. atroparvus that contained rabbit blood, nine (27%) were positive for myxoma virus. Results demonstrate that a single DNA extract from a blood-fed mosquito can be successfully used for molecular identification of members of the An. maculipennis complex, blood

  2. Xenomonitoring of Mosquitoes (Diptera: Culicidae for the Presence of Filarioid Helminths in Eastern Austria

    Sarah Susanne Übleis

    2018-01-01

    Full Text Available Information on mosquito-borne filarioid helminths in Austria is scarce, but recent discoveries of Dirofilaria repens indicate autochthonous distribution of this parasite in Eastern Austria. In the current xenomonitoring study, more than 48,000 mosquitoes were collected in Eastern Austria between 2013 and 2015, using different sampling techniques and storage conditions, and were analysed in pools with molecular tools for the presence of filarioid helminth DNA. Overall, DNA of D. repens, Setaria tundra, and two unknown filarioid helminths were documented in twenty mosquito pools within the mitochondrial cox1 gene (barcode region. These results indicate that S. tundra, with roe deer as definite hosts, is common in Eastern Austria, with most occurrences in floodplain mosquitoes (e.g., Aedes vexans. Moreover, DNA of D. repens was found in an Anopheles plumbeus mosquito close to the Slovakian border, indicating that D. repens is endemic in low prevalence in Eastern Austria. This study shows that xenomonitoring is an adequate tool to analyse the presence of filarioid helminths, but results are influenced by mosquito sampling techniques, storage conditions, and molecular protocols.

  3. The Seasonality and Ecology of the Anopheles gambiae complex (Dipetra: Culicidae) in Liberia Using Molecular Identification.

    Fahmy, N T; Villinski, J T; Bolay, F; Stoops, C A; Tageldin, R A; Fakoli, L; Okasha, O; Obenauer, P J; Diclaro, J W

    2015-05-01

    Members of the Anopheles gambiae sensu lato (Giles) complex define a group of seven morphologically indistinguishable species, including the principal malaria vectors in Sub-Saharan Africa. Members of this complex differ in behavior and ability to transmit malaria; hence, precise identification of member species is critical to monitoring and evaluating malaria threat levels. We collected mosquitoes from five counties in Liberia every other month from May 2011 until May 2012, using various trapping techniques. A. gambiae complex members were identified using molecular techniques based on differences in the ribosomal DNA (rDNA) region between species and the molecular forms (S and M) of A. gambiae sensu stricto (s.s) specimens. In total, 1,696 A. gambiae mosquitoes were collected and identified. DNA was extracted from legs of each specimen with species identification determined by multiplex polymerase chain reaction using specific primers. The molecular forms (M or S) of A. gambiae s.s were determined by restriction fragment length polymorphism. Bivariate and multivariate logistic regression models identified environmental variables associated with genomic differentiation. Our results indicate widespread occurrence of A. gambiae s.s., the principal malaria vector in the complex, although two Anopheles melas Theobald/A. merus Donitz mosquitoes were detected. We found 72.6, 25.5, and 1.9% of A. gambiae s.s specimens were S, M, and hybrid forms, respectively. Statistical analysis indicates that the S form was more likely to be found in rural areas during rainy seasons and indoor catchments. This information will enhance vector control efforts in Liberia. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

  4. Limitation of using synthetic human odours to test mosquito repellents

    Mbeyela Edgar

    2009-07-01

    Full Text Available Abstract Background Gold-standard tests of mosquito repellents involve exposing human volunteers to host-seeking mosquitoes, to assess the protective efficacy of the repellents. These techniques are not exposure-free and cannot be performed prior to toxicological evaluation. It is postulated that synthetic lures could provide a useful assay that mimics in-vivo conditions for use in high-throughput screening for mosquito repellents. Methods This paper reports on a semi-field evaluation of repellents using a synthetic blend of human derived attractants for the malaria vector, Anopheles gambiae sensu stricto Different concentrations of known repellents, N, N diethyl-3-methylbenzamide (deet and Para-methane-3, 8, diol (PMD were added into traps baited with the synthetic blend, and resulting changes in mosquito catches were measured. Results All test concentrations of deet (0.001% to 100% reduced the attractiveness of the synthetic blend. However, PMD was repellent only at 0.25%. Above this concentration, it significantly increased the attractiveness of the blend. There was no relationship between the repellent concentrations and the change in mosquito catches when either deet (r2 = 0.033, P = 0.302 or PMD (r2 = 0.020, P = 0.578 was used. Conclusion It is concluded that while some repellents may reduce the attractiveness of synthetic human odours, others may instead increase their attractiveness. Such inconsistencies indicate that even though the synthetic attractants may provide exposure-free and consistent test media for repellents, careful selection and multiple-repellent tests are necessary to ascertain their suitability for use in repellent screening. The synthetic odour blend tested here is not yet sufficiently refined to serve as replacement for humans in repellent testing, but may be developed further and evaluated in different formats for exposure free repellent testing purposes.

  5. The Cry Toxin Operon of Clostridium bifermentans subsp. malaysia Is Highly Toxic to Aedes Larval Mosquitoes

    Qureshi, Nadia; Chawla, Swati; Likitvivatanavong, Supaporn; Lee, Han Lim

    2014-01-01

    The management and control of mosquito vectors of human disease currently rely primarily on chemical insecticides. However, larvicidal treatments can be effective, and if based on biological insecticides, they can also ameliorate the risk posed to human health by chemical insecticides. The aerobic bacteria Bacillus thuringiensis and Lysinibacillus sphaericus have been used for vector control for a number of decades. But a more cost-effective use would be an anaerobic bacterium because of the ease with which these can be cultured. More recently, the anaerobic bacterium Clostridium bifermentans subsp. malaysia has been reported to have high mosquitocidal activity, and a number of proteins were identified as potentially mosquitocidal. However, the cloned proteins showed no mosquitocidal activity. We show here that four toxins encoded by the Cry operon, Cry16A, Cry17A, Cbm17.1, and Cbm17.2, are all required for toxicity, and these toxins collectively show remarkable selectivity for Aedes rather than Anopheles mosquitoes, even though C. bifermentans subsp. malaysia is more toxic to Anopheles. Hence, toxins that target Anopheles are different from those expressed by the Cry operon. PMID:25002432

  6. Qualitative Study Of Anopheles Species In Konduga Lake Area Of ...

    The investigation on Anopheles species in Konduga lake area, Borno State of Nigeria, was carried out to identify various Anopheles species prevalent in the area and to determine their relative population densities. Six Anopheles species were recorded, namely, A. gambiae, A. funestus, A. ziemanni, A. squamosus, ...

  7. Spread of anti-malarial drug resistance: Mathematical model with implications for ACT drug policies

    Dondorp Arjen M

    2008-11-01

    Full Text Available Abstract Background Most malaria-endemic countries are implementing a change in anti-malarial drug policy to artemisinin-based combination therapy (ACT. The impact of different drug choices and implementation strategies is uncertain. Data from many epidemiological studies in different levels of malaria endemicity and in areas with the highest prevalence of drug resistance like borders of Thailand are certainly valuable. Formulating an appropriate dynamic data-driven model is a powerful predictive tool for exploring the impact of these strategies quantitatively. Methods A comprehensive model was constructed incorporating important epidemiological and biological factors of human, mosquito, parasite and treatment. The iterative process of developing the model, identifying data needed, and parameterization has been taken to strongly link the model to the empirical evidence. The model provides quantitative measures of outcomes, such as malaria prevalence/incidence and treatment failure, and illustrates the spread of resistance in low and high transmission settings. The model was used to evaluate different anti-malarial policy options focusing on ACT deployment. Results The model predicts robustly that in low transmission settings drug resistance spreads faster than in high transmission settings, and treatment failure is the main force driving the spread of drug resistance. In low transmission settings, ACT slows the spread of drug resistance to a partner drug, especially at high coverage rates. This effect decreases exponentially with increasing delay in deploying the ACT and decreasing rates of coverage. In the high transmission settings, however, drug resistance is driven by the proportion of the human population with a residual drug level, which gives resistant parasites some survival advantage. The spread of drug resistance could be slowed down by controlling presumptive drug use and avoiding the use of combination therapies containing drugs with

  8. Bionomics of Anopheles latens in Kapit, Sarawak, Malaysian Borneo in relation to the transmission of zoonotic simian malaria parasite Plasmodium knowlesi

    Matusop Asmad

    2008-03-01

    Full Text Available Abstract Background A large focus of human infections with Plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques was discovered in the Kapit Division of Sarawak, Malaysian Borneo. A study was initiated to identify the vectors of malaria, to elucidate where transmission is taking place and to understand the bionomics of the vectors in Kapit. Methods Three different ecological sites in the forest, farm and longhouse in the Kapit district were selected for the study. Mosquitoes were collected by human landing collection at all sites and at the forest also by monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites. Results and Discussions Over an 11-month period, a total of 2,504 Anopheles mosquitoes comprising 12 species were caught; 1,035 at the farm, 774 at the forest and 425 at the longhouse. Anopheles latens (62.3% and Anopheles watsonii (30.6% were the predominant species caught in the forested ecotypes, while in the farm Anopheles donaldi (49.9% and An. latens (35.6% predominated. In the long house, An. latens (29.6% and An. donaldi (22.8% were the major Anopheline species. However, An. latens was the only mosquito positive for sporozoites and it was found to be attracted to both human and monkey hosts. In monkey-baited net traps, it preferred to bite monkeys at the canopy level than at ground level. An. latens was found biting early as 18.00 hours. Conclusion Anopheles latens is the main vector for P. knowlesi malaria parasites in the Kapit District of Sarawak, Malaysian Borneo. The study underscores the relationship between ecology, abundance and bionomics of anopheline fauna. The simio-anthropophagic and acrodendrophilic behaviour of An. latens makes it an efficient vector for the transmission of P. knowlesi parasites to both human and monkey hosts.

  9. Host feeding patterns and preference of Anopheles minimus (Diptera: Culicidae in a malaria endemic area of western Thailand: baseline site description

    Tisgratog Rungarun

    2012-06-01

    Full Text Available Abstract Background Host feeding patterns of Anopheles minimus in relation to ambient environmental conditions were observed during a 2-year period at Tum Sua Village, located in Mae Sot District, Tak Province, in western Thailand, where An. minimus is found in abundance and regarded as the most predominant malaria vector species. Detailed information on mosquito behavior is important for understanding the epidemiology of disease transmission and developing more effective and efficient vector control methods. Methods Adult mosquitoes were collected every 2 months for two consecutive nights from 1800 to 0600 hrs. Three collection methods were used; indoor human-landing collections (HLC, outdoor HLC, and outdoor cattle-bait collections (CBC. Results A total of 7,663 female Anopheles mosquitoes were collected of which 5,392 were identified as members of 3 different species complexes, the most prevalent being Anopheles minimus complex (50.36%, followed by Anopheles maculatus complex (19.68% and Anopheles dirus complex (0.33%. An. minimus s.s. comprised virtually all (> 99.8 percent of Minimus Complex species captured. Blood feeding behavior of An. minimus was more pronounced during the second half of the evening, showing a slight preference to blood feed outdoors (~60% versus inside structures. Significantly (P An. minimus were collected from human-baited methods compared with a tethered cow, indicating a more anthropophilic feeding behavior. Although a significant difference in total number of mosquitoes from the HLC was recorded between the first and second year, the mean biting frequency over the course of the evening hours remained similar. Conclusions The Human landing activity of An. minimus in Tum Sua Village showed a stronger preference/attraction for humans compared to a cow-baited collection method. This study supports the incrimination of An. minimus as the primary malaria vector in the area. A better understanding of mosquito

  10. Bionomics of Anopheles latens in Kapit, Sarawak, Malaysian Borneo in relation to the transmission of zoonotic simian malaria parasite Plasmodium knowlesi

    Tan, Cheong H; Vythilingam, Indra; Matusop, Asmad; Chan, Seng T; Singh, Balbir

    2008-01-01

    Background A large focus of human infections with Plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques was discovered in the Kapit Division of Sarawak, Malaysian Borneo. A study was initiated to identify the vectors of malaria, to elucidate where transmission is taking place and to understand the bionomics of the vectors in Kapit. Methods Three different ecological sites in the forest, farm and longhouse in the Kapit district were selected for the study. Mosquitoes were collected by human landing collection at all sites and at the forest also by monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites. Results and Discussions Over an 11-month period, a total of 2,504 Anopheles mosquitoes comprising 12 species were caught; 1,035 at the farm, 774 at the forest and 425 at the longhouse. Anopheles latens (62.3%) and Anopheles watsonii (30.6%) were the predominant species caught in the forested ecotypes, while in the farm Anopheles donaldi (49.9%) and An. latens (35.6%) predominated. In the long house, An. latens (29.6%) and An. donaldi (22.8%) were the major Anopheline species. However, An. latens was the only mosquito positive for sporozoites and it was found to be attracted to both human and monkey hosts. In monkey-baited net traps, it preferred to bite monkeys at the canopy level than at ground level. An. latens was found biting early as 18.00 hours. Conclusion Anopheles latens is the main vector for P. knowlesi malaria parasites in the Kapit District of Sarawak, Malaysian Borneo. The study underscores the relationship between ecology, abundance and bionomics of anopheline fauna. The simio-anthropophagic and acrodendrophilic behaviour of An. latens makes it an efficient vector for the transmission of P. knowlesi parasites to both human and monkey hosts. PMID:18377652

  11. Entomologic inoculation rates of Anopheles arabiensis in southwestern Ethiopia.

    Massebo, Fekadu; Balkew, Meshesha; Gebre-Michael, Teshome; Lindtjørn, Bernt

    2013-09-01

    We collected anophelines every second week for one year from randomly selected houses in southwestern Ethiopia by using Centers for Disease Control (CDC) light traps, pyrethrum spray catches, and artificial pit shelter constructions to detect circumsporozoite proteins and estimate entomologic inoculation rates (EIRs). Of 3,678 Anopheles arabiensis tested for circumsporozoite proteins, 11 were positive for Plasmodium falciparum and three for P. vivax. The estimated annual P. falciparum EIR of An. arabiensis was 17.1 infectious bites per person per year (95% confidence interval = 7.03-34.6) based on CDC light traps and 0.1 infectious bites per person per year based on pyrethrum spray catches. The P. falciparum EIRs from CDC light traps varied from 0 infectious bites per person per year (in 60% of houses) to 73.2 infectious bites per person per year in the house nearest the breeding sites. Risk of exposure to infectious bites was higher in wet months than dry months, with a peak in April (9.6 infectious bites per person per month), the period of highest mosquito density.

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

    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

  13. Irritant and repellent responses of Anopheles harrisoni and Anopheles minimus upon exposure to bifenthrin or deltamethrin using an excito-repellency system and a live host.

    Kongmee, Monthathip; Boonyuan, Wasana; Achee, Nicole L; Prabaripai, Atchariya; Lerdthusnee, Kriangkrai; Chareonviriyaphap, Theeraphap

    2012-03-01

    Feeding responses of Anopheles harrisoni and An. minimus were evaluated following exposure to 2 pyrethroid insecticides, bifenthrin or deltamethrin, using an excito-repellency test system in the presence and absence of live host cues. The results demonstrated that contact irritancy was the primary action of bifenthrin or deltamethrin in both mosquito species. There was no noncontact repellency effect elicited by either insecticide. Anopheles minimus showed rapid escape response with high mortality rates following direct contact with deltamethrin in the absence of a host and delayed escape responses when a host was present. Similarly, exposure of An. minimus to bifenthrin also elicited a delayed escape response in the presence of a host but with lower mortality rates. In experiments using An. harrisoni, the presence or absence of a host had no significant effect on behavioral responses to either insecticide (P > 0.05). We conclude that deltamethrin elicited stronger irritant chemical effects than bifenthrin but that behavioral responses in vector populations are dampened in the presence of an available host. This information is useful for estimating probability of pathogen transmission when using irritant chemicals in proximity to a blood-meal source.

  14. Genetic Dissection of Anopheles gambiae Gut Epithelial Responses to Serratia marcescens

    Stathopoulos, Stavros; Neafsey, Daniel E.; Lawniczak, Mara K. N.; Muskavitch, Marc A. T.; Christophides, George K.

    2014-01-01

    Genetic variation in the mosquito Anopheles gambiae profoundly influences its ability to transmit malaria. Mosquito gut bacteria are shown to influence the outcome of infections with Plasmodium parasites and are also thought to exert a strong drive on genetic variation through natural selection; however, a link between antibacterial effects and genetic variation is yet to emerge. Here, we combined SNP genotyping and expression profiling with phenotypic analyses of candidate genes by RNAi-mediated silencing and 454 pyrosequencing to investigate this intricate biological system. We identified 138 An. gambiae genes to be genetically associated with the outcome of Serratia marcescens infection, including the peptidoglycan recognition receptor PGRPLC that triggers activation of the antibacterial IMD/REL2 pathway and the epidermal growth factor receptor EGFR. Silencing of three genes encoding type III fibronectin domain proteins (FN3Ds) increased the Serratia load and altered the gut microbiota composition in favor of Enterobacteriaceae. These data suggest that natural genetic variation in immune-related genes can shape the bacterial population structure of the mosquito gut with high specificity. Importantly, FN3D2 encodes a homolog of the hypervariable pattern recognition receptor Dscam, suggesting that pathogen-specific recognition may involve a broader family of immune factors. Additionally, we showed that silencing the gene encoding the gustatory receptor Gr9 that is also associated with the Serratia infection phenotype drastically increased Serratia levels. The Gr9 antibacterial activity appears to be related to mosquito feeding behavior and to mostly rely on changes of neuropeptide F expression, together suggesting a behavioral immune response following Serratia infection. Our findings reveal that the mosquito response to oral Serratia infection comprises both an epithelial and a behavioral immune component. PMID:24603764

  15. Biological control of Anopheles darlingi, Aedes aegypti and Culex quinquefasciatus larvae using shrimps

    Willian Marinho Dourado Coelho

    2017-08-01

    Full Text Available Mosquitoes can act as vectors of important diseases such as malaria, dengue, Zika virus, yellow fever, Chikungunya and Mayaro fever, in addition to filariasis. The use of insecticides, larvicides, bed nets and repellents, besides the use of drugs as chemoprevention and the treatment of the sick are currently the pillars of the control of these vectors. We studied the biological control against of Anopheles darlingi, Aedes aegypti and Culex quinquefasciatus larvae using shrimps of the species M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii. Larvae of mosquitoes were collected from the breeding environment and placed in a 500 and 1000 l tank containing 60 shrimps/m2. The predatory activity was evaluated for 30 days and, in all groups it was observed that 100% of the larvae were consumed in few minutes. In the environment, these same species of crustaceans were released in water bodies with the presence of larvae of these insects. In just 72 h there was a marked reduction of the larvae in the release sites of shrimps. Similarly, there was a reduction in the number of adult mosquitoes caught near the breeding sites, allowing to infer that, in places where the crustaceans were released, the predatory activity on the larvae of mosquitoes was sufficient to reduce the number of adult mosquitoes p ≤ 0,05. This is the first description of the predatory activity of M. pantanalense, M. amazonicum, M. brasiliense and M. jelskii on An. darlingi, A. aegypti and C. quinquefasciatus larvae, constituting an important tool of biological control of these parasites-vectors.

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

    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

  17. The susceptibility of Anopheles lesteri to infection with Korean strain of Plasmodium vivax

    Kim Tong-Soo

    2009-03-01

    Full Text Available Abstract Background Following its recent re-emergence, malaria has gained renewed attention as a serious infectious disease in Korea. Three species of the Hyrcanusgroup, Anopheles lesteri, Anopheles sinensis and Anopheles pullus, have long been suspected malaria vectors. However, opinions about their vector ability are controversial. The present study was designed with the aim of determining the susceptibility of these mosquitoes to a Korean isolate of Plasmodium vivax. Also, An. sinensis is primarily suspected to be vector of malaria in Korea, but in Thailand, the same species is described to have less medical importance. Therefore, comparative susceptibility of Thai and Korean strains of An. sinensis with Thai strain of P. vivax may be helpful to understand whether these geographically different strains exhibit differences in their susceptibility or not. Methods The comparative susceptibility of An. lesteri, An. sinensis and An. pullus was studied by feeding laboratory-reared mosquitoes on blood from patients carrying gametocytes from Korea and Thailand. Results In experimental feeding with Korean strain of P. vivax, oocysts developed in An. lesteri, An. sinensis and An. pullus. Salivary gland sporozoites were detected only in An. lesteri and An. sinensis but not in An. pullus. Large differences were found in the number of sporozoites in the salivary glands, with An. lesteri carrying much higher densities, up to 2,105 sporozoites in a single microscope field of 750 × 560 μM, whereas a maximum of 14 sporozoites were found in any individual salivary gland of An. sinensis. Similar results were obtained from a susceptibility test of two different strains of An. sinensis to Thai isolate of P. vivax, and differences in vector susceptibility according to geographical variation were not detected. Conclusion The high sporozoite rate and sporozoite loads of An. lesteri indicate that this species is highly susceptible to infection with P. vivax

  18. Laboratory and field efficacy of Pedalium murex and predatory copepod, Mesocyclops longisetus on rural malaria vector, Anopheles culicifacies

    Thangadurai Chitra

    2013-04-01

    Full Text Available Objective: To test the potentiality of the leaf extract of Pedalium murex (P. murex and predatory copepod Mesocyclops longisetus (M. longisetus in individual and combination in controlling the rural malarial vector, Anopheles culicifacies (An. culicifacies in laboratory and field studies. Methods: P. murex leaves were collected from in and around Erode, Tamilnadu, India. The active compounds were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. Laboratory studies on larvicidal and pupicidal effects of methanolic extract of P. murex tested against the rural malarial vector, An. culicifacies were significant. Results: Evaluated lethal concentrations (LC50 of P. murex extract were 2.68, 3.60, 4.50, 6.44 and 7.60 mg/L for I, II, III, IV and pupae of An. culicifacies, respectively. Predatory copepod, M. longisetus was examined for their predatory efficacy against the malarial vector, An. culicifacies. M. longisetus showed effective predation on the early instar (47% and 36% on I and II instar when compared with the later ones (3% and 1% on III and IV instar. Predatory efficacy of M. longisetus was increased (70% and 45% on I and II instar when the application was along with the P. murex extract. Conclusions: Predator survival test showed that the methanolic extract of P. murex is non-toxic to the predatory copepod, M. longisetus. Experiments were also conducted to evaluate the efficacy of methanolic extract of P. murex and M. longisetus in the direct breeding sites (paddy fields of An. culicifacies. Reduction in larval density was very high and sustained for a long time in combined treatment of P. murex and M. longisetus.

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  20. Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae).

    Porretta, Daniele; Mastrantonio, Valentina; Crasta, Graziano; Bellini, Romeo; Comandatore, Francesco; Rossi, Paolo; Favia, Guido; Bandi, Claudio; Urbanelli, Sandra

    2016-11-02

    Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of

  1. Intra-instar larval cannibalism in Anopheles gambiae (s.s. and Anopheles stephensi (Diptera: Culicidae

    Daniele Porretta

    2016-11-01

    Full Text Available Abstract Background Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1 has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4 of Anopheles gambiae (s.s. and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Results Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s. than in An. stephensi. In both species the total number of cannibalistic events increased from 0–24 to 0–48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. Conclusions The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s. and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior

  2. The effects of blood feeding and exogenous supply of tryptophan on the quantities of xanthurenic acid in the salivary glands of Anopheles stephensi (Diptera: Culicidae).

    Okech, Bernard; Arai, Meiji; Matsuoka, Hiroyuki

    2006-03-24

    Xanthurenic acid (XA), produced as a byproduct during the biosynthesis of insect eye pigment (ommochromes), is a strong inducer of Plasmodium gametogenesis at very low concentrations. In previous studies, it was shown that XA is present in Anopheles stephensi (Diptera: Culicidae) mosquito salivary glands and that during blood feeding the mosquitoes ingested their own saliva into the midgut. Considering these two facts together, it is therefore likely that XA is discharged with saliva during blood feeding and is swallowed into the midgut where it exerts its effect on Plasmodium gametocytes. However, the quantities of XA in the salivary glands and midgut are unknown. In this study, we used high performance liquid chromatography with electrochemical detection to detect and quantify XA in the salivary glands and midgut. Based on the results of this study, we found 0.28+/-0.05 ng of XA in the salivary glands of the mosquitoes, accounting for 10% of the total XA content in the mosquito whole body. The amounts of XA in the salivary glands reduced to 0.13+/-0.06 ng after mosquitoes ingested a blood meal. Approximately 0.05+/-0.01 ng of XA was detected in the midgut of nonblood fed An. stephensi mosquitoes. By adding synthetic tryptophan as a source of XA into larval rearing water (2 mM) or in sugar meals (10 mM), we evaluated whether XA levels in the mosquito (salivary glands, midgut, and whole body) were boosted and the subsequent effect on infectivity of Plasmodium berghei in the treated mosquito groups. A female specific increase in XA content was observed in the whole body and in the midgut of mosquito groups where tryptophan was added either in the larval water or sugar meals. However, XA in the salivary glands was not affected by tryptophan addition to larval water, and surprisingly it reduced when tryptophan was added to sugar meals. The P. berghei oocyst loads in the mosquito midguts were lower in mosquitoes fed tryptophan treated sugar meals than in mosquitoes

  3. Repelling mosquitoes with essential oils

    Riley, L.

    2017-12-01

    Mosquitoes carry diseases than can lead to serious illness and death. According to the World Health Organization, mosquitoes infect over 300 million people a year with Malaria and Dengue Fever, two life threatening diseases vectored by mosquitoes. Although insecticides are the most effective way to control mosquitoes, they are not always environmentally friendly. Therefore, alternative tactics should be considered. In this study, we looked at the repellency of various essential oils on female Aedes aegypti through a series of laboratory assays.

  4. Role of wastewater irrigation in mosquito breeding in south Punjab, Pakistan

    Mukhtar, Muhammad; Herrel, Nathaly; Amerasinghe, Felix P

    2003-01-01

    and the wastewater disposal system. Overall, 17.3% of the samples were positive for Anopheles, 12.0% for Culex and 15.0% for Aedes. Four anopheline species, viz, Anopheles stephensi (84.3% of total anophelines), An. subpictus (11.8%), An. culicifacies (2.0%) and An. pulcherrimus (0.2%) were present, as were two...... species of Culex, viz, Cx. quinquefasciatus (66.5% of culicines) and Cx. tritaeniorhynchus (20.1%). Aedes were not identified to species level. The occurrence of different species was linked to particular habitats and habitat characteristics such as physical water condition, chemical water quality...... and the presence of fauna and flora. Anophelines and Aedes mosquitos were mainly collected during the month of July, while Culex were collected in September. The prevalence of established vectors of human diseases such as An. stephensi (malaria), Cx. tritaeniorhynchus (West Nile fever, Japanese encephalitis...

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

    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.

  6. Demasculinization of the Anopheles gambiae X chromosome

    Magnusson Kalle

    2012-05-01

    Full Text Available Abstract Background In a number of organisms sex-biased genes are non-randomly distributed between autosomes and the shared sex chromosome X (or Z. Studies on Anopheles gambiae have produced conflicting results regarding the underrepresentation of male-biased genes on the X chromosome and it is unclear to what extent sexual antagonism, dosage compensation or X-inactivation in the male germline, the evolutionary forces that have been suggested to affect the chromosomal distribution of sex-biased genes, are operational in Anopheles. Results We performed a meta-analysis of sex-biased gene expression in Anopheles gambiae which provides evidence for a general underrepresentation of male-biased genes on the X-chromosome that increased in significance with the observed degree of sex-bias. A phylogenomic comparison between Drosophila melanogaster, Aedes aegypti and Culex quinquefasciatus also indicates that the Anopheles X chromosome strongly disfavours the evolutionary conservation of male-biased expression and that novel male-biased genes are more likely to arise on autosomes. Finally, we demonstrate experimentally that transgenes situated on the Anopheles gambiae X chromosome are transcriptionally silenced in the male germline. Conclusion The data presented here support the hypothesis that the observed demasculinization of the Anopheles X chromosome is driven by X-chromosome inactivation in the male germline and by sexual antagonism. The demasculinization appears to be the consequence of a loss of male-biased expression, rather than a failure in the establishment or the extinction of male-biased genes.

  7. Population Dynamics and Plasmodium falciparum (Haemosporida: Plasmodiidae) Infectivity Rates for the Malaria Vector Anopheles arabiensis (Diptera: Culicidae) at Mamfene, KwaZulu-Natal, South Africa.

    Dandalo, Leonard C; Brooke, Basil D; Munhenga, Givemore; Lobb, Leanne N; Zikhali, Jabulani; Ngxongo, Sifiso P; Zikhali, Phineas M; Msimang, Sipho; Wood, Oliver R; Mofokeng, Mohlominyana; Misiani, Eunice; Chirwa, Tobias; Koekemoer, Lizette L

    2017-11-07

    Anopheles arabiensis (Patton; Diptera: Culicidae) is a major malaria vector in the southern African region. In South Africa, effective control of this species using indoor-based interventions is reduced owing to its tendency to rest outdoors. As South Africa moves towards malaria elimination there is a need for complementary vector control strategies. One of the methods under consideration is the use of the sterile insect technique (SIT). Key to the successful implementation of an SIT programme is prior knowledge of the size and spatial distribution of the target population. Understanding mosquito population dynamics for both males and females is critical for efficient programme implementation. It is thus necessary to use outdoor-based population monitoring tools capable of sampling both sexes of the target population. In this project mosquito surveillance and evaluation of tools capable of collecting both genders were carried out at Mamfene in northern KwaZulu-Natal Province, South Africa, during the period January 2014 to December 2015. Outdoor- and indoor-resting Anopheles mosquitoes were sampled in three sections of Mamfene over the 2-yr sampling period using modified plastic buckets, clay pots and window exit traps. Morphological and molecular techniques were used for species identifications of all samples. Wild-caught adult females were tested for Plasmodium falciparum (Welch; Haemosporida: Plasmodiidae) infectivity. Out of 1,705 mosquitoes collected, 1,259 (73.8%) and 255 (15%) were identified as members of either the Anopheles gambiae complex or Anopheles funestus group respectively. An. arabiensis was the most abundant species contributing 78.8% of identified specimens. Mosquito density was highest in summer and lowest during winter. Clay pots yielded 16.3 mosquitoes per trap compared to 10.5 for modified plastic buckets over the 2-yr sampling period. P. falciparum infection rates for An. arabiensis were 0.7% and 0.5% for 2014 and 2015, respectively

  8. Anopheline and culicine mosquitoes are not repelled by surfaces treated with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

    Mnyone Ladslaus L

    2010-08-01

    Full Text Available Abstract Background Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, are promising bio-pesticides for application against adult malaria mosquito vectors. An understanding of the behavioural responses of mosquitoes towards these fungi is necessary to guide development of fungi beyond the 'proof of concept' stage and to design suitable intervention tools. Methods Here we tested whether oil-formulations of the two fungi could be detected and avoided by adult Anopheles gambiae s.s., Anopheles arabiensis and Culex quinquefasciatus. The bioassays used a glass chamber divided into three compartments (each 250 × 250 × 250 mm: release, middle and stimulus compartments. Netting with or without fungus was fitted in front of the stimulus compartment. Mosquitoes were released and the proportion that entered the stimulus compartment was determined and compared between treatments. Treatments were untreated netting (control 1, netting with mineral oil (control 2 and fungal conidia formulated in mineral oil evaluated at three different dosages (2 × 1010, 4 × 1010 and 8 × 1010 conidia m-2. Results Neither fungal strain was repellent as the mean proportion of mosquitoes collected in the stimulus compartment did not differ between experiments with surfaces treated with and without fungus regardless of the fungal isolate and mosquito species tested. Conclusion Our results indicate that mineral-oil formulations of M. anisopliae and B. bassiana were not repellent against the mosquito species tested. Therefore, both fungi are suitable candidates for the further development of tools that aim to control host-seeking or resting mosquitoes using entomopathogenic fungi.

  9. Attractiveness of MM-X Traps Baited with Human or Synthetic Odor to Mosquitoes (Diptera: Culicidae) in The Gambia

    QIU, YU TONG; SMALLEGANGE, RENATE C.; TER BRAAK, CAJO J. F.; SPITZEN, JEROEN; VAN LOON, JOOP J. A.; JAWARA, MUSA; MILLIGAN, PAUL; GALIMARD, AGNES M.; VAN BEEK, TERIS A.; KNOLS, BART G. J.; TAKKEN, WILLEM

    2013-01-01

    Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to which carbon dioxide (CO2) was added were tested in four sets of experiments. In a second series of experiments, MM-X traps with 14 odor blends without CO2 were tested. A blend of ammonia and l-lactic acid with or without CO2 was used as control odor in series 1 and 2, respectively. Centers for Disease Control and Prevention (CDC) traps were placed in a traditional house and an experimental house to monitor mosquito densities during the experiments. The MM-X traps caught a total number of 196,756 mosquitoes, with the most abundant species belonging to the genera Mansonia (70.6%), Anopheles (17.5%), and Culex (11.5%). The most abundant mosquito species caught by the CDC traps (56,290 in total) belonged to the genera Mansonia (59.4%), Anopheles (16.0% An. gambiae s.l. Giles, and 11.3% An. ziemanni Grünberg), and Culex (11.6%). MM-X traps baited with synthetic blends were in many cases more attractive than MM-X traps baited with human odors. Addition of CO2 to synthetic odors substantially increased the catch of all mosquito species in the MM-X traps. A blend of ammonia + L-lactic acid + CO2 + 3-methylbutanoic acid was the most attractive odor for most mosquito species. The candidate odor blend shows the potential to enhance trap collections so that traps will provide better surveillance and possible control. PMID:18047195

  10. Mediation of deet repellency in mosquitoes (Diptera: Culicidae) by species, age, and parity.

    Barnard, D R

    1998-05-01

    Laboratory bioassays assessed differences in the protection time provided by the repellent deet (N,N-diethyl-3-methylbenzamide) against 5-d-old nulliparous and 10-, 15-, and 20-d-old nulliparous and parous female Aedes aegypti (L.), Anopheles albimanus (Weidemann), and Anopheles quadrimaculatus Say sensu lato. Mean protection time was shortest against An. albimanus (1.6 h) and An. quadrimaculatus (1.5 h) and longest against Ae. aegypti (6.5 h), but was not significantly influenced by mosquito age or parity. Mean percentage of biting at repellent failure time was highest in An. albimanus (14.2%), followed by An. quadrimaculatus (7.0%) and Ae. aegypti (2.9%), was higher in parous females (10.8%) than in nulliparous females (5.9%), and was highest overall (35%) in 20-d-old parous An. albimanus. Interaction between mosquito species and parity and between parity and age factors, respectively, resulted from a significant decrease in percentage of biting by parous An. quadrimaculatus compared with other females, and a significant increase in biting by 20-d-old parous females compared with other females. The main finding of this study is that repellent protection time is unaffected by parity; this is important because parous mosquitoes are the primary target of personal-protection measures in disease-endemic areas. When repellent failure did occur, there was a higher risk of bite by old, parous An. albimanus than for any other species, age, or parity grouping of females.

  11. Effects of in vivo exposure to DEET on blood feeding behavior and fecundity in Anopheles quadrimaculatus (Diptera: Culicidae).

    Xue, Rui-De; Ali, Arshad; Barnard, Donald R

    2007-07-01

    This study determined the effects of contact with DEET on guinea pig skin on mortality, probing time, blood feeding rate, engorgement time, and fecundity responses in female Anopheles quadrimaculatus Say. Exposure, in this manner, to 10% DEET (in ethanol) for 5 min, resulted in 98% mortality in mosquitoes after 24h. The median probing time (PT(50)) required by females, when exposed to 0.1%, 1.0%, and 10% DEET, was significantly (Pblood feeding rates in populations of females exposed to 1.0% DEET for feeding on the control guinea pigs (105.9s). The mean number of mature oöcytes per female (fecundity) in treatment (1.0% DEET) and control mosquitoes was not significantly different. The responses to DEET observed in this study suggest that repeated exposure of female A. quadrimaculatus populations to this repellent, in laboratory bioassays, could result in confounding of toxicant and repellent effects and inaccurate estimates of DEET repellency.

  12. Flavivirus-Mosquito Interactions

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  13. Escaping blood-fed malaria mosquitoes minimize tactile detection without compromising on take-off speed.

    Muijres, F T; Chang, S W; van Veen, W G; Spitzen, J; Biemans, B T; Koehl, M A R; Dudley, R

    2017-10-15

    To escape after taking a blood meal, a mosquito must exert forces sufficiently high to take off when carrying a load roughly equal to its body weight, while simultaneously avoiding detection by minimizing tactile signals exerted on the host's skin. We studied this trade-off between escape speed and stealth in the malaria mosquito Anopheles coluzzii using 3D motion analysis of high-speed stereoscopic videos of mosquito take-offs and aerodynamic modeling. We found that during the push-off phase, mosquitoes enhanced take-off speed using aerodynamic forces generated by the beating wings in addition to leg-based push-off forces, whereby wing forces contributed 61% of the total push-off force. Exchanging leg-derived push-off forces for wing-derived aerodynamic forces allows the animal to reduce peak force production on the host's skin. By slowly extending their long legs throughout the push-off, mosquitoes spread push-off forces over a longer time window than insects with short legs, thereby further reducing peak leg forces. Using this specialized take-off behavior, mosquitoes are capable of reaching take-off speeds comparable to those of similarly sized fruit flies, but with weight-normalized peak leg forces that were only 27% of those of the fruit flies. By limiting peak leg forces, mosquitoes possibly reduce the chance of being detected by the host. The resulting combination of high take-off speed and low tactile signals on the host might help increase the mosquito's success in escaping from blood-hosts, which consequently also increases the chance of transmitting vector-borne diseases, such as malaria, to future hosts. © 2017. Published by The Company of Biologists Ltd.

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

    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

  15. Male and mosquito larvae survey at the Arenal-Tempisque irrigation project, Guanacaste, Costa Rica

    Mario Vargas V

    2003-09-01

    Full Text Available A monitoring of male and larvae of mosquitoes was conducted during 1991-1994, at the Irrigation Project in Arenal-Tempisque, Guanacaste, Costa Rica. CDC CO2 -baited traps were used to collect adults of mosquitoes and dips were used for immatures of culicids. A total of 1 480 larvae and 1 129 males of culicids were identified resulting in, Aedes with 6 species, Anopheles, Mansonia and Psorophora with 2 species, Culex with 21 species and Haemagogus, Limatus, Toxorhynchites and Uranotaenia with only one species each. The results indicate that, as occurred in other countries, irrigation projects must be under strict monitoring programs to prevent and control possible health problems in which mosquitoes act as vectorsSe realizó un monitoreo de machos y larvas de mosquitos durante los años 1991 a 1994 en el Proyecto de Riego Arenal-Tempisque, Guanacaste, Costa Rica. Los especímenes fueron colectados en 32 giras de cuatro días cada una y cada 15 días. La colecta de adultos se hizo mediante trampas tipo CDC y la de larvas con la técnica estándar del cucharón. Se identificaron un total de 1 480 larvas y 1 129 machos de culícidos, correspondientes a 21 especies de Culex, 6 especies de Aedes, 2 especies de Anopheles, Mansonia, y Psorophora y una especie de Haemagogus, Limatus, Toxorhynchites y Uranotaenia. Los resultados indican que tal y como ha ocurrido en proyectos de riego en otros países, se deben mantener estrictos programas de monitoreo con el fin de prevenir y controlar posibles problemas de salud humana y animal, en los cuales los mosquitos actúen como vectores

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

    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

  17. Molasses as a source of carbon dioxide for attracting the malaria mosquitoes Anopheles gambiae and Anopheles funestus

    Mweresa, C.K.; Omusula, P.; Otieno, B.; Loon, van J.J.A.; Takken, W.; Mukabana, W.R.

    2014-01-01

    Background. Most odour baits for haematophagous arthropods contain carbon dioxide (CO2). The CO2 is sourced artificially from the fermentation of refined sugar (sucrose), dry ice, pressurized gas cylinders or propane. These sources of CO2 are neither cost-effective nor sustainable for use in remote

  18. 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

    Luiz Gonzaga dos Santos-Neto

    2008-01-01

    Full Text Available Um estudo foi realizado sobre mosquitos adultos de abril 1995 a março 1996 na Mata Atlântica do município de Morretes, Paraná, Brasil. A investigação foi procedida com auxílio de duas armadilhas luminosas CDC-M instaladas em estratos verticais diferentes. Os mosquitos foram capturados mensalmente durante um ano, com início às 18 horas e término às 6 horas do dia seguinte, totalizando 144 horas de trabalho de campo. Obteve-se 1.408 exemplares de mosquitos (409 na copa e 999 próximo ao solo, pertencentes a 10 gêneros e 31 espécies. Anopheles cruzii e Culex ribeirensis foram predominantes e são objetos do presente estudo. Não foi observada diferença entre as armadilhas para Anopheles cruzii. Mas Culex ribeirensis foi coletado em maior número pela CDC-M/solo. Anopheles cruzii, quanto à freqüência horária, apresentou picos nas primeiras horas da noite, depois a sua atividade decresceu progressivamente até o crepúsculo matutino, sem apresentar um pico secundário. Em referência a distribuição mensal, Anopheles cruzii foi mais freqüente nos meses de abril e maio de 1995 e março de 1996. Não houve correlação do número de exemplares com a temperatura ou precipitações pluviométricas. Culex ribeirensis apresentou maior atividade de vôo de 22h às 4h, mas não houve picos significativos. Nas coletas obtidas por mês, Culex ribeirensis teve picos em dezembro e janeiro. Houve correlação do número de espécimes deste culicíneo com a temperatura e precipitações pluviométricas. Constituem os primeiros registros para o Estado do Paraná: Ochlerotatus rhyacophilus, Culex misionensis, Culex pedroi, Culex ribeirensis e Culex zeteki.A study of adult mosquitoes was performed from April 1995 to March 1996 in the Atlantic Forest near to Morretes city, Paraná, Brazil. The research was carried out by using two CDC-M light traps installed in different vertical stratification levels. Mosquitoes were collected monthly throughout

  19. A list of mosquito species of the Brazilian State of Pernambuco, including the first report of Haemagogus janthinomys (Diptera: Culicidae, yellow fever vector and 14 other species (Diptera: Culicidae Lista de espécies de mosquitos do Estado de Pernambuco e primeiro relato de Haemagogus janthinomys (Diptera: Culicidae vetor de febre amarela silvestre e outras 14 espécies (Diptera: Culicidae

    Nádia Consuelo Aragão

    2010-08-01

    Full Text Available INTRODUCTION: Besides mosquito species adapted to urban environments (Culex quinquefasciatus, Aedes aegypti and Aedes albopictus, only 15 species of Anopheles had been recorded in the State of Pernambuco. METHODS: Human-landing mosquitoes were collected in Dois Irmãos Park, in Recife. RESULTS: The first report for the state of Haemagogus janthinomys, an important vector of yellow fever virus, and 14 other species, including Trichoprosopon lampropus, a first reported for Brazil. CONCLUSIONS: The mosquito fauna in the area is diversified and has potential medical and veterinary importance.INTRODUÇÃO: Além de mosquitos adaptados ao ambiente urbano (Culex quinquefasciatus, Aedes aegypti e Ae. albopictus, apenas 15 espécies de Anopheles haviam sido relatadas no Estado de Pernambuco. MÉTODOS: Mosquitos que pousavam em humanos no Parque Dois Irmãos, em Recife foram coletados. RESULTADOS: Haemagogus janthinomys, importante vetor de vírus de febre amarela, e outras 14 espécies são relatadas pela primeira vez no estado, incluindo Trichoprosopon lampropus, relatado pela primeira vez no Brasil. CONCLUSÕES: A fauna de mosquitos na área é muito diversificada e tem potencial importância médica e veterinária.

  20. Mosquito Bites are Bad!

    2016-08-11

    In this podcast for kids, the Kidtastics talk about the dangers of mosquito bites and how to prevent getting them.  Created: 8/11/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/11/2016.

  1. Play the Mosquito Game

    ... and Work Teachers' Questionnaire Malaria Play the Mosquito Game Play the Parasite Game About the games Malaria is one of the world's most common ... last will in Paris. Play the Blood Typing Game Try to save some patients and learn about ...

  2. Anopheles (Nyssorhynchus deaneorum: a new species in the albitarsis complex (Diptera: culicidae Anopheles (Nyssorhynchus deaneorum: uma nova espécie no complexo albitarsis (Diptera: Culicidae

    Maria Goreti Rosa-Freitas

    1989-12-01

    Full Text Available Anopheles (Nyssorhynchus deaneorum sp. n. is described from specimens collected in Guajará-Mirim, Rondônia state and Rio Branco, Acre state, Brazil, on human and animal baits, inside dwellings and from the progenies of engorged females. A detailed description of the shape of egg, external appearance of adult female and male, genitalias, female cibarial armature and complete chaetotaxy of pupa and larva show that it can be distinguished from Anopheles albitarsis from the type-locality and other areas by the paler general external appearance of the adult, the posterolateral tufts of scales, on the female abdominal terga and the branching of the outer anterior clypeal seta (3-C of the fourth instar larva (as shown in illustrations. If species can also be distinguished from An. albitarsis from the type locality by the allele frequencies at 11 enzymic loci as represented by Nei's Genetic Distance.Anopheles (Nyssorhynchus deaneorum sp. n. é descrito a partir de exemplares coletados em capturas comparativas no intradomicílio e no peridomicílio usando isca humana e animal e progênies de fêmeas ingurgitadas, em Guarajá-Mirim, Rondônia e Rio Branco, Acre. A descrição detalhada do ovo, dos adultos fêmea e macho, inclusive cibário da fêmea, genitália, quetotaxia da pupa e da larva e seu perfil isoenzimático, mostram que esse mosquito pode ser distinguido do Anopheles albitarsis na fase adulta pelo aspecto geral mais claro, pela presença de tufos laterais de escamas escuras somente a partir do quarto ou quinto tergitos abdominais, enquanto em albitarsis começam no terceiro e, na fase larvária, pela ramificação das cerdas clipeais anteriores externas, que em albitarsis são aciculadas (como mostram as ilustrações, bem como pelo padrão isoenzimático.

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

    John C Morgan

    2010-07-01

    Full Text Available 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.A new forced egg laying technique used in this study significantly inc