WorldWideScience
 
 
1

Physicochemical characteristics of habitats in relation to the density of container-breeding mosquitoes in Asom, India  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: Container-breeding mosquitoes, especially Aedes spp are vectors of diseases such as dengue and chikungunya. The abundance of these disease vectors in an area depends on the availability of container habitats and their physicochemical characteristics. The species composition of container-breeding mosquitoes in Asom, India was studied and the larval density was correlated with the habitat characteristics. Methods: Natural and man-made water-holding containers in Sonitpur district of Asom were surveyed for the presence of mosquito larvae. The percent composition of container-breeding mosquitoes and container index were calculated. The physicochemical characteristics of breeding water such as pH, conductivity, salinity, total dissolved solids, turbidity and dissolved oxygen were measured. Results: Aedes albopictus (93.7% was the predominant species in the container-breeding habitats whereas Culex quinquefasciatus (2.77%, Armigeres subalbatus (2.26%, Ae. aegypti (0.76%, Toxorhynchites sp (0.4% and Lutzia sp (0.11% were recorded in relatively low numbers. The larval density (mean ± SEmean of the container breeding mosquitoes ranged from 4.4 ± 1.8 to 15.4 ± 8.2, while the container index ranged from 1.58 to 5.68%. The mean (± SEmean pH, conductivity, salinity, total dissolved solids, turbidity, and dissolved oxygen of water in the container habitats were 7.15 ± 0.11; 396.1 ± 58.5 ?S/cm; 0.24 ± 0.04 ppt; 207.1 ± 30.4 mg/l; 32.3 ± 5.1 NTU; and 1.42 ± 0.12% respectively. The mosquito larval density in the container habitats was having significant negative correlation with the conductivity of breeding water (r = - 0.89; p = 0.003. Salinity, total dissolved solids and turbidity of water in the habitats were negatively correlated, whereas pH and dissolved oxygen were positively correlated with the larval density. Interpretation & conclusion: The studies indicated the predominance of Ae. albopictus in the container-breeding habitats and reiterated its importance as a potential vector of dengue and chikungunya in the region. The spread of Ae. aegypti, the principal vector of dengue, in the semi-urban areas probably through road transport is a matter of public health concern. The use of conductivity of breeding water as an index for the proliferation of container breeding mosquitoes in the region could be explored further.

Reji Gopalakrishnan

2013-08-01

2

Breeding Habitats and Seasonal Prevalences of The Dengue Vector Mosquitoes, Aedes (Stg) spp. in Sulawesi, Indonesia and Okinawa, Japan.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Breeding habitats and seasonal prevalences of the dengue vector mosquitoes, Aedes (Stegomyia) species in and around human houses were suveyed from 1994 to 1996 in South Sulawesi, Indonesia. The latter study was also carried out in Okonawa, Japan for comparative study. Aedes aegypti was dominant species indoors especially in the coastal villages of Barru, South Sulawesi in both, dry and rainy seasons. Aedes albopictus in outdoor containers increased in the rainy season mainly in the hill an...

Hasanuddin, Ishak

2008-01-01

3

Studies on the breeding habitats of the vector mosquito Anopheles baimai and its relationship to malaria incidence in Northeastern region of India. Breeding habitats of Anopheles baimai and its role in incidence of malaria in Northeastern region of India.  

Science.gov (United States)

Entomological survey was conducted to know the breeding habitat preference of the forest breeder malaria vector Anopheles baimaii, known earlier as An. dirus species D in the northeastern region of India. Breeding potential of the vector in forest areas was found to be high in water stored in jungle pool (69.84%) followed by elephant footprints with clear water (39.13%) and with turbid water (26.19%), whereas in forest fringe areas, the vector breeding was more prominent in elephant footprints: 65.11% in clear water and 62.5% in turbid water. Although other habitats had shown only low breeding of the vector, all types of habitats were positively correlated with malaria occurrence. Cattle hoof marks (r = 0.998) and elephant footprint (turbid; r = 0.999) explained nearly the same amount of variance. It was observed that deforestation as well as elephant habitat-type destruction had engendered man-elephant conflicts intensively in fringe areas. Seasonal abundance pattern of this vector was found to vary in forest and forest fringe areas in relation to different habitats. Seasonal abundance of An. baimaii was significantly different in different habitats. The Tukey post hoc comparisons indicated that the abundance of An. baimaii in different habitats was significantly higher (P < 0.05) in monsoon season than that of premonsoon and postmonsoon seasons. No significant difference was observed between premonsoon and postmonsoon seasons. The findings therefore will eventually help to predict transmission of malaria in targeted area and in formulating an improved malaria control program in the northeastern region of India. PMID:20652822

Dutta, Prafulla; Khan, Siraj Ahmed; Bhattarcharyya, Dibya Ranjan; Khan, Abdul Mabood; Sharma, Chandra Kanta; Mahanta, Jagdish

2010-12-01

4

Selection of cyanobacteria isolated from mosquito breeding sites as a potential food source for mosquito larvae.  

Science.gov (United States)

One way to increase the persistence of larvicidal toxins in mosquito breeding sites is to clone the corresponding genes in microorganisms, such as cyanobacteria, which could serve as a source of food for the larvae. We isolated and cultured 10 strains of cyanobacteria from three mosquito breeding sites along the French Mediterranean coast. Most of the strains were tolerant to a relatively wide range of salt concentrations, and all of them were totally or partially resistant to at least four of the five biological or chemical larvicides used in the local mosquito control program. Six unicellular strains from these habitats and Synechococcus strain PCC 7942, a strain maintained for more than 10 years under laboratory conditions, were assessed for ingestion and digestion by larvae Culex pipiens and Anopheles gambiae mosquitoes. The numbers of cells ingested and digested were dependent on the cyanobacterial strain and varied with the mosquito species. Three of the new isolates, Synechococcus strain PCC 8905 and Synechocystis strains PCC 8906 and PCC 8912, were ingested and digested rapidly by larvae of both mosquito species. Since these strains are also tolerant to larvicides and relatively resistant to elevated salt concentrations, they meet the basic requirements for potential recipients of bacterial genes that encode endotoxins. PMID:1677241

Thiery, I; Nicolas, L; Rippka, R; Tandeau de Marsac, N

1991-01-01

5

Observations on anopheline breeding in relation to aquatic plants in different breeding habitats of Kheda (Gujarat).  

Science.gov (United States)

Water bodies infested with aquatic vegetations may pose problems in mosquito control through bio-environmental methods. Paucity of information pertaining to association of mosquito breeding with aquatic vegetation was the basis for present investigation. The mosquito breeding sites infested with solitary/dominating plant community viz., Eichhornia crassipes, Ipomoea aquatica, Hydrilla verticillata, Nymphea neuchali, Trapa bispinosa, Lemna paucicostata, Trachelomonas spp., Azolla pinnata, Algae spp. and Cynodon dactylon were selected for the study. The investigation revealed that breeding of eleven anopheline species was associated with Eichhornia in different habitats followed by Hydrilla, algae and Cynodon (8 each), Ipomoea and Trapa (6), Lemna. and Nymphea (5), Azolla and Trachelomonas (4). An. subpictus was associated with all types of vegetation. An. annularis, An. nigerrimus and An. barbirostris were associated with nine plant species. An. culicifacies, the principal malaria vector was found breeding in association with seven aquatic plants and showed strong association with Cynodon, Hydrilla and algae. The species diversity in habitats infested with Hydrilla, algae and Cynodon seems to be most favourable for the breeding of An. culicifacies. It is suggested that thinning or removal of such vegetations at regular interval may help to reduce vector population and enhance the efficacy of biological control agents particularly the larvivorous fishes in such habitats. PMID:16509256

Kant, Rajni; Srivastava, H C

2004-09-01

6

Analysing the generality of spatially predictive mosquito habitat models.  

Science.gov (United States)

The increasing spread of multi-drug resistant malaria in African highlands has highlighted the importance of malaria suppression through vector control. Its historical success has meant that larval control has been proposed as part of an integrated malaria vector control program. Due to high operation costs, larval control activities would benefit greatly if the locations of mosquito habitats could be identified quickly and easily, allowing for focal habitat source suppression. Several mosquito habitat models have been developed to predict the location of mosquito habitats. However, to what extent these models can be generalised across time and space to predict the distribution of dynamic mosquito habitats remains largely unexplored. This study used mosquito habitat data collected in six different time periods and four different modelling approaches to establish 24 mosquito habitat models. We systematically tested the generality of these 24 mosquito habitat models. We found that although habitat--environment relationships change temporally, a modest level of performance was attained when validating the models using data collected from different time periods. We also describe flexible approaches to the predictive modelling of mosquito habitats, that provide novel modelling architecture for future research efforts. PMID:21527240

Li, Li; Bian, Ling; Yakob, Laith; Zhou, Guofa; Yan, Guiyun

2011-07-01

7

Dry Season Refugia Breeding Ecology of Mosquitoes (Diptera: Culicidae in Minna, North Central Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available This study was carried out in Minna, Nigeria, to elucidate the dry season breeding ecology of mosquitoes in the area thus, providing a basis for all-year-round effective implementation of informed larviciding interventions. Mosquito larvae were sampled bi-weekly between the hours of 0800 and 1100 from randomly selected larval breeding habitats in the city, using a 350 mL capacity Dipper. The physical characteristics of the selected habitats were evaluated and related to larval productivity. The results indicated that Anopheles mosquitoes constituted 55.00% of all larvae collected, followed by Culex (36.29% and Aedes (17.49%. The patterns of mean monthly density distribution of the three mosquito Genera were similar, i.e., decreasing significantly (pAnopheles and Aedes preferring the Drains (24.40±5.13 and 14.20±5.12 larvae/sampling day, respectively and Culex mosquitoes encountered more frequently in the Swamps (16.80±6.22 larvae/sampling day. The Drains were the most productive habitats, accounting for over 50% larval production during the period, distantly followed by the Swamp (31.60±16.38 larvae/sampling day while, the densities of larvae in the Wells and Rivers were significantly low (7.40±7.79 and 3.40±5.24 larvae/sampling day, respectively. Again, in terms of physical attributes, the Drains were the most ideal habitat for larval development, been relatively small (diameter = 2.30±0.00 m; most shallow (depth = 0.14±0.01 m; warmest (27.52±0.48°C and nearest to human habitations (2.80±0.00 m. The epidemiological implications of these results were discussed and concluded that targeting dry season larviciding interventions at the productive larval breeding habitats will go a long way in reducing the menace of mosquito-borne diseases in Minna.

I.C.J. Omalu

2012-01-01

8

Selection of cyanobacteria isolated from mosquito breeding sites as a potential food source for mosquito larvae.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One way to increase the persistence of larvicidal toxins in mosquito breeding sites is to clone the corresponding genes in microorganisms, such as cyanobacteria, which could serve as a source of food for the larvae. We isolated and cultured 10 strains of cyanobacteria from three mosquito breeding sites along the French Mediterranean coast. Most of the strains were tolerant to a relatively wide range of salt concentrations, and all of them were totally or partially resistant to at least four o...

Thiery, I.; Nicolas, L.; Rippka, R.; Tandeau Marsac, N.

1991-01-01

9

Habitat modification for mosquito control in the Ilparpa Swamp, Northern Territory, Australia.  

Science.gov (United States)

Habitat modification is an established method of effective long-term mosquito management, particularly in salt-marsh environments. It is especially pertinent when mosquitoes are known vectors of life-threatening disease and their larval breeding habitat is in close proximity to residential areas. The Ilparpa Swamp is located less than 10 km from Alice Springs, Northern Territory. Wet season rainfall, often followed by effluent discharges to the swamp from the adjacent sewage treatment plant, create ideal sites for the immature stages of the common banded mosquito Culex annulirostris (Skuse), a major vector of Murray Valley encephalitis (MVEV) and Kunjin (KUNV) viruses. Subsequent to increases in notifications of MVEV disease cases in 2000 and 2001, a drainage system was established in the Ilparpa Swamp in early 2002. This paper evaluates the drainage intervention effects. Results indicate a significant reduction in mosquito numbers following habitat modification, which remain low. There have been no seroconversions in sentinel chickens to MVEV or KUNV and no human infections from these viruses in the Alice Springs urban region since the drains were completed. Habitat modification has successfully reduced mosquito numbers and minimized the risk for mosquito-borne disease to residents in Alice Springs urban and surrounding areas, which has never before been documented in Australia. PMID:22129400

Jacups, Susan; Kurucz, Nina; Whitters, Raelene; Whelan, Peter

2011-12-01

10

Simple intervention to reduce mosquito breeding in waste stabilisation ponds.  

Science.gov (United States)

Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas the control ponds had a significant number of positive samples. This suggests that a combination of simple low-cost interventions is a feasible environmental management strategy for vector control in WSP systems that are located in areas where medically important mosquitoes may breed in the shallow ponds. PMID:17825333

Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim; Konradsen, Flemming

2007-11-01

11

Mass Breeding of AEDES Aegypti Mosquitoes.  

Science.gov (United States)

A method for mass breeding of Aedes Aegypti is described. The results were obtained with larvae grown with an infusion of guinea pig excrement with brewer's yeast, in which a rich microflora developed. Specially constructed closets used for breeding mosqu...

V. V. Vladimirova

1969-01-01

12

Studies on mosquitoes breeding in rock pools on inselbergs around Zaria, northern Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: Rainwater often collects in depressions on rocks to form pools that are ideal breeding sites of mosquito vectors of diseases. Knowledge on the existence of disease vectors in these remote and relatively inaccessible locations could improve epidemiologic understanding and control capabilities. This study identifies mosquito species, their relative abundance and physicochemical characteristics of breeding microhabitats in rock pools on four inselbergs in northern Nigeria.Methods: Soup ladle dipper was used to obtain representative samples of larval mosquitoes breeding in 141 rock pools on four inselbergs. Physicochemical parameters (depth, electrical conductivity, pH, surface area, temperature and total dissolved solids of the pools were determined. Larvae were preserved in 70% alcohol and identified microscopically to species using taxonomic keys. Statistical correlation analysis and ANOVA were used to test the associations between physicochemical parameters and mosquito abundance, and for differences amongst inselbergs. Results: Of 2991 larvae, five species of mosquito distributed in three genera (Anopheles, Aedes and Culex including Ae. vittatus (92.88%, An. ardensis (0.13%, An. distinctus (1.67%, An. wilsoni (0.13% and Cx. ingrami (5.18% bred in the rock pools, Up to five species occurred per pool in various conspecific and heterogeneric combinations. Except for Ae. vittatus, the physicochemical parameters of the pools correlate significantly with species abundance. Conclusion: Ae. vittatus, a potential vector of yellow fever in Nigeria breeds profusely in rock pools on inselbergs around Zaria. For comprehensive vector implication and control, rock pools should be amongst the habitats of focus in yellow fever epidemiology.

David A. Adebote

2008-02-01

13

Physico-chemical characteristics of the mosquito breeding water in two urban areas of Cairo Governorate, Egypt  

Directory of Open Access Journals (Sweden)

Full Text Available Certain physico-chemical characteristics of mosquito breeding habitats [temperature, pH, salinity, turbidity, dissolved oxygen (DO and nitrite] were examined relative to the distribution of mosquito larval species in two urban areas of Cairo Governorate namely El- Muqattam (M and Abu-Seir (A. Mean values and ranges of such characteristics for the reported mosquito species (Culex pipiens, Cx. perexiguus, Ochlerotatus caspius, Cx. pusillus and Culiseta longiareolata were reported. In conclusion, based on the significant correlations of the different characteristics with the abundance of the two common larval species (Culex pipiens and Cx. perexiguus, salinity and DO may be considered the predictor variables associated with the immature abundance. Considering altogether mosquitoes, there is an increasing presence from planned safe (M to unplanned unsafe (A habitats mainly due to turbidity and nitrite.

M.A. Kenawy

2013-12-01

14

British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, abun...

Townroe, Susannah; Callaghan, Amanda

2014-01-01

15

Habitat characterization and mapping of Anopheles maculatus (Theobald) mosquito larvae in malaria endemic areas in Kuala Lipis, Pahang, Malaysia.  

Science.gov (United States)

In Peninsular Malaysia, a large proportion of malaria cases occur in the central mountainous and forested parts of the country. As part of a study to assess remote sensing data as a tool for vector mapping, we conducted entomological surveys to determine the type of mosquitoes, their characteristics and the abundance of habitats of the vector Anopheles maculatus in malaria endemic areas in Pos Senderot. An. maculatus mosquitoes were collected from 49 breeding sites in Pos Senderot. An. maculatus preferred to breed in water pockets formed on the bank of rivers and waterfalls. The most common larval habitats were shallow pools 5.0-15.0 cm deep with clear water, mud substrate and plants or floatage. The mosquito also preferred open or partially shaded habitats. Breeding habitats were generally located at 100-400 m from the nearest human settlement. Changes in breeding characteristics were also observed. Instead of breeding in slow flowing streams, most larvae bred in small water pockets along the river margin. PMID:21073056

Rohani, A; Wan Najdah, W M A; Zamree, I; Azahari, A H; Mohd Noor, I; Rahimi, H; Lee, H L

2010-07-01

16

Habitat characterization and spatial distribution of Anopheles sp. mosquito larvae in Dar es Salaam (Tanzania during an extended dry period  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Introduction By 2030, more than 50% of the African population will live in urban areas. Controlling malaria reduces the disease burden and further improves economic development. As a complement to treated nets and prompt access to treatment, measures targeted against the larval stage of Anopheles sp. mosquitoes are a promising strategy for urban areas. However, a precise knowledge of the geographic location and potentially of ecological characteristics of breeding sites is of major importance for such interventions. Methods In total 151 km2 of central Dar es Salaam, the biggest city of Tanzania, were systematically searched for open mosquito breeding sites. Ecologic parameters, mosquito larvae density and geographic location were recorded for each site. Logistic regression analysis was used to determine the key ecological factors explaining the different densities of mosquito larvae. Results A total of 405 potential open breeding sites were examined. Large drains, swamps and puddles were associated with no or low Anopheles sp. larvae density. The probability of Anopheles sp. larvae to be present was reduced when water was identified as "turbid". Small breeding sites were more commonly colonized by Anopheles sp. larvae. Further, Anopheles gambiae s.l. larvae were found in highly organically polluted habitats. Conclusions Clear ecological characteristics of the breeding requirements of Anopheles sp. larvae could not be identified in this setting. Hence, every stagnant open water body, including very polluted ones, have to be considered as potential malaria vector breeding sites.

Tanner Marcel

2005-01-01

17

Habitat characterization and spatial distribution of Anopheles sp. mosquito larvae in Dar es Salaam (Tanzania) during an extended dry period  

Science.gov (United States)

Introduction By 2030, more than 50% of the African population will live in urban areas. Controlling malaria reduces the disease burden and further improves economic development. As a complement to treated nets and prompt access to treatment, measures targeted against the larval stage of Anopheles sp. mosquitoes are a promising strategy for urban areas. However, a precise knowledge of the geographic location and potentially of ecological characteristics of breeding sites is of major importance for such interventions. Methods In total 151 km2 of central Dar es Salaam, the biggest city of Tanzania, were systematically searched for open mosquito breeding sites. Ecologic parameters, mosquito larvae density and geographic location were recorded for each site. Logistic regression analysis was used to determine the key ecological factors explaining the different densities of mosquito larvae. Results A total of 405 potential open breeding sites were examined. Large drains, swamps and puddles were associated with no or low Anopheles sp. larvae density. The probability of Anopheles sp. larvae to be present was reduced when water was identified as "turbid". Small breeding sites were more commonly colonized by Anopheles sp. larvae. Further, Anopheles gambiae s.l. larvae were found in highly organically polluted habitats. Conclusions Clear ecological characteristics of the breeding requirements of Anopheles sp. larvae could not be identified in this setting. Hence, every stagnant open water body, including very polluted ones, have to be considered as potential malaria vector breeding sites. PMID:15649333

Sattler, Michael A; Mtasiwa, Deo; Kiama, Michael; Premji, Zul; Tanner, Marcel; Killeen, Gerry F; Lengeler, Christian

2005-01-01

18

Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, south-east Nigeria.  

Science.gov (United States)

The study of tree-hole breeding mosquitoes was carried out in the tropical rainforest of Imo State Nigeria (two rural areas and two forest reserves in some parts of Orlu Senatorial Zone) between May-October 2002. Using standard entomological procedures, two macrohabitats (natural tree-holes and bamboo traps) and two microhabitats (leaf axils of cocoyams/pineapples and leaf axils of plantain/banana) were sampled for various mosquito species. Mosquitoes were recovered from all the various biotypes sampled. Types of mosquitoes species encountered, their relative abundance, as well as genera varied significantly during the study (p<0.05). Four genera of mosquitoes: Aedes, Culex, Anopheles and Toxorhynchites were recovered while 16 species of mosquitoes encountered include: Aedes aegypti, Ae. africanus, Ae. simpsoni, Ae. albopictus, Ae. stokesi, Ae. taylori, Ae. apicoargenteus, Culex quinquefasciatus, Cx. nebulosus, Cx. trigripes, Cx. decens, Anopheles gambiae, An. funiestus, An. coustani and Toxorhynchites viridibasis. Most of the mosquitoes showed oviposition preferences for one or more habitats. The presence of Ae. africanus, Ae. simpsoni and Ae. aegypti indicate that the study areas were at risk of yellow fever epidemic. The presence of Anopheles and Culex species ensured endemicity of malaria and filariasis, while the recovery of Ae. albopictus in this region suggests a possible outbreak of dengue fever in future if not properly controlled. PMID:17655174

Anosike, Jude C; Nwoke, Bertram E B; Okere, Anthony N; Oku, Ene E; Asor, Joe E; Emmy-Egbe, Ifeyinwa O; Adimike, Desmond A

2007-01-01

19

Fatty acids in anopheline mosquito larvae and their habitats.  

Science.gov (United States)

Larvae of the three important Central American malaria vectors, Anopheles albimanus, An. vestitipennis, and An. darlingi, are found in distinctly different habitats broadly defined by hydrology and aquatic vegetation, but little is known about the actual food quality and quantity of these habitats. Polyunsaturated fatty acids (PUFA) are of special interest, because mosquitoes require 20:5?3 (EPA), 20:4?6 (ARA), and 22:6?3 (DHA) and without an adequate supply of these PUFAs they are not able to complete their life cycle. We collected samples of larvae and their corresponding habitats and analyzed their fatty acid (FA) composition to reveal if there are any species-specific and habitat-specific differences in FA composition, and if habitat FA differences can be linked to differences in the mosquito FA pattern and, ultimately, mosquito performance. We also assessed how FA of wild larvae compare to the laboratory-reared larvae. Habitats were generally low in essential PUFAs and there were no significant differences among the FA composition of habitat samples. There were significant differences in FA composition of larvae. An. darlingi contained significantly higher amounts of FA, specifically a higher content of ?-6 PUFA, represented mainly by the linoleic acid (18:2?-6). Large differences were found between field-collected and laboratory-reared An. vestitipennis larvae, especially in the content of PUFAs. The laboratory-reared larvae contained significantly more of the total FA, ?3 PUFA, and MUFA. The laboratory-reared larvae contained three to five times more essential PUFAs, EPA, and DHA. However, there were no differences in the total dry weight of the 4(th) instar larvae between the wild vs laboratory-reared larvae. Total FA in both larvae and habitats of An. albimanus and An. darlingi were positively correlated with the concentration of particulate organic carbon and nitrogen (POC, PON) in their respective habitats, but no such correlation was found for An. vestitipennis. PUFA are a good indicator of nutritional quality, although factors controlling the success of anopheline development from larval habitats are likely to be more complex and would include the presence of predators, pathogens, and toxins as interacting factors. PMID:23181863

Komínková, Dana; Rejmánková, Eliška; Grieco, John; Achee, Nicole

2012-12-01

20

Mapping of mosquito breeding sites in malaria endemic areas in Pos Lenjang, Kuala Lipis, Pahang, Malaysia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The application of the Geographic Information Systems (GIS to the study of vector transmitted diseases considerably improves the management of the information obtained from the field survey and facilitates the study of the distribution patterns of the vector species. Methods As part of a study to assess remote sensing data as a tool for vector mapping, geographical features like rivers, small streams, forest, roads and residential area were digitized from the satellite images and overlaid with entomological data. Map of larval breeding habitats distribution and map of malaria transmission risk area were developed using a combination of field data, satellite image analysis and GIS technique. All digital data in the GIS were displayed in the WGS 1984 coordinate system. Six occasions of larval surveillance were also conducted to determine the species of mosquitoes, their characteristics and the abundance of habitats. Results Larval survey studies showed that anopheline and culicine larvae were collected and mapped from 79 and 67 breeding sites respectively. Breeding habitats were located at 100-400 m from human settlement. Map of villages with 400 m buffer zone visualizes that more than 80% of Anopheles maculatus s.s. immature habitats were found within the buffer zone. Conclusions This study amplifies the need for a broadening of the GIS approach which is emphasized with the aim of rejuvenating the dynamic aspect of entomological studies in Malaysia. In fact, the use of such basic GIS platforms promote a more rational basis for strategic planning and management in the control of endemic diseases at the national level.

Ahmad Rohani

2011-12-01

 
 
 
 
21

Diversity and abundance of mosquito species in relation to their larval habitats in Mizoram, North Eastern Himalayan region.  

Science.gov (United States)

The abundance, richness and diversity of anopheline and culicid mosquitoes associated with their habitats, season, and physico-chemical quality of water were surveyed along six districts of Mizoram, North Eastern Himalayan region. The productivity of permanent and temporary habitat types was quantified by carrying out weekly larval sampling using a standard dipping method for a period of three years. Diversity was estimated using the Shannon index (H'), Evenness index (Heve), similarity measures cluster analysis and MANOVA. In total, 5 genera and 20 species of mosquitoes were identified: Culex quinquefasciatus, Anopheles barbirostris and Anopheles vagus were the most abundant and widely-distributed species, representing 39.71%, 29.39% and 14.52% of total mosquito individuals sampled, respectively. Anopheles sp. diversity was lowest in Lunglei district (H'=0.48) and highest in Aizawl (H'=2.03), whereas Culex sp. diversity was lowest in Lawngtlai (H'=0.38), and highest in Aizawl (H'=2.99) and Kolasib (H'=2.13). This represents the first update on the diversity and geographic distribution of the mosquitoes of Mizoram. Mosquito larvae were present in both temporary and permanent habitats suitable for breeding with monthly variations dependent on rainfall intensity, temperature, humidity and location. Early instars were more abundant significantly (P<0.0001) than late instars among the habitat types in all study sites. The productivity of mosquito larvae was significantly (P<0.0001) higher in ponds especially in permanent than semi-permanent and temporary. Weekly rainfall intensity led to an increase or decrease in anopheline and culicid larval abundance depending on the location. Mosquito diversity was highest in monsoon season (July-September) and lowest in January-March. A. barbirostris, A. vagus and C. quinquefasciatus appear the most likely habitat generalist as it demonstrates both widespread distribution. Abundance and diversity of culicine and anopheline larvae were strongly associated (MANOVA) with pH, temperature, dissolved oxygen, alkalinity, phosphates and chlorides concentration of water. This information will be essential for designing and implementing mosquito larval control programs. PMID:24795213

Vanlalruia, Khawling; Senthilkumar, Nachimuthu; Gurusubramanian, Guruswami

2014-09-01

22

Characterization of aquatic mosquito habitat, natural enemies, and immature mosquitoes in the Artibonite Valley, Haiti.  

Science.gov (United States)

This paper characterizes water body types harboring immature mosquitoes in a low-lying area of Haiti and investigates the relationship between immature Anopheles albimanus abundance and aquatic predator presence. Larval An. albimanus were found in permanent and semi-permanent groundwater habitats including (in order of greatest abundance) hoof/footprints, ditches, rice fields, and ground pools. High levels of species co-occurrence were observed in habitats. Among water bodies positive for immature Anopheles, 42.9% also contained immature Culex species. Significant association between An. albimanus abundance and the absence of fish predators was detected. Results from the multivariate negative binomial regression suggest that the interactive effect of increasing distance from the Artibonite River and elevation are positively associated with the abundance of immature An. albimanus. The presence of fish predators was not associated with the abundance of An. albimanus larvae in habitats while controlling for habitat distance and elevation. The results of this study provide baseline entomological information to inform vector control programs in the country. PMID:18697323

Caillouët, Kevin A; Keating, Joseph; Eisele, Thomas P

2008-06-01

23

Diversity of bacterial communities in container habitats of mosquitoes.  

Science.gov (United States)

We investigated the bacterial diversity of microbial communities in water-filled, human-made and natural container habitats of the mosquitoes Aedes aegypti and Aedes albopictus in suburban landscapes of New Orleans, Louisiana in 2003. We collected water samples from three classes of containers, including tires (n = 12), cemetery urns (n = 23), and miscellaneous containers that included two tree holes (n = 19). Total genomic DNA was extracted from water samples, and 16S ribosomal DNA fragments (operational taxonomic units, OTUs) were amplified by PCR and separated by denaturing gradient gel electrophoresis (DGGE). The bacterial communities in containers represented diverse DGGE-DNA banding patterns that were not related to the class of container or to the local spatial distribution of containers. Mean richness and evenness of OTUs were highest in water samples from tires. Bacterial phylotypes were identified by comparative sequence analysis of 90 16S rDNA DGGE band amplicons. The majority of sequences were placed in five major taxa: Alpha-, Beta- and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and an unclassified group; Proteobacteria and Bacteroidetes were the predominant heterotrophic bacteria in containers. The bacterial communities in human-made containers consisted mainly of undescribed species, and a phylogenetic analysis based on 16S rRNA sequences suggested that species composition was independent of both container type and the spatial distribution of containers. Comparative PCR-based, cultivation-independent rRNA surveys of microbial communities associated with mosquito habitats can provide significant insight into community organization and dynamics of bacterial species. PMID:18373113

Ponnusamy, Loganathan; Xu, Ning; Stav, Gil; Wesson, Dawn M; Schal, Coby; Apperson, Charles S

2008-11-01

24

Ross River virus risk associated with dispersal of Aedes (Ochlerotatus) camptorhynchus (Thomson) from breeding habitat into surrounding residential areas: muddy lakes, Western Australia.  

Science.gov (United States)

Rapid population growth in Western Australia has resulted in increased development of land for residential housing, and new developments are often proposed close to water because of intrinsic aesthetic values. However, this placement may place future residents at risk of mosquito-borne disease, of which Ross River virus (RRV) disease is the most common in Australia. Mosquito dispersal data were combined with a spatial analysis of human RRV cases to show that mosquitoes dispersed readily from larval habitat into surrounding low- and high-density residential areas and that residents living within 2 km of mosquito breeding habitat had a significantly higher rate of RRV disease. This finding highlights the importance of planning authorities in state and local governments to consider the implications of mosquito-borne disease risks when assessing residential development applications. PMID:24799370

Jardine, Andrew; Neville, Peter J; Dent, Colin; Webster, Carla; Lindsay, Michael D A

2014-07-01

25

CONTAINER SURVEY OF MOSQUITO BREEDING SITES IN AN UNIVERSITY CAMPUS IN CHENNAI, TAMILNADU  

Directory of Open Access Journals (Sweden)

Full Text Available The Container survey was conducted from 15th – 19th October 2013 for a period of five days in the University Campus of Chennai, Tamilnadu. The campus has an area of 175 acres (0.71 km2 and most of the main administrative buildings and faculties are located here. The surroundings of the campus have been planted with vegetation and trees, providing ideal resting sites for mosquitoes. A total of 60 containers were identified as potential breeding sites, However, more than 50% (32 containers were found containing larvae, with Tyers being the most dominant (number of containers =25, followed by plastic container (5, natural containers (2.Among all types of containers, 42% of the total surveyed Tyers were positive with mosquito larvae, followed by plastic containers (33% and natural containers (20%, especially tree holes, were the dominant breeding sites for mosquitoes in the campus. The collected mosquito larvae were Aedes aegypti (100%.

Sriram Chandramohan

2014-04-01

26

Remote Sensing and Modeling of Mosquito Abundance and Habitats in Coastal Virginia, USA  

Directory of Open Access Journals (Sweden)

Full Text Available The increase in mosquito populations following extreme weather events poses a major threat to humans because of mosquitoes’ ability to carry disease-causing pathogens, particularly in low-lying, poorly drained coastal plains vulnerable to tropical cyclones. In areas with reservoirs of disease, mosquito abundance information can help to identify the areas at higher risk of disease transmission. Using a Geographic Information System (GIS, mosquito abundance is predicted across the City of Chesapeake, Virginia. The mosquito abundance model uses mosquito light trap counts, a habitat suitability model, and dynamic environmental variables (temperature and precipitation to predict the abundance of the species Culiseta melanura, as well as the combined abundance of the ephemeral species, Aedes vexans and Psorophora columbiae, for the year 2003. Remote sensing techniques were used to quantify environmental variables for a potential habitat suitability index for the mosquito species. The goal of this study was to produce an abundance model that could guide risk assessment, surveillance, and potential disease transmission. Results highlight the utility of integrating field surveillance, remote sensing for synoptic landscape habitat distributions, and dynamic environmental data for predicting mosquito vector abundance across low-lying coastal plains. Limitations of mosquito trapping and multi-source geospatial environmental data are highlighted for future spatial modeling of disease transmission risk.

A. Scott Bellows

2011-12-01

27

Larval habitats and species composition of mosquitoes in Darjeeling Himalayas, India  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: A preliminary survey of larval mosquito habitats and temporal variationin mosquito diversity in the hill town of Darjeeling, India was made during 2003, for a qualitativeand quantitative assessment of mosquito distribution.Methods: The possible larval habitats of mosquitoes were surveyed and the species diversity in thesites positive for mosquito larvae was noted. Bi-weekly sampling from a particular habitat wascarried out to reveal the temporal variation in mosquito species.Results: A good number of lentic aquatic habitats were found to be hosting mosquito immatures,though difference in the physical and biological features of these habitats was prominent. Altogether,immatures of six mosquito species, belonging to four genera — Aedes, Armigeres, Culex andToxorhynchites were noted with significant difference in temporal variation in their relative andabsolute numbers. A positive correlation (r = + 0.707 was found between population of the preymosquito immatures and the population of immatures of Tx. splendens. The species diversity index(H’ for the mosquitoes remained between 0.87 and 1.53. The evenness components ranged between54.03 and 95.03% and differed significantly.Interpretation & conclusion: In the present study, the aquatic bodies could be categorised into sixtypes depending on the size and structural complexity that may account for the observed variation inthe species composition of the larval habitats. In addition to this, other factors like temperature,rainfall and other related climatic attributes may be responsible for the observed species variation,which needs to be confirmed through further studies.

Gautam Aditya,b, Mihir K. Pramanik & Goutam K. Saha

2006-03-01

28

Application of bactoculicide (Bacillus thuringiensis H-14) for controlling mosquito breeding in industrial scrap at BHEL, Hardwar (U.P.).  

Science.gov (United States)

Bactoculicide (Bacillus thuringiensis) was evaluated in field trials for controlling mosquito breeding of Aedes, Culex and Anopheles in industrial scraps such as broken heavy machine parts, iron moulds and discarded drums. A dose of 0.5 g/m2 was controlled 96-100% mosquito breeding up to five weeks. PMID:8100539

Dua, V K; Sharma, S K; Sharma, V P

1993-03-01

29

The impact of encroachment of mangroves into saltmarshes on saltwater mosquito habitats.  

Science.gov (United States)

Will mangrove encroachment into saltmarshes affect saltwater mosquito habitats? To address this, we synthesized information from two perspectives: 1) at a detailed level, the immature mosquito habitat within mangroves; 2) at a more general or regional level, changes due to mangrove expansion into saltmarshes. This is a synthesis of two research projects. One showed that mosquito larval habitats in mangroves are complex, related to the detailed interactions between topography and tidal patterns and that not all parts of a mangrove forest are suitable habitat. The other, based on remote sensing and analysis of rainfall data, showed that mangrove encroachment in eastern Australia is related to both climate and human land use over several decades (1972-2004). An important question emerged: when mangroves encroach into saltmarshes will they displace saltmarsh immature mosquito habitats or will they replace them with mangrove ones? There is no simple answer: it will vary with climate change and sea level scenario and how these affect the system. We conclude that mosquito management, which is locally implemented, needs to be integrated with land use planning systems, which often operate at a more general level. PMID:24581363

Dale, Pat; Eslami-Andargoli, Leila; Knight, Jon

2013-12-01

30

Adaptive breeding habitat selection: Is it for the birds?  

Science.gov (United States)

The question of why animals choose particular habitats has important implications for understanding behavioral evolution and distribution of organisms in the wild and for delineating between habitats of different quality for conservation and management. Habitats chosen by animals can influence fitness outcomes via the costs (e.g., predation risk) and benefits (e.g., food availability) of habitat use. Habitat preferences should therefore be under selection to favor those that confer fitness advantages (Clark and Shutler 1999). Indeed, prevailing theory suggests that the habitat preferences of animals should be adaptive, such that fitness is higher in preferred habitats (Hildén 1965, Southwood 1977, Martin 1998). However, studies have often identified apparent mismatches between observed habitat preferences and fitness outcomes across a wide variety of taxa (Valladares and Lawton 1991, Mayhew 1997, Kolbe and Janzen 2002, Arlt and Pärt 2007, Mägi et al. 2009). Certainly, one limitation of studies may be that assessment of “fitness” is typically constrained to fitness surrogates such as nest success rather than lifetime reproductive success or classic Fisherian fitness (Endler 1986). Nevertheless, important habitat choices such as nest sites influence the probability that temporarily sedentary, dependent young are discovered by enemies such as predators and parasites. We therefore expect, on average, to see congruence between evolved habitat preferences and relevant components of fitness (e.g., nest success). Here, we (1) review the prevalence of apparent mismatches between avian breeding-habitat preferences and fitness outcomes using nest-site selection as a focus; (2) describe several potential mechanisms for such mismatches, including anthropogenic, methodological, and ecological–evolutionary; and (3) suggest a framework for understanding the contexts in which habitat preferences represent adaptive decisions, with a primary focus on ecological information theory. We largely focus on habitat selection as a behavioral process at the scale of individuals (e.g., Robertson and Hutto 2006), rather than at the scale of population-level patterns (Fretwell and Lucas 1970, Morris 2003, Johnson 2007). However, these two scales cannot be wholly divorced from one another, as we will discuss.

Chalfoun, Anna D.; Schmidt, Kenneth A.

2012-01-01

31

Heavy metals in mosquito larval habitats in urban Kisumu and Malindi, Kenya, and their impact  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Concentrations and distribution of cadmium, chromium, copper, iron, lead, manganese and zinc in mosquito larval habitats in urban Kisumu and Malindi, Kenya and their effect on the presence of Anopheles gambiae, Aedes aegypti, Culex quinquefasciatus and Anopheles funestus larvae were investigated. Manganese and iron were the most prevalent heavy metals in water of larval habitats in urban Kisumu and Malindi, respectively. Iron was the most prevalent heavy metal in bottom sediments in larval ha...

Mireji, Paul O.; Keating, Joseph; Hassanali, Ahmed; Mbogo, Charles M.; Nyambaka, Hudson; Kahindi, Samuel; Beier, John C.

2008-01-01

32

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

Science.gov (United States)

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. PMID:17657957

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

2007-01-01

33

Temporal and spatial habitat preferences and biotic interactions between mosquito larvae and antagonistic crustaceans in the field.  

Science.gov (United States)

Investigations on natural antagonists of mosquito larvae found that micro-crustaceans (e.g., Cladocera) control mosquito populations under experimental conditions. However, their relevance for mosquito control under field situations remains widely unclear because important information about habitat preferences and time of occurrence of crustaceans and mosquito larvae are still missing. In order to fill this knowledge gap, a field study was undertaken in different wetland areas of Saxony, Germany, in different habitats (i.e., grassland, forest, and reed-covered wetlands). We found negative interactions between larvae of Ae. vexans and predatory Cyclopoida (Crustacean: Copepoda), which both were dominant during the first two weeks of hydroperiod, at ponds located at grassland habitats. Larvae of Cx. pipiens were spatially associated with competing Cladocera, but they colonized ponds more rapidly. Populations of Cladocera established from the third week of hydroperiod and prevented Cx. pipiens colonization thereafter. Ostracoda were highly abundant during the whole hydroperiod, but their presence was restricted to habitats of reed-covered wetland at one geographical area. Mosquito larvae hardly occurred at those ponds. In general, we found that ponds at the reed-covered wetlands provided better conditions for the initial development of crustaceans and hence, mosquito larval colonization was strongly inhibited. Grassland habitat, in contrast, favored early development of mosquito larvae. This study showed that micro-crustaceans are relevant for mosquito management but their impact on mosquito larvae varies between species and depends on environmental conditions. PMID:24820562

Kroeger, Iris; Liess, Matthias; Duquesne, Sabine

2014-06-01

34

Mosquito Vector Diversity across Habitats in Central Thailand Endemic for Dengue and Other Arthropod-Borne Diseases  

Science.gov (United States)

Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand. PMID:24205420

Thongsripong, Panpim; Green, Amy; Kittayapong, Pattamaporn; Kapan, Durrell; Wilcox, Bruce; Bennett, Shannon

2013-01-01

35

Effect of habitat complexity on the predation of Buenoa fuscipennis (Heteroptera: Notonectidae) on mosquito immature stages and alternative prey.  

Science.gov (United States)

Notonectids are well-known predators in aquatic habitats, where mosquito larvae, chironomids, and cladocerans constitute their main diet. Our purpose was to assess the effect of structural complexity on the predatory ability of Buenoa fuscipennis, a common predator in aquatic habitats of Buenos Aires city (Argentina). Buenoa fuscipennis showed type 2 functional responses in both the presence and absence of prey refuge and no differences in attack rate or handling time between refuge treatments. Regarding mosquito size classes, B. fuscipennis exhibited a significantly higher preference for 2(nd) instar larvae and no predation on pupae. In the presence of mosquito larvae and alternative prey, B. fuscipennis preferred mosquitoes over chironomid larvae and adult cladocerans over mosquito larvae. No switching behavior was detected in our experiments. Habitat structure only slightly affected the predator´s consumption rates on mosquito larvae. Overall, preference for prey did not vary with the presence of refuge, except for the preference for mosquitoes over chironomid larvae, which was significantly decreased in the presence of refuge as a consequence of reduced predation on mosquito larvae. The results suggest that B. fuscipennis could efficiently control mosquitoes in structurally simple habitats where chironomids are the most abundant alternative prey but not in temporary pools where cladocerans are abundant. PMID:24581348

Fischer, Sylvia; Zanotti, Gabriela; Castro, Andrés; Quiroga, Laura; Vargas, Daniel Vazquez

2013-12-01

36

Upland Habitat Quality and Historic Landscape Composition Influence Genetic Variation of a Pond-Breeding Salamander  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Understanding the temporal and spatial scale at which habitat alteration impacts populations is important for conservation and management. Amphibians have declined more than other vertebrates, and pond-breeding species are particularly susceptible to habitat loss and fragmentation because they have terrestrial and aquatic life stages. One approach to management of pond-breeding species is protection of core upland habitat surrounding the breeding pond. We used genetic variation as an indicato...

Alexander, Jeremiah R.; Kross, Chelsea S.; Price, Steven J.; Richter, Stephen C.; Dorcas, Michael E.

2013-01-01

37

Detection of potential mosquito breeding sites based on community sourced geotagged images  

Science.gov (United States)

Various initiatives have been taken all over the world to involve the citizens in the collection and reporting of data to make better and informed data-driven decisions. Our work shows how the geotagged images collected through the general population can be used to combat Malaria and Dengue by identifying and visualizing localities that contain potential mosquito breeding sites. Our method first employs image quality assessment on the client side to reject the images with distortions like blur and artifacts. Each geotagged image received on the server is converted into a feature vector using the bag of visual words model. We train an SVM classifier on a histogram-based feature vector obtained after the vector quantization of SIFT features to discriminate images containing either a small stagnant water body like puddle, or open containers and tires, bushes etc. from those that contain flowing water, manicured lawns, tires attached to a vehicle etc. A geographical heat map is generated by assigning a specific location a probability value of it being a potential mosquito breeding ground of mosquito using feature level fusion or the max approach presented in the paper. The heat map thus generated can be used by concerned health authorities to take appropriate action and to promote civic awareness.

Agarwal, Ankit; Chaudhuri, Usashi; Chaudhuri, Subhasis; Seetharaman, Guna

2014-06-01

38

Arbovirus circulation, temporal distribution, and abundance of mosquito species in two Carolina bay habitats.  

Science.gov (United States)

Carolina bays, a type of geomorphic feature, may be important in the ecology of mosquito vectors in South Carolina. Their hydrology varies from wetland habitats with marked flooding/drying regimes to permanently flooded spring-fed lakes. Moreover, they possess characteristics that contribute to the support of a particularly abundant and diverse invertebrate fauna. Although it has been estimated that 2,700+ bays exist in South Carolina, approximately 97% have been altered; projects. We conducted a study in two distinct Carolina bay habitats, Savage Bay Heritage Preserve (SBHP) and Woods Bay State Park (WBSP), from June 1997 to July 1998 to determine mosquito temporal distribution, species composition, and the occurrence of arbovirus activity. The largest mosquito collection was obtained at WBSP (n = 31,172) representing 25 species followed by SBHP (n = 3,940) with 24 species. Anopheles crucians complex were the most common species encountered in both bays. Two virus isolates were obtained from SBHP in 1997: Keystone (KEY) virus from Ochlerotatus atlanticus-tormentor and Cache Valley (CV) virus from Oc. canadensis canadensis. Twenty-nine (29) arbovirus-positive pools were obtained from WBSP: 28 in 1997 and one in 1998. KEY virus was isolated from three pools of Oc. atlanticus-tormentor and Tensaw (TEN) virus was isolated from two pools of An. crucians complex; 10 isolates could not be identified with the sera available. Additionally, 14 pools of An. crucians complex tested positive for Eastern equine encephalitis (EEE) virus antigen. These represent the first record of KEY and CV viruses in South Carolina. Our data indicate the presence of high mosquito density and diversity in both Carolina bay habitats, which may be influenced, in part, by seasonal changes in their hydroperiods. The study of mosquito and arbovirus ecology in Carolina Bay habitats could provide more information on the transmission dynamics of arboviruses and its impact on human and animal arboviral disease occurrence in South Carolina. PMID:15815146

Ortiz, D I; Wozniak, A; Tolson, M W; Turner, P E

2005-01-01

39

Using adult mosquitoes to transfer insecticides to Aedes aegypti larval habitats.  

Science.gov (United States)

Vector control is a key means of combating mosquito-borne diseases and the only tool available for tackling the transmission of dengue, a disease for which no vaccine, prophylaxis, or therapeutant currently exists. The most effective mosquito control methods include a variety of insecticidal tools that target adults or juveniles. Their successful implementation depends on impacting the largest proportion of the vector population possible. We demonstrate a control strategy that dramatically improves the efficiency with which high coverage of aquatic mosquito habitats can be achieved. The method exploits adult mosquitoes as vehicles of insecticide transfer by harnessing their fundamental behaviors to disseminate a juvenile hormone analogue (JHA) between resting and oviposition sites. A series of field trials undertaken in an Amazon city (Iquitos, Peru) showed that the placement of JHA dissemination stations in just 3-5% of the available resting area resulted in almost complete coverage of sentinel aquatic habitats. More than control mortality occurred in 95-100% of the larval cohorts of Aedes aegypti developing at those sites. Overall reductions in adult emergence of 42-98% were achieved during the trials. A deterministic simulation model predicts amplifications in coverage consistent with our observations and highlights the importance of the residual activity of the insecticide for this technique. PMID:19561295

Devine, Gregor J; Perea, Elvira Zamora; Killeen, Gerry F; Stancil, Jeffrey D; Clark, Suzanne J; Morrison, Amy C

2009-07-14

40

Importance of Hydrilla verticillata (hydrocharitaceae) as habitat for immature mosquitoes at the Ross River reservoir, Australia.  

Science.gov (United States)

From November 1990 to November 1992, immature mosquitoes were sampled from the shoreline and from emergent beds of the submerged aquatic plant Hydrilla verticillata at the Ross River reservoir, northern Australia. Aerial mapping of Hydrilla beds was done in conjunction with sampling to estimate total immature mosquito numbers. Larvae of 7 species were found. Culex annulirostris. Anopheles annulipes s.l., and Anopheles amictus comprised 80.4% of the total. Peak larval densities occurred in the late wet season period in both habitat types (March to May) but Hydrilla generally supported higher densities, particularly of An. annulipes s.l. (43.7% of the total sample), than the shoreline habitats. Anopheles annulipes replaced Cx. annulirostris as the predominant taxon when 1990-92 data were compared with data for 1985-86. The Hydrilla beds supported on the order of 5.6 x 10(9) immatures during the period of peak density. This suggests that where human exposure is of concern, mosquito control in habitats such as Hydrilla is warranted. PMID:9249656

Hearnden, M N; Kay, B H

1997-06-01

 
 
 
 
41

Integrating the Public in Mosquito Management: Active Education by Community Peers Can Lead to Significant Reduction in Peridomestic Container Mosquito Habitats  

Science.gov (United States)

Mosquito species that utilize peridomestic containers for immature development are commonly aggressive human biters, and because they often reach high abundance, create significant nuisance. One of these species, the Asian tiger mosquito Aedes albopictus, is an important vector of emerging infectious diseases, such as dengue, chikungunya, and Zika fevers. Integrated mosquito management (IMM) of Ae. albopictus is particularly difficult because it requires access to private yards in urban and suburban residences. It has become apparent that in the event of a public health concern due to this species, homeowners will have to be active participants in the control process by reducing mosquito habitats in their properties, an activity known as source reduction. However, limited attempts at quantifying the effect of source reduction by homeowners have had mixed results. Of note, many mosquito control programs in the US have some form of education outreach, however the primary approach is often passive focusing on the distribution of education materials as flyers. In 2010, we evaluated the use of active community peer education in a source reduction program, using AmeriCorps volunteers. The volunteers were mobilized over a 4-week period, in two areas with approximately 1,000 residences each in urban Mercer and suburban Monmouth counties in New Jersey, USA. The volunteers were first provided training on peridomestic mosquitoes and on basic approaches to reducing the number of container habitats for mosquito larvae in backyards. Within the two treatment areas the volunteers successfully engaged 758 separate homes. Repeated measures analysis of variance showed a significant reduction in container habitats in the sites where the volunteers actively engaged the community compared to untreated control areas in both counties. Our results suggest that active education using community peer educators can be an effective means of source reduction, and a critical tool in the arsenal against peridomestic mosquitoes. PMID:25255027

Healy, Kristen; Hamilton, George; Crepeau, Taryn; Healy, Sean; Unlu, Isik; Farajollahi, Ary; Fonseca, Dina M.

2014-01-01

42

The effect of West Nile virus perceptions and knowledge on protective behavior and mosquito breeding in residential yards in Upstate New York  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A knowledge, attitudes, and practices (KAP) questionnaire combined with entomological surveys of residential mosquito-breeding sites were conducted in two Upstate New York neighborhoods. We tested the hypothesis that “correct” West Nile virus (WNV) knowledge and perceptions correspond with the use of practices that prevent mosquitoes from breeding and biting. Our results demonstrate that perceptions of WNV relate to the number of positive containers in yards and the use of mosquito preven...

Tuiten, W.; Koenraadt, C. J. M.; Mccomas, K.; Harrington, L. C.

2009-01-01

43

Biocontrol from a mosquito control director's point of view.  

Science.gov (United States)

Two principal mosquito breeding problems that occur in Florida are discussed from the standpoint of a manager of a mosquito abatement district: 1) mosquitoes that breed in standing or permanent water, and 2) mosquitoes that breed in temporary habitats such as floodwater pools. The efficacies of several different types of biological control agents are discussed for each type of problem. Fish are used in permanent water sites, and several other organisms are being evaluated. No programs are based exclusively on biological control agents. Biological control is generally not used in temporary sites. Relative costs of chemical and biological control are discussed. PMID:7595458

Beidler, E J

1995-06-01

44

Urban Habitat Evaluation For West Nile Virus Surveillance In Mosquitoes In Albuquerque, New Mexico  

Science.gov (United States)

As part of an ongoing mosquito surveillance program, 27 sites in the greater metropolitan Albuquerque area (Bernalillo County, New Mexico) were trapped from May through September 2004. Each site was sampled for 1 night weekly, using a standard CO2-baited Centers for Disease Control and Prevention light trap and a gravid trap. Captured mosquitoes were catalogued by location, species, and date, and selected pools were tested for West Nile virus (WNV) by reverse transcription–polymerase chain reaction. Based on previous surveillance, WNV was already established in the state of New Mexico. Surveillance during 2003, the 1st year of WNV detection in New Mexico mosquitoes, was focused on the bosque forest of the Rio Grande river valley. Surveillance during summer of 2004 was extended to additional areas around the city of Albuquerque, the state's largest population center. In addition to the standard surveillance objectives, a secondary goal was to determine whether foci of WNV activity were detectable in other habitats besides the riparian ecosystem of the Rio Grande, and in other species not previously identified as vectors. There was no demonstrable advantage to extending the traditional trapping area outside of the Rio Grande valley. Sites in the valley area had WNV-positive mosquitoes earlier in the season, and for a longer period than the added sites. In addition, riparian sites had the highest diversity of species, the largest numbers of Culex spp. captured, and the largest proportion of the WNV-positive mosquito pools from the study. Species found in other areas of the metropolitan area were also represented in the valley. Although WNV activity was detected in other areas of the city, its activity began later and ended earlier than in the river valley. We surmise that the greatest benefit to mosquito surveillance could be achieved by focusing on the river valley area. PMID:17847847

DiMenna, Mark A.; Bueno, Rudy; Parmenter, Robert R.; Norris, Douglas E.; Sheyka, Jeff M.; Molina, Josephine L.; LaBeau, Elisa M.; Hatton, Elizabeth S.; Roberts, Christine M.; Glass, Gregory E.

2014-01-01

45

The unexpected importance of mosquito oviposition behaviour for malaria: non-productive larval habitats can be sources for malaria transmission  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Mosquitoes commute between blood-meal hosts and water. Thus, heterogeneity in human biting reflects underlying spatial heterogeneity in the distribution and suitability of larval habitat as well as inherent differences in the attractiveness, suitability and distribution of blood-meal hosts. One of the possible strategies of malaria control is to identify local vector species and then attack water bodies that contain their larvae. Methods Biting and host seeking, not oviposition, have been the focus of most previous studies of mosquitoes and malaria transmission. This study presents a mathematical model that incorporates mosquito oviposition behaviour. Results The model demonstrates that oviposition is one potential factor explaining heterogeneous biting and vector distribution in a landscape with a heterogeneous distribution of larval habitat. Adult female mosquitoes tend to aggregate around places where they oviposit, thereby increasing the risk of malaria, regardless of the suitability of the habitat for larval development. Thus, a water body may be unsuitable for adult mosquito emergence, but simultaneously, be a source for human malaria. Conclusion Larval density may be a misleading indicator of a habitat's importance for malaria control. Even if mosquitoes could be lured to oviposit in sprayed larval habitats, this would not necessarily mitigate – and might aggravate – the risk of malaria transmission. Forcing mosquitoes to fly away from humans in search of larval habitat may be a more efficient way to reduce the risk of malaria than killing larvae. Thus, draining, fouling, or filling standing water where mosquitoes oviposit can be more effective than applying larvicide.

Flahault Antoine

2005-05-01

46

Classification of immature mosquito species according to characteristics of the larval habitat in the subtropical province of Chaco, Argentina  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidit...

Marina Stein; Francisco Ludueña-Almeida; Juana Alicia Willener; Walter Ricardo Almirón

2011-01-01

47

Malaria knowledge and agricultural practices that promote mosquito breeding in two rural farming communities in Oyo State, Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Agricultural practices such as the use of irrigation during rice cultivation, the use of ponds for fish farming and the storage of water in tanks for livestock provide suitable breeding grounds for anthropophylic mosquitoes. The most common anthropophylic mosquito in Nigeria which causes much of the morbidity and mortality associated with malaria is the anopheles mosquito. Farmers are therefore at high risk of malaria - a disease which seriously impacts on agricultural productivity. Unfortunately information relating to agricultural practices and farmers' behavioural antecedent factors that could assist malaria programmers plan and implement interventions to reduce risk of infections among farmers is scanty. Farmers' knowledge about malaria and agricultural practices which favour the breeding of mosquitoes in Fashola and Soku, two rural farming communities in Oyo State were therefore assessed in two rural farming communities in Oyo State. Methods This descriptive cross-sectional study involved the collection of data through the use of eight Focus Group Discussions (FGDs and the interview of 403 randomly selected farmers using semi-structured questionnaires. These sets of information were supplemented with observations of agricultural practices made in 40 randomly selected farms. The FGD data were recorded on audio-tapes, transcribed and subjected to content analysis while the quantitative data were analyzed using descriptive and inferential statistics. Results Most respondents in the two communities had low level of knowledge of malaria causation as only 12.4% stated that mosquito bite could transmit the disease. Less than half (46.7% correctly mentioned the signs and symptoms of malaria as high body temperature, body pains, headache, body weakness and cold/fever. The reported main methods for preventing mosquito bites in the farming communities included removal of heaps of cassava tuber peelings (62.3%, bush burning/clearing (54.6% and clearing of ditches (33.7%. The dumping of cassava tuber peelings which allows the collection of pools of water in the farms storage of peeled cassava tubers soaked in water in uncovered plastic containers, digging of trenches, irrigation of farms and the presence of fish ponds were the observed major agricultural practices that favoured mosquito breeding on the farms. A significant association was observed between respondents' knowledge about malaria and agricultural practices which promote mosquito breeding. Respondents' wealth quintile level was also seen to be associated with respondents' knowledge about malaria and agricultural practices which promote mosquito breeding. Conclusion Farmers' knowledge of malaria causation and signs and symptoms was low, while agricultural practices which favour mosquito breeding in the farming communities were common. There is an urgent need to engage farmers in meaningful dialogue on malaria reduction initiatives including the modification of agricultural practices which favour mosquito breeding. Multiple intervention strategies are needed to tackle the factors related to malaria prevalence and mosquito abundance in the communities.

Oshiname Frederick O

2010-04-01

48

Habitat complexity and sex-dependent predation of mosquito larvae in containers  

Science.gov (United States)

Studies in aquatic systems have shown that habitat complexity may provide refuge or reduce the number of encounters prey have with actively searching predators. For ambush predators, habitat complexity may enhance or have no effect on predation rates because it conceals predators, reduces prey detection by predators, or visually impairs both predators and prey. We investigated the effects of habitat complexity and predation by the ambush predators Toxorhynchites rutilus and Corethrella appendiculata on their mosquito prey Aedes albopictus and Ochlerotatus triseriatus in container analogs of treeholes. As in other ambush predator-prey systems, habitat complexity did not alter the effects of T. rutilus or C. appendiculata whose presence decreased prey survivorship, shortened development time, and increased adult size compared to treatments where predators were absent. Faster growth and larger size were due to predator-mediated release from competition among surviving prey. Male and female prey survivorship were similar in the absence of predators, however when predators were present, survivorship of both prey species was skewed in favor of males. We conclude that habitat complexity is relatively unimportant in shaping predator-prey interactions in this treehole community, where predation risk differs between prey sexes. PMID:16041612

Griswold, Marcus W.; Lounibos, L. Philip

2012-01-01

49

Habitat Suitability Index Models: Bald Eagle (Breeding Season)  

Science.gov (United States)

A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the bald eagle (Haliaeetus leucocephalus). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

Peterson, Allen

1986-01-01

50

Factors influencing differential larval habitat productivity of Anopheles gambiae complex mosquitoes in a western Kenyan village  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: The study was undertaken to characterize factors influencing differential productivityof Anopheles gambiae complex mosquitoes at larval habitats in a rural village in western Kenya.Methods: Longitudinal larval sampling was done using an area sampler for 3 months. Emerged adults wereidentified to species level morphologically using taxonomic keys and to sub-species by polymerase chain reaction(PCR. Nutrient content was analyzed using persulphate oxidation method. Water pH was measured using anOrion pH/conductivity meter. Turbidity was measured using a Hach 2100A turbidity meter. Algal count densitywas estimated using a sedge-wick rafter cell.Results: A total 3367 larvae were harvested. Out of 500 adults subjected to PCR analysis 358 (71.6% wereAnopheles gambiae s.s., 127 (25.4% An. arabiensis while PCR amplification failed for 15 (3% specimens.Rainwater pools were the most productive habitat type. There was a positive association between algal densityand larval density (p<0. Total nitrogen, water pH and turbidity were positively correlated with larval density(p<0.01 and pH was negatively associated with larval density.Conclusion: Results indicate water nutrient and algal content in larval habitats of An. gambiae play crucial,dual roles in the resource ecology of these mosquitoes. Overall, the findings of this study support the notion thatanti-larval source reduction measures aimed at manipulating physicochemical variables in larval habitats toeliminate larval production have a chance of succeeding in an integrated vector control program.

Albert O. Mala & Lucy W. Irungu

2011-03-01

51

Household disposables as breeding habitats of dengue vectors: Linking wastes and public health  

International Nuclear Information System (INIS)

Highlights: ? An assessment of different household wastes as larval habitats of dengue vectors Aedes aegypti and Aedes albopictus was made using Kolkata, India as a model geographical area. ? Household wastes of four major categories namely earthen, porcelain, plastic and coconut shells varied significantly for Aedes immature depending on species, month and location. ? Based on the relative density of Aedes immature, cluster analyses allowed segregation and classification of the waste containers and relative importance as mosquito larval habitats. ? Conversion of disposed wastes into larval habitats cautions for continuance of Aedes population in Kolkata and similar cities of tropics lacking suitable waste management practices. - Abstract: An assessment of the household wastes as larval habitats of the dengue vectors was made considering Kolkata, India, as geographical area. Wastes of four major categories, namely, earthen, porcelain, plastic and coconut shells were monitored for positive with immature of either Aedes aegypti or Aedes albopictus. Twenty six types of wastes with varying size and shape, resembling containers, were identified that hosted mosquito immature. The number of waste containers positive for Aedes immature varied significantly (P < 0.05) with respect to location, type and month. The relative density of Aedes immature in the waste containers varied significantly (P < 0.05) with the types and months. The significant interaction between the gnificant interaction between the month, waste container types and density of Aedes immature suggest that the household wastes are important contributors to the maintenance of the population of Aedes mosquito in the city. Based on the relative density of mosquito immature in the wastes, cluster analysis allowed segregation and classification of the wastes and their importance as mosquito larval habitats. Apparently, the containers that are most frequently disposed off contributed largely to the sustenance of Aedes mosquito population in the city. This calls for a strict legislation towards disposal as well as enhanced management of the household wastes. A link between the wastes disposed and subsequent conversion to the mosquito larval habitats cautions for continuance of Aedes population and possibility of dengue epidemics if the existing management practices are not improved.

52

Mosquito larval habitat mapping using remote sensing and GIS: Implications of coalbed methane development and West Nile virus  

Energy Technology Data Exchange (ETDEWEB)

Potential larval habitats of the mosquito Culex tarsalis (Coquillett), implicated as a primary vector of West Nile virus in Wyoming, were identified using integrated remote sensing and geographic information system (GIS) analyses. The study area is in the Powder River Basin of north central Wyoming, an area that has been undergoing a significant increase in coalbed methane gas extractions since the late 1990s. Large volumes of water are discharged, impounded, and released during the extraction of methane gas, creating aquatic habitats that have the potential to support immature mosquito development. Landsat TM and ETM + data were initially classified into spectrally distinct water and vegetation classes, which were in turn used to identify suitable larval habitat sites. This initial habitat classification was refined using knowledge-based GIS techniques requiring spatial data layers for topography, streams, and soils to reduce the potential for overestimation of habitat. Accuracy assessment was carried out using field data and high-resolution aerial photography commensurate with one of the Landsat images. The classifier can identify likely habitat for ponds larger than 0.8 ha (2 acres) with generally satisfactory results (72.1%) with a lower detection limit of approximate to 0.4 ha (1 acre). Results show a 75% increase in potential larval habitats from 1999 to 2004 in the study area, primarily because of the large increase in small coalbed methane water discharge ponds. These results may facilitate mosquito abatement programs in the Powder River Basin with the potential for application throughout the state and region.

Zou, L.; Miller, S.N.; Schmidtmann, E.T. [University of Wyoming, Laramie, WY (United States). Dept. of Renewable Resources

2006-09-15

53

Vigilancia y control en criaderos temporales y permanentes de culícidos en Villa Clara (Vigilance and control in temporal and permanent breeding ground of mosquitoes in Villa Clara  

Directory of Open Access Journals (Sweden)

Full Text Available El trabajo se desarrolló en la Unidad Provincial de Vigilancia y Lucha Antivectorial de la provincia de Villa Clara, en el período comprendido entre el primero de julio al primero de noviembre del 2005. Para el mismo se representaron gráficamente los 304 criaderos permanentes y 218 temporales de culícidos; distribuidos en los 13 municipios de dicha provincia. Se tomaron muestras de cuerpos de agua (28 criaderos existentes en los 13 municipios de la provincia para detectar la Densidad Larvaria según la metodología del cucharón. Se determinaron las principales especies de culícidos que habitan en la provincia y se compararon dos métodos (Temephos al 2% y peces de control para estos vectores, determinándose el costo – riesgo del Temephos al 2%, el Bacillus thurigiensis y los peces como métodos de control de mosquitos mediante una ponderización. Los datos primarios se procesaron en el sistema computarizado Excel del paquete Office XP y para el procesamiento estadístico de la efectividad de cada tratamiento se empleó la prueba de comparación de proporciones del paquete Statgraphics plus 4.1, ambos sistemas sustentados en WindowsÒ. Los resultados muestran que las especies de mosquitos más difundidas en la provincia son: el Anopheles albimanus, el Aedes mediovitatus, el Aedes scapularis, el Aedes confinis, el Culex quinquefasciatus, el Culex nigripalpus y el Culex corniger; además, los resultados demuestran la superioridad del control con peces sobre el control con Temephos ya que es más eficiente (99% versus 87% para p < 0.01 en el control de culícidos. La vigilancia con peces (no gastos en divisas y $ 1 035.08 MN es más económica que el Temephos (847 500 CUC y $ 12 490.96 MN y que el Bacillus thurigiensis (6 328 cuc y $ 8 280.64 MN. Se concluye que los peces constituyen un efectivo control para las poblaciones de culícidos, recomendando el uso de los mismos por todos los beneficios que estos representan. This work was developed in the Provincial Unit of Vigilance and Vectors Against fight in Villa Clara province, between the first July to first November 2005. For the same was graphically represented the 304 permanent and 218 temporal breeding ground of mosquitoes; distributed in the 13 municipalities of this province. Were taken shows of water body (28 breeding ground existence in the 13 municipalities of the province that to detect the Density of Larva according the methodology of ladle. Were determined the species main of mosquitoes that habitat in the province and were compared two methods (Temephos 2% and fish of control for this vectors, determining the cost – risk of Temephos 2%, the Bacillus thurigiensis and fish as mosquitoes control thorough a consideration. Were primary dates process in the computerized system Excel of packet Office XP and that statistic process of effectively of each treatment was use the test of proportions comparison of packet Statgraphics plus 4.1, both systems sustained in WindowsÒ. The results showing that the mosquitoes species more disseminated in the province are: Anopheles albimanus, Aedes mediovitatus, Aedes scapularis, Aedes confinis, Culex quinquefasciatus, Culex nigripalpus and Culex corniger; besides, the results demonstrating the superiority of control with fish on the Temephos control, already that is more efficient (99% versus 87% that p < 0.01 in the mosquitoes control. The fish control (no spending in CUC and $ 1 035.08 MN is more economic than Temephos (847 500 CUC and $ 12 490.96 MN and than Bacillus thurigiensis (6 328 cuc and $ 8 280.64 MN. Was conclude that the fish constitute a control effective that the mosquitoes people, recommended the use of fish for all benefice that this represent.

Janhad L. Rodríguez Mendieta

2006-07-01

54

Efficacy of a mermithid nematode Romanomermis iyengari (Welch) (Nematoda: Mermithidae) in controlling tree hole-breeding mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) in a rubber plantation area of Kerala, India.  

Science.gov (United States)

In rubber plantations, tree holes are one of the major types of breeding habitats of Aedes mosquitoes which transmit dengue and chikungunya. A mermithid nematode, Romanomermis iyengari, was evaluated in tree holes for its efficacy in controlling Aedes albopictus. Infection of mosquito larvae by the nematode was determined through microscopic examination on the next day of application, and evaluation of immature density of mosquito was done on the seventh day. After application of the infective stage of the nematode in a host-parasite ratio of 1:3 or 1:4, the infection rates on the different larval instars of mosquito were similar, 85.7-95.8 % in first to third instars and 79.3 % in fourth instar larvae or 100 and 92.9 %, respectively. Parasite burden varied from 1.1 to 2.4, respectively, among first and third instar larvae applied at 1:3. At 1:4, the parasite burden was between 1.6 (fourth instar) and 4 (second instar). The increase in parasite burden due to parasite density was significant in all the larval instars (P?iyengari in infecting the mosquito and controlling pupal emergence. PMID:23306387

Paily, K P; Chandhiran, K; Vanamail, P; Kumar, N Pradeep; Jambulingam, P

2013-03-01

55

Detection, identification, and classification of mosquito larval habitats using remote sensing scanners in earth-orbiting satellites*  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method of identifying mosquito larval habitats associated with fresh-water plant communities, wetlands, and other aquatic locations at Lewis and Clark Lake in the states of Nebraska and South Dakota, USA, using remote sensing imagery obtained by multispectral scanners aboard earth-orbiting satellites (Landsat 1 and 2) is described. The advantages and limitations of this method are discussed.

Hayes, Richard O.; Maxwell, Eugene L.; Mitchell, Carl J.; Woodzick, Thomas L.

1985-01-01

56

Locating suitable habitats for West Nile Virus-infected mosquitoes through association of environmental characteristics with infected mosquito locations: a case study in Shelby County, Tennessee  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Since its first detection in 2001, West Nile Virus (WNV poses a significant health risk for residents of Shelby County in Tennessee. This situation forced public health officials to adopt efficient methods for monitoring disease spread and predicting future outbreaks. Analyses that use environmental variables to find suitable habitats for WNV-infected mosquitoes have the potential to support these efforts. Using the Mahalanobis Distance statistic, we identified areas of Shelby County that are ecologically most suitable for sustaining WNV, based on similarity of environmental characteristics to areas where WNV was found. The environmental characteristics in this study were based on Geographic Information Systems (GIS data, such as elevation, slope, land use, vegetation density, temperature, and precipitation. Results Our analyses produced maps of likely habitats of WNV-infected mosquitoes for each week of August 2004, revealing the areas that are ecologically most suitable for sustaining WNV within the core of the Memphis urban area. By comparing neighbourhood social characteristics to the environmental factors that contribute to WNV infection, potential social drivers of WNV transmission were revealed in Shelby County. Results show that human population characteristics and housing conditions such as a high percentage of black population, low income, high rental occupation, old structures, and vacant housing are associated with the focal area of WNV identified for each week of the study period. Conclusion We demonstrated that use of the Mahalanobis Distance statistic as a similarity index to assess environmental characteristics is a potential raster-based approach to identify areas ecologically most suitable for sustaining the virus. This approach was also useful to monitor changes over time for likely locations of infected mosquito habitats. This technique is very helpful for authorities when making decisions related to an integrated mosquito management plan and targeted health education outreach.

Bialkowska-Jelinska Elzbieta

2008-03-01

57

Urbanization Increases Aedes albopictus Larval Habitats and Accelerates Mosquito Development and Survivorship  

Science.gov (United States)

Introduction Aedes albopictus is a very invasive and aggressive insect vector that causes outbreaks of dengue fever, chikungunya disease, and yellow fever in many countries. Vector ecology and disease epidemiology are strongly affected by environmental changes. Urbanization is a worldwide trend and is one of the most ecologically modifying phenomena. The purpose of this study is to determine how environmental changes due to urbanization affect the ecology of Aedes albopictus. Methods Aquatic habitats and Aedes albopictus larval population surveys were conducted from May to November 2013 in three areas representing rural, suburban, and urban settings in Guangzhou, China. Ae. albopictus adults were collected monthly using BG-Sentinel traps. Ae. albopictus larva and adult life-table experiments were conducted with 20 replicates in each of the three study areas. Results The urban area had the highest and the rural area had the lowest number of aquatic habitats that tested positive for Ae. albopictus larvae. Densities in the larval stages varied among the areas, but the urban area had almost two-fold higher densities in pupae and three-fold higher in adult populations compared with the suburban and rural areas. Larvae developed faster and the adult emergence rate was higher in the urban area than in suburban and rural areas. The survival time of adult mosquitoes was also longer in the urban area than it was in suburban and rural areas. Study regions, surface area, water depth, water clearance, surface type, and canopy coverage were important factors associated with the presence of Ae. albopictus larvae. Conclusions Urbanization substantially increased the density, larval development rate, and adult survival time of Ae. albopictus, which in turn potentially increased the vector capacity, and therefore, disease transmissibility. Mosquito ecology and its correlation with dengue virus transmission should be compared in different environmental settings. PMID:25393814

Li, Yiji; Kamara, Fatmata; Zhou, Guofa; Puthiyakunnon, Santhosh; Li, Chunyuan; Liu, Yanxia; Zhou, Yanhe; Yao, Lijie; Yan, Guiyun; Chen, Xiao-Guang

2014-01-01

58

Efectividad y supervivencia de Romanomermis culicivorax en criaderos naturales de larvas de mosquitos / Effectiveness and survival of Romanomermis culicivorax in natural breeding sites of mosquito larvae  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish 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, p [...] or 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 experimental fue completamente al azar con arreglo factorial de dos factores (dos dosis de nemátodos y tres especies de mosquitos). La dosis de 500 nemátodos causó 74.3-87.8 % de parasitismo en larvas de las tres especies; la dosis de 1000 causó 77.2-96.9 % de parasitismo, con un incremento del parasitismo al aumentar la dosis de nemátodos (p Abstract in english Mosquitoes (Díptera: Culicidae) transmit causal agents of malaria, dengue and western Nile encephalitis, besides being extremely annoying for humans. The objective of this study was to determine the control effect of releasing 500 and 1000 Romanomermis culicivorax Ross and Smith nematodes per square [...] meter into larval populations of Anopheles albimanus Wiedeman, Culex nigripalpus Theobald, and Uranotenia sapphiriuna Oster-Sacken in 13 natural breeding sites. The experimental design was completely randomized with a factorial arrangement of two factors (two dosages of nematodes and three species of mosquitoes). The doses of 500 nematodes m-2 caused 74.3-87.8 % parasitism in larvae of the three species; the dose of 1000 nematodes m-2 caused 77.2-96.9 % parasitism; that is, parasitism was higher with the higher dose of nematodes (p

Rafael, Pérez-Pacheco; Alberto, Santamarina-Mijares; Alfonso, Vásquez-López; Sabino H., Martínez-Tomás; Javier, Suárez-Espinosa.

2009-12-01

59

Breeding bird populations and habitat associations within the Savannah River Site (SRS).  

Energy Technology Data Exchange (ETDEWEB)

Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

Gauthreaux, Sidney, A.; Steven J. Wagner.

2005-06-29

60

Habitat and sex differences in physiological condition of breeding Southwestern Willow Flycatchers (Empidonax traillii extimus)  

Science.gov (United States)

The Southwestern Willow Flycatcher (Empidonax traillii extimus; hereafter "flycatcher") is a federally listed endangered species that breeds in densely vegetated riparian habitats dominated by native and exotic plants, including introduced monotypic saltcedar (Tamarix ramosissima). Some workers have theorized that saltcedar is unsuitable habitat for the flycatcher, primarily because it generally supports a smaller and less diverse invertebrate community (the flycatcher's food base) than native habitats (e.g. Salix spp.). However, differences in insect communities between native and saltcedar habitats are not proof that saltcedar habitats are inferior. The only way to evaluate whether the habitats differ in dietary or energetic quality is to document actual food limitation or its manifestations. Measurements of an individual's body condition and metabolic state can serve as indicators of environmental stressors, such as food limitation and environmental extremes. We captured 130 flycatchers breeding in native and saltcedar habitats in Arizona and New Mexico and measured 12 variables of physiological condition. These variables included body mass, fat level, body condition index, hematocrit, plasma triglycerides, plasma free fatty acids and glycerol, plasma glucose and beta-hydroxybutyrate, plasma uric acid, total leukocyte count, and heterophil-to-lymphocyte ratio. We found substantial sex-based differences in the condition of male and female flycatchers. Ten of the 12 measures of physiological condition differed significantly between the sexes. In all cases where male and female condition differed (except mass), the differences suggest that males were in poorer condition than females. We found few habitat-based differences in flycatcher condition. Only 3 of the 12 physiological condition indices differed significantly between habitats. Our data show that, at least in some parts of the flycatcher's range, there is no evidence that flycatchers breeding in saltcedar habitats exhibit poorer nutritional condition or are suffering negative physiological affects. ?? The American Ornithologists' Union, 2005.

Owen, J.C.; Sogge, M.K.; Kern, M.D.

2005-01-01

 
 
 
 
61

An Educational Interventional Study to Assess Awareness about Mosquito Breeding, Diseases Caused and Protective Measures Against them among Families Residing in an Urban Slum of Indore City  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Community participation plays an important role in control of Mosquito borne diseases. This study tries to assess impact of educational intervention on various aspects of mosquito borne diseases in an urban slum. Methodology: An educational interventional study was done in 200 families residing in a slum (Badi Gwaltoli which is in field practice area of Urban Health Centre attached to Department of Community Medicine of M.G.M.Medical College, Indore. A pretested semi-structured questionnaire was administered to the Head of the family which studied their awareness and perception regarding breeding sites and biting habits of mosquitoes, diseases spread by them and personal protective measures used, followed by an educational intervention and post assessment. Data was entered into Microsoft excel spread sheet and analysed using SPSS version 20 software. Results: 46% of study population knew the correct breeding season of mosquitoes (monsoon season during pre-intervention and 68% of the population post- intervention (p- value 0.004. When asked at what time mosquitoes bite the most, maximum number (92% of people said that mosquitoes bite most in the evening and night, while only 6% and 2% were for morning and noon, respectively. Only 3.5% of the population who knew about breeding sites knew about artificial collections of water. Majority said mosquito breed in dirty stagnant water (78.5%. About 96%of the study population was aware that mosquitoes spread diseases. However, only 33.3%of respondents knew correctly about the diseases spread which improved to 68% in the post-intervention period (p-value=.000. 46% knew all the protection measures against mosquitoes in the pre-intervention which increased to 86% in the post intervention (p.value-.005. Conclusion: Awareness about Aedes mosquitoes and its habits is quite poor and many people still believe that only dirty water serves as a breeding place in mosquitoes. Regular IEC sessions informing community about mosquito-borne diseases will improve community participation.

Deepa Raghunath

2013-08-01

62

Upland Habitat Quality and Historic Landscape Composition Influence Genetic Variation of a Pond-Breeding Salamander  

Directory of Open Access Journals (Sweden)

Full Text Available Understanding the temporal and spatial scale at which habitat alteration impacts populations is important for conservation and management. Amphibians have declined more than other vertebrates, and pond-breeding species are particularly susceptible to habitat loss and fragmentation because they have terrestrial and aquatic life stages. One approach to management of pond-breeding species is protection of core upland habitat surrounding the breeding pond. We used genetic variation as an indicator of population status in a common amphibian species, spotted salamanders (Ambystoma maculatum, to determine how amount of suitable upland habitat relates to population status in the greater Charlotte, North Carolina, USA metropolitan area. We developed candidate models to evaluate the relative influence of historical and contemporary forested habitat availability on population genetic variation at two spatial scales of upland area (164 m and 2000 m at four time intervals over the past seven decades (1938, 1978, 1993, 2005. We found that historical land cover best predicted contemporary allelic richness. Inbreeding coefficient and observed heterozygosity were not effectively predicted by forest cover at either spatial or temporal scales. Allelic richness was best predicted at the smaller spatial scale in the 1993 time interval. Predicting and understanding how future landscape configuration affects genetic variation of common and rare species is imperative for the conservation of amphibian and other wildlife populations.

Jeremiah R. Alexander

2013-09-01

63

A study on container breeding mosquitoes with special reference to Aedes (Stegomyia aegypti and Aedes albopictus in Thiruvananthapuram district, India  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: The district of Thiruvananthapuram reports the maximum number of cases of dengue in the state of Kerala. To determine the larval diversity, density and breeding site preferences of Aedes mosquitoes, during pre-monsoon and monsoon periods in urban and rural areas of Thiruvananthapuram district. Methods: Based on the daily reports of dengue cases, 70 clusters were identified in Thiruvananthapuram district. A cross-sectional larval survey was done in the domestic and peri-domestic areas of 1750 houses, using the WHO standard techniques. The larval indices were calculated, and the larvae were identified by using taxonomic keys. Urban and rural differences and the variations during pre-monsoon and monsoon seasons were also studied. Results: In the surveyed houses, 15% had mosquito breeding, with 88% having Aedes larvae. The house index, container index and the breteau index were 13.08, 13.28 and 16.57%, respectively. About 86% of the clusters were found positive for Aedes albopictus and 11% for Ae. aegypti. Aedes albopictus was distributed almost equally in rural and urban clusters, whereas the distribution of Ae. aegypti was significantly higher in urban areas (p = 0.03. The most common water holding containers found (outdoor were of plastic, followed by coconut shells. The breeding preference ratio was highest for tyres. Significantly lesser positivity was found for containers during monsoon period when compared to pre-monsoon period. Conclusion: The geographical distribution of Ae. albopictus is significantly high in peri-domestic areas and, therefore, its epidemiological role in the widespread disease occurrence needs to be studied. The discarded tyres being the most preferred breeding sites, where IEC activities will help in source reduction.

K. Vijayakumar

2014-01-01

64

Field Efficacy of Vectobac GR as a Mosquito Larvicide for the Control of Anopheline and Culicine Mosquitoes in Natural Habitats in Benin, West Africa  

Science.gov (United States)

Introduction The efficacy of Vectobac GR (potency 200 ITU/mg), a new formulation of bacterial larvicide Bacillus thuringiensis var. israelensis Strain AM65-52, was evaluated against Anopheles gambiae and Culex quinquefasciatus in simulated field and natural habitats in Benin. Methods In simulated field conditions, Vectobac GR formulation was tested at 3 dosages (0.6, 0.9, 1.2 g granules/m2 against An. gambiae and 1, 1.5, 2 g granules/m2 against Cx. quinquefasciatus) according to manufacturer’s product label recommendations. The dosage giving optimum efficacy under simulated field conditions were evaluated in the field. The efficacy of Vectobac GR in terms of emergence inhibition in simulated field conditions and of reduction of larval and pupal densities in rice fields and urban cesspits was measured following WHO guidelines for testing and evaluation of mosquito larvicides. Results Vectobac GR caused emergence inhibition of ?80% until 21 [20]–[22] days for An. gambiae at 1.2 g/m2 dose and 28 [27–29] days for Cx. quinquefasciatus at 2 g/m2 in simulated field habitats. The efficacy of Vectobac GR in natural habitats was for 2 to 3 days against larvae and up to 10 days against pupae. Conclusions Treatment with Vectobac GR caused complete control of immature mosquito within 2–3 days but did not show prolonged residual action. Larviciding can be an option for malaria and filariasis vector control particularly in managing pyrethroid-resistance in African malaria vectors. Since use of larvicides among several African countries is being emphasized through Economic Community of West Africa States, their epidemiological impact should be carefully investigated. PMID:24505334

Djenontin, Armel; Pennetier, Cedric; Zogo, Barnabas; Soukou, Koffi Bhonna; Ole-Sangba, Marina; Akogbeto, Martin; Chandre, Fabrice; Yadav, Rajpal; Corbel, Vincent

2014-01-01

65

Tire-breeding mosquitoes of public health importance along an urbanisation gradient in Buenos Aires, Argentina  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Used vehicle tires are a source of mosquito vectors and a means of their introduction and expansion. With the aim of assessing the effects of urbanisation on the main mosquito vectors in temperate Argentina, the infestation levels of Aedes aegypti (L.) and Culex pipiens L. were studied in used tires [...] from highly urbanised cities to low-urbanised small towns in Buenos Aires. Immatures of both species accounted for 96% of the 9,722 individuals collected; the total individuals collected represented seven species. The percentage of water-filled tires containing mosquitoes [container index (CI)] was 33% and the percentage of infested sites [site index (SI)] was 65.2%. These indexes decreased significantly from low to high urbanisation levels for both mosquito species. The relative abundance (RA) of Ae. aegypti immatures was slightly higher toward large cities, but showed no difference for Cx. pipiens. The CI of shaded tires was significantly higher than the CI of exposed tires for both mosquito species. There was no difference in RA values between shaded and sunlit tires. The CI and the SI were highest during the summer across the urbanisation levels, except for Cx. pipiens, which continued to increase during the autumn in small towns. Results related to urbanisation gradient, sunlit exposure and seasonality are discussed.

Alejandra, Rubio; María Victoria, Cardo; Darío, Vezzani.

2011-09-01

66

Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human dis...

Webber, Alyson F.; Heath, Julie A.; Fischer, Richard A.

2013-01-01

67

Habitat Requirements of Breeding Black-Backed Woodpeckers (Picoides arcticus in Managed, Unburned Boreal Forest  

Directory of Open Access Journals (Sweden)

Full Text Available We investigated home-range characteristics and habitat selection by Black-backed Woodpeckers (Picoides arcticus in an unburned, boreal forest landscape managed by mosaic harvesting in Quebec, Canada. Habitat selection by this species was specifically examined to determine home-range establishment and foraging activities. We hypothesized that Black-backed Woodpeckers would respond to harvesting by adjusting their home-range size as a function of the amount of dead wood available. Twenty-two birds were tracked using radiotelemetry, and reliable estimates of home-range size were obtained for seven breeding individuals (six males and one female. The average home-range size was 151.5 ± 18.8 ha (range: 100.4–256.4 ha. Our results indicate that this species establishes home ranges in areas where both open and forested habitats are available. However, during foraging activities, individuals preferentially selected areas dominated by old coniferous stands. The study also showed that the spatial distribution of preferred foraging habitat patches influenced space use, with home-range area increasing with the median distance between old coniferous habitat patches available within the landscape. Finally, these data show that Black-backed Woodpeckers may successfully breed in an unburned forest with at least 35 m3 ? ha-1 of dead wood, of which 42% (15 m3 ? ha-1 is represented by dead wood at the early decay stage.

Junior A. Tremblay

2009-06-01

68

Characterization of potential larval habitats for Anopheles mosquitoes in relation to urban land-use in Malindi, Kenya  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background This study characterized Anopheles mosquito larval habitats in relation to ecological attributes about the habitat and community-level drainage potential, and investigated whether agricultural activities within or around urban households increased the probability of water body occurrence. Malindi, a city on the coast of Kenya, was mapped using global positioning system (GPS technology, and a geographic information system (GIS was used to overlay a measured grid, which served as a sampling frame. Grid cells were stratified according to the level of drainage in the area, and 50 cells were randomly selected for the study. Cross-sectional household and entomological surveys were conducted during November and December 2002 within the 50 grid cells. Chi-square analysis was used to test whether water bodies differed fundamentally between well and poorly drained areas, and multi-level logistic regression was used to test whether household-level agricultural activity increased the probability of water body occurrence in the grid cell. Results Interviews were conducted with one adult in 629 households. A total of 29 water bodies were identified within the sampled areas. This study found that characteristics of water bodies were fundamentally the same in well and poorly drained areas. This study also demonstrated that household-level urban agriculture was not associated with the occurrence of water bodies in the grid cell, after controlling for potential confounders associated with distance to the city center, drainage, access to resources, and population density. Conclusions Household-level urban agricultural activity may be less important than the other types of human perturbation in terms of mosquito larval habitat creation. The fact that many larvae were coming from few sites, and few sites in general were found under relatively dry conditions suggests that mosquito habitat reduction is a reasonable and attainable goal in Malindi.

Keating Joseph

2004-05-01

69

Influence of biological and physicochemical characteristics of larval habitats on the body size of Anopheles gambiae mosquitoes (Diptera: Culicidae along the Kenyan coast  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: The number and productivity of larval habitats ultimately determine thedensity of adult mosquitoes. The biological and physicochemical conditions at the larval habitataffect larval development hence affecting the adult body size. The influence of biological and physicochemicalcharacteristics on the body size of Anopheles gambiae was assessed in Jaribuni village,Kilifi district along the Kenyan Coast.Methods: Ten cages measuring 1 × 1 × 1 m (1 m3 with a netting material were placed in 10 differentaquatic habitats, which were positive for anopheline mosquito larvae. Emergent mosquitoes werecollected daily by aspiration and the wing lengths were determined by microscopy. In the habitats,physicochemical parameters were assessed: pH, surface debris, algae and emergent plants, turbidity,substrate, nitrate, ammonia, phosphate and chlorophyll a content.Results: A total of 685 anopheline and culicine mosquitoes were collected from the emergent cages.Only female mosquitoes were considered in this study. Among the Anopheles spp, 202 were An.gambiae s.s., eight An. arabiensis, two An. funestus, whereas the Culex spp was composed of 214Cx. quinquefasciatus, 10 Cx. tigripes, eight Cx. annulioris and one Cx. cumminsii. The mean winglength of the female An. gambiae s.s. mosquitoes was 3.02 mm (n = 157, while that of An. arabiensiswas 3.09 mm (n = 9. There were no associations between the wing lengths and the environmentaland chemical parameters, except for a positive correlation between wing length of An. gambiae andchlorophyll a content (r = 0.622. The day on which the mosquitoes emerged was not significant forthe anopheline (p = 0.324 or culicine mosquitoes (p = 0.374, because the mosquito emerged fromthe cages on a daily basis.Interpretation & conclusion: In conclusion, there was variability in production of emergent mosquitoesfrom different habitats, which means that there should be targeted control on these habitatsbased on productivity.

Joseph M. Mwangangi, Charles M. Mbogo, Ephantus J. Muturi, Joseph G. Nzovu, Ephantus W. Kabiru, John I. Githure, Robert J. Novak , John C. Beier

2007-06-01

70

Sergentomyia spp.: breeding sites in vertisols and peri-domestic habitats in North West Ethiopia.  

Science.gov (United States)

Sand flies belonging to the genus Sergentomyia Franca & Parrot, 1920, are hematophagous insects feeding mostly on reptiles and birds, but some species feed also on mammals including humans. Sergentomyia spp. frequently comprise the vast majority of sand flies trapped along with Phlebotomus spp., the vectors of mammalian leishmaniasis. Within the framework of a project on the ecology and transmission of visceral leishmaniasis in Ethiopia, putative breeding sites of phlebotomine sand flies were studied. Large horizontal sticky traps (LHSTs) covered with sand fly-proof mesh were deployed over cracked vertisol and related habitats for up to 3 nights, and emerging sand flies were collected daily. Emergence traps (ETs) were also adapted to sample other putative breeding sites including tree trunks, termite mounds, rock piles and vertical river banks. Productive breeding sites were identified in the trunks and roots systems of trees, vertisol fields, cracks and burrows in vertisol dry river banks and termite mounds. Emerging flies were also collected form a stone wall and a rock pile situated inside a village. Significantly more Sergentomyia spp. were trapped in vertisols by ETs deployed over root system than in open fields. Similarly, more sand flies emerged from cracks in the vertisol in fallow Sorghum than in fallow sesame fields. Productive breeding sites were characterized by stable micro-climatic conditions. Species composition of emerging sand flies varied with habitat, season and geographical location. PMID:24841132

Moncaz, Aviad; Kirstein, Oscar; Gebresellassie, Araya; Lemma, Wossenseged; Gebre-Michael, Teshome; Balkew, Meshesha; Belay, Shewaye; Hailu, Asrat; Warburg, Alon

2014-09-01

71

Evaluating the Potential Impact of a Gas Pipeline on Whimbrel Breeding Habitat in the Outer Mackenzie Delta, Northwest Territories  

Directory of Open Access Journals (Sweden)

Full Text Available We used ground surveys to identify breeding habitat for Whimbrel (Numenius phaeopus in the outer Mackenzie Delta, Northwest Territories, and to test the value of high-resolution IKONOS imagery for mapping additional breeding habitat in the Delta. During ground surveys, we found Whimbrel nests (n = 28 in extensive areas of wet-sedge low-centered polygon (LCP habitat on two islands in the Delta (Taglu and Fish islands in 2006 and 2007. Supervised classification using spectral analysis of IKONOS imagery successfully identified additional areas of wet-sedge habitat in the region. However, ground surveys to test this classification found that many areas of wet-sedge habitat had dense shrubs, no standing water, and/or lacked polygon structure and did not support breeding Whimbrel. Visual examination of the IKONOS imagery was necessary to determine which areas exhibited LCP structure. Much lower densities of nesting Whimbrel were also found in upland habitats near wetlands. We used habitat maps developed from a combination of methods, to perform scenario analyses to estimate the potential effects of the Mackenzie Gas Project on Whimbrel habitat. Assuming effective complete habitat loss within 20 m, 50 m, or 250 m of any infrastructure or pipeline, the currently proposed pipeline development would result in loss of 8%, 12%, or 30% of existing Whimbrel habitat. If subsidence were to occur, most Whimbrel habitat could become unsuitable. If the facility is developed, follow-up surveys will be required to test these models.

Lisa D. Pirie

2009-12-01

72

Boosting the sterile insect technique to control mosquitoes.  

Science.gov (United States)

Mosquitoes are vectors of major diseases. Auto-dissemination recently proved very efficient to control Aedes species, using adult females contaminated with dissemination stations of juvenile hormone to treat breeding habitats, but cannot be used at large scales. Here we propose to combine it to the Sterile Insect Technique (SIT) to create a new control concept, named 'boosted SIT' that might enable the area-wide eradication of mosquitoes and many other vectors and insect pests. PMID:24746400

Bouyer, Jérémy; Lefrançois, Thierry

2014-06-01

73

Immature Development of the Malaria Vector Mosquito, Anopheles gambiae S.L. (Diptera: Culicidae, in Relation to Soil-substrate Organic Matter Content of Larval Habitats in Northcentral Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available This study elucidated the relationships between larval habitat soil-substrate Organic Matter Content (OMC and immature development of the mosquito Anopheles gambiae s.l. Day-old larvae of the mosquito were reared in media substrated with typical soil samples (i.e., sandy, silt, clayey and loamy soils, from established anopheline breeding sites, to provide a gradient in soil-substrate OMC. The OMC of the soil samples were determined by ignition to a constant weight; while the developing A. gambiae mosquitoes in the culture media were monitored daily for survivorship and duration of immature life stages. The results indicated significant (p0.05 among the soil-substrate types; results contrary to those of Larval Success Rates (LSR (i.e., range = 52.07±13.64 to 74.39±6.60%. Daily Pupation Rate (DPR of the mosquitoes varied significantly among the soil-substrates, ranging from 13.87±2.39% in clayey to 25.00±4.30% in loamy substrates. Soil-substrate OMC significantly extended the Duration of Immature Life Stages (DILS of the mosquitoes only in the sandy soil type (range = 12.76±1.74 to 15.81±2.40 days. On the whole, DILS was inversely related to soil-substrate OMC. Cross-correlational analysis revealed significant positive association among most of the variables tested. The findings of this study should serve as baseline information for the development of effective environmental management strategies for malaria larval-vector control.

I.K. Olayemi

2013-01-01

74

Immature development of the malaria vector mosquito, Anopheles gambiae S.L. (Diptera: Culicidae), in relation to soil-substrate organic matter content of larval habitats in northcentral Nigeria.  

Science.gov (United States)

This study elucidated the relationships between larval habitat soil-substrate Organic Matter Content (OMC) and immature development of the mosquito Anopheles gambiae S.L. Day-old larvae of the mosquito were reared in media substrated with typical soil samples (i.e., sandy, silt, clayey and loamy soils), from established anopheline breeding sites, to provide a gradient in soil-substrate OMC. The OMC of the soil samples were determined by ignition to a constant weight; while the developing A. gambiae mosquitoes in the culture media were monitored daily for survivorship and duration of immature life stages. The results indicated significant (p 0.05) among the soil-substrate types; results contrary to those of Larval Success Rates (LSR) (i.e., range = 52.07 +/- 13.64 to 74.39 +/- 6.60%). Daily Pupation Rate (DPR) of the mosquitoes varied significantly among the soil-substrates, ranging from 13.87 +/- 2.39% in clayey to 25.00 +/- 4.30% in loamy substrates. Soil-substrate OMC significantly extended the Duration of Immature Life Stages (DILS) of the mosquitoes only in the sandy soil type (range = 12.76 +/- 1.74 to 15.81 +/- 2.40 days). On the whole, DILS was inversely related to soil-substrate OMC. Cross-correlational analysis revealed significant positive association among most of the variables tested. The findings of this study should serve as baseline information for the development of effective environmental management strategies for malaria larval-vector control. PMID:24171275

Olayemi, I K; Ojo, V O

2013-02-01

75

Influence of leaf detritus type on production and longevity of container-breeding mosquitoes.  

Science.gov (United States)

Freshwater ecosystems are positioned at low levels in the landscape and receive large inputs of diverse plant-based detritus, a major source of energy for consumers in aquatic ecosystems. We conducted field experiments in Urbana, IL to determine the independent and combined effects of leaves of common tree species including the northern red oak (Quercus rubra L.), sugar maple (Acer saccharum Marshall), and common hackberry (Celtis occidentalis L.) on the performance of container-dwelling mosquitoes, especially Culex restuans Theobald (Diptera: Culicidae). We tested the hypothesis that leaf species have asymmetric effects on adult mosquito production and longevity. Hackberry followed by combined leaf treatments and maple produced the greatest number of pupae, whereas oak leaves produced the fewest. Leaf treatments had no significant effects on adult female sizes but female longevity was significantly lower in oak leaf treatments compared with the other leaf treatments. These findings support the hypothesis that leaf species identity influences the performance of container-dwelling mosquitoes with potential consequences for the transmission of infectious diseases. PMID:23068161

Muturi, Ephantus J; Allan, Brian F; Ricci, James

2012-10-01

76

Fusion of High Resolution Aerial Multispectral and LiDAR Data: Land Cover in the Context of Urban Mosquito Habitat  

Directory of Open Access Journals (Sweden)

Full Text Available Remotely sensed multi-spectral and -spatial data facilitates the study of mosquito-borne disease vectors and their response to land use and cover composition in the urban environment. In this study we assess the feasibility of integrating remotely sensed multispectral reflectance data and LiDAR (Light Detection and Ranging-derived height information to improve land use and land cover classification. Classification and Regression Tree (CART analyses were used to compare and contrast the enhancements and accuracy of the multi-sensor urban land cover classifications. Eight urban land-cover classes were developed for the city of Tucson, Arizona, USA. These land cover classes focus on pervious and impervious surfaces and microclimate landscape attributes that impact mosquito habitat such as water ponds, residential structures, irrigated lawns, shrubs and trees, shade, and humidity. Results show that synergistic use of LiDAR, multispectral and the Normalized Difference Vegetation Index data produced the most accurate urban land cover classification with a Kappa value of 0.88. Fusion of multi-sensor data leads to a better land cover product that is suitable for a variety of urban applications such as exploring the relationship between neighborhood composition and adult mosquito abundance data to inform public health issues.

Willem J. D. van Leeuwen

2011-11-01

77

High-resolution remote-sensing data in amphibian studies: identification of breeding sites and contribution to habitat models  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Remote sensing can provide an alternative to field data sampling in many species-habitat studies. However, its usefulness may depend on the species, habitat studied, spatial resolution and extent. We used a high spatial and spectral remote- sensing image to locate and delineate small amphibian breeding sites in a Mediterranean ecosystem (Doñana National Park). We also evaluated its usefulness in detecting habitat heterogeneity (number and evenness of different radiometric zones) within ponds...

Go?mez-rodri?guez, Carola; Bustamante, Javier; Koponen, Sampsa; Di?az-paniagua, Carmen

2008-01-01

78

Classification of immature mosquito species according to characteristics of the larval habitat in the subtropical province of Chaco, Argentina  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related [...] to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species.

Marina, Stein; Francisco, Ludueña-Almeida; Juana Alicia, Willener; Walter Ricardo, Almirón.

2011-06-01

79

Breeding habitat selection and home range of radio-marked black ducks (Anas rubripes) in Maine  

Science.gov (United States)

Telemetry techniques were used to monitor the movements and habitat use of 13 female and 7 male black ducks (Anas rubripes) in an inland breeding region of south central Maine in 1977-1980. Black ducks preferred persistent emergent, broad-leaved deciduous forested, and broad-leaved deciduous scrub-shrub wetlands over unconsolidated organic bottom, needle-leaved evergreen forested, and broad-leaved evergreen scrub-shrub ponds. Birds also made frequent use of small ephemeral pools and streams throughout the breeding period. Nests were located in several habitats ranging from wetland sites to upland areas 1.5 km from the most frequently used pond. Home range size averaged 119 ha for females and 231 ha for males and did not differ by reproductive stage. Three pairs used only a single pond during the incubation period. Home ranges were linear (linearity index = 2.8), averaging 1956 m long for females and 2755 m for males. Wetlands used most by hens during incubation recesses were not always those located closest to the nest. Radio-marked ducks that returned in subsequent breeding seasons demonstrated fidelity to the previously used home range. Pair bonds of marked birds lasted until day 19 or 20 of incubation for initial nesting attempts.

Ringelman, J.K.; Longcore, J.R.; Owen, R.B., Jr.

1982-01-01

80

Alterations in the breeding habitats for two endangered raptor species along the Sava River basin, Croatia.  

Science.gov (United States)

Changes in habitat suitable for breeding of two sympatric raptor species (Haliaeetus albicilla and Aquila pomarina) were analysed along one of the most important breeding sites in Croatia for both species. The habitat suitability modelling was used to assess the influence of forestry practice during 2000-2006 using the known data on nesting places along research area. The four most important variables for lesser spotted eagle were elevation, distance from the nearest pasture, vertical distance to the nearest channel network and broadleaved forest placement (second axis from the principal component analysis of the enhanced vegetation index (EVI) index of MODIS images; November-March). The variables where white-tailed eagles showed greatest shift from overall habitat characteristics in the research area were broadleaved forest (second axis from the principal component analysis of the EVI index), height above the sea level, distance from the small settlements, vertical distance to channel network - all with negative loadings. The results clearly reveal the disproportion of suitable forests for raptors that were cut down in comparison to maturation of suitable forests. PMID:21800060

Radovi?, Andreja; Jelaska, Sven D

2012-07-01

 
 
 
 
81

Habitat selection by breeding waterbirds at ponds with size-structured fish populations  

Science.gov (United States)

Fish may significantly affect habitat use by birds, either as their prey or as competitors. Fish communities are often distinctly size-structured, but the consequences for waterbird assemblages remain poorly understood. We examined the effects of size structure of common carp ( Cyprinus carpio) cohorts together with other biotic and abiotic pond characteristics on the distribution of breeding waterbirds in a seminatural system of monocultured ponds, where three fish age classes were separately stocked. Fish age corresponded to a distinct fish size gradient. Fish age and total biomass, macroinvertebrate and amphibian abundance, and emergent vegetation best explained the differences in bird density between ponds. Abundance of animal prey other than fish (aquatic macroinvertebrates and larval amphibians) decreased with increasing carp age in the ponds. Densities of ducks and smaller grebes were strongly negatively associated with fish age/size gradient. The largest of the grebes, the piscivorous great crested grebe ( Podiceps cristatus), was the only species that preferred ponds with medium-sized fish and was positively associated with total fish biomass. Habitat selection by bitterns and most rallids was instead strongly influenced by the relative amount of emergent vegetation cover in the ponds. Our results show that fish size structure may be an important cue for breeding habitat choice and a factor affording an opportunity for niche diversification in avian communities.

Kloskowski, Janusz; Nieoczym, Marek; Polak, Marcin; Pitucha, Piotr

2010-07-01

82

Breeding habitats of Aedes aegypti (L) and Aedes. albopictus (Skuse) in villages of Barru, South Sulawesi, Indonesia.  

Science.gov (United States)

The breeding habitats of the dengue vector, Aedes aegypti and Aedes albopictus, were studied using larval collection method inside and outside houses in 6 villages of Barru, South Sulawesi, Indonesia from July 1994 to August 1995. Aedes aegypti was the dominant species, being abundant indoors especially in the coastal areas. Aedes albopictus was breeding primarily in outdoor containers in the hill and mountain areas. Earthen jar was the most common breeding habitat of Aedes aegypti in all villages surveyed. Drum can was the most common outdoor breeding habitat of Aedes albopictus in the hill and mountain areas. The high Breteau indices of Aedes aegypti and Aedes albopictus suggests that these species may play an important role in the transmission of dengue hemorrhagic fever in Barru where epidemics of the fever occur occasionally. PMID:9656413

Ishak, H; Miyagi, I; Toma, T; Kamimura, K

1997-12-01

83

Some water chemistry parameters of breeding habitats of the Caucasian salamander, Mertensiella caucasica in the Western Lesser Caucasus.  

Science.gov (United States)

Selection of breeding habitat plays a fundamental role in the reproductive success of urodeles and anurans. We studied the influence of water chemistry variables on the selection of a specific water resource as breeding habitat in Mertensiella caucasica. To determine the influence of water chemistry parameters on their habitat selection, we surveyed a total of 45 small river, streams and brooks in the Western Lesser Caucasus (northeastern Turkey and southwestern Georgia). The water samples taken from these localities were analyzed for 14 chemical variables and the results submitted to multiple logistic regression analysis in order to evaluate the influence of these parameters on the presence or absence of the species in the localities. Of these parameters, chloride concentration influenced the breeding habitat selection of Mertensiella caucasica significantly. PMID:19393978

Sayim, Ferah; Ba?kale, Eyup; Tarkhnishvili, David; Kaya, U?ur

2009-05-01

84

Environmental Effects on a Breeding Pair of Eagles- A Lesson on Habitats and Ecology  

Science.gov (United States)

The purpose of this lesson is to simulate feeding practices of breeding eagles in a helpful or stressful situation to Grade 10 high school students. This activity works well near the end of a unit on Ecology. Students should have a basic understanding of biotic and abiotic factors, populations, niches, habitats and feeding relationships because once the activity is completed, students will be able to identify these characteristics of bald eagles. This teaching resource was developed by a K-12 science teacher in the American Physiological SocietyÃÂs 2007 Frontiers in Physiology Program. For more information on this program, please visit www.frontiersinphys.org.

Nancy Beuhner (Deubrook Area Schools)

2008-08-01

85

Field irradiator gamma: pre-irradiation occurrence of breeding birds in three boreal habitats  

International Nuclear Information System (INIS)

A trail census was conducted of the breeding birds found in three major habitats in the Field Irradiator Gamma area at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba. The area sampled was about 10.50 ha in size, and included 4.25 ha of upland forest, 4.75 ha of lowland conifers, and 1.50 ha of black spruce-tamarack bog. Forty-four species of birds were identified, of which 24 were considered to be resident in the study area. The highest population density was observed in the bog, followed by upland forest and lowland conifer respectively. In contrast, species diversity was greatest in the upland forest, while it decreased markedly in the relatively monotypic lowland conifer and bog habitats. (author)

86

Diet and foraging habitats of non-breeding white storks (Ciconia ciconia in Bulgaria  

Directory of Open Access Journals (Sweden)

Full Text Available The diet of non-breeding White Storks was studied by pellet analysis and included mainly insects (99.9%, n=28947 with a predominance of grasshoppers (Orthoptera, 76.1%, and beetles (Coleoptera, 26.1%. The bush crickets Decticus albifrons/verrucivorus were the most numerous prey (29.9% by items, occurring in almost all pellets (98% occurrence in pellets, n=147 and predominating in half of them (49.7%. The grasshopper associations in the pellets specify foraging mainly in mesophytic grasslands that usually replace abandoned fields and overgrown pastures with a low level of grazing. The xerophytic grass-shrubby habitats, not rare on stony terrains, were of less importance, providing around 20% by prey. The typical aquatic inhabitants and the use of carrion around villages were exceptions in the study diet. The number of innutritious materials in the pellets rose when the White Storks hunted on nippy and agile grasshoppers and decreased when the main pray was slower beetles taken from the ground. The roosting of non-breeding White Storks disappeared when their preferred feeding habitats were ploughed up in the following years.

Milchev Boyan

2013-01-01

87

Identifying malaria vector breeding habitats with remote sensing data and terrain-based landscape indices in Zambia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Malaria, caused by the parasite Plasmodium falciparum, is a significant source of morbidity and mortality in southern Zambia. In the Mapanza Chiefdom, where transmission is seasonal, Anopheles arabiensis is the dominant malaria vector. The ability to predict larval habitats can help focus control measures. Methods A survey was conducted in March-April 2007, at the end of the rainy season, to identify and map locations of water pooling and the occurrence anopheline larval habitats; this was repeated in October 2007 at the end of the dry season and in March-April 2008 during the next rainy season. Logistic regression and generalized linear mixed modeling were applied to assess the predictive value of terrain-based landscape indices along with LandSat imagery to identify aquatic habitats and, especially, those with anopheline mosquito larvae. Results Approximately two hundred aquatic habitat sites were identified with 69 percent positive for anopheline mosquitoes. Nine species of anopheline mosquitoes were identified, of which, 19% were An. arabiensis. Terrain-based landscape indices combined with LandSat predicted sites with water, sites with anopheline mosquitoes and sites specifically with An. arabiensis. These models were especially successful at ruling out potential locations, but had limited ability in predicting which anopheline species inhabited aquatic sites. Terrain indices derived from 90 meter Shuttle Radar Topography Mission (SRTM digital elevation data (DEM were better at predicting water drainage patterns and characterizing the landscape than those derived from 30 m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER DEM. Conclusions The low number of aquatic habitats available and the ability to locate the limited number of aquatic habitat locations for surveillance, especially those containing anopheline larvae, suggest that larval control maybe a cost-effective control measure in the fight against malaria in Zambia and other regions with seasonal transmission. This work shows that, in areas of seasonal malaria transmission, incorporating terrain-based landscape models to the planning stages of vector control allows for the exclusion of significant portions of landscape that would be unsuitable for water to accumulate and for mosquito larvae occupation. With increasing free availability of satellite imagery such as SRTM and LandSat, the development of satellite imagery-based prediction models is becoming more accessible to vector management coordinators.

Shiff Clive

2010-11-01

88

Energy crop cultivations of reed canary grass - An inferior breeding habitat for the skylark, a characteristic farmland bird species  

Energy Technology Data Exchange (ETDEWEB)

Here, I present the first comparison of the abundance of farmland birds in energy grass fields and in cereal-dominated conventionally cultivated fields (CCFs). I demonstrate that in boreal farmland, skylark (Alauda arvensis) densities were significantly lower in reed canary grass (RCG) (Phalaris arundinacea) fields than in CCFs. I found that during the early breeding season RCG fields and CCFs are equally good habitats, but over the ensuing couple of weeks RCG rapidly grows too tall and dense for field-nesting species. Consequently, RCG is an inferior habitat for skylark for laying replacement clutches (after failure of first nesting) or for a second clutch after one successful nesting. The results imply that if RCG cultivation is to be expanded, the establishment of large monocultures should be avoided in farmland landscapes; otherwise the novel habitat may affect detrimentally the seriously depleted skylark population, and probably also other field-nesting bird species with similar breeding habitats. (author)

Vepsaelaeinen, Ville [Finnish Museum of Natural History, P.O. Box 17, University of Helsinki, FI-00014 Helsinki (Finland)

2010-07-15

89

Post-breeding habitat use by adult Boreal Toads (Bufo boreas) after wildfire in Glacier National Park, USA  

Science.gov (United States)

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area was unburned and the expected number of observations in unburned habitat was toads are more likely to occupy habitats that have diverged from historic fire return intervals. Copyright ?? 2008. C. Gregory Guscio. All rights reserved.

Guscio, C. G.; Hossack, B. R.; Eby, L. A.; Corn, P. S.

2008-01-01

90

Environmental variables associated with immature stage habitats of culicidae collected in aboriginal villages in Pahang, Malaysia.  

Science.gov (United States)

Many of the most widely spread vector-borne diseases are water related, in that the mosquito vectors concerned breed or pass part of their lifecycle in or close to water. A major reason for the study of mosquito larval ecology is to gather information on environmental variables that may determine the species of mosquitoes and the distribution of larvae in the breeding habitats. Larval surveillance studies were conducted six times between May 2008 and October 2009 in Pos Lenjang, Kuala Lipis, Pahang. Twelve environmental variables were recorded for each sampling site, and samples of mosquito larvae were collected. Larval survey studies showed that anopheline and culicine larvae were collected from 79 and 67 breeding sites, respectively. All breeding sites were classified into nine habitat groups. Culicine larvae were found in all habitat groups, suggesting that they are very versatile and highly adaptable to different types of environment. Rock pools or water pockets with clear water formed on the bank of rivers and waterfalls were the most common habitats associated with An. maculatus. Environmental variables influence the suitability of aquatic habitats for anopheline and culicine larvae, but not significantly associated with the occurrence of both larvae genera (p>0.05). This study provides information on mosquito ecology in relation to breeding habitats that will be useful in designing and implementing larval control operations. PMID:23413702

Ali, Wan Najdah Wan Mohamad; Ahmad, Rohani; Nor, Zurainee Mohamed; Ismail, Zamree; Ibrahim, Mohd Noor; Hadi, Azahari Abdul; Hassan, Rahimi; Lim, Lee Han

2012-11-01

91

Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season.  

Science.gov (United States)

Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human activity. The specific areas that require this protection may vary across snowy plover life history stages. PMID:23610630

Webber, Alyson F; Heath, Julie A; Fischer, Richard A

2013-04-01

92

Ecology of mosquitoes of Midwestern Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: The ecology and distribution of various mosquito species is important inthe determination of mosquito vector abundance and associated diseases prevalence. The distributionof various mosquito genera in natural and artificial habitats and their relative species abundancewas studied between August 2002 and July 2003 in three foci (Uromi, Ekpoma and Auchi comprisingthe Esan and Etsako regions of Midwestern Nigeria.Methods: Sampling was carried out by the method of Hopkins (1952 by dipping using a pipette orladle depending on container types. Pooled contents of smaller containers were sampled with a pondnet. All breeding sources of mosquito larvae were grouped into five (5 depending on their nature,constitution and the physiochemical properties. Artificial mosquito cultures were also carried out infour different container types; plastics, metal cans, earthenware pots and bamboo strips, in parts oftwo different macro habitats subdivided into area of high human activities (AHHA and areas ofderived/secondary vegetation (ADSV. Environmental temperatures, rainfall and relative humiditywere monitored during the study.Results: The present study revealed 17 mosquito species belonging to three genera (Anopheles,Culex and Aedes which are potential vectors of four human diseases in the areas surveyed. A total of736 mosquito larvae were encountered in artificial sources and 568 larvae were harvested from naturalsources. Pools, plastics and metal cans were the predominant artificial sources of mosquito larvae.Conclusion: The contribution of human activities and increasing environmental modification to thebreeding of human disease vector mosquitoes is of importance and selective vector control measuresincluding larviciding are recommended particularly before onset of rainy season

Godwin R.A. Okogun, Jude C. Anosike, Anthony N. Okere & Bethran E.B. Nwoke

2005-03-01

93

Dispersal of Adult Culex Mosquitoes in an Urban West Nile Virus Hotspot: A Mark-Capture Study Incorporating Stable Isotope Enrichment of Natural Larval Habitats  

Science.gov (United States)

Dispersal is a critical life history behavior for mosquitoes and is important for the spread of mosquito-borne disease. We implemented the first stable isotope mark-capture study to measure mosquito dispersal, focusing on Culex pipiens in southwest suburban Chicago, Illinois, a hotspot of West Nile virus (WNV) transmission. We enriched nine catch basins in 2010 and 2011 with 15N-potassium nitrate and detected dispersal of enriched adult females emerging from these catch basins using CDC light and gravid traps to distances as far as 3 km. We detected 12 isotopically enriched pools of mosquitoes out of 2,442 tested during the two years and calculated a mean dispersal distance of 1.15 km and maximum flight range of 2.48 km. According to a logistic distribution function, 90% of the female Culex mosquitoes stayed within 3 km of their larval habitat, which corresponds with the distance-limited genetic variation of WNV observed in this study region. This study provides new insights on the dispersal of the most important vector of WNV in the eastern United States and demonstrates the utility of stable isotope enrichment for studying the biology of mosquitoes in other disease systems. PMID:24676212

Hamer, Gabriel L.; Anderson, Tavis K.; Donovan, Danielle J.; Brawn, Jeffrey D.; Krebs, Bethany L.; Gardner, Allison M.; Ruiz, Marilyn O.; Brown, William M.; Kitron, Uriel D.; Newman, Christina M.; Goldberg, Tony L.; Walker, Edward D.

2014-01-01

94

Breeding habitat of sparrowhawks, Accipiter nisus on spoil heaps after coal mining  

Science.gov (United States)

Natural succession of spoil heaps after brown coal mining leads to the development of rich plant and invertebrate communities and therefore has been considered a proper alternative to conventional reclamation practice. Little is known, however, about the effects of these alternative approaches on vertebrate predators. This study analyses nest-site choice of the sparrowhawk, Accipiter nisus on afforested spoil heaps in the brown coal basin of north-west Bohemia, Czech Republic. Nest places of sparrowhawks, numbers of their main prey (small birds) and habitat attributes were investigated in 2007 and 2008 on 28 individual spoil heaps that were either reclaimed by silviculture or spontaneously afforested. Our results revealed preferences of breeding sparrowhawks for spontaneously developed birch growths with diverse mosaics of tree clumps, open patches and edge structures, all providing for opportunities to hunt. In addition, the proximity of large forests positively influenced nest-site choice of sparrowhawks. Although small birds were more abundant on Successions than Reclamations, our results did not suggest that numbers of this main prey were of higher importance for the sparrowhawks than habitat components of prey availability. These results highlight the importance of spontaneous succession as a rehabilitation alternative in post-mining landscapes.

Šálek, Miroslav; Hendrychová, Markéta; ?eho?, Michal

2010-03-01

95

Using a Dynamic Hydrology Model To Predict Mosquito Abundances in Flood and Swamp Water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We modeled surface wetness at high resolution, using a dynamic hydrology model, to predict flood and swamp water mosquito abundances. Historical meteorologic data, as well as topographic, soil, and vegetation data, were used to model surface wetness and identify potential fresh and swamp water breeding habitats in two northern New Jersey watersheds. Surface wetness was positively associated with the subsequent abundance of the dominant floodwater mosquito species, Aedes vexans, and the swamp ...

Shaman, Jeffrey; Stieglitz, Marc; Stark, Colin; Le Blancq, Sylvie; Cane, Mark

2002-01-01

96

Riqueza de especies de mosquitos, distribución y sitios de cría en el municipio Boyeros / Wealth of mosquito species, their distribution and breeding sites in Boyeros municipality  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Introducción: la identificación de las especies de mosquitos en cada municipio en Cuba forma parte del Programa de Control de Aedes aegypti y Aedes albopictus, lo cual representa un factor importante en la aparición de eventos epidemiológicos o zoonóticos que involucren estos insectos. Objetivo: con [...] ocer la riqueza de especies de mosquitos y su distribución en el municipio Boyeros. Métodos: el trabajo se desarrolló en el municipio Boyeros, La Habana en el período 1982-2011. Las muestras de mosquitos se colectaron por los trabajadores del programa de control de Aedes aegypti y Aedes albopictus. Resultados: la riqueza de especies de mosquitos fue de 35, de estas 10 se encuentran distribuidas en todas las áreas del municipio. El área con mayor riqueza de especie fue Mulgoba seguida por Wajay, y la de menor correspondió a Boyeros. Se colectaron 8 especies en depósitos artificiales y naturales como hueco de árboles; mientras que 22 se colectaron en reservorios de aguas naturales, lagunas de oxidación, zanjas, arroyos, lagunatos y ríos. Del total de especies, 5 solo fueron colectadas en estadio adulto. Conclusiones: la emergencia y reemergencia de algunas enfermedades transmitidas por mosquitos es uno de los aspectos que más seguimiento tiene en estos momentos en el continente americano, por lo que conocer la fauna de mosquitos del municipio así como su distribución es importante. De presentarse algún brote o epidemia que involucren a estos insectos obligaría a establecer las estrategias de control, para evitar la propagación de enfermedades de transmisión vectorial. Abstract in english Introduction: the identification of mosquito species in each municipality of Cuba is part of the Aedes aegypti and Aedes albopictus control program. This is an important factor in the occurrence of epidemiological or zoonotic events involving these insects. Objective: to identify the wealth of mosqu [...] ito species and their distribution in Boyeros municipality. Methods: the study was developed in Boyeros municipality from 1982 to 2011. The mosquito samples were taken by the Aedes aegypti and Aedes albopictus control program workers. Results: the wealth of mosquito species includes 35 species of which 10 are distributed in all the areas of the municipality. The area with the largest wealth of species was Mulgoba, followed by Wajay, and the smallest one was found in Boyeros. Eight species were collected in artificial and natural reservoirs such as tree holes, whereas 22 were observed in natural water reservoirs, oxidation lagoons, ditches, streams and rivers. Of all the species, just 5 were collected in their adult stage. Conclusions: emergency and reemergence of some mosquito-borne diseases is one of the more watched aspects at this time in the American continent, thus the mosquito fauna of the municipality and its distribution is fundamental. If any outbreak or epidemic involving these insects occurs, it would be compulsory to set up control strategies to prevent the spread of vector-borne diseases.

Vivian, Valdés Miró; Mayra, Reyes Arencibia; María del Carmen, Marquetti Fernández; Raúl, González Broche.

2013-04-01

97

Sexual differences in the post-breeding movements and habitats selected by Western toads (Bufo boreas) in southeastern Idaho  

Science.gov (United States)

We used radio-telemetry to study the movements and habitat use of Western toads (Bufo boreas) in the Targhee National Forest in southeastern Idaho. Eighteen toads (10 male and 8 female) that bred in a seasonally flooded pond, were fitted with radio-transmitters, tracked, and their movements mapped and analyzed with global positioning and geographic information systems. We also analyzed their patterns of habitat selection at micro- and macro-scales by comparing sites used by toads with randomly selected sites. After breeding, two male and six female toads left the breeding pond and used terrestrial habitats extensively. Male and female toads showed different patterns of movement and habitat use, although all toads seemed to behave in ways that reduced loss of body water (e.g., such as traveling on nights of high humidity). Male toads traveled shorter distances from the pond than females (581 ?? 98 m and 1105 ?? 272 m, respectively). Female toads used terrestrial habitats extensively and were selective of cover types (e.g., shrub) that provided greater protection from dehydration. Female toads also preferred certain habitat edges and open forests over forests with closed canopies or clearcuts. Information from this study can assist land managers in establishing protective buffers and managing forests for the protection of toad populations.

Bartelt, P.E.; Peterson, C.R.; Klaver, R.W.

2004-01-01

98

Rainforest Birds: A Land Manager's Guide to Breeding Bird Habitat in Young Conifer Forests in the Pacific Northwest  

Science.gov (United States)

Purpose of the Guide This document (hereafter Guide) has been prepared to assist land managers interested in conducting conservation and management activities to benefit breeding birds associated with young conifer forests in the Pacific Northwest. Audiences targeted for use of the Guide include land trusts, watershed councils, non-commercial private land owners, forest products companies, land-managing conservation organizations, government agencies, tribes, and First Nations. We hope the Guide will be a useful and valuable tool to support any of the variety of reasons to manage for bird habitat in young conifer forests (for example, regulatory, biodiversity, bird conservation, and forest certification standards). Information provided in the Guide is intended to support both the development of conservation or management plans and the implementation of on-the-ground management activities that have the potential to benefit breeding bird populations. The degree to which a land manager is willing or able to manage for bird habitat is a decision based on many factors which are beyond the scope of the Guide. We assume users of the Guide already have an interest in managing for bird habitat as one of several objectives that land managers must typically balance. However, it is not our purpose in the Guide to discuss integration of bird habitat management with other management objectives. Our objective is simply to provide those interested in bird conservation with information and recommendations on: * the habitat conditions and features needed by breeding bird species, and * how breeding bird species respond to particular management activities. Much of the information on breeding bird habitat is presented in tabular format in the appendices. Because the latitudinal and elevational coverage of the Guide is extensive, there can be considerable variation in the habitat types and conditions with which bird species are associated. Thus, it is important to recognize that the habitat relationships of a species may vary throughout the Pacific Northwest. Information presented in the appendices that categorizes bird-habitat relationships should not be regarded as absolute, but should be used as a tool to help prioritize conservation efforts toward species that have a significant degree of association with habitat parameters, such as forest type or successional stage. An underlying premise of the Guide is that forest management has a direct and significant influence on bird populations. Consequently, manipulation of forest conditions as part of forest management can be designed and implemented to achieve bird conservation objectives (Busing and Garman, 2002; Lehmkuhl and others, 2002). It is not our intent to describe all the potential forest management activities that could be conducted to achieve the desired habitat conditions for birds. Those need to be determined locally by assessing the most ecologically appropriate management at each site. However, to assist land managers, the Guide offers some basic forest management activities that are widely accepted for achieving habitat conditions and features which benefit breeding birds.

Altman, Bob; Hagar, Joan

2007-01-01

99

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract 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 mosquito larvae, and indirectly affect the dynamics of mosquito-borne diseases. The aim of this study was to assess the feasibility of implementing an integrated approach to larval source management under the distinct ecological settings. Methods The study was conducted in two highland villages and one village, at a lower altitude, in the Lake Victoria basin, where malaria is endemic and transmitted by the same Anopheles mosquito species. In each village the stability of mosquito larval habitats was classified as either temporary or permanent. The productivity of these habitat types was quantified by carrying out weekly larval sampling using a standard dipping method for a period of two years. During sampling the physical characteristic of the larval habitat, including the vegetation cover were noted. Ambient temperature, rainfall and relative humidity were recorded on a 21 × Micro-datalogger in each study site. Results Anopheles gambiae sensu lato larvae were found in all study sites. Anopheles arabiensis was more abundant (93% in Nyalenda (Lake Victoria basin and Fort Ternan (highland area; 71%. In Lunyerere (highland area, An. gambiae sensu stricto comprised 93% of the total An. gambiae s.l. larvae. Larvae of An. gambiae s.l. mosquitoes were present in both temporary and permanent habitats with monthly variations dependent on rainfall intensity and location. Anopheles larvae were more likely to be found in man-made as opposed to natural habitats. Grassy habitats were preferred and were, therefore, more productive of Anopheles larvae compared to other habitat types. Weekly rainfall intensity led to an increase or decrease in mosquito larval abundance depending on the location. Conclusion The majority of mosquito breeding habitats were man made in all sites. Both temporary and permanent habitats were suitable for An. gambiae breeding. In Fort Ternan temporary sites were favoured for mosquito breeding above permanent sites. Significant differences in larval abundance were found depending on weekly rainfall intensity. Larval source management programmes should target permanent and temporary habitats equally and work closely with land and home owners as a majority of the breeding habitats are man made.

Mukabana Wolfgang R

2011-04-01

100

Underwater topography determines critical breeding habitat for humpback whales near Osa Peninsula, Costa Rica: implications for Marine Protected Areas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migrating humpback whales from northern and southern feeding grounds come to the tropical waters near Osa Peninsula, Pacific of Costa Rica, to reproduce and raise their calves. Planning effective marine protected areas that encompass humpback critical habitats require data about which oceanographic features influence distribution during the breeding period. This study examines the relationship between water depth and ocean floor slope with humpback whale distribution, based on sightings durin...

Oviedo, L.; Soli?s, M.

2008-01-01

 
 
 
 
101

Larval Habitat Diversity and Species Composition of Mosquitoes (Diptera: Culicidae in Hamadan Province  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction & Objective: The aim of the study was to identify larval habitats and new species and determine the exact distribution of Culicidae in Hamadan Province.Materials & Methods: This descriptive,cross -sectional study was conducted in six regions of Hamadan Province during 2010. Sampling method was carried out by standard Dipping method. Specimens were mounted by lactophenol solution and were sent to Medical Entomology Laboratory, Tehran University of Medical Sciences with related codes. The accurate diagnosis of Culex pipiens was made with male genitalia morphology. The data were analyzed using standard statistical software (SPSS version 11.5. Results: In total, 4751 larvae of the three genera including Anopheles, Culex, Culiseta ,and nine species including An.superpictus, An.maculipennis sl and An.claviger, Cx.pipiens,Cx.theileri, Cx.hortensis and Cx.prexiguuus ,Cu.longiareolata ,and Cu.subochrea in 36 larval habitat sites in the province were collected and identified. Among Culicidae larvae collected, Culex. Pipiens and Culiseta.subochrea with 58%, and 0.4% of samples were the most and the least species collected. Conclusion: Culex pipiens was reported as the dominant species . Based on morphology of male genitalia, only Culex pipiens was identified among the complex species .The species of Anopheles claviger and Culex prexiguus were found for the first time in this area. The molecular analysis and the egg ridge counts of anopheles maculipennis sl must be extensively studied in the future. (Sci J Hamadan Univ Med Sci 2011;18(3:50-58

H. Dehghan

2011-10-01

102

Mosquito control by plankton management: the potential of indigestible green algae.  

Science.gov (United States)

Most kinds of phytoplankton are good food for mosquito larvae. However, Culex, Aedes and Anopheles larvae fail to develop successfully in water where certain species of closely related green algae in the order Chlorococcales are the main source of food; apparently because the larvae are unable to digest them. Many species of Scenedesmus, Kirchneriella, Dactylococcus, Elakotothrix, Tetrallantos, Coelastrum, Selenastrum and Tetradesmus have this effect. These algae may offer a practical possibility for mosquito control when introduced into mosquito breeding habitats. Introduction of these algae could be assisted by simultaneous introduction of select filter-feeding zooplankton such as Daphnia. PMID:2879045

Marten, G G

1986-10-01

103

Evaluation of 1-octen-3-ol, carbon dioxide, and light as attractants for mosquitoes associated with two distinct habitats in North Carolina.  

Science.gov (United States)

Field studies were conducted in North Carolina to determine the responses of mosquitoes found in salt marsh and inland creek flood plain areas to 1-octen-3-ol (octenol), carbon dioxide (CO2), and light in various combinations with Centers for Disease Control (CDC) light traps. Over 56,000 adult mosquito specimens of 12 species in 4 genera were collected in the salt marsh. They exhibited a general response pattern of octenol + CO2 + light > CO2 + light = octenol + CO2 > octenol + light > octenol alone. Significantly, more Aedes sollicitans, Ae. taeniorhynchus, Anopheles bradleyi, and Culex salinarius were attracted to octenol + CO2 + light than to CO2 + light. Over 19,000 specimens of 24 species in 7 genera were collected in the inland creek flood plain. Although the response patterns to the attractants were similar to those in the salt marsh area, there was no significant difference between octenol + CO2 + light and CO2 + light. Aedes vexans, An. crucians, and An. punctipennis were attracted nearly equally to these two attractant combinations. These studies demonstrate that responses to combinations of these attractants are species specific. However, different combinations of attractants can significantly increase the collection of targeted species important in arbovirus transmission. The use of these combinations would be very beneficial in mosquito-borne virus surveillance studies. The use of octenol by itself or in conjunction with light was found the least useful for collecting mosquitoes in both habitats. PMID:11345421

Rueda, L M; Harrison, B A; Brown, J S; Whitt, P B; Harrison, R L; Gardner, R C

2001-03-01

104

A Study of the Effects of Gas Well Compressor Noise on Breeding Bird Populations of the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico  

Energy Technology Data Exchange (ETDEWEB)

This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.

LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.

2001-06-04

105

Aquatic insects of New York salt marsh associated with mosquito larval habitat and their potential utility as bioindicators.  

Science.gov (United States)

The aquatic insect fauna of salt marshes is poorly characterized, with the possible exception of biting Diptera. Aquatic insects play a vital role in salt marsh ecology, and have great potential importance as biological indicators for assessing marsh health. In addition, they may be impacted by measures to control mosquitoes such as changes to the marsh habitat, altered hydrology, or the application of pesticides. Given these concerns, the goals of this study were to conduct the first taxonomic survey of salt marsh aquatic insects on Long Island, New York, USA and to evaluate their utility for non-target pesticide impacts and environmental biomonitoring. A total of 18 species from 11 families and five orders were collected repeatedly during the five month study period. Diptera was the most diverse order with nine species from four families, followed by Coleoptera with four species from two families, Heteroptera with three species from three families, then Odonata and the hexapod Collembola with one species each. Water boatmen, Trichocorixa verticalis Fieber (Heteroptera: Corixidae) and a shore fly, Ephydra subopaca Loew (Diptera: Ephydridae), were the two most commonly encountered species. An additional six species; Anurida maritima Guérin-Méneville (Collembola: Neanuridae), Mesovelia mulsanti White (Heteroptera: Mesovelidae), Enochrus hamiltoni Horn (Coleoptera: Hydrophilidae), Tropisternus quadristriatus Horn (Coleoptera: Hydrophilidae), Dasyhelea pseudocincta Waugh and Wirth (Diptera: Ceratopogonidae), and Brachydeutera argentata Walker (Diptera: Ephydridae), were found regularly. Together with the less common Erythrodiplax berenice Drury (Odonata: Libellulidae), these nine species were identified as the most suitable candidates for pesticide and environmental impact monitoring due to abundance, position in the food chain, and extended seasonal occurrence. This study represents a first step towards developing an insect-based index of biological integrity for salt marsh health assessment. PMID:22957707

Rochlin, Ilia; Dempsey, Mary E; Iwanejko, Tom; Ninivaggi, Dominick V

2011-01-01

106

Mosquito Species Associated Within Some Western Himalayas Phytogeographic Zones in the Garhwal Region of India  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thirty four species of mosquitoes (Diptera: Culicidae) were collected across three phytogeographic zones; tropical (300 to 1000 m), sub tropical (1000 to 2000 m) and temperate (2000 to 3000 m) in the Garhwal region of India. They included 5 genera: Aedes, Anopheles, Armigeres, Culex and Uranotaenia. Of these, the immature forms of 23 species were recovered from different breeding habitats. The larval habitats were seepage pools, river beds, rice fields, tanks, forest pools, ditches, streams, ...

Pemola Devi, N.; Jauhari, R. K.

2007-01-01

107

Species Composition and Relative Abundance of Mosquitoes in Swat, Pakistan  

Directory of Open Access Journals (Sweden)

Full Text Available A comprehensive survey of mosquitoes (Diptera: Culicidae was conducted in Swat Pakistan, from April to September during 2000. The survey involved the sampling of both, adult and immature stages of mosquitoes, and recovered a total of 21 species in five genera. Sampling of adult mosquitoes involved Pyrethrum spray collections, Man-biting collections, and Animal-biting collection. Immature stages of mosquitoes were collected from variety of habitats including springs, irrigation channels, rice fields, marshes, temporary pools, construction pools, agriculture pools, river margins, ditches, waste water drains, wells and tree holes. During the study most of the species built up their populations in June, July and August, while a few increased their populations in September. During the survey of immature stages, from a total of 138 samples taken, Cx. quinquefasciatus showed maximum frequency of occurrence (recovered from 48 samples followed by An. maculatus (17 samples, Cx. pseudovishnui (14 samples, An. annularis and An. stephensi (13 samples each, Cx. bitaeniorhynchus (11 samples, An. splendidus (5 samples and Cx. theileri (4 samples. The rest of the species occurred infrequently. The observations on habitat specificity of different species of mosquitoes showed the rice fields as the most favorable site for mosquito breeding (harboring 12 species followed by river margins (five species and temporary pools and springs (four species each. During this study Ae. aegypti was recovered from tyres in Mingora; it was not reported earlier from Swat.

Ikram Ilahi

2013-04-01

108

Effects of stop-level habitat change on cerulean warbler detections along breeding bird survey routes in the central appalachians  

Science.gov (United States)

We examined the effects of habitat change on Cerulean Warbler (Dendroica cerulea) populations at stops along Breeding Bird Survey (BBS) routes in the central Appalachians. We used aerial photographs to compare early (1967/1971), middle (1982/1985), and late (2000/2003) periods and compared 1992 and 2001 National Land Cover Data (NLCD). Mean Cerulean Warbler detections per stop decreased at 68 BBS stops between the early (0.05) and middle (0.01) time periods and their distribution became more restricted (15 vs. 3% of stops), but the amount of deciduous/mixed forest increased. Mean detections at 240 stops decreased from the middle (0.09) to the late (0.06) time periods, but the deciduous/mixed forest land cover and fragmentation metrics did not change. The amounts of deciduous/mixed forest, core forest area, and edge density in the NLCD analysis decreased from 1992 to 2001, whereas the amount of non-forest land cover increased. The number of Cerulean Warbler detections did not change (1992 ?=? 0.08, 2001 ?=? 0.10; P ?=? 0.11). The lack of concordance between Cerulean Warbler detections and broad habitat features suggests that smaller, microhabitat features may be most important in affecting Cerulean Warbler breeding habitat suitability. ?? 2011 by the Wilson Ornithological Society.

McElhone, P.M.; Wood, P.B.; Dawson, D.K.

2011-01-01

109

Breeding Behaviour of Eurasian Marsh Harriers (Circus aeruginosus L., 1758; Aves, Accipitridae Nesting on Three Habitats in Eastern Poland  

Directory of Open Access Journals (Sweden)

Full Text Available Breeding behaviour of Eurasian marsh harriers Circus aeruginosus pairs nesting in marshes, water reservoir and fish pond of SE Poland were compared. Harriers nesting on the marshes were most efficient during aerial prey transfers, which could suggest that the habitat was taken by experienced, better quality birds when set against the ones occupying nests on the ponds and reservoir. Additional evidence that higher quality birds nested on marshes is that egg laying was earlier there. Marsh Harriers performed U-shape undulation, in the nestling period and these appeared more intense for marsh nesters as well.

Ignacy Kitowski

2006-01-01

110

Mosquito control in Dar es Salaam. II. Impact of expanded polystyrene beads and pyriproxyfen treatment of breeding sites on Culex quinquefasciatus densities.  

Science.gov (United States)

In two contrasting areas of Dar es Salaam (Ilala and Mikocheni) all enclosed breeding sites of Culex quinquefasciatus, such as latrines and septic tanks, were treated with a floating layer of expanded polystyrene beads. 7 months later checks in both study areas revealed only one site (from which the polystyrene had been removed during emptying) containing immature stages of Cx quinquefasciatus. Open breeding sites such as areas of flooded land and blocked drains were treated with pyriproxyfen (an insect growth regulator) at a concentration of 0.1 ppm. Emergence of Cx quinquefasciatus adults from these sites was inhibited for 4 weeks during the rainy season and for up to 11 weeks during the dry season. The problem of mosquito breeding sites caused by bathroom sullage water was addressed through a combination of health education and indirect pressure from the Urban Malaria Control Project (UMCP) via local community leaders. Households responsible for these sites were encouraged to eliminate them by diverting the water into an enclosed drainage structure, usually a pit latrine. After two weekly visits 64.7% of households had complied and 93.4% had complied after five visits. 5 months later, only 15.7% had reverted to allowing sullage water to collect into puddles. Densities of Cx quinquefasciatus adults dropped by 76.7% in Mikocheni and by 46.2% in Ilala following intervention, but increased by 84.9% and 25.6% in two untreated comparison areas. The reasons for differential success of the combined interventions in the two treated areas are discussed. PMID:7787222

Chavasse, D C; Lines, J D; Ichimori, K; Majala, A R; Minjas, J N; Marijani, J

1995-04-01

111

Underwater topography determines critical breeding habitat for humpback whales near Osa Peninsula, Costa Rica: implications for Marine Protected Areas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Las ballenas jorobadas viajan a aguas tropicales para reproducirse y criar a sus ballenatos. Es importante entender las características oceanográficas que influencian su distribución para lograr una planificación efectiva de áreas marinas protegidas con hábitats críticos para estos cetáceos. Este es [...] tudio examina la relación entre la profundidad, la pendiente del suelo oceánico y la distribución de estas ballenas, usando avistamientos del 2005 y 2006 en la costa Pacífica de la Península de Osa, Costa Rica (temporada de reproducción del sur y norte en el Pacífico Tropical Oriental). Usamos Análisis de Factores de Nicho Ecológico (ENFA por sus siglas en inglés), donde los índices de Marginalidad y Tolerancia ilustran las restricciones en uso de hábitat. En una escala local, factores físicos como la profundidad y la pendiente definen el hábitat crítico de reproducción y cría de M. novaeangliae. Las divergencias entre las medias de las sub-muestras y la media global del área de estudio en ambas variables eco-geográficas, determinan las limitaciones en requerimientos de hábitat en aspectos topográficos como la profundidad (>100 m) y la pendiente del fondo (>10%), localizando los hábitat críticos para reproducción y cría dentro de la plataforma continental. Los planes y propuestas para un sistema de áreas marinas protegidas deben de considerar la conectividad de la isla del Caño y la Bahía de Drake, así como la extensión de los límites marinos del Parque Nacional Corcovado. Abstract in english Migrating humpback whales from northern and southern feeding grounds come to the tropical waters near Osa Peninsula, Pacific of Costa Rica, to reproduce and raise their calves. Planning effective marine protected areas that encompass humpback critical habitats require data about which oceanographic [...] features influence distribution during the breeding period. This study examines the relationship between water depth and ocean floor slope with humpback whale distribution, based on sightings during two breeding seasons (2005 and 2006). Data are from the Southern and Northern subpopulations in the Eastern Tropical Pacific (ETP). Analysis followed the basic principles of the Ecological Niche Factors Analysis (ENFA), where indices of Marginality and Tolerance provide insights on the restrictiveness of habitat use. At a fine scale, physical factors such as water depth and slope define the critical breeding and nursing habitat for M. novaeangliae. Divergence in the subsamples means of depths and slope distribution, with the global mean of the study area in both eco-geographical variables, determine habitat requirements restricted by topographic features such as depths (

L, Oviedo; M, Solís.

112

Underwater topography determines critical breeding habitat for humpback whales near Osa Peninsula, Costa Rica: implications for Marine Protected Areas  

Directory of Open Access Journals (Sweden)

Full Text Available Migrating humpback whales from northern and southern feeding grounds come to the tropical waters near Osa Peninsula, Pacific of Costa Rica, to reproduce and raise their calves. Planning effective marine protected areas that encompass humpback critical habitats require data about which oceanographic features influence distribution during the breeding period. This study examines the relationship between water depth and ocean floor slope with humpback whale distribution, based on sightings during two breeding seasons (2005 and 2006. Data are from the Southern and Northern subpopulations in the Eastern Tropical Pacific (ETP. Analysis followed the basic principles of the Ecological Niche Factors Analysis (ENFA, where indices of Marginality and Tolerance provide insights on the restrictiveness of habitat use. At a fine scale, physical factors such as water depth and slope define the critical breeding and nursing habitat for M. novaeangliae. Divergence in the subsamples means of depths and slope distribution, with the global mean of the study area in both eco-geographical variables, determine habitat requirements restricted by topographic features such as depths (Las ballenas jorobadas viajan a aguas tropicales para reproducirse y criar a sus ballenatos. Es importante entender las características oceanográficas que influencian su distribución para lograr una planificación efectiva de áreas marinas protegidas con hábitats críticos para estos cetáceos. Este estudio examina la relación entre la profundidad, la pendiente del suelo oceánico y la distribución de estas ballenas, usando avistamientos del 2005 y 2006 en la costa Pacífica de la Península de Osa, Costa Rica (temporada de reproducción del sur y norte en el Pacífico Tropical Oriental. Usamos Análisis de Factores de Nicho Ecológico (ENFA por sus siglas en inglés, donde los índices de Marginalidad y Tolerancia ilustran las restricciones en uso de hábitat. En una escala local, factores físicos como la profundidad y la pendiente definen el hábitat crítico de reproducción y cría de M. novaeangliae. Las divergencias entre las medias de las sub-muestras y la media global del área de estudio en ambas variables eco-geográficas, determinan las limitaciones en requerimientos de hábitat en aspectos topográficos como la profundidad (>100 m y la pendiente del fondo (>10%, localizando los hábitat críticos para reproducción y cría dentro de la plataforma continental. Los planes y propuestas para un sistema de áreas marinas protegidas deben de considerar la conectividad de la isla del Caño y la Bahía de Drake, así como la extensión de los límites marinos del Parque Nacional Corcovado.

L Oviedo

2008-06-01

113

Underwater topography determines critical breeding habitat for humpback whales near Osa Peninsula, Costa Rica: implications for Marine Protected Areas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Las ballenas jorobadas viajan a aguas tropicales para reproducirse y criar a sus ballenatos. Es importante entender las características oceanográficas que influencian su distribución para lograr una planificación efectiva de áreas marinas protegidas con hábitats críticos para estos cetáceos. Este es [...] tudio examina la relación entre la profundidad, la pendiente del suelo oceánico y la distribución de estas ballenas, usando avistamientos del 2005 y 2006 en la costa Pacífica de la Península de Osa, Costa Rica (temporada de reproducción del sur y norte en el Pacífico Tropical Oriental). Usamos Análisis de Factores de Nicho Ecológico (ENFA por sus siglas en inglés), donde los índices de Marginalidad y Tolerancia ilustran las restricciones en uso de hábitat. En una escala local, factores físicos como la profundidad y la pendiente definen el hábitat crítico de reproducción y cría de M. novaeangliae. Las divergencias entre las medias de las sub-muestras y la media global del área de estudio en ambas variables eco-geográficas, determinan las limitaciones en requerimientos de hábitat en aspectos topográficos como la profundidad (>100 m) y la pendiente del fondo (>10%), localizando los hábitat críticos para reproducción y cría dentro de la plataforma continental. Los planes y propuestas para un sistema de áreas marinas protegidas deben de considerar la conectividad de la isla del Caño y la Bahía de Drake, así como la extensión de los límites marinos del Parque Nacional Corcovado. Abstract in english Migrating humpback whales from northern and southern feeding grounds come to the tropical waters near Osa Peninsula, Pacific of Costa Rica, to reproduce and raise their calves. Planning effective marine protected areas that encompass humpback critical habitats require data about which oceanographic [...] features influence distribution during the breeding period. This study examines the relationship between water depth and ocean floor slope with humpback whale distribution, based on sightings during two breeding seasons (2005 and 2006). Data are from the Southern and Northern subpopulations in the Eastern Tropical Pacific (ETP). Analysis followed the basic principles of the Ecological Niche Factors Analysis (ENFA), where indices of Marginality and Tolerance provide insights on the restrictiveness of habitat use. At a fine scale, physical factors such as water depth and slope define the critical breeding and nursing habitat for M. novaeangliae. Divergence in the subsamples means of depths and slope distribution, with the global mean of the study area in both eco-geographical variables, determine habitat requirements restricted by topographic features such as depths (

L, Oviedo; M, Solís.

2008-06-01

114

Mosquito Control  

Science.gov (United States)

... Environmental Protection Agency Search Search Contact Us Mosquito Control About Mosquitoes General Information Life Cycle Information on ... is Right for You DEET Pesticides for Mosquito Control Larvicides Adulticides Misting Systems Getting Help with Mosquito ...

115

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  

Science.gov (United States)

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 important for An. pharoensis and An. gambiae s.l. which are important vectors of malaria in the area.

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

2010-12-01

116

The spatial distribution and size of rook (Corvus frugilegus) breeding colonies is affected by both the distribution of foraging habitat and by intercolony competition.  

Science.gov (United States)

Explanations for the variation in the number of nests at bird colonies have focused on competitive or habitat effects without considering potential interactions between the two. For the rook, a colonial corvid which breeds seasonally but forages around the colony throughout the year, both the amount of foraging habitat and its interaction with the number of competitors from surrounding colonies are important predictors of colony size. The distance over which these effects are strongest indicates that, for rooks, colony size may be limited outside of the breeding season when colony foraging ranges are larger and overlap to a greater extent. PMID:10983832

Griffin, L R; Thomas, C J

2000-07-22

117

The spatial distribution and size of rook (Corvus frugilegus) breeding colonies is affected by both the distribution of foraging habitat and by intercolony competition.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Explanations for the variation in the number of nests at bird colonies have focused on competitive or habitat effects without considering potential interactions between the two. For the rook, a colonial corvid which breeds seasonally but forages around the colony throughout the year, both the amount of foraging habitat and its interaction with the number of competitors from surrounding colonies are important predictors of colony size. The distance over which these effects are strongest indica...

Griffin, L. R.; Thomas, C. J.

2000-01-01

118

Between a Rock and a Hard Place: Habitat Selection in Female-Calf Humpback Whale (Megaptera novaeangliae) Pairs on the Hawaiian Breeding Grounds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Au'au Channel between the islands of Maui and Lanai, Hawaii comprises critical breeding habitat for humpback whales (Megaptera novaeangliae) of the Central North Pacific stock. However, like many regions where marine mega-fauna gather, these waters are also the focus of a flourishing local eco-tourism and whale watching industry. Our aim was to establish current trends in habitat preference in female-calf humpback whale pairs within this region, focusing specifically on the busy, eastern ...

Cartwright, Rachel; Gillespie, Blake; Labonte, Kristen; Mangold, Terence; Venema, Amy; Eden, Kevin; Sullivan, Matthew

2012-01-01

119

Invasive Parasites, Habitat Change and Heavy Rainfall Reduce Breeding Success in Darwin's Finches  

Science.gov (United States)

Invasive alien parasites and pathogens are a growing threat to biodiversity worldwide, which can contribute to the extinction of endemic species. On the Galápagos Islands, the invasive parasitic fly Philornis downsi poses a major threat to the endemic avifauna. Here, we investigated the influence of this parasite on the breeding success of two Darwin's finch species, the warbler finch (Certhidea olivacea) and the sympatric small tree finch (Camarhynchus parvulus), on Santa Cruz Island in 2010 and 2012. While the population of the small tree finch appeared to be stable, the warbler finch has experienced a dramatic decline in population size on Santa Cruz Island since 1997. We aimed to identify whether warbler finches are particularly vulnerable during different stages of the breeding cycle. Contrary to our prediction, breeding success was lower in the small tree finch than in the warbler finch. In both species P. downsi had a strong negative impact on breeding success and our data suggest that heavy rain events also lowered the fledging success. On the one hand parents might be less efficient in compensating their chicks' energy loss due to parasitism as they might be less efficient in foraging on days of heavy rain. On the other hand, intense rainfalls might lead to increased humidity and more rapid cooling of the nests. In the case of the warbler finch we found that the control of invasive plant species with herbicides had a significant additive negative impact on the breeding success. It is very likely that the availability of insects (i.e. food abundance)is lower in such controlled areas, as herbicide usage led to the removal of the entire understory. Predation seems to be a minor factor in brood loss. PMID:25248092

Cimadom, Arno; Ulloa, Angel; Meidl, Patrick; Zottl, Markus; Zottl, Elisabet; Fessl, Birgit; Nemeth, Erwin; Dvorak, Michael; Cunninghame, Francesca; Tebbich, Sabine

2014-01-01

120

[Foraging habitat selection of Otis tarda dybowskil during its breeding season].  

Science.gov (United States)

From April to July of 2000 and 2001, the authors studied the foraging habitat selection of Otis tarda dybowskil in the southeast Keerqin of Inner Mongolia by sampling method. The results showed that whether at burned or at non-burned grassland, the foraging habitat of Otis tarda dybowski had the same feature in vegetation structure, the plant height was about 13 cm on average, with the highest of 30 cm, and there were abundant species of plants and insects with big density that the bird favored to eat. The bird more concerned with the abundance of plants at burned grassland, while that of insects at non-burned grassland. PMID:15943365

Zhao, Jiang; Wan, Dongmei; Wang, Haitao; Gao, Wei

2005-03-01

 
 
 
 
121

Linking deforestation to malaria in the Amazon: characterization of the breeding habitat of the principal malaria vector, Anopheles darlingi.  

Science.gov (United States)

This study examined the larval breeding habitat of a major South American malaria vector, Anopheles darlingi, in areas with varying degrees of ecologic alteration in the Peruvian Amazon. Water bodies were repeatedly sampled across 112 km of transects along the Iquitos-Nauta road in ecologically varied areas. Field data and satellite imagery were used to determine the landscape composition surrounding each site. Seventeen species of Anopheles larvae were collected. Anopheles darlingi larvae were present in 87 of 844 sites (10.3%). Sites with A. darlingi larvae had an average of 24.1% forest cover, compared with 41.0% for sites without A. darlingi (P < 0.0001). Multivariate analysis identified seasonality, algae, water body size, presence of human populations, and the amount of forest and secondary growth as significant determinants of A. darlingi presence. We conclude that deforestation and associated ecologic alterations are conducive to A. darlingi larval presence, and thereby increase malaria risk. PMID:19556558

Vittor, Amy Y; Pan, William; Gilman, Robert H; Tielsch, James; Glass, Gregory; Shields, Tim; Sánchez-Lozano, Wagner; Pinedo, Viviana V; Salas-Cobos, Erit; Flores, Silvia; Patz, Jonathan A

2009-07-01

122

Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae, a predator of container breeding mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Food utilization by the larvae of Toxorhynchites splendens (Wiedemann was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston, and Culex quinquefasciatus (Say. Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id and food availability were higher when offered early instars of prey (first and second instars than late instars. Consumption rate (Cr of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

D Dominic Amalraj

2005-12-01

123

Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892) (Copepoda: Cyclopidea) as a predator of container-breeding mosquitoes in Argentina  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period [...] . When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.

María V, Micieli; Gerardo, Marti; Juan J, García.

2002-09-01

124

Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892 (Copepoda: Cyclopidea as a predator of container-breeding mosquitoes in Argentina  

Directory of Open Access Journals (Sweden)

Full Text Available In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.

María V Micieli

2002-09-01

125

Cliffs of the National Park of Porto Conte, Sardinia (Italy, habitat and breeding site to the last European Rock dove populations  

Directory of Open Access Journals (Sweden)

Full Text Available Cliffs of the National Park of Porto Conte, Sardinia (Italy, habitat and breeding site to the last European Rock dove populations. See Skandrani's article in this issue for more information about the Rock dove. Picture by Zina Skandrani.

Editorial Staff Frontiers of Biogeography

2014-09-01

126

Population interactions between Culex vishnui mosquitoes and their natural enemies in Pondicherry, India.  

Science.gov (United States)

Population interactions among mosquitoes in the Culex vishnui subgroup, which are vectors of Japanese Encephalitis, and their natural enemies were studied in Pondicherry, India. We tested the hypothesis that the breakdown of interactions between the larvae and their natural enemies due to drought followed by rain was responsible for the sudden increase in the vector population above the threshold for disease transmission during the heavy rainy period. We randomly sampled mosquito larvae and their predators in different breeding habitats and subjected the mean densities of prey, predator, and mosquito larvae infected with parasites/pathogens to covariate analysis to understand the interaction between prey and their natural enemies in relation to environmental factors. In rice fields, neither prey nor predator showed any positive correlation with temperature, RH, or the number of rainy days. However, the pathogen/parasite of mosquito immatures showed a positive correlation with RH. Among the mosquito predators, notonectids exhibited a significant positive correlation with Cx. vishnui larvae. The parasitic Romanomermis iyengari and pathogenic Coelomomyces anopheliscus also showed positive correlations with immatures. No parasites and pathogens of mosquito larvae were recorded in shallow water pools (SWP) or cement tanks (CT) during the study period. Important predators recorded in SWP were notonectids, damselfly nymphs, Diplonychus indicus, and hydrophilids. Dragonfly nymphs, gerrids, and tadpole shrimps were recorded in CT. In CT, prey and their predators were positively correlated with RH and rainy days. In SWP, there was a highly significant correlation between prey, predators and environmental factors. We conclude that rice fields are a stable ecosystem where regular interaction occurs between larvae and their natural enemies and a sudden increase in mosquito populations is uncommon. In transient habitats, no such stability is present and they become more important as breeding habitats in terms of seasonality and number. Shallow water pools should be seriously considered for the control of these vectors. PMID:16859094

Das, P K; Sivagnaname, N; Amalraj, D Dominic

2006-06-01

127

Breeding habitat selection of an endangered species in an arid zone: the case of Alytes dickhilleni Arntzen & García-París, 1995  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of environmental variables on the selection of a particular water body as breeding habitat by Alytes dickhilleni was studied in the southeastern and most arid zone of its distribution range. From November 2002 to October 2003, 50 water bodies were monitored in the south east of the Iberian Peninsula. Environmental data were submitted to a stepwise logistic regression analysis at macrohabitat, water body typology and microhabitat scales in order to establish the main factors influencing the use of a given water body as breeding habitat by this species. Statistical analysis showed that the reproduction of Alytes dickhilleni is associated with the macrohabitat variable topography, and the water body typology. This species breeds mainly in permanent water bodies located in mountainous topography in the study area. These results should be taken into account when populations of this species are subjected to management and/or recovery programmes in arid areas.

Miguel Tejedo

2006-11-01

128

Aedes mosquito larvae collected from Ishigaki-jima and Taketomi-jima Islands in southern Japan.  

Science.gov (United States)

An investigation of habitat preference for larval breeding sites by Aedes (Diptera: Culicidae) mosquitoes which occur around human dwellings in Ishigaki-jima and Taketomi-jima Islands revealed that Ae. albopictus Skuse 1894 preferred pools in tires and boats and was distributed widely from the coast, inland. Although Ae. riversi Bohart & Ingram, 1946 and Ae. flavopictus miyarai (Tanaka et al, 1979) shared tree holes as larval breeding sites, Ae. riversi was collected near the ocean whereas Ae. flavopictus miyarai was collected inland. Ae. togoi Theobald, 1907 was collected near the coast and strongly preferred boats. Our study showed that habitat preference was different between four species of Aedes mosquito in Ishigaki-jima and Taketomi-jima Islands. PMID:23413700

Tsunoda, Takashi; Fukuchi, Atsuko; Nanbara, Sho; Higa, Yukiko; Takagi, Masahiro

2012-11-01

129

Habitat stability and occurrences of malaria vector larvae in western Kenya highlands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Although the occurrence of malaria vector larvae in the valleys of western Kenya highlands is well documented, knowledge of larval habitats in the uphill sites is lacking. Given that most inhabitants of the highlands actually dwell in the uphill regions, it is important to develop understanding of mosquito breeding habitat stability in these sites in order to determine their potential for larval control. Methods A total of 128 potential larva...

Atieli Harrysone; Munga Stephen; Afrane Yaw; Yakob Laith; Zhou Guofa; Himeidan Yousif E; El-Rayah El-Amin; Githeko Andrew K; Yan Guiyun

2009-01-01

130

Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro - Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importanc [...] e as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex) pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07%) and five of Ae. albopictus(0.18%) were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats.

Márcio Goulart, Mocellin; Taynãna César, Simões; Teresa Fernandes Silva do, Nascimento; Maria Lucia França, Teixeira; Leon Philip, Lounibos; Ricardo Lourenço de, Oliveira.

1171-11-01

131

Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro - Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?  

Directory of Open Access Journals (Sweden)

Full Text Available Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07% and five of Ae. albopictus(0.18% were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats.

Márcio Goulart Mocellin

2009-12-01

132

Changes in local mosquito fauna following beaver (Castor canadensis) activity--an update.  

Science.gov (United States)

Drastic reduction of populations of univoltine temporary pool mosquitoes followed impoundment of breeding areas by beavers. Mosquito populations persist at very low levels over a 10-year period with no evidence of mosquito development in the impoundment. PMID:1357092

Butts, W L

1992-09-01

133

Effects of grazing and burning on densities and habitats of breeding ducks in North Dakota  

Science.gov (United States)

Native grassland communities controlled by public agencies become increasingly important to the maintenance of many wildlife species as privately owned grasslands are destroyed or degraded for farming, mining, and development. In turn, wildlife on publicly owned grasslands are affected by the management techniques practiced by local managers. We studied the effects of grazing and prescribed burning on upland-nesting ducks and the structure and type of vegetation from 1980 to 1988 at the Lostwood National Wildlife Refuge (NWR) in northwestern North Dakota. Mallard (Anas platyrhynchos), the most abundant species at Lostwood NWR, had lower (P < 0.05) annual nest densities on experimental and control fields in the later years than in the early years of the study. Spring burning reduced (P = 0.016) nest densities of gadwall (A. strepera). Spring grazing reduced nest densities of gadwall (P = 0.014), and blue-winged teal (A. discors, P = 0.023). Nest density of gadwall increased (P = 0.018) after spring grazing was terminated. On the summer burn/spring graze fields, blue-winged teal had lower (P = 0.010) nest densities after treatments (1987-88) than before treatments (1980-81). Nest success was high (mallard 34%, gadwall 45%, blue-winged teal 31%) but was not influenced (P 0.16) by the burning and grazing treatments. During the study, the amount of grass/brush increased, whereas the amount of brush and brush/grass decreased on control and treatment fields. During the years with burning and grazing, short vegetation increased and tall vegetation decreased. On the spring graze fields, 1 year after grazing ended the vegetation was similar to that on the control fields. The spring burn and summer burn/spring graze fields recovered more slowly. Brushy species such as western snowberry (Symphoricarpos occidentalis) provided attractive nesting habitat for many upland-nesting waterfowl species, especially mallard, gadwall, American wigeon (A. americana), and northern pintail (A. acuta). Habitat needs of additional species of wildlife that depend on grasslands may need to be considered when deciding how to manage habitat.

Kruse, A. D.; Bowen, B. S.

1996-01-01

134

Breeding ecology and nesting habitat associations of five marsh bird species in western New York  

Science.gov (United States)

Nesting habitats and nest success of five species of marsh birds were studied during 1997 and 1998 at the Iroquois National Wildlife Refuge (NWR) and the adjacent Oak Orchard and Tonawanda State Wildlife Management Areas (WMA) located in western New York. Nest searches located 18 American Bittern (Botaurus lentiginosus), 117 Least Bittern (Ixobrychus exilis), 189 Pied-billed Grebe (Podilymbus podiceps), 23 Sora (Porzana carolina), and 72 Virginia Rail (Rallus limicola) nests. Average nest densities in 1998, our best nest searching year, ranged from 0.01/ha for Soras (N = 8) to 0.28/ha for Pied-billed Grebes (N = 160). Mayfield nest success estimates for Least Bittern were 80% (N = 16) in 1997 and 46% (N = 37) in 1998. Nest success estimates were 72% (N = 55) for Pied-billed Grebe, 43% (N = 6) for Sora, and 38% (N = 20) for Virginia Rail. Nests of all five species were located in ???70% emergent vegetation with a mean water depth of 24-56 cm and an average vegetation height that ranged from 69-133 cm. Logistic regression models were developed for each species using habitat variables at nest and random site locations. Each model was ranked with Akaike's Information Criterion for small sample size (AICc). In general, our best models indicated that increased emergent vegetation and horizontal cover with shallow water depths improved the odds of encountering marsh bird nests in the wetlands of western New York. We suggest that managing wetlands as a complex, at different stages of succession, would best benefit marsh bird species.

Lor, S.; Malecki, R. A.

2006-01-01

135

Effect of food on immature development, consumption rate, and relative growth rate of Toxorhynchites splendens (Diptera: Culicidae), a predator of container breeding mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Food utilization by the larvae of Toxorhynchites splendens (Wiedemann) was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston), and Culex quinquefasciatus (Say). Quantitative analyses of data indicated that immature development was significantly faste [...] r with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id) and food availability were higher when offered early instars of prey (first and second instars) than late instars. Consumption rate (Cr) of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR) of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.

D, Dominic Amalraj; N, Sivagnaname; PK, Das.

2005-12-01

136

Mosquitos dendrícolas (Diptera, Culicidae) em internódios de taquara da Floresta Atlântica, Serra do Mar e do Primeiro Planalto, Paraná, Brasil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english During two consecutive years, from january 1985 to december 1986, studies were carried out on mosquitoes living in the internodes of bamboo in two distinct regions, the Atlantic Forest of the Serra do Mar and the First Plateau, both in the state of Paraná, Brazil. These dendricolous habitats are ver [...] y different from other recorded mosquito breeding sites. The internodes of the green, living bamboo are closed reservoirs of water with only some small, lateral holes made by boring insects Eucalyptra barbara Schaus, 1894 and Eucalyptra fumida Schaus, 1894 (Lepidoptera, Noctuidae), and other animals. The water in the internodes derives from the bamboo itself. These are the first observations of this breeding behavior. Some females entirely enter the hole to oviposit while others dont't. Similar, artificially constructed habitats were studied at the same time by producing transvere openings and introducing water into the reservoir. Seventeen species of dendricolous mosquitoes were observed utilizing this unique habitat. Additional studies have elaborated other behavioral aspects of these mosquitoes.

Ana Leuch, Lozovei.

1998-08-01

137

Criadouros de imaturos de mosquitos (Diptera, Culicidae) introduzidos em mata preservada na área urbana de Curitiba, Paraná, Brasil / Immature mosquitoes breeding (Diptera, Culicidae) placed inside a preserved forest in the urban area of Curitiba, Paraná, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english Mosquitoes ecological features were studied in a preserved forest - Capão da Imbuia - placed in the urban area of Curitiba City, Paraná, Brasil. In this research were noted immature forms in artificial recipients made by different materiais. Five species were found in this recipients: Culex (Culex) [...] acharistus Root, 1927, Culex (Culex) group coronator Dyar & Kanb, 1906, Culex (Culex) eduardoi Casal & Garcia, 1968, Culex (Culex) quinquefasciatus Say, 1823 and Toxorhynchites (Lynchiella) theobaldi (Dyar & Kanb, 1906). It's very important to know the mosquitoes that in urban area due they carry human desease agents by some species.

Mario Antonio Navarro da, Silva; Ana Leuch, Lozovei.

138

Global climate change and its potential impact on disease transmission by salinity-tolerant mosquito vectors in coastal zones  

Directory of Open Access Journals (Sweden)

Full Text Available Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5–30 ppt and >30 ppt salt are termed fresh, brackish and saline respectively will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross-McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal

RanjanRamasamy

2012-06-01

139

Influence of resource levels, organic compounds and laboratory colonization on interspecific competition between the Asian tiger mosquito Aedes albopictus (Stegomyia albopicta) and the southern house mosquito Culex quinquefasciatus.  

Science.gov (United States)

The mosquitoes Aedes albopictus (Stegomyia albopicta) (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae) are common inhabitants of tyres and other artificial containers, which constitute important peridomestic mosquito breeding habitats. We tested the hypotheses that interspecific resource competition between the larvae of these species is asymmetrical, that the concentration of chemicals associated with decomposing detritus affects the competitive outcomes of these species, and that wild and colonized strains of Cx. quinquefasciatus are affected differently by competition with Ae. albopictus. We conducted two laboratory competition experiments wherein we measured survivorship and estimated population growth (?') in both species under multiple mixed-species densities. Under varying resource levels, competition was asymmetrical: Ae. albopictus caused competitive reductions or exclusions of Cx. quinquefasciatus under conditions of limited resources. In a second experiment, which used both wild and colonized strains of Cx. quinquefasciatus, organic chemical compounds associated with decomposing detritus did not affect the competitive outcome. The colonized strain of Cx. quinquefasciatus had greater survivorship and adult mass, and faster development times than the wild strain, but both strains were similarly affected by competition with Ae. albopictus. Competition between these species may have important consequences for vector population dynamics, especially in areas in which tyres and artificial containers constitute the majority of mosquito breeding habitats. PMID:24444185

Allgood, D W; Yee, D A

2014-09-01

140

Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965, but only detected Anopheles larvae in 12.6% (29/230 of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111, the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR [95% confidence interval (CI] = 0.16 [0.130, 0.203], P Conclusions Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP system for larval surveillance in cities must be urgently revised to improve access to enclosed compounds and the sensitivity with which habitats are searched for larvae.

Shoo Bryson

2009-12-01

 
 
 
 
141

[The evaluation of the infectious capacity of the parasitic nematode Romanomermis iyengari (Welch, 1964) (Nematoda: Mermithidae) in natural mosquito larval breeding areas].  

Science.gov (United States)

Field tests were carried out with the nematode parasite Romanomermis iyengari (Welch, 1964) to fight 3 species of mosquito larvae Anopheles albimanus (Wiedeman, 1821); Culex nigripalpus (Theobald, 1901); and Culex quinquefasciatus (Say, 1823) in three ecologically different natural mosquito reservoirs. The release of the nematode embryos (infective stage) in the above-mentioned reservoirs was carried out with a Holder-planta 5 manual sprayer, at 2 atm, and an application dose of 1000 parasite embryos/m2. The parasite embryos were obtained from 6 nematode cultures, soaked in distilled water. Results showed that mosquito larvae were parasitized by R. iyengari as follows: 100% of the A. albimanus and 85% of the C. nigripalpus, in the first reservoir; 85% of the C. nigripalpus, in the second reservoir; and 80% of the C. nigripalpus and 75% of the C. quinquefasciatus in the third one. Thus, the potential use of the nematode parasite Romanomermis iyengari as a biological control agent of mosquito larvae was shown. PMID:7984816

Santamarina Mijares, A; García Avila, I; González Broche, R

1993-01-01

142

Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa  

Science.gov (United States)

Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.

Endo, N.; Eltahir, E. A.

2013-12-01

143

Use of Normalized Difference Vegetation Index (NDVI) habitat models to predict breeding birds on the San Pedro River, Arizona  

Science.gov (United States)

Successful management practices of avian populations depend on understanding relationships between birds and their habitat, especially in rare habitats, such as riparian areas of the desert Southwest. Remote-sensing technology has become popular in habitat modeling, but most of these models focus on single species, leaving their applicability to understanding broader community structure and function largely untested. We investigated the usefulness of two Normalized Difference Vegetation Index (NDVI) habitat models to model avian abundance and species richness on the upper San Pedro River in southeastern Arizona. Although NDVI was positively correlated with our bird metrics, the amount of explained variation was low. We then investigated the addition of vegetation metrics and other remote-sensing metrics to improve our models. Although both vegetation metrics and remotely sensed metrics increased the power of our models, the overall explained variation was still low, suggesting that general avian community structure may be too complex for NDVI models.

McFarland, Tiffany Marie; van Riper, Charles, III

2013-01-01

144

Mosquitoes and their potential predators in rice agroecosystems of the Mekong Delta, southern Vietnam.  

Science.gov (United States)

Culex tritaeniorhynchus, Cx. gelidus, and Cx. quinquefasciatus, known vectors of Japanese encephalitis (JE), are distributed in rice agroecosystems in Asian countries. Very few integrated studies on the breeding habitats of rice-field mosquitoes, including JE vectors, have been conducted in Vietnam. We investigated the mosquito fauna and potential predators in 8 rice growing areas in the Mekong Delta region of southern Vietnam, during the wet and dry seasons of 2009. Mosquitoes and their predators were collected from a variety of aquatic habitats (rice fields, ponds, wetlands, shrimp ponds, ditches, canals, and rivers). We collected 936 Culex spp. (354 Cx. tritaeniorhynchus, 240 Cx. vishnui s.l., 189 Cx. fuscocephala, and 42 Cx. gelidus), 33 Uranotaenia, 25 Anopheles, and 9 Mimomyia (4 Mi. chamberlaini) in the dry season. During the rainy season, we collected 1,232 Culex spp. (132 Cx. vishnui s.l., 66 Cx. tritaeniorhynchus, 9 Cx. gelidus, 4 Cx. fuscocephala, and 2 Cx. bitaeniorhynchus), 236 Anopheles spp. (40 An. vagus and 1 An. sinensis), and 7 Uranotaenia (3 Ur. lateralis). Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both seasons. Based on a stepwise generalized linear model, the abundance of mosquitoes and their predators in rice fields was high when the rice plant length was short and water depth was shallow. Therefore, the use of insecticides during the earlier stages of rice growth should be avoided in order to preserve the predator populations. PMID:22329270

Ohba, Shin-Ya; Huynh, T T Trang; Le, Loan Luu; Ngoc, Huu Tran; Hoang, San Le; Takagi, Masahiro

2011-12-01

145

Mosquito Modifications: New Approaches to Controlling Malaria  

Science.gov (United States)

This article from the November 2007 issue of BioScience examines the historical and current methods to control Malaria.Malaria kills about one million people each year, but efforts to destroy disease-carrying mosquitoes have succeeded only in breeding tougher bugs. Researchers have begun to look for ways to create malaria-resistant mosquitoes. One approach is to bioengineer transgenic mosquitoes that, when released into the wild, would lead to a new race of malaria-proof young. Another approach uses mosquitoes' natural resistance to Plasmodium infection.

Sharon Levy (;)

2007-11-01

146

North American Wetlands and Mosquito Control  

Science.gov (United States)

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O'Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

2012-01-01

147

North American Wetlands and Mosquito Control  

Directory of Open Access Journals (Sweden)

Full Text Available Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere.

Gabrielle E. Sakolsky-Hoopes

2012-12-01

148

North American wetlands and mosquito control.  

Science.gov (United States)

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

Rey, Jorge R; Walton, William E; Wolfe, Roger J; Connelly, C Roxanne; O'Connell, Sheila M; Berg, Joe; Sakolsky-Hoopes, Gabrielle E; Laderman, Aimlee D

2012-12-01

149

Mosquito (Diptera: Culicidae) Fauna of Qom Province, Iran  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae) fauna, larval collections were carried out from different habitats on 19 occasions usi...

Saghafipour, A.; MR Abai; Farzinnia, B.; Nafar, R.; Ladonni, H.; Azari-hamidian, S.

2012-01-01

150

The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence of water in the form of hibernating embryos. Once introduced either as embryos or juveniles in ponds, the annual killifish can effectively reduce the larval population because of its aggressive predatory activity.

Adrias Araceli Q

2010-05-01

151

Bdelloid rotifer, Philodina species in the breeding containers of Aedes aegypti and Aedes albopictus.  

Science.gov (United States)

The vector mosquitoes of dengue and chikungunya fever, Aedes aegypti and Aedes albopictus have adapted to feed on humans and undergo larval and pupal development in natural and artificial freshwater collections. Although several studies reported, still, much information is required to understand the successful survival of Aedes mosquitoes in small temporary containers. In an investigation conducted in the chikungunya affected areas of Kerala state, India, the presence of Bdelloid rotifer, Philodina in 95% of breeding habitats of Ae. aegypti and Ae. albopictus was recorded. The role of Philodina in the breeding containers was investigated. It was found that while in control the number of Philodina was found increasing in the water sample during the study period of seven days, the number found decreased in the containers with larvae of Aedes. The gut content analysis also confirmed the presence of the rotating wheel, corona of Philodina in some of the specimen suggests its role as major larval food. PMID:23202612

Muniaraj, M; Arunachalam, N; Paramasivan, R; Mariappan, T; Philip Samuel, P; Rajamannar, V

2012-12-01

152

Spatial distribution of mosquito larvae and the potential for targeted larval control in The Gambia.  

Science.gov (United States)

We examined the distribution of aquatic stages of malaria vectors in a 400-km(2) area in rural Gambia to assess the practicality of targeting larval control. During the rainy season, the peak period of malaria transmission, breeding sites were 70% more likely to have anopheline larvae in the floodplain of the Gambia River than upland sites (P < 0.001). However, mosquitoes were found in some examples of all habitats, apart from moving water. Habitats most often colonized by anopheline larvae were the largest water bodies, situated near the landward edge of the flood-plain, where culicine larvae were present. In the wet season, 49% of sites had anophelines versus 19% in the dry season (P < 0.001). Larval control targeted at specific habitats is unlikely to be successful in this setting. Nonetheless, larval control initiated at the end of the dry season and run throughout the rainy season could help reduce transmission. PMID:18606759

Majambere, Silas; Fillinger, Ulrike; Sayer, David R; Green, Clare; Lindsay, Steven W

2008-07-01

153

Ecologia de mosquitos (Diptera, Culicidae) em áreas do Parque Nacional do Iguaçu, Brasil: 1 ­ Distribuição por hábitat / Mosquito (Diptera, Culicidae) ecology in the Iguaçu National Park, Brazil: 1 ­ Habitat distribution  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estabelecemos a influência exercida pela cobertura vegetal de quatro diferentes biótopos em áreas do Parque Nacional do Iguaçu (PNI) sobre a fauna local de mosquitos. Realizaram-se capturas bimestrais, em isca humana e armadilha Shannon, em três diferentes períodos do dia, em ambiente silvestre e do [...] miciliar, durante 24 meses consecutivos. Dentre os 20.273 espécimes de fêmeas adultas capturadas, pertencentes a 44 espécies, Ochlerotatus serratus (10,3%), Haemagogus leucocelaenus (9,7%), Mansonia titillans (9,6%) e Chagasia fajardoi (8,8%) foram predominantes. Anopheles cruzii, Runchomyia theobaldi, Wyeomyia aporonoma e Wy. confusa ocorreram exclusivamente em áreas com vegetação bem preservada e densa configuração. Culex nigripalpus, Oc. pennai, Oc. serratus, Sabethes purpureus e Sa. albiprivus foram capturados nos três biótopos essencialmente silvestres. Na mata no entorno da represa foram capturadas principalmente An. albitarsis s.l., An. galvaoi, An. evansae, An. fluminensis, Coquillettidia venezuelensis, Cq. juxtamansonia, Wy. quasilongirostris e Onirion personatum. As espécies que apresentaram maiores incidências na área sob ação antrópica foram Ch. fajardoi, Cq. fasciolata, Cq. nitens e Ma. titillans. Abstract in english A study of the mosquito fauna in the Iguaçu National Park focused on population behavior in four biotopes with different types of plant cover inside the Park. Systematic bimonthly diurnal and nocturnal human bait and Shannon trap captures were conducted in both forest and domiciliary environments ov [...] er the course of 24 months. A total of 20,273 adult mosquito specimens belonging to 44 species were collected: Ochlerotatus serratus (10.3%), Haemagogus leucocelaenus (9.7%), Mansonia titillans (9.6%), and Chagasia fajardoi (8.8%) were the most frequently captured mosquitoes. Anopheles cruzii, Runchomyia theobaldi, Wyeomyia aporonoma, and Wy. confusa were captured almost exclusively in well-preserved areas with dense forest cover. Culex nigripalpus, Oc. pennai, Oc. serratus, Sabethes purpureus, and Sa. albiprivus were captured in three essentially sylvatic biotopes. Species captured in the forest areas around a dam were: An. albitarsis s.l., An. galvaoi, An. evansae, An. fluminensis, Coquillettidia venezuelensis, Cq. juxtamansonia, Wy. quasilongirostris, and Onirion personatum, Ch. fajardoi, Cq. fasciolata, Cq nitens, and Ma. titillans were the most frequently captured species in a residential area.

Anthony Érico, Guimarães; Catarina Macedo, Lopes; Rubens Pinto de, Mello; Jeronimo, Alencar.

154

Ecologia de mosquitos (Diptera, Culicidae) em áreas do Parque Nacional do Iguaçu, Brasil: 1 ­ Distribuição por hábitat / Mosquito (Diptera, Culicidae) ecology in the Iguaçu National Park, Brazil: 1 ­ Habitat distribution  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese Estabelecemos a influência exercida pela cobertura vegetal de quatro diferentes biótopos em áreas do Parque Nacional do Iguaçu (PNI) sobre a fauna local de mosquitos. Realizaram-se capturas bimestrais, em isca humana e armadilha Shannon, em três diferentes períodos do dia, em ambiente silvestre e do [...] miciliar, durante 24 meses consecutivos. Dentre os 20.273 espécimes de fêmeas adultas capturadas, pertencentes a 44 espécies, Ochlerotatus serratus (10,3%), Haemagogus leucocelaenus (9,7%), Mansonia titillans (9,6%) e Chagasia fajardoi (8,8%) foram predominantes. Anopheles cruzii, Runchomyia theobaldi, Wyeomyia aporonoma e Wy. confusa ocorreram exclusivamente em áreas com vegetação bem preservada e densa configuração. Culex nigripalpus, Oc. pennai, Oc. serratus, Sabethes purpureus e Sa. albiprivus foram capturados nos três biótopos essencialmente silvestres. Na mata no entorno da represa foram capturadas principalmente An. albitarsis s.l., An. galvaoi, An. evansae, An. fluminensis, Coquillettidia venezuelensis, Cq. juxtamansonia, Wy. quasilongirostris e Onirion personatum. As espécies que apresentaram maiores incidências na área sob ação antrópica foram Ch. fajardoi, Cq. fasciolata, Cq. nitens e Ma. titillans. Abstract in english A study of the mosquito fauna in the Iguaçu National Park focused on population behavior in four biotopes with different types of plant cover inside the Park. Systematic bimonthly diurnal and nocturnal human bait and Shannon trap captures were conducted in both forest and domiciliary environments ov [...] er the course of 24 months. A total of 20,273 adult mosquito specimens belonging to 44 species were collected: Ochlerotatus serratus (10.3%), Haemagogus leucocelaenus (9.7%), Mansonia titillans (9.6%), and Chagasia fajardoi (8.8%) were the most frequently captured mosquitoes. Anopheles cruzii, Runchomyia theobaldi, Wyeomyia aporonoma, and Wy. confusa were captured almost exclusively in well-preserved areas with dense forest cover. Culex nigripalpus, Oc. pennai, Oc. serratus, Sabethes purpureus, and Sa. albiprivus were captured in three essentially sylvatic biotopes. Species captured in the forest areas around a dam were: An. albitarsis s.l., An. galvaoi, An. evansae, An. fluminensis, Coquillettidia venezuelensis, Cq. juxtamansonia, Wy. quasilongirostris, and Onirion personatum, Ch. fajardoi, Cq. fasciolata, Cq nitens, and Ma. titillans were the most frequently captured species in a residential area.

Anthony Érico, Guimarães; Catarina Macedo, Lopes; Rubens Pinto de, Mello; Jeronimo, Alencar.

155

Ecology of the mosquito larvae in urban environments of Cairo Governorate, Egypt.  

Science.gov (United States)

Mosquitoes were surveyed over one year period in two localities in Cairo representing different levels of urban planning: El-Muqattam (planned) and Abu-Seir (unplanned). Culex pipiens, Cx. perexiguus, Cx. pusillus, Ochlerotatus caspius, Culiseta longiareolata and Anopheles multicolor were the collected species at both sites. Mosquitoes were more common in Abu-Seir than in El-Muqattam, with larvae of the filaria vector Cx. pipiens accounting for 81% and 52% of recorded individuals at these sites, respectively. Five types of the potential breeding habitats were detected of which, the cesspits (El-Muqattam) and drainage canals (Abu-Seir) were the most common while springs in El-Muqattam and drainage canals in Abu-Seir were the most productive types. Both Cx. pipiens and Cx. perexiguus bred year round with peaks of abundance coinciding with higher temperatures. PMID:22662608

Ammar, Sherif E; Kenawy, Mohamed A; Abdel-Rahman, Hashim A; Gad, Adel M; Hamed, Adel F

2012-04-01

156

Trichomycete fungi (Zygomycota) associated with mosquito larvae (Diptera: Culicidae) in natural and artificial habitats in Manaus, AM Brazil / Fungos Trichomycetes (Zygomicota) associados com larvas de mosquitos (Diptera: Culicidae) em criadouros naturais e artificiais em Manaus, AM  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Espécies de fungos da classe Trichomycete (Zygomycota) estão associados com o trato digestivo dos Arthropoda. A relação entre esses fungos e seus hospedeiros ainda é pouco conhecida, podendo ser comensal, benéfica ou deletéria. Conhecimentos da estrutura de comunidades parasitas/ patógenos e os habi [...] tats de larvas de Culicidae podem ser importantes em estudos que utilizam medidas combinadas para o controle populacional. Larvas de Culicidae e os fungos Trichomycetes associados foram coletados no município de Manaus, AM; amostras de criadouros incluindo plantas (habitat natural) e reservatórios antrópicos (habitat artificial). O total de 1518 larvas foi coletado, 913 em criadouros naturais e 605 em criadouros artificiais, distribuídas em 12 espécies de sete gêneros. O total de 661 indivíduos (4° estádio) foi dissecado para verificar a presença de fungos Trichomycetes no intestino médio e posterior. Infecção de fungos Trichomycetes no intestino posterior foram observados em 15% de Culex urichii Coquillett, 13% de Culex (Culex) sp1, 9% of Limatus spp., 49% de Aedes aegypti Linnaeus e 1% de Ochlerotatus argyrothorax Bonne-Wepster & Bonne. Somente em Ae. aegypti foram observados fungos Trichomycetes na matriz peritrófica, no intestino médio; porém este fato é provavelmente, um resultado de um desenvolvimento anormal deste fungo. Abstract in english Fungal species of the class Trichomycete fungi (Zygomycota) are associated with the digestive tracts of Arthropoda. The relationships between these fungi and their hosts are still little understood: they may be commensal, beneficial or deleterious. Knowledge of the community structure of parasites/ [...] pathogens and of the habitats of each species of Culicidae larvae can be important in studies that intend to use combined approaches to population control. Larvae of Culicidae and their associated trichomycete fungi were collected in Manaus County, AM, Brazil; sampling habitats included plants (natural habitat) and anthropic containers (artificial habitats). The total of 1,518 larvae were collected, 913 of which were in natural habitats and 605 were in artificial habitats, distributed in 12 species of seven genera. The total of 661 individuals (4th instar) were dissected to verify the presence of trichomycete fungi in the mid and hindgut. Infection of trichomycete fungi in the hindgut was observed in 15% of Culex urichii Coquillett, 13% of Culex (Culex) sp1, 9% of Limatus spp., 49% of Aedes aegypti Linnaeus and 1% of Ochlerotatus argyrothorax Bonne-Wepster & Bonne. Only in Ae. aegypti were trichomycete fungi observed in the peritrophic matrix, in the midgut; however, this fact is probably, a result of abnormal development of the fungi.

Eleny da S., Pereira; Ruth L.M., Ferreira; Neusa, Hamada; Robert W., Lichtwardt.

2005-04-01

157

Global Climate Change and Its Potential Impact on Disease Transmission by Salinity-Tolerant Mosquito Vectors in Coastal Zones  

Science.gov (United States)

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with 30?ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross–McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased coastal transmission of mosquito-borne diseases consequent to climate change and a rise in sea levels. It is proposed that the Jaffna peninsula in Sri Lanka may be a useful case study for the impact of rising sea levels on mosquito vectors in tropical coasts. PMID:22723781

Ramasamy, Ranjan; Surendran, Sinnathamby Noble

2012-01-01

158

[Mosquito allergy].  

Science.gov (United States)

Althought serious illnesses can be transmitted by mosquitoes, the most frequent manifestations are due to the contact with saliva of mosquitoes during the blood meal. Culex and Aedes are meeting in countries with moderate climates. Clinical signs vary according to the immunoallergical response, from simple pruritic wheals to immediate and/or delayed allergic reactions. Some reactions can provoke confusion with an infectious cellulitis and an inappropriate antibiotherapy. The natural history of insect bite reactions in an individual tends to progress through 5 stages until immunizing tolerance settles down. Skin prick testing or Serum specific IgE of whole body extracts are lacking sensibility and specificity. Actually, they must be reserved for the most invalidating or severe cases. The recombinant allergens of the saliva of mosquitoes should allow to improve diagnosis and to envisage immunotherapy. PMID:24954785

Haas, H; Tran, A

2014-08-01

159

Time budgets of Tibetan eared pheasants during the non-breeding season in an alpine scrub habitat  

Directory of Open Access Journals (Sweden)

Full Text Available Time allocations of the group-living Tibetan eared pheasants Crossoptilon harmani with and without supplementary food were investigated by full-day sampling from winter through spring in an alpine shrub zone, south Tibet. At a flock scale, both the different food-supply flocks displayed similar daily patterns of activity, foraging in the morning and evening, and resting around midday. In terms of individual activity, either foraging or resting was highly synchronous with the flock’s. Non-provisioned birds spent more time feeding and less resting in midwinter than in late autumn. In early spring as climates became warmer and day longer, however, non-provisioned birds did not decrease their feeding efforts significantly but the provisioned birds did. Across the non-breeding seasons, the provisioned birds (relying on nutrition-rich artificial foods devoted less time to feeding and more to resting than did the non-provisioned ones (relying on nutrition-poor plant roots. Multivariate analysis showed increased food supply and ambient temperature resulted in a reduced foraging effort. However, the fact that the non-provisioned birds can save daily time for resting even in the cold short midwinter indicated that they faced no energetic constraint. Thus, protecting shelter vegetation rather than providing extra food is suggested to be important for long-term survival of the endangered galliform birds [Current Zoology 55(3:193–199,2009].

Xin LU

2009-06-01

160

Mosquito control by larvivorous fish.  

Science.gov (United States)

There is growing of the effects of insecticide used controlling the vectors of human diseases. Manipulating or introducing an auto-reproducing predator into the ecosystem may provide sustained biological control of pest populations. The selection of a biological agent should be based on its self-replicating capacity, preference for the target pest population in the presence of alternate natural prey, adaptability to the introduced environment, and overall interaction with indigenous organisms. In order to achieve an acceptable range of control, a sound knowledge of various attributes of interactions between the pest population and the predator to be introduced is desirable. Biological larviciding for the control of mosquito borne diseases is feasible and effective only when breeding sites are relatively few or are easily identified and treated. Larval control appears to be promising in urban areas, given that the density of humans needing protection is higher than the limited number of breeding sites. Since 1937, fish have been employed for controlling mosquito larvae. Different types of fish have been used so far in this operational technique. However, use of fish of indigenous origin is found to be more appropriate in this operation. This review presents information on different larvivorous fish species and the present status of their use in mosquito control and provides a ready reference for workers involved and interested in mosquito research. PMID:18316849

Chandra, G; Bhattacharjee, I; Chatterjee, S N; Ghosh, A

2008-01-01

 
 
 
 
161

Registros de mayor altitud para mosquitos (Diptera: Culicidae) en Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish Los mosquitos (Diptera: Culicidae) son insectos holometábolos con estadios inmaduros acuáticos que utilizan una amplia variedad de hábitats larvales, desde cuerpos de agua en el suelo hasta Fitotelmata (depósitos de agua en las plantas) y depósitos artificiales. La disponibilidad de sitios de reprod [...] ucción a menudo determina el límite superior del ámbito de los mosquitos. Nosotros construimos una base de datos de 9 607 registros, 432 localidades, 19 géneros y 254 especies. La coordillera Andina posee el 77% de los registros con mayor altitud incluyendo Aedes euris con un registro a 3 300 m, seguido por tres especies de Anopheles -subgénero Kerteszia- con una altitud máxima de 2 680 m. Wyeomyia bicornis y Culex daumastocampa a 2 550 m fueron los registros de mayor altitud en la cordillera Costera- Central, mientras que el record más alto en Pantepui fue Wyeomyia zinzala a 2 252 m. El 60% de los registros de máxima altitud están representados por especies asociadas con fitotelmata (Bromeliaceae y Sarraceniaceae). Los límites superiores de Culex quinquefasciatus y Anopheles (Kerteszia) podría representar el límite teórico para la transmisión de filariasis o arbovirus, por Culex y malaria por Anopheles (Kerteszia) en Venezuela. Del mismo modo, un vector del dengue, Aedes aegypti, no ha sido registrado por encima de 2 000 m. Abstract in english Highest mosquito records (Diptera: Culicidae) in Venezuela. Mosquitoes (Diptera: Culicidae) are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants) and artificial deposits. The availab [...] ility of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9 607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3 133 m, followed by three species of Anopheles -subgenera Kerteszia- with the upper limit of 2 680 m. Wyeomyia bicornis and Culex daumastocampa at 2 550 m were the highest records in the Central- Coastal cordillera, while the highest record in Pantepui was Wyeomyia zinzala at 2 252 m. The species associated with phytothelmata (Bromeliaceae and Sarraceniaceae) represent 60% of the records. The upper limits of Culex quinquefasciatus and Anopheles (Kerteszia) species could represent the theoretical limit for transmission of filariasis or arboviruses, by Culex, and malaria by Anopheles (Kerteszia) in Venezuela. Similarly, a vector of Dengue, Aedes aegypti, has not been not recorded above 2 000 m. Rev. Biol. Trop. 58 (1): 245-254. Epub 2010 March 01.

Juan-Carlos, Navarro; Fabiola, Del Ventura; Adriana, Zorrilla; Jonathan, Liria.

2010-03-01

162

Effects of dairy wastewater on mosquitoes in southern California.  

Science.gov (United States)

The effect of dairy pond water quality on mosquito biology was studied under laboratory conditions during 2004. Due to high turbidity and larval toxicity of raw water samples from dairy ponds with no mosquito breeding, water samples from both mosquito breeding and non-breeding ponds were filtered and diluted 5X with distilled water prior to being tested for sublethal effects on mosquito development. The diluted pond waters showed no significant deleterious effects on the overall development of Culex quiquefasciatus Say at 23.9 degrees and 26.6 degrees C. However, the 3rd and 4th instar larvae were significantly shorter and lighter in weight when reared in diluted water samples from mosquito non-breeding ponds. Similar effects were found on the developmental stages of Cx. tarsalis Coquillette. Data on water quality parameters of filtered pond waters showed higher levels of hexavalent chromium (4X), nitrites (10X), nitrates (2X), sulfates (5X), and salinity (2X) in water samples from non-breeding ponds. Based on these data, the presence of high levels of hexavalent chromium and sulfate appear to be responsible for the absence of mosquito breeding in some dairy ponds. PMID:17249348

Mian, Lal S

2006-12-01

163

Mosquito diapause.  

Science.gov (United States)

Diapause, a dominant feature in the life history of many mosquito species, offers a mechanism for bridging unfavorable seasons in both temperate and tropical environments and serves to synchronize development within populations, thus directly affecting disease transmission cycles. The trait appears to have evolved independently numerous times within the Culicidae, as exemplified by the diverse developmental stages of diapause in closely related species. Its impact is pervasive, not only influencing the arrested stage, but also frequently altering physiological processes both before and after diapause. How the diapause response can be molded evolutionarily is critical for understanding potential range expansions of native and newly introduced species. The study of hormonal regulation of mosquito diapause has focused primarily on adult diapause, with little current information available on larval diapause or the intriguing maternal effects that regulate egg diapause. Recent quantitative trait locus, transcriptome, and RNA interference studies hold promise for interpreting the complex suite of genes that subserve the diapause phenotype. PMID:24160427

Denlinger, David L; Armbruster, Peter A

2014-01-01

164

Beta-cyfluthrin, a synthetic pyrethroid for mosquito control.  

Science.gov (United States)

Beta-cyfluthrin (OMS 3051), a new synthetic pyrethroid and one of the stereoisomers of cyfluthrin, was studied for insecticidal activity against eight mosquito species. Its larvicidal activity with LC50 values of 5.62 x 10(-5) and 1.19 x 10(-4) mg/l respectively for Culex quinquefasciatus and Aedes aegypti was comparable with that of deltamethrin. This pyrethroid was more effective against the larvae of Armigeres subalbatus (LC50 - 7.76 x 10(-7)) and the adults of Anopheles culicifacies LT50 - 27.76 min at 2.0 mu/cm2) than the other species tested. Residual efficacy at 50 mg(ai)/m2 was more persistent (for 14-25 weeks) on thatch and asbestos among the four treated surfaces. This compound also elicited oviposition deterrent activity at 0.001 mg/l against Cx.quinquefasciatus. beta-cyfluthrin is a good insecticide for mosquito control. However, care should be exercised while using it as a larvicide in breeding habitats considering its toxicity to fish. PMID:1359650

Vasuki, V; Rajavel, A R

1992-06-01

165

Microhabitats de mosquitos (Diptera, Culicidae em internódios de taquara na Mata Atlântica, Paraná, Brasil Mosquitoes microhabitats (Diptera, Culicidae in bamboo internodes in Atlantic forest, Paraná, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available During two consecutive years, from January 1985 to December 1986, a comparative study of mosquitoes preferences for breeding habitat was carried out in the Atlantic Forest of the Serra do Mar, Paraná State, Brazil. To achieve it, 1875 bamboo internodes aligned vertically in live green, bamboo plants Merostachys speciosa Munro and Merostachys sp. were used, in which metabolic water was exuded from the plant itself, and presenting different size/pattern holes at their lateral walls, bored by the local sylvan fauna. Another group of 1200 individual internode traps was used as comparative element, carved out with a transversal cut by a saw, filled with local stream water and held in branches at different heights in the vegetal strata nearby. At both microhabitat types, a total of 17 culicid species was registered. Culex (Microculex neglectus Lutz, 1904, Cx. (Carrollia soperi Antunes & Lane, 1937, Sabethes (Sabethes batesi Lane & Cerqueira, 1942 and Sa. (Sabethinus melanonymphe (Dyar, 1924colonized exclusively live plant internodes, while Culex (Microculex elongatus Rozeboom & Lane, 1950, Cx. (Carrollia iridescens (Lutz, 1905, Cx. (Carrollia kompi Valencia,1973and Trichoprosopon (Trichoprosopon soaresi Dyar & Knab, 1907 bred only in internode traps. The remaining nine species colonized both habitats indistinctly. Quantitatively, was detected the abundance of 60.1% at live green internodes, against 39.9% for internode traps. Concerning the different patterns of bored live internode holes, 40.3% of the total computed specimens were collected in square or rectangular holes, 31.9% in two hole internodes, one minute circular, the other wider, and the remaining 28.8% of specimens distributed in other pattern type internodes. The mosquitoes breeding at these microhabitats fall in the culicid entomofauna specialized at locating and detecting peculiar and propitious mesogen conditions for breeding purposes.

Ana Leuch Lozovei

166

Microhabitats de mosquitos (Diptera, Culicidae) em internódios de taquara na Mata Atlântica, Paraná, Brasil / Mosquitoes microhabitats (Diptera, Culicidae) in bamboo internodes in Atlantic forest, Paraná, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese [...] Abstract in english During two consecutive years, from January 1985 to December 1986, a comparative study of mosquitoes preferences for breeding habitat was carried out in the Atlantic Forest of the Serra do Mar, Paraná State, Brazil. To achieve it, 1875 bamboo internodes aligned vertically in live green, bamboo plants [...] Merostachys speciosa Munro and Merostachys sp. were used, in which metabolic water was exuded from the plant itself, and presenting different size/pattern holes at their lateral walls, bored by the local sylvan fauna. Another group of 1200 individual internode traps was used as comparative element, carved out with a transversal cut by a saw, filled with local stream water and held in branches at different heights in the vegetal strata nearby. At both microhabitat types, a total of 17 culicid species was registered. Culex (Microculex) neglectus Lutz, 1904, Cx. (Carrollia) soperi Antunes & Lane, 1937, Sabethes (Sabethes) batesi Lane & Cerqueira, 1942 and Sa. (Sabethinus) melanonymphe (Dyar, 1924)colonized exclusively live plant internodes, while Culex (Microculex) elongatus Rozeboom & Lane, 1950, Cx. (Carrollia) iridescens (Lutz, 1905), Cx. (Carrollia) kompi Valencia,1973and Trichoprosopon (Trichoprosopon) soaresi Dyar & Knab, 1907 bred only in internode traps. The remaining nine species colonized both habitats indistinctly. Quantitatively, was detected the abundance of 60.1% at live green internodes, against 39.9% for internode traps. Concerning the different patterns of bored live internode holes, 40.3% of the total computed specimens were collected in square or rectangular holes, 31.9% in two hole internodes, one minute circular, the other wider, and the remaining 28.8% of specimens distributed in other pattern type internodes. The mosquitoes breeding at these microhabitats fall in the culicid entomofauna specialized at locating and detecting peculiar and propitious mesogen conditions for breeding purposes.

Ana Leuch, Lozovei.

2001-05-25

167

Mosquito Vectors Survey in the AL-Ahsaa District of Eastern Saudi Arabia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study aimed to identify the mosquito vectors distributed throughout AL-Ahsaa district situated in the eastern region of Saudi Arabia. Mosquito larvae were collected seasonally for one year (October 2009 to September 2010) from different breeding sites in seven rural areas utilizing long aquatic nets. Salinity and pH of these breeding sites were also measured seasonally. The survey revealed the presence of five mosquito species, Aedes caspius Pallas (Diptera: Culicidae), Anopheles ...

Ahmed, Ashraf M.; Shaalan, Essam A.; Aboul-soud, Mourad A. M.; Tripet, Fre?de?ric; Al-khedhairy, Abdulaziz A.

2011-01-01

168

La Prevention Contre les Moustiques dans les Terres Irriguees (Mosquito Prevention on Irrigated Farms).  

Science.gov (United States)

This book tells what measures to take to control mosquitos. The nature and extent of the problem is discussed, its socio-economic and public health aspects are given. The mosquitos' biology and habitat, and problems of reconciling mosquito control with ot...

1969-01-01

169

Habitat stability and occurrences of malaria vector larvae in western Kenya highlands  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Although the occurrence of malaria vector larvae in the valleys of western Kenya highlands is well documented, knowledge of larval habitats in the uphill sites is lacking. Given that most inhabitants of the highlands actually dwell in the uphill regions, it is important to develop understanding of mosquito breeding habitat stability in these sites in order to determine their potential for larval control. Methods A total of 128 potential larval habitats were identified in hilltops and along the seasonal streams in the Sigalagala area of Kakamega district, western Kenya. Water availability in the habitats was followed up daily from August 3, 2006 to February 23, 2007. A habitat is defined as stable when it remains aquatic continuously for at least 12 d. Mosquito larvae were observed weekly. Frequencies of aquatic, stable and larvae positive habitats were compared between the hilltop and seasonal stream area using ?2-test. Factors affecting the presence/absence of Anopheles gambiae larvae in the highlands were determined using multiple logistic regression analysis. Results Topography significantly affected habitat availability and stability. The occurrence of aquatic habitats in the hilltop was more sporadic than in the stream area. The percentage of habitat occurrences that were classified as stable during the rainy season is 48.76% and 80.79% respectively for the hilltop and stream area. Corresponding frequencies of larvae positive habitats were 0% in the hilltop and 5.91% in the stream area. After the rainy season, only 23.42% of habitat occurrences were stable and 0.01% larvae positive habitats were found in the hilltops, whereas 89.75% of occurrences remained stable in the stream area resulting in a frequency of 12.21% larvae positive habitats. The logistic regression analysis confirmed the association between habitat stability and larval occurrence and indicated that habitat surface area was negatively affecting the occurrence of An. gambiae larvae. While An. gambiae and An. funestus larvae occurred throughout the study period along the streams, a total of only 15 An. gambiae larvae were counted in the hilltops, and no An. funestus were found. Moreover, no larvae managed to develop into adults in the hilltops, and the density of adult An. gambiae was consistently low, averaging at 0.06 females per house per survey. Conclusion The occurrence of malaria vector larvae in the hilltop area was uncommon as a result of the low availability and high instability of habitats. To optimize the cost-effectiveness of malaria interventions in the western Kenya highlands, larval control should be focused primarily along the streams, as these are likely the only productive habitats at high altitude.

Atieli Harrysone

2009-10-01

170

Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 [...] larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Marta, Grech; Paolo, Sartor; Elizabet, Estallo; Francisco, Luduena-Almeida; Walter, Almiron.

2013-09-01

171

Climate and geographic trends in hatch delay of the treehole mosquito, Aedes triseriatus Say (Diptera: Culicidae).  

Science.gov (United States)

Eggs of Aedes triseriatus mosquitoes are stimulated to hatch when inundated with water, but only a small fraction of eggs from the same batch will hatch for any given stimulus. Similar hatching or germination patterns are observed in desert plants, copepods, rotifers, insects, and many other species. Bet hedging theory suggests that parents stagger offspring emergence into vulnerable life history stages in order to avoid catastrophic reproductive failures. For Ae. triseriatus, a treehole breeding mosquito, immediate hatching of an entire clutch leaves all of the parent's progeny vulnerable to extinction in the event of a severe drought. Natural selection has likely favored parents that pursued a bet hedging strategy where the risk of reproductive failure is distributed over time. Considering treehole mosquitoes, bet hedging theory could be used to predict that hatch delay would be positively correlated with the likelihood of drought. To test this prediction, we collected Ae. triseriatus from habitats that varied widely in mean annual precipitation and exposed them to several hatch stimuli in the laboratory. Here we report that, as predicted, Ae. triseriatus eggs from high precipitation regions showed less hatch delay than areas of low precipitation. This strategy probably allows Ae. triseriatus to cope with the wide variety of climatic conditions that it faces in its extensive geographical range. PMID:20836812

Khatchikian, Camilo E; Dennehy, John J; Vitek, Christopher J; Livdahl, Todd

2009-06-01

172

Influence of short time exposure to an insect growth regulator, hexaflumuron, on mortality and adult emergence of vector mosquitoes.  

Science.gov (United States)

Hexaflumuron, an insect growth regulator (IGR), was found to greatly affect the development of immatures and emergence of adults of three species of vector mosquitoes, Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi, when larvae were subjected to short time exposure of < or = 1 h. This IGR could completely prevent adult emergence even at a minimum exposure time of 10 min at 0.001, 0.01 and 0.1 mg/l. On treatment, larval and pupal mortality as well as varying degrees of morphogenetic abnormalities were induced in immatures and adults of the three species. Four weeks of control achieved in a slow moving sullage canal breeding Culex quinquefasciatus indicates that this IGR can be of use in such breeding habitats. PMID:1308571

Vasuki, V; Rajavel, A R

1992-01-01

173

Influence of short time exposure to an insect growth regulator, hexaflumuron, on mortality and adult emergence of vector mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Hexaflumuron, an insect growth regulator (IGR), was found to greatly affect the development of immatures and emergence of adults of three species of vector mosquitoes, Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi, when larvae were subjected to short time exposure of [...] IGR could completely prevent adult emergence even at a minimum exposure time of 10 min at 0.001, 0.01 and 0.1 mg/l. On treatment, larval and pupal mortality as well as varying degrees of morphogenetic abnormalities were induced in immatures and adults of the three species. Four weeks of control achieved in a slow moving sullage canal breeding Culex quinquefasciatus indicates that this IGR can be of use in such breeding habitats.

V., Vasuki; A. R., Rajavel.

1992-06-01

174

Survey of the mosquitoes (Diptera: Culicidae) of Mayotte.  

Science.gov (United States)

A transversal survey of immature mosquitoes was conducted on Mayotte Island (France) in the Comoros Archipelago, western Indian Ocean, with the aim to inventory the Culicidae and to document inter-species relationships in different habitats. In total 420 habitats were sampled for larvae and/or pupae mosquitoes, resulting in more than 6,000 specimens. Forty species belonging to 15 genera were collected, with eight taxa integrated for the first time to the Mayotte mosquito list. The most frequently recorded species were Stegomyia aegypti, St. albopicta, Anopheles gambiae and Eretmapodites subsimplicipes, the first three species being known vectors of viruses and parasites transmitted to humans. Mean species richness in habitats ranged from 1.00 to 3.29, with notable differences between habitats. For example, water-filled axils of banana leaves, tree-holes and crab-holes had low species richness, while cut bamboo, water pools, abandoned tires and marsh and swamp water had notably higher species richness. Twenty-seven mosquito species belonging to 12 genera were routinely collected (in ?20% of at least one type of larval habitat) suggesting that multiple species play a role in the biocenosis of these aquatic habitats. Multispecies association was observed in 52% of the habitats. The co-occurrence of up to six species belonging to five genera was recorded in a single habitat. The mosquitoes of Mayotte show notable biogeographical affinities to those of Madagascar, as compared to the African continent. These two potential source areas are nearly equidistant from Mayotte, which in turn indicates biased dispersal from east to west. Our findings suggest that with relatively short-term intensive sampling in different habitats, it is possible to approach exhaustive species inventories based on collection of larvae. Mayotte, with its modest elevation range and land surface, has a notable species richness of mosquitoes with 45 well-documented species belonging to 15 genera. PMID:25004163

Le Goff, Gilbert; Goodman, Steven M; Elguero, Eric; Robert, Vincent

2014-01-01

175

Current procedures of the integrated urban vector-mosquito control as an example in Cotonou (Benin, West Africa) and Wroc?aw area (Poland).  

Science.gov (United States)

Current strategy of Integrated Vector Management (IVM) comprises the general approach of environmentally friendly control measures. With regard to mosquitoes it includes first of all application of microbial insecticides based on Bacillus thuringiensis israelensis (Bti) and B. sphaericus (Bs) delta-endotoxins as well as the reduction of breeding habitats and natural enemy augmentation. It can be achieved thorough implementation of the interdisciplinary program, i. e., understanding of mosquito vector ecology, the appropriate vector-diseases (e. g., malariometric) measurements and training of local personnel responsible for mosquito abatement activities, as well as community involvement. Biocontrol methods as an alternative to chemical insecticides result from the sustainability development concept, growing awareness of environmental pollution and the development of insecticide-resistant strains of vector-mosquito populations in many parts of the world. Although sustainable trends are usually considered in terms of the monetary and training resources within countries, environmental concerns are actually more limiting factors for the duration of an otherwise successful vector control effort. In order to meet these new needs, increasing efforts have been made in search of and application of natural enemies, such as parasites, bacterial pathogens and predators which may control populations of insect vectors. The biological control agent based on the bacterial toxins Bti and Bs has been used in the Wroc?aw's University and Municipal Mosquito Control Programs since 1998. In West-Africa biocontrol appears to be an effective and safe tool to combat malaria in addition to bed-nets, residual indoor spraying and appropriate diagnosis and treatment of malaria parasites which are the major tools in the WHO Roll Back Malaria Program. IVM studies carried out 2005-2008 in Cotonou (Benin) as well those in Wroc?aw Irrigated Fields during the last years include the following major steps: 1. Mapping of all breeding sites in the project area and recording data in a geographical information system (GIS/relational database). All districts, streets and houses are numbered for quick reference during the operation; 2. Studying mosquito vector bionomics, migration and vectorial capacity in the project area, before, during and after the routine Bti treatments; 3. Assessment of the optimum for effective larvicide insecticide dosages at major breeding sites against the different target mosquito species; 4. Implementation of the microbial control agents in the integrated routine program. Adaptation of the application equipment to the local situation, training of the field staff, and routine treatments; 5. Conducting surveillance of vector-disease (e. g., malariometric) parameters in the control and experimental area before, during, and after the application of biocontrol agents. PMID:20209805

Rydzanicz, Katarzyna; Lonc, Elzbieta; Becker, Norbert

2009-01-01

176

Does the spillage of petroleum products in Anopheles breeding sites have an impact on the pyrethroid resistance?  

Directory of Open Access Journals (Sweden)

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 further studies on the mechanisms of insecticide resistance and the various factors selecting resistant populations of mosquitoes. This research targeted the analysis of breeding sites and the oviposition behaviour of susceptible and resistant populations of Anopheles in localities of spilled petroleum products. The aim was to establish the possible contribution of oil spillage in the selection of pyrethroid resistance in malaria vectors. Methods Anopheles breeding sites were identified and the insecticide susceptibility of the Anopheles gambiae populations mapped in 15 localities of South Western Nigeria. The presence of oil particles as well as the turbidity, the dissolved oxygen and the pH of each identified breeding site was recorded. Data were cross-analysed to correlate the habitat types and the insecticide susceptibility status of emerging mosquitoes. The second phase of this study was basically a laboratory model to provide more information on the implication of the spillage of petroleum on the selection of pyrethroid resistance in An. gambiae. Results Moderate levels of resistance following exposure to permethrin-impregnated papers were recorded with the majority of An. gambiae samples collected in the South Western Nigeria. Data from this study established a link between the constituency of the breeding sites and the resistance status of the emerging Anopheles. Conclusion This study has revealed the segregational occupation of breeding habitats by pyrethroid resistant and susceptible strains of An. gambiae in south-western Nigeria. Compiled results from field and laboratory research point out clear relationships between oil spillage and pyrethroid resistance in malaria vectors. The identification of this factor of resistance could serve as strong information in the management of insecticide resistance in some West African settings.

Kossou Hortense

2007-12-01

177

Aqueous Neem Extract Versus Neem Powder on Culex quinquefasciatus: Implications for Control in Anthropogenic Habitats  

Science.gov (United States)

Control programs using conventional insecticides to target anthropogenic mosquito habitats are very expensive because these habitats are widespread, particularly in cities of most African countries. Additionally, there are serious environmental concerns regarding large-scale application of most conventional insecticides. Clearly there is a need for alternative methods that are more effective, less expensive, and environmentally friendly. One such method would be the application of preparations made from parts of the neem tree, Azadirachta indica A. Jussieu (Sapindales: Meliaceae). In this study, aqueous crude extracts and crude powder were prepared from different parts of neem, and the efficacies of the preparations on juvenile stages of Culex quinquefasciatus Say (Diptera: Culicidae) were evaluated in the laboratory. When larvae were exposed to a concentration of 0.1 g/mL extract for 24 hours, percent mean mortality (± SE) was 72.7 plusmn; 1.8 for the bark, 68.7 ± 1.6 for fruits and 60 ± 1.6 for leaves. These means were not significantly different (?2 = 4.12; df = 2; p = 0.127). At a concentration of 0.01 g/mL, > 95% of the larvae died within 24 hours of exposure to powdered neem leaf, but it took 120 hours to reach the same level of larval mortality in aqueous leaf extract. The crude extract slowly inhibited the growth and development of mosquitoes while the crude powder acted more as a barrier; the mosquitoes probably died from suffocation. However, both types of preparations can be made and used by local people to control mosquito breeding in anthropogenic habitats, especially in urbanized areas. PMID:22233153

Kudom, Andreas A.; Mensah, Ben A.; Botchey, Mary A.

2011-01-01

178

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

Directory of Open Access Journals (Sweden)

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

Fontenille Didier

2011-05-01

179

Mosquito Specimens Making Technology  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito is a kind of important medical insects. Mosquito biological and morphological taxonomic research is the premise of effective control of mosquitoes. Specimen making of the mosquito egg, larvae, pupa and adult, genitalia is essential for taxonomic study. However, the technology for mosquito specimens making is yet to be improved and perfected. With many years of practice and improvement, this paper proposes the ideal and portable tools of specimen making, and the specimen making processing of the eggs, larvae, pupae, larval and pupal exuviae, adults, male and female genitalia, and also introduces the packaging and mailing method of mosquito pincushion specimens and slide specimens. These techniques have a lot of improvements on the basis of earlier protocols, and can provide with for the making, and transport of mosquito specimens.

WANG Chuang-xin

2013-05-01

180

Native Argentinean cyclopoids (Crustacea: Copepoda) as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae) mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops ur...

Tranchida, Mari?a C.; Micieli, Mari?a V.; Arnaldo Maciá; Garci?a, Juan J.

2009-01-01

 
 
 
 
181

Aquatic macrophytes and the associated mosquitoes in and around Madurai City (Tamil Nadu).  

Science.gov (United States)

A survey of mosquitoes was carried out in 7 weeded astatic ponds in and around Madurai from October 1990 to January 1991 to qualitatively determine the macrophyte-mosquito larvae association. Members of Culex vishnui subgroup were associated with most of the macrophytes. Eichhornia crassipes, Marsilea quadrifolia and Spirodella polyrhiza showed a high potential for mosquito breeding and Azolla sp., a very low potential for both anophelines and culicines. PMID:1688022

Victor, T J; Marimuthu, S; Sivaramakrishnan, K G

1991-09-01

182

Brazilian mosquito (Diptera: Culicidae) fauna: I. Anopheles species from Porto Velho, Rondônia state, western Amazon, Brazil / Fauna brasileira de mosquitos (Diptera: Culicidae): I. Espécies de Anopheles de Porto Velho, estado de Rondônia, oeste da Amazônia, Brasil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este estudo contribui para o conhecimento de espécies de Anopheles, incluindo vetores de Plasmodium do oeste da Amazônia brasileira, em Porto Velho, no estado de Rondônia. Esta região vem passando por mudanças ambientais, como consequência de agricultura extensiva e projetos hidroelétricos que causa [...] m desmatamento, favorecendo o desenvolvimento de algumas espécies de mosquitos. Assim, a proposta deste estudo é registrar a presença de espécies de anofelinos na área, sendo conduzidas coletas de mosquitos em três locais, ao longo de uma linha de transmissão de energia elétrica. Cada uma das localidades foi amostrada três vezes, no período de 2010 a 2011. Os principais mosquitos adultos capturados em armadilhas de Shannon foram Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi e An. costai. Assim como as formas larvárias Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. e An. oswaldoi-konderi, coletadas em criadouros. Anopheles darlingi foi a espécie mais coletada na região. Em adição, discutiu-se sistemática de Culicidae, distribuição de fauna e aspectos da malária em ambientes modificados do oeste da Amazônia brasileira. Abstract in english This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondônia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused [...] intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon.

Sirlei Antunes, Morais; Paulo Roberto, Urbinatti; Maria Anice Mureb, Sallum; Adriana Akemi, Kuniy; Gilberto Gilmar, Moresco; Aristides, Fernandes; Sandra Sayuri, Nagaki; Delsio, Natal.

2012-12-01

183

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

Directory of Open Access Journals (Sweden)

Full Text Available Dengue Hemorrhagic Fever (DHF prevention programs in Semarang, were focused through controlling mosquito breeding sites (PSN, but the implementation of PSN was not become a habit in every household. The objective of this study was to explore knowledge and experience of dengue mosquitoes among housewives in the endemic villages.The research was using qualitative methods. Subjects of the study were 17 housewives which selected by purposive sampling. The data collection was carried in Sendangmulyo village, Semarang, through observation, focus groups discussions, and indepth interviews. The techniques used to test data validity were triangulation and member checking method. Data were analyzed using content analysis approached. The results showed that housewives classifying mosquito based on time occurrence whether the presence of mosquito in environment was perceived naturally. Unoptimalized PSN behavior was based on the lack of housewives knowledge on larvae development stages. Mosquito was not considered as a threatening because night mosquito biting was directly more disturbing rather than day mosquitoes’. Health promotion program could increase dasa wisma cadres knowledge and skill, particularly on mosquito life cycle and the correct stages of PSN behavior. This study did not distinguish the demographic characteristics of informants. Further reserch could explore it or develop media based on local knowledge and experience.

Atik Triratnawati

2011-06-01

184

Examining Landscape Factors Influencing Relative Distribution of Mosquito Genera and Frequency of Virus Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito-borne infections cause some of the most debilitating human diseases, including yellow fever and malaria, yet we lack an understanding of how disease risk scales with human-driven habitat changes. We present an approach to study variation in mosquito distribution and concomitant viral infections on the landscape level. In a pilot study we analyzed mosquito distribution along a 10-km transect of a West African rainforest area, which included primary forest, secondary forest, planta...

Junglen, Sandra; Kurth, Andreas; Kuehl, H.; Quan, Phenix-lan; Ellerbrok, Heinz; Pauli, Georg; Nitsche, Andreas; Nunn, Charles L.; Rich, S. M.; Briese, Thomas; Leendertz, Fabian

2009-01-01

185

Larval ecology of mosquitoes in sylvatic arbovirus foci in southeastern Senegal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Although adult mosquito vectors of sylvatic arbovirus [yellow fever (YFV), dengue-2 (DENV-2) and chikungunya (CHIKV)] have been studied for the past 40 years in southeastern Senegal, data are still lacking on the ecology of larval mosquitoes in this area. In this study, we investigated the larval habitats of mosquitoes and characterized their seasonal and spatial dynamics in arbovirus foci. Methods We searched for wet microhabitats, classifie...

Diallo Diawo; Diagne Cheikh T; Hanley Kathryn A; Sall Amadou A; Buenemann Michaela; Ba Yamar; Dia Ibrahima; Weaver Scott C; Diallo Mawlouth

2012-01-01

186

Use of Expanded Polystyrene (EPS) and Shredded Waste Polystyrene (SWAP) Beads for Control of Mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Mosquitoes transmit several diseases to human. There are several measures for control of larvae. As part of Integrated Vector Management (IVM) program, the utility of floating layers of polystyrene beads (EPS) is a po­ten­tial alternative in habitats of mosquito larva. EPS beads prevent oviposition of mosquito as well as killing the im­ma­ture stages by forming a tick layer on the water surface.  They are cheap, environmentally safe and do ...

Soltani, A.; Vatandoost, H.; Jabbari, H.; Ar, Mesdaghinia; Ah, Mahvi; Younesian, M.; Aa, Hanafi-bojd; Bozorgzadeh, S.; MR Abai; Pakari, A.; Shabkhiz, H.

2008-01-01

187

Rationalizing Historical Successes of Malaria Control in Africa in Terms of Mosquito Resource Availability Management.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Environmental management of mosquito resources is a promising approach with which to control malaria, but it has seen little application in Africa for more than half a century. Here we present a kinetic model of mosquito foraging for aquatic habitats and vertebrate hosts that allows estimation of malaria transmission intensity by defining the availability of these resources as the rate at which individual mosquitoes encounter and use them. The model captures historically observed responses of...

Killeen, Gerry F.; Seyoum, Aklilu; Knols, Bart G. J.

2004-01-01

188

Origin of the Dengue Fever Mosquito, Aedes aegypti, in California  

Science.gov (United States)

Dengue fever is among the most widespread vector-borne infectious diseases. The primary vector of dengue is the Aedes aegypti mosquito. Ae. aegypti is prevalent in the tropics and sub-tropics and is closely associated with human habitats outside its native range of Africa. While long established in the southeastern United States of America where dengue is re-emerging, breeding populations have never been reported from California until the summer of 2013. Using 12 highly variable microsatellite loci and a database of reference populations, we have determined that the likely source of the California introduction is the southeastern United States, ruling out introductions from abroad, from the geographically closer Arizona or northern Mexico populations, or an accidental release from a research laboratory. The power to identify the origin of new introductions of invasive vectors of human disease relies heavily on the availability of a panel of reference populations. Our work demonstrates the importance of generating extensive reference databases of genetically fingerprinted human-disease vector populations to aid public health efforts to prevent the introduction and spread of vector-borne diseases. PMID:25077804

Gloria-Soria, Andrea; Brown, Julia E.; Kramer, Vicki; Hardstone Yoshimizu, Melissa; Powell, Jeffrey R.

2014-01-01

189

Olfaction in mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Female mosquitoes are vectors of diseases, affecting both livestock and humans. The host-seeking and identification behaviors of mosquitoes are mediated mainly by olfactory cues. The peripheral olfactory organs of mosquitoes which perceive olfactory cues are the antennae and maxillary palps. These appendages bear numerous hair shaped structures, sensilla, in which olfactory receptor neurons (ORNs) are housed. The ORNs detect and discriminate various odorant molecules and send information rega...

Ghaninia, Majid

2007-01-01

190

Bacterial communities associated with culex mosquito larvae and two emergent aquatic plants of bioremediation importance.  

Science.gov (United States)

Microbes are important for mosquito nutrition, growth, reproduction and control. In this study, we examined bacterial communities associated with larval mosquitoes and their habitats. Specifically, we characterized bacterial communities associated with late larval instars of the western encephalitis mosquito (Culextarsalis), the submerged portions of two emergent macrophytes (California bulrush, Schoenoplectuscalifornicus and alkali bulrush, Schoenoplectusmaritimus), and the associated water columns to investigate potential differential use of resources by mosquitoes in different wetland habitats. Using next-generation sequence data from 16S rRNA gene hypervariable regions, the alpha diversity of mosquito gut microbial communities did not differ between pond mesocosms containing distinct monotypic plants. Proteobacteria, dominated by the genus Thorsellia (Enterobacteriaceae), was the most abundant phylum recovered from C. tarsalis larvae. Approximately 49% of bacterial OTUs found in larval mosquitoes were identical to OTUs recovered from the water column and submerged portions of the two bulrushes. Plant and water samples were similar to one another, both being dominated by Actinobacteria, Bacteroidetes, Cyanobacteria, Proteobacteria and Verrucomicrobia phyla. Overall, the bacterial communities within C. tarsalis larvae were conserved and did not change across sampling dates and between two distinct plant habitats. Although Thorsellia spp. dominated mosquito gut communities, overlap of mosquito gut, plant and water-column OTUs likely reveal the effects of larval feeding. Future research will investigate the role of the key indicator groups of bacteria across the different developmental stages of this mosquito species. PMID:23967314

Duguma, Dagne; Rugman-Jones, Paul; Kaufman, Michael G; Hall, Michael W; Neufeld, Josh D; Stouthamer, Richard; Walton, William E

2013-01-01

191

Do the Golden-winged Warbler and Blue-winged Warbler Exhibit Species-specific Differences in their Breeding Habitat Use?  

Directory of Open Access Journals (Sweden)

Full Text Available We compared habitat features of Golden-winged Warbler (Vermivora chrysoptera territories in the presence and absence of the Blue-winged Warbler (V. cyanoptera on reclaimed coal mines in southeastern Kentucky, USA. Our objective was to determine whether there are species specific differences in habitat that can be manipulated to encourage population persistence of the Golden-winged Warbler. When compared with Blue-winged Warblers, Golden-winged Warblers established territories at higher elevations and with greater percentages of grass and canopy cover. Mean territory size (minimum convex polygon was 1.3 ha (se = 0.1 for Golden-winged Warbler in absence of Blue-winged Warbler, 1.7 ha (se = 0.3 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 2.1 ha (se = 0.3 for Blue-winged Warbler. Territory overlap occurred within and between species (18 of n = 73 territories, 24.7%. All Golden-winged and Blue-winged Warblers established territories that included an edge between reclaimed mine land and mature forest, as opposed to establishing territories in open grassland/shrubland habitat. The mean distance territories extended from a forest edge was 28.0 m (se = 3.8 for Golden-winged Warbler in absence of Blue-winged Warbler, 44.7 m (se = 5.7 for Golden-winged Warbler coexisting with Blue-winged Warbler, and 33.1 m (se = 6.1 for Blue-winged Warbler. Neither territory size nor distances to forest edges differed significantly between Golden-winged Warbler in presence or absence of Blue-winged Warbler. According to Monte Carlo analyses, orchardgrass (Dactylis glomerata, green ash (Fraxinus pennsylvanica seedlings and saplings, and black locust (Robinia pseudoacacia saplings were indicative of sites with only Golden-winged Warblers. Sericea lespedeza, goldenrod (Solidago spp., clematis vine (Clematis spp., and blackberry (Rubus spp. were indicative of sites where both species occurred. Our findings complement recent genetic studies and add another factor for examining Golden-winged Warbler population decline. Further, information from our study will aid land managers in manipulating habitat for the Golden-winged Warbler.

David S. Maehr

2010-12-01

192

Ross River virus in mosquitoes (Diptera:Culicidae) during the 1994 epidemic around Brisbane, Australia.  

Science.gov (United States)

During the summer 1994 outbreak of epidemic polyarthritis in suburban Brisbane, 29,931 adult female mosquitoes were collected by octenol-CO2 light traps and tested for virus by species in pools of approximately 20 using an in situ enzyme-linked immunoassay. Overall, 63 isolations of Ross River (RR) virus were made from 7 different mosquito species, including 23 from freshwater-breeding Culex annulirostris Skuse, 13 from peridomestic Aedes notoscriptus (Skuse), 4 from Aedes procax (Skuse), 12 from the brackish water-breeding Aedes funereus (Theobald), 9 from saltmarsh Aedes vigilax (Skuse), and 1 each from Culex sitiens Wiedemann and Aedes alternans (Westwood). The RR virus minimum infection rate in mosquitoes ranged from 1.6 to 2.5/1,000 from March to June 1994. This study implicates freshwater and brackish water mosquitoes as important suburban vectors of RR virus and indicates the need for refocusing mosquito control priorities. PMID:9103757

Ritchie, S A; Fanning, I D; Phillips, D A; Standfast, H A; McGinn, D; Kay, B H

1997-03-01

193

Species Composition and Diversity of Mosquitoes in Neka County, Mazandaran Province, Northern Iran  

Directory of Open Access Journals (Sweden)

Full Text Available "nAbstract                                                                                                   "nBackground: Regarding to the significant of the possibility of the malaria epidemic and nuisance of mosquitoes dur­ing the active season, the fauna and some ecological activities of mosquitoes in related to tree holes were investi­gated from April to December 2009 in Neka county of Mazandaran Province, northern Iran. "nMethods: Larval collection was carried out from natural, artificial breeding places, and tree holes inside the forest in Neka County, Mazandaran Province in 2009. In addition, human bait net trap collection was conducted using suction tube several times during this investigation. "nResults: Four genera and five species were found in tree holes. Anopheles plumbeus, Culiseta annulata, Culex  pipiens, and Ochlerotatus geniculatus were collected by larval collection whereas, Ochlerotatus pulcritarsis was found by adult collection. Overall Cx. pipiens 44.6%, Oc. geniculatus 32.6%, An. plumbeus 22.5%, and Cs. annulata 0.3% were collected by larval collection. During the bait net collection five specie were identified including: Oc. genicula­tus 55.87%, Oc. echinus 1.33%, Oc. pulchritarsis 8.8 %, Cx. pipiens 33.8%, and An. plumbeus 0.2%. Cs.  annu­lata larvae was detected for the first time with a low abundance in tree cavity. "nConclusion: Tree holes were found the main habitat for the species of Oc. geniculatus. The species of Cs.  annulata was found in tree holes "n  "nKeywords: Mosquito, fauna, tree holes, diversity, Iran

A Kianinasab

2010-12-01

194

Surveillance should be strengthened to improve epidemiological understandings of mosquito-borne Barmah Forest virus infection  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Barmah Forest virus (BFV is a mosquito-borne virus causing epidemic polyarthritis in Australia. This study used case follow-up of cases from the surveillance system to demonstrate that routinely collected BFV notification data were an unreliable indicator of the true location of exposure.Methods: BFV notifications from June 2001 to May 2011 were extracted from the New South Wales (NSW Notifiable Conditions Information Management System to study case distribution. Disease cluster analysis was performed using spatial scan statistics. Exposure history data were collected from cases notified in 2010 and 2011 to accurately determine travel to high-risk areas.Results: Cluster analysis using address data identified an area of increased BFV disease incidence in the mid-north coast of NSW contiguous with estuarine wetlands. When travel to this area was investigated, 96.7% (29/30 cases reported having visited coastal regions within four weeks of developing symptoms.Discussion: Along the central NSW coastline, extensive wetlands occur in close proximity to populated areas. These wetlands provide ideal breeding habitats for a range of mosquito species implicated in the transmission of BFV. This is the first study to fully assess case exposure with findings suggesting that sporadic cases of BFV in people living further away from the coast do not reflect alternative exposure sites but are likely to result from travel to coastal regions. Spatial analysis by case address alone may lead to inaccurate understandings of the true distribution of arboviral diseases. Subsequently, this information has important implications for the collection of mosquito-borne disease surveillance information and public health response strategies.

David Durrheim

2012-08-01

195

Mosquito, egg raft (image)  

Science.gov (United States)

Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito lays the eggs one at a time sticking them together in the shape of a raft. An egg raft ...

196

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009.Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed.Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively.

A Saghafipour

2012-06-01

197

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009. Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed.Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively.

A Saghafipour

2012-06-01

198

UV light and urban pollution: Bad cocktail for mosquitoes?  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field.

Tetreau, Guillaume, E-mail: guillaume.tetreau@gmail.com [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France); Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456 (United States); Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud’homme, Sophie M.; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France)

2014-01-15

199

Natural and engineered mosquito immunity.  

Science.gov (United States)

A recent paper in BMC Microbiology shows how suppression of mosquito innate immunity against a virus that the mosquito can normally tolerate increases mosquito mortality. This is just one of several approaches that may soon bring genetics-based mosquito control methods from the laboratory into the field. PMID:19439051

Alphey, Luke

2009-01-01

200

Culicinae mosquitoes in Sanandaj county, Kurdistan province, western Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: This study aims at studying mosquito-borne diseases as the major publichealth threat in Iran. Sanandaj outskirts are considered suitable habitats for mosquito larvae. Inview of scanty reports on mosquito-borne disease implementation in this area, a study was undertakento determine the mosquito fauna and frequency of mosquito larvae at Sanandaj City.Methods: In order to study the mosquito (Diptera: Culicidae fauna, the samples were collectedfrom May to July 2009 using dipping and night catch methods in Sanandaj district, Kurdistanprovince, western Iran.Results: Three genera and 11 species of the Culicinae subfamily were identified—Aedes vexansMeigen, Ochlerotatus caspius s.l. Pallas (indicating new occurrence records for the province,Culex hortensis Ficalbi, Cx. pipiens Linnaeus, Cx. mimeticus Noe, Cx. theileri Theobald, Culisetalongiareolata Macquart, and Cs. subochrea Edwards.Interpretation & conclusion: Present study revealed that Ae. vexans and Ochlerotatus caspius s.lcaught had not been previously recorded in Kurdistan province, highlighting the deficient knowledgeof the fauna and distribution of Culicinae mosquitoes of this part of Iran

S.H. Moosa Kazemi

2010-06-01

 
 
 
 
201

UV light and urban pollution: bad cocktail for mosquitoes?  

Science.gov (United States)

Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field. PMID:24275062

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

2014-01-01

202

The mosquitoes (Diptera: Culicidae) in Maliuc (Danube delta)--faunistical and ecological data.  

Science.gov (United States)

The paper reports the results of the survey of the mosquito fauna in the Maliuc area (Danube delta) in 1983-1985. 16 mosquito species have been recorded in the area during the investigations: Anopheles maculipennis--complex, An. hyrcanus, Uranotaenia unguiculata, Coquillettidia richiardii, Culiseta annulata, Aedes vexans, Ae. cinereus, Ae. caspius, Ae. dorsalis, Ae. excrucians, Ae. flavescens, Ae. leucomelas, Ae. intrudens, Culex pipiens, C. martinii, Cx. modestus. They have been captured by light traps, on human bait, with entomological hand net and within an indoor resting site (building). Six types of habitats of adult mosquitoes, taking into account the characteristics of the soil and vegetation have been identified in the area. The quantitative and qualitative differences of the mosquito fauna within these six habitats have been recorded. Also, the suitable capture methods within every habitat have been established. PMID:1983702

Velehorschi, N; Nicolescu, G; Ceianu, C; Giurc?, I; Bîlbîe, I

1990-01-01

203

Habitat Suitability Index Models: Eastern Brown Pelican  

Science.gov (United States)

A review and synthesis of existing information were used to develop a habitat model for the eastern brown pelican (Pelecanus occidentalis carolinensis). The model is scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1.0 (optimal habitat) for coastal areas within the eastern brown pelican's breeding range. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for application of the eastern brown pelican habitat model and techniques for measuring model variables are described.

Hingtgen, Terrence M.; Mulholland, Rosemarie; Zale, Alexander V.

1985-01-01

204

The effect of domestic detergents on the population dynamics of the immature stages of two competitor mosquitoes, Culex cinereus Theobald and Culex quinquefasciatus Say (Diptera, Culicidae) in Kenya.  

Science.gov (United States)

In some rural areas of Kenya pit latrines are the most important breeding places of Culex quinquefasciatus, but this vector is often rapidly displaced by a competitor, Culex cinereus, which then breeds prolifically in the latrines. In urban settlements, however, cesspools are the main breeding sites of C. quinquefasciatus and no such species replacement occurs. These latter habitats contain water contaminated with domestic detergents. When detergents were introduced into a pit latrine colonized only by C. cinereus this mosquito was eliminated after about 3 weeks. When both species were reared in water containing detergents C. cinereus had lower pupal yields than C. quinquefasciatus. In two pit latrines where C. cinereus normally displaced C. quinquefasciatus, the addition of detergent prevented this, and after their coexistence for a few weeks, C. cinereus eventually disappeared. These observations suggest that during the last few decades domestic detergents, together with other pollutants such as insecticides, may have contributed to the elimination of competitors, such as C. cinereus, from C. quinquefasciatus breeding sites. PMID:6143485

Subra, R; Service, M W; Mosha, F W

1984-03-01

205

Altitudinal distribution of mosquitoes in mountainous area of Garhwal region : Part–I  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives : Mosquito fauna diversity in mountainous areas of Garhwal region wasstudied during November 2000 to October 2002 to correlate the altitudinal vegetation and distributionof mosquitoes.Methods : Adult mosquitoes and mosquito immatures were collected using WHO methods and identifiedusing standard keys and catalogues. Altitude of mosquito habitat was measured using portablealtimeter and also by GPS.Results : Altogether 34 species in five genera — Aedes, Anopheles, Armigeres, Culex and Uranotaeniawere encountered in the present study in the altitude range of 300 to 2000 m. Majority of themosquitoes were found in between 300 to 900 m altitude except Culex vagus and Anopheles maculatus,which were found throughout the range.Interpretation & conclusion : The mosquitoes were categorised into six groups based on their altitudinaldistribution. The areas at lowest elevation were having the greatest number of species but notthe corresponding greater number of specimens in the present study.

N. Pemola Devi , R.K. Jauhari

2004-03-01

206

Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs  

Directory of Open Access Journals (Sweden)

Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

Todd G. Smith

2012-04-01

207

PERCEPTIONS REGARDING MOSQUITO BORNE DISEASES IN AN URBAN AREA OF RAJKOT CITY  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Mosquito borne diseases is a growing urban problem because of unplanned urbanization, industrialization and excessive population growth coupled with rural to urban migration. For developing a suitable and effective health education strategy, it is inevitable to understand the level of knowledge of the community, their attitude and practices regarding mosquito borne diseases. Materials and Methods: The present study was carried out in an urban field practice area of Urban Health Centre in Rajkot city. Total 500 houses were selected for study by systematic random sampling. Data was collected using a semi-structured questionnaire during transmission season of vector borne diseases. The results were analyzed using the SPSS 17 software. Results: 90% respondents agreed that mosquitoes are a problem. 30.4% didn?t know breeding sites of mosquitoes. Only 11.6% of people associated clean water collections with mosquito breeding. Regarding diseases transmitted by mosquito, 62% answered malaria, 37.4% were not aware and 8.8% people mentioned about Filariasis, Dengue or Japanese encephalitis. 4.7% granted mosquito control as responsibility of community. 61.4 % were using repellents for prevention against mosquito bites and 39% not taking any preventive measure. 67.8% consulted private practitioner for treatment. Conclusion: Intensified efforts towards creating public awareness and mobilizing the community regarding the preventive measures they can take are needed. [National J of Med Res 2011; 1(2.000: 45-47

Amul B. Patel

2011-04-01

208

Higher Mosquito Production in Low-Income Neighborhoods of Baltimore and Washington, DC: Understanding Ecological Drivers and Mosquito-Borne Disease Risk in Temperate Cities  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito-vectored pathogens are responsible for devastating human diseases and are (reemerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC. Seven species of mosquito larvae were recorded. The invasive Aedes albopictus was the only species found in all neighborhoods. Culex pipiens, a primary vector of West Nile virus (WNV, was most abundant in Baltimore, which also had more tire habitats. Both Culex and Aedes pupae were more likely to be sampled in neighborhoods categorized as being below median income level in each city and Aedes pupae density was also greater in container habitats found in these lower income neighborhoods. We infer that lower income residents may experience greater exposure to potential disease vectors and Baltimore residents specifically, were at greater risk of exposure to the predominant WNV vector. However, we also found that resident-reported mosquito nuisance was not correlated with our measured risk index, indicating a potentially important mismatch between motivation needed to engage participation in control efforts and the relative importance of control among neighborhoods.

Danielle Bodner

2013-04-01

209

Mosquito Surveillance for Prevention and Control of Emerging Mosquito-Borne Diseases in Portugal — 2008–2014  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program—REVIVE (REde de VIgilância de VEctores—has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes—collected mainly with Centre for Disease Control light traps baited with CO2—and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III. Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs.

Hugo C. Osório

2014-11-01

210

Mosquito surveillance for prevention and control of emerging mosquito-borne diseases in portugal - 2008-2014.  

Science.gov (United States)

Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program-REVIVE (REde de VIgilância de VEctores)-has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV) and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes-collected mainly with Centre for Disease Control light traps baited with CO2-and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III). Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs) non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs. PMID:25396768

Osório, Hugo C; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria J

2014-01-01

211

Distribution and occurrence of mosquito species in the municipal areas of Imo State, Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A study of the ecology of drainage - breeding mosquito vectors was conducted in the three urban centers (Owerri, Orlu and Okigwe) of Imo State, Nigeria. Four drainage sites located around markets, residential, stream and hotel premises were selected in each urban centre. Dipping method of sampling was employed and a total of 8,820 mosquitoes comprising eight species namely; Aedes aegypti, Aedes vittatus, Culex quinquefasciatus, Culex tigripes, Culex horridus, Culex cinereus, Culex annuliorus ...

Mgbemena, Ifeyinwa Celestina; Ebe, Tochi

2012-01-01

212

Seasonal and diel patterns of biting midges (Ceratopogonidae) and mosquitoes (Culicidae) on the Parris Island Marine Corps Recruit Depot.  

Science.gov (United States)

The Marine Corps Recruit Depot on Parris Island, SC, is surrounded by tidal salt marshes, which are breeding habitats for many pestiferous biting flies. Knowledge of biting fly behavior patterns is needed to develop effective pest management strategies in urban areas adjacent to salt marshes. We measured biting midge (Ceratopogonidae) and mosquito (Culicidae) seasonal abundance and diel activity patterns on Parris Island using CO(2)-baited suction traps from November 2001 - November 2004. Of the three biting midge species collected, Culicoides furens was most abundant (86.2% of total) and was present in high numbers from late March to November. Culicoides hollensis (12.0% of total) was present during spring and fall but absent in summer and winter; and Culicoides melleus (1.7% of total) was present in spring through fall but absent in winter. Abundance of C. furens had a positive linear correlation with air temperature and rainfall. There were nonlinear correlations between air temperature and C. hollensis and C. melleus numbers, which were most abundant at moderate temperatures. Of 18 mosquito species collected, the most abundant were Aedes taeniorhynchus (42.7% of total), Aedes sollicitans (26.3% of total), Culex salinarius (15.6% of total), Culex quinquefasciatus (7.3% of total), and Aedes vexans (5.7% of total); other species comprised <5% of collections. Aedes taeniorhynchus numbers were positively correlated with temperature and rainfall, and Cx. salinarius was correlated with soil moisture. Activity of most biting midges and mosquitoes were highest the first two hours following sunset. Species of biting flies were present in all months, suggesting that year-round control measures are necessary to reduce exposure to potential disease vectors and nuisance biting. PMID:20836813

Breidenbaugh, Mark S; Clark, James W; Brodeur, Robert M; de Szalay, Ferenc A

2009-06-01

213

Transfer of toxin genes to alternate bacterial hosts for mosquito control  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquitoes are vector of serious human and animal diseases, such as malaria, dengue, yellow fever, among others. The use of biological control agents has provide an environmentally safe and highly specific alternative to the use of chemical insecticides in the control of vector borne diseases. Bacillus thuringiensis and B. sphaericus produce toxic proteins to mosquito larvae. Great progress has been made on the biochemical and molecular characterization of such proteins and the genes encoding them. Nevertheless, the low residuality of these biological insecticides is one of the major drawbacks. This article present some interesting aspects of the mosquito larvae feeding habits and review the attempts that have been made to genetically engineer microorganisms that while are used by mosquito larvae as a food source should express the Bacillus toxin genes in order to improve the residuality and stability in the mosquito breeding ponds.

Sergio Orduz

1995-02-01

214

Breeding patterns of the JE vector Culex gelidus and its insect predators in rice cultivation areas of northern peninsular Malaysia.  

Science.gov (United States)

Japanese encephalitis (JE) virus activity is an important cause of viral encephalitis in Southeast Asia. In Malaysia, JEV activity has been first detected in Culex gelidus in 1976. Since then, no study has fully addressed the seasonal dynamics of this mosquito. As irrigated rice production expands, the incidence of JEV vectors, particularly Cx. gelidus is expected to increase. We surveyed Penang Island to determine the breeding patterns of Cx. gelidus and their potential insect predators, in relation to habitat/niche and rice growing period. Six rice fields proper (RFP) and related drainage canals (DC) were visited through three cultivation cycles (CCs) over 17 months. Weekly visits were performed to each of the 36 sites and mosquito larvae and aquatic insects were sampled from RFP and DCs using dippers. Culex gelidus was abundant in RFP and almost absent in DCs. Its densities usually were high during the first and 3rd CC and when the RFs were in Fp, Pp and Gp. In DCs, the mosquito was abundant during Mp, e.g., 2nd CC. Predators, especially those belonging to the families Corixidae, Coenagrionidae and Dytiscidae, were more present in RFP. Predator numbers usually were high during the first CC; in some cases predator abundance peaked during other CCs, e.g., corixids and dysticids. In RFP, neither corixids nor coenagrionids showed any positive correlation with densities of Cx. gelidus. However, dytiscids' population peaked when the mosquito densities were on the rise. These observations suggest that Cx. gelidus is active during the period of rice cultivation. Operational vector control through bio-control or with insecticides near the end of the rice cultivation season in RFP may prove beneficial in reducing the density of Cx. gelidus, but also the amount of bio-agent or insecticide applied on riceland. PMID:21399580

Abu Hassan, A; Hamady, D; Tomomitsu, S; Michael, B; Jameel S L, A S

2010-12-01

215

Flavivirus-Mosquito Interactions  

Directory of Open Access Journals (Sweden)

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.

Yan-Jang S. Huang

2014-11-01

216

Study of mosquito attractants for photo catalytic mosquito trap  

Directory of Open Access Journals (Sweden)

Full Text Available Photo catalytic mosquito trap is made of TiO2-Activated Carbon (AC with a certain composition of AC. Research concerns on the heat spectrum which is produced by combination process of existing CO2 and humid air. The purpose of performance testing is to observe capability of this device in trapping mosquitoes related to the air temperature profile for heat spectrum is play important role for attracting mosquitoes. Result shows photo catalytic mosquito trap is more effective than devices which only consist of UV light or stream of CO2 and the humid air. A number of mosquitoes trapped by the photo catalyst coated panel configuration and UV lamps were lit proved far more effective because the heat production from recombination process. A little difference in temperature can be detected by mosquito.   Keywords: Photo Catalytic, Mosquito, Recombination.

Dewi Tristantini

2014-01-01

217

Contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to UV-A.  

Science.gov (United States)

Mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. Because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. Numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. Mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure. This ecological feature may affect the general physiology of the insect, including the resistance status against insecticides. In the context of their contrasted breeding sites, we assessed the impact of low-energetic ultraviolet exposure on mosquito sensitivity to biological and chemical insecticides. We show that several mosquito detoxification enzyme activities (cytochrome P450, glutathione S-transferases, esterases) were increased upon low-energy UV-A exposure. Additionally, five specific genes encoding detoxification enzymes (CYP6BB2, CYP6Z7, CYP6Z8, GSTD4, and GSTE2) previously shown to be involved in resistance to chemical insecticides were found over-transcribed in UV-A exposed mosquitoes, revealed by RT-qPCR experiments. More importantly, toxicological bioassays revealed that UV-exposed mosquitoes were more tolerant to four main chemical insecticide classes (DDT, imidacloprid, permethrin, temephos), whereas the bioinsecticide Bacillus thuringiensis subsp. israelensis (Bti) appeared more toxic. The present article provides the first experimental evidence of the capacity of low-energy UV-A to increase mosquito tolerance to major chemical insecticides. This is also the first time that a metabolic resistance to chemical insecticides is linked to a higher susceptibility to a bioinsecticide. These results support the use of Bti as an efficient alternative to chemical insecticides when a metabolic resistance to chemicals has been developed by mosquitoes. PMID:23911355

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Raveton, Muriel; Reynaud, Stéphane

2013-09-15

218

A Tale of Two City Blocks: Differences in Immature and Adult Mosquito Abundances between Socioeconomically Different Urban Blocks in Baltimore (Maryland, USA  

Directory of Open Access Journals (Sweden)

Full Text Available Infrastructure degradation in many post-industrial cities has increased the availability of potential mosquito habitats, including container habitats that support infestations of invasive disease-vectors. This study is unique in examining both immature and adult mosquito abundance across the fine-scale variability in socio-economic condition that occurs block-to-block in many cities. We hypothesized that abundant garbage associated with infrastructure degradation would support greater mosquito production but instead, found more mosquito larvae and host-seeking adults (86% in parcels across the higher socio-economic, low-decay block. Aedes albopictus and Culex pipiens were 5.61 (p < 0.001 and 4.60 (p = 0.001 times more abundant, respectively. Most discarded (garbage containers were dry during peak mosquito production, which occurred during the 5th hottest July on record. Containers associated with human residence were more likely to hold water and contain immature mosquitoes. We propose that mosquito production switches from rain-fed unmanaged containers early in the season to container habitats that are purposefully shaded or watered by mid-season. This study suggests that residents living in higher socioeconomic areas with low urban decay may be at greater risk of mosquito-borne disease during peak mosquito production when local container habitats are effectively decoupled from environmental constraints.

Brian Becker

2014-03-01

219

Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.  

Science.gov (United States)

This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

Barrett, Katharine; Willard, Carolyn

220

Mosquito glutathione transferases.  

Science.gov (United States)

The glutathione transferases (glutathione S-transferases, GSTs) are a diverse family of enzymes involved in a wide range of biological processes, many of which involve the conjugation of the tripeptide glutathione to an electrophilic substrate. Relatively little is known about the endogenous substrates of mosquito GSTs, and most studies have focused on their role in insecticide metabolism, because elevated levels of GST activity have been associated with resistance to all the major classes of insecticides. In addition, there is growing interest in the role of this enzyme family in maintaining the redox status of the mosquito cell, particularly in relation to vectorial capacity. Most GSTs are cytosolic dimeric proteins, although a smaller class of microsomal GSTs exists in insects, mammals, and plants. Each GST subunit has a G site that binds glutathione and a substrate-binding site or H site. There are more than 30 GST genes in mosquitoes. Additional diversity is contributed by alternative splicing to produce GSTs with differing substrate specificities. In this review, we first discuss the diversity of insect GST enzymes and their mode of action before focusing on the various functions that have been attributed to specific mosquito GSTs. PMID:16399389

Ranson, Hilary; Hemingway, Janet

2005-01-01

 
 
 
 
221

Population control of the malaria vector Anopheles pseudopunctipennis by habitat manipulation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Insect vector-borne diseases continue to present a major challenge to human health. Understanding the factors that regulate the size of mosquito populations is considered fundamental to the ability to predict disease transmission rates and for vector population control. The mosquito, Anopheles pseudopunctipennis, a vector of Plasmodium spp., breeds in riverside pools containing filamentous algae in Mesoamerica. Breeding pools along 3 km sections of the River Coatan, Chiapas, Mexico were subje...

Bond, J. Guillermo; Rojas, Julio C.; Arredondo-jime?nez, Juan I.; Quiroz-marti?nez, Humberto; Valle, Javier; Williams, Trevor

2004-01-01

222

Mosquito community structure in phytotelmata from a South American temperate wetland.  

Science.gov (United States)

Phytotelmata, or plant-held waters, are considered to be good model systems for the study of community ecology. The fauna of these natural container habitats, particularly the mosquitoes, have been extensively investigated in tropical regions, but there is little known about them in temperate South America. We assessed the structure of immature mosquito communities in leaf axils, tree holes, and bamboo stumps from a temperate wetland of Argentina. A total of 4,330 immature mosquitoes were collected among the 2,606 phytotelmata inspected. Leaf axils of eight plant species and tree holes were larval habitats for nine mosquito species belonging to the genus Culex, Wyeomyia, Isostomyia, and Toxorhynchites. The mosquito communities showed richness ranging from one to four species. Marked differences were detected in the plant specificity for the species collected. Some of them were exclusively found in one plant species (Isostomyia paranensis in Scirpus giganteus), whereas others were collected in up to five plant species but belonging to the same phytotelm class, the leaf axils. Those from tree holes are well-known dwellers of artificial containers and ground water habitats, such as Culex pipiens. Our results support the idea of low mosquito richness in phytotelmata from temperate regions in comparison with tropical areas, but the observed specificity patterns echo the findings of tropical forests. PMID:22129416

Albicócco, Andrea Paola; Carbajo, Aníbal Eduardo; Vezzani, Darío

2011-12-01

223

New Zealand's northern mosquito survey, 1988-89.  

Science.gov (United States)

The latest mosquito survey of the warmer regions of New Zealand (NZ) sampled 2,304 larval mosquito habitats of all major categories. While revealing no evidence of new establishments of exotic mosquitoes, it produced important data revealing the underutilization of types of habitats that could be invaded now or in the future (especially if the "greenhouse effect" eventually causes even quite small rises in average temperatures and sea levels). Although long feared additions of malaria vectors to a fauna still lacking any species of Anopheles, or of essentially tropical arbovirus vectors from neighboring countries to the north and northeast, may not materialize failing climatic amelioration, a new danger appeared at the beginning of the 1988-89 Northern Mosquito Survey when Aedes albopictus was reported for the first time from Fiji. This vector of dengue hemorrhagic fever and Ross River virus has since been spreading widely on the archipelago's main island, Viti Levu, whence much air and sea traffic reaches NZ. Information presented and discussed herein strongly supports the continuance and improvement of international aircraft disinsection and other insect quarantine measures. PMID:1973449

Laird, M

1990-06-01

224

Environmental management of mosquito-borne viruses in Rhode Island  

Science.gov (United States)

West Nile Virus (WNV) and Eastern Equine Encephalitis Virus (EEEV) are both primarily bird viruses, which can be transmitted by several mosquito species. Differences in larval habitats, flight, and biting patterns of the primary vector species result in substantial differences in epidemiology, with WNV more common, primarily occurring in urban areas, and EEEV relatively rare, typically occurring near swamp habitats. The complex transmission ecology of these viruses complicates prediction of disease outbreaks. The Rhode Island Department of Environmental Management (DEM) and Department of Health (DoH) provide prevention assistance to towns and maintain a mosquito surveillance program to identify potential disease risk. Responses to potential outbreaks follow a protocol based on surveillance results, assessment of human risk, and technical consultation.

Ginsberg, Howard S.; Gettman, Alan; Becker, Elisabeth; Bandyopadhyay, Ananda S.; Lebrun, Roger A.

2013-01-01

225

Native Argentinean cyclopoids (Crustacea: Copepoda) as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae) mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversi [...] dad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis Abstract in english Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cy [...] clopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis

María C, Tranchida; María V, Micieli; Arnaldo, Maciá; Juan J, García.

226

Native Argentinean cyclopoids (Crustacea: Copepoda) as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae) mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversi [...] dad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis Abstract in english Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cy [...] clopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis

María C, Tranchida; María V, Micieli; Arnaldo, Maciá; Juan J, García.

1059-10-01

227

Mosquito-Degradative-Potential of Cockroach and Mosquito Borne Bacteria  

Directory of Open Access Journals (Sweden)

Full Text Available The type of bacteria present on two insects (cockroach and mosquito were investigated. These microorganisms were screened for microbial control of mosquito employing their degradative ability at various microbial cell loads. The degradation of the mosquito was observed spectrophotometrically for an incubation period of 5 to 7 days. Six bacterial species (Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Serratia marcescens, Staphylococcus aureus and Aerobacter aerogenes were isolated from cockroach. Mosquito borne E. coli, P. aeruginosa, B. cereus and Staph. aureus. All the bacteria digested the mosquito with activity ranging from 0.02 to 1.27. Microorganisms associated with cockroach showed higher degradation activity (0.02-1.27 during the incubation than those obtained from mosquito (0.02-1.00.

F.O. Omoya

2009-01-01

228

Temporal and spatial stability of Anopheles gambiae larval habitat distribution in Western Kenya highlands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Localized mosquito larval habitat management and the use of larvicides have been proposed as important control tools in integrated malaria vector management programs. In order to optimize the utility of these tools, detailed knowledge of the spatial distribution patterns of mosquito larval habitats is crucial. However, the spatial and temporal changes of habitat distribution patterns under different climatic conditions are rarely quantified and their impli...

Zhou Guofa; Yakob Laith; Bian Ling; Li Li(State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China); Yan Guiyun

2009-01-01

229

Estructura y fenología reproductiva de una población remanente de Adesmia bijuga Phil., Fabaceae, en un hábitat costero mediterráneo perturbado de Chile central / Structure and breeding phenology of a remaining population of Adesmia bijuga Phil., Fabaceae, in a mediterranean coastal habitat disturbed of central Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish [...] Abstract in english In this note we examine the population structure and breeding phenology of Adesmia bijuga Phil. The area of development of the study was Curepto, Maule Región, central Chile. Our results indicate a high vulnerability of local extinction of the studied population due low population size and disturbed [...] habitat. Flowering and fructification of individuals exists, nevertheless absence of seedlings suggesting restrictions to the regeneration in the population of A. bijuga. It is recommended to continue with the research. Actions of conservation ex situ for the species are realized by the botanical garden of the Talca University.

PERSY, GÓMEZ; STEFFEN, HAHN; JOSÉ, SAN MARTÍN.

2014-06-01

230

Dog Breeds  

Science.gov (United States)

Recently, designer mutts like the Labradoodle -- a cross between a Labarador retriever and a poodle -- have become popular. A listener wanted to know if some kinds of dogs are just too different to make puppies. This Science Update explores the cross breeding of species.

;

2004-07-05

231

Simulated Breeding  

Science.gov (United States)

This chapter describes a basic framework of simulated breeding, a type of interactive evolutionary computing to breed artifacts, whose origin is Blind Watchmaker by Dawkins. These methods make it easy for humans to design a complex object adapted to his/her subjective criteria, just similarly to agricultural products we have been developing over thousands of years. Starting from randomly initialized genome, the solution candidates are improved through several generations with artificial selection. The graphical user interface helps the process of breeding with techniques of multifield user interface and partial breeding. The former improves the diversity of individuals that prevents being trapped at local optimum. The latter makes it possible for the user to fix features he/she already satisfied. These methods were examined through artistic applications by the author: SBART for graphics art and SBEAT for music. Combining with a direct genome editor and exportation to another graphical or musical tool on the computer, they can be powerful tools for artistic creation. These systems may contribute to the creation of a type of new culture.

Unemi, Tatsuo

232

Habitats and Distribution of Anopheles Sinensis and Associated Anopheles Hyrcanus Group in Japan.  

Science.gov (United States)

Mosquito collections were carried out in August 2002 and July 2003 in Japan. Anopheles sinensis of the Hyrcanus Group. Myzomyia Series of Anopheles. was the most common species encountered. The distribution and habitats of 5 Anopheles Hyrcanus Group speci...

B. F. Prendergast, L. M. Rueda, M. Iwakami, M. Mogi, M. O'Guinn

2005-01-01

233

SPECIES COMPOSITION AND WNV SCREENING OF MOSQUITOES FROM LAGOONS IN A WETLAND AREA OF THE ALGARVE, PORTUGAL.  

Directory of Open Access Journals (Sweden)

Adult mosquitoes were collected with CDC traps baited with CO2, and potential breeding sites were surveyed for immature stages. Morphological identification of 1,432 adult mosquitoes and 85 larvae revealed the presence of 10 species: Anopheles atroparvus, An. algeriensis, Coquillettidia richiardii, Culex modestus, Cx. pipiens, Cx. theileri, Cx. univittatus, Culiseta longiareolata, Aedes caspius and Ae. detritus. Adult mosquito peak densities were recorded in July, contrasting with null larval breeding in the same month in the surveyed biotopes. Most abundant species were Cx. pipiens (52%, Cx. theileri (29% and Ae. caspius (11%. Lagoon Salgados and Quinta das Salinas, exhibited the highest similarity of culicid fauna, despite being most distant from each other, Female mosquitoes (1,249 specimens screened by RT-PCR, did not reveal WNV products. However, previous detection of WNV activity in this area, susceptible to re-introductions, demands for continued vigilance.

A. PauloGouveiaAlmeida

2012-01-01

234

A Tale of Two City Blocks: Differences in Immature and Adult Mosquito Abundances between Socioeconomically Different Urban Blocks in Baltimore (Maryland, USA)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Infrastructure degradation in many post-industrial cities has increased the availability of potential mosquito habitats, including container habitats that support infestations of invasive disease-vectors. This study is unique in examining both immature and adult mosquito abundance across the fine-scale variability in socio-economic condition that occurs block-to-block in many cities. We hypothesized that abundant garbage associated with infrastructure degradation would support greater mosquit...

Brian Becker; Leisnham, Paul T.; Ladeau, Shannon L.

2014-01-01

235

Seasonal mosquito larval abundance and composition in Kibwezi, lower eastern Kenya  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: Changes in weather patterns especially rainfall affects the distribution and densities of mosquitoes. The objective of this study was to describe mosquito aquatic habitats, to determine larval abundance, species composition, and habitat types found in Kasayani village of Kibwezi division.Methods: A cross-sectional survey of mosquito larval habitats was conducted in Kasayani village in Kibwezi division to determine species composition, larval abundance, and habitat types found in this village. This survey was conducted during the rainy season in November and December 2006 and during the dry season in February and March 2007. Larvae were collected using the standard dipping technique and a total of 24 habitats were sampled. The primary habitats identified were water reservoir tanks, puddles, temporary pools, and tyre tracks. Results: A total of 2660 mosquito larvae were collected of which 2140 (80.45% were culicines, 503 (18.91% were Anopheles and 17 (0.64% were pupae. For culicines, 1787 (83.5% were categorized as early instars and 353 (16.5% were as late instars while in the Anopheles, 425 (84.49% were classified as early instars and 78 (15.51% were late instars. Morphological identification of the III and IV instar larvae by use of microscopy yielded 16.24% (n = 70 Anopheles gambiae complex, 1.16% (n = 5 An. funestus, 0.70% (n = 3 An. coustani, 42.46% (n = 183 Culex quinquefasciatus, 6.26% (n = 27 Cx. duttoni, and 33.18% (n = 143 Ae. aegypti. Puddles, tyre tracks and pools had highly turbid water while water reservoir tanks had clear water. Anopheles gambiae and Cx. quinquefasciatus were found in all habitat categories while Ae. aegypti were found only in water storage tanks. Interpretation & conclusion: The mosquito larval densities indicate that the inhabitants of this village are at risk of mosquito-borne diseases including malaria, which is one of the greatest causes of morbidity and mortality in this area. Furthermore, mosquito control measures targeting both the mosquito immatures and adults should be enhanced especially during the rainy season to ensure maximum protection of the inhabitants.

Joseph M. Mwangangi

2009-02-01

236

Effect of ten chlorophytes on larval survival, development and adult body size of the mosquito Aedes aegypti.  

Science.gov (United States)

The effect of ten microalgal chlorophytes isolated from mosquito breeding containers on the survival, larval development and adult body size of the mosquito Aedes aegypti was investigated. All larvae fed with six of the microalgal isolates died after 7 days. These isolates were found to be resistant to digestion by mosquito larvae. Delayed pupation and body size reduction of the mosquitos fed with Chlorococcum UMACC 218 and Scenedesmus UMACC 220 were observed. In contrast, larvae fed with Ankistrodesmus convolutus UMACC 101 and Chlorococcum UMACC 213 were bigger in size than those fed with normal insectory feed. The present study showed that microalgal chlorophytes have the potential to be used as larvicidal agents for mosquitos. PMID:15272748

Ahmad, Rohani; Chu, Wan-Loy; Ismail, Zamree; Lee, Han-Lim; Phang, Siew-Moi

2004-03-01

237

Molecular Epidemiology of Japanese Encephalitis Virus in Mosquitoes in Taiwan during 2005–2012  

Science.gov (United States)

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

2014-01-01

238

Influence of density on intraguild predation of aquatic Hemiptera (Heteroptera: implications in biological control of mosquito  

Directory of Open Access Journals (Sweden)

Full Text Available The water bugs Diplonychus rusticus (Fabricius (Heteroptera: Belostomatidae and Anisops bouvieri (Kirkaldy (Heteroptera: Notonectidae co-occur in wetlands sharing mosquito larvae as prey. As a consequence, an asymmetrical intraguild predation (IGP involving D. rusticus as IG predator and A. bouvieri as IG prey can be possible, the outcome of which may vary with the relative density of interacting species. Based on this proposition density dependent effects on the IG prey and shared prey mortality were assessed in the laboratory using varying numbers of IG predator and shared prey (IV instar Culex quinquefasciatus larva. In contrast to single predator system, mosquito larvae were proportionately less vulnerable to predation in IGP, at low density of shared prey. An increase in density of mosquito decreased the mortality of IG prey (A. bouvieri, but the mean mortality of the IG prey increased with the density of IG predator, in IGP system. Increase in density of mosquito and D. rusticus enhanced risk to predation of mosquito while reducing the mortality of A. bouvieri. Interaction between D. rusticus and A. bouvieri as a part of IGP system provides a possible reason of coexistence of mosquito immature along with predators in wetlands. Biological regulation of mosquitoes may be affected, if appropriate predator numbers are not available in the habitats.

S. Brahma

2014-04-01

239

Molecular Epidemiology of Japanese Encephalitis Virus in Mosquitoes in Taiwan during 2005-2012.  

Science.gov (United States)

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

2014-10-01

240

Leaf-associated bacterial and fungal taxa shifts in response to larvae of the tree hole mosquito, Ochlerotatus triseriatus.  

Science.gov (United States)

Larvae of the eastern tree hole mosquito, Ochlerotatus triseriatus (Say), and related container-breeding species are known to feed upon substrate-associated microorganisms. Although the importance of these microbial resources to larval growth has been established, almost nothing is known about the taxonomic composition and dynamics of these critical microbial food sources. We examined bacterial and fungal community compositional changes on oak leaves tethered in natural tree hole habitats of O. triseriatus. We eliminated larvae experimentally in a subset of the tree holes and examined 16S rDNA gene sequences for bacteria and ergosterol concentrations and 18S rRNA gene sequences for fungi collected from leaf material subsamples. Leaf ergosterol content varied significantly with time, but not treatment. Principal component analysis (PCA) was used to compare microbial taxonomic patterns found in leaves incubated with or without larvae present, and we found that larval presence affected both bacterial and fungal groups, either from loosely attached or strongly adherent categories. Bacterial communities generally grouped more tightly when larvae were present, and class level taxa proportions changed when larvae were present, suggesting selection by larval feeding or activities for particular taxa such as members of the Bacteroidetes, Alphaproteobacteria, and Betaproteobacteria classes. Fungal taxa composite scores also separated along PC axes related to the presence of larvae and indicated larval feeding effects on several higher taxonomic groups, including Saccharomycetes, Dothideomycetes, and Chytridiomycota. These results support the hypothesis that larval mosquito feeding and activities altered microbial communities associated with substrate surfaces, potentially leading to decreased food value of the resource and affecting decomposition of particulate matter in the system. PMID:17899246

Kaufman, Michael G; Chen, Shicheng; Walker, Edward D

2008-05-01

 
 
 
 
241

Temporal and spatial stability of Anopheles gambiae larval habitat distribution in Western Kenya highlands  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Localized mosquito larval habitat management and the use of larvicides have been proposed as important control tools in integrated malaria vector management programs. In order to optimize the utility of these tools, detailed knowledge of the spatial distribution patterns of mosquito larval habitats is crucial. However, the spatial and temporal changes of habitat distribution patterns under different climatic conditions are rarely quantified and their implications to larval control are unknown. Results Using larval habitat data collected in western Kenya highlands during both dry and rainy seasons of 2003-2005, this study analyzed the seasonal and inter-annual changes in the spatial patterns in mosquito larval habitat distributions. We found that the spatial patterns of larval habitats had significant temporal variability both seasonally and inter-annually. Conclusions The pattern of larval habitats is extremely important to the epidemiology of malaria because it results in spatial heterogeneity in the adult mosquito population and, subsequently, the spatial distribution of clinical malaria cases. Results from this study suggest that larval habitat management activities need to consider the dynamic nature of malaria vector habitats.

Zhou Guofa

2009-12-01

242

Geostatistical evaluation of integrated marsh management impact on mosquito vectors using before-after-control-impact (BACI) design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background In many parts of the world, salt marshes play a key ecological role as the interface between the marine and the terrestrial environments. Salt marshes are also exceedingly important for public health as larval habitat for mosquitoes that are vectors of disease and significant biting pests. Although grid ditching and pesticides have been effective in salt marsh mosquito control, marsh degradation and other environmental considerations compel a different app...

Dempsey Mary E; Iwanejko Tom; Rochlin Ilia; Ninivaggi Dominick V

2009-01-01

243

Native Argentinean cyclopoids (Crustacea: Copepoda as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversidad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis < A. robustus < M. albidus < M. longisetus. También se evaluó la tolerancia a la desecación del hábitat y la capacidad de resistir en agua de contenedores artificiales. D. uruguayensis y A. robustus sobrevivieron en condiciones de sequía, pero D. uruguayensis presentó menor supervivencia en agua de floreros de cementerio. M. albidus no sobrevivió condiciones de sequía y no toleró el agua extraída de contenedores artificiales. Los ciclopoides neotropicales D. uruguayensis and A. robustus son buenos candidatos y merecen investigación ulterior como agentes de control biológico de mosquitos.

María C Tranchida

2009-12-01

244

Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Genetically-modified (GM mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available on perspectives to GMOs. Here, results are presented of a qualitative survey of public attitudes to GM mosquitoes for malaria control in rural and urban areas of Mali, West Africa between the months of October 2008 and June 2009. Methods The sample consisted of 80 individuals - 30 living in rural communities, 30 living in urban suburbs of Bamako, and 20 Western-trained and traditional health professionals working in Bamako and Bandiagara. Questions were asked about the cause of malaria, heredity and selective breeding. This led to questions about genetic alterations, and acceptable conditions for a release of pest-resistant GM corn and malaria-refractory GM mosquitoes. Finally, participants were asked about the decision-making process in their community. Interviews were transcribed and responses were categorized according to general themes. Results Most participants cited mosquitoes as one of several causes of malaria. The concept of the gene was not widely understood; however selective breeding was understood, allowing limited communication of the concept of genetic modification. Participants were open to a release of pest-resistant GM corn, often wanting to conduct a trial themselves. The concept of a trial was reapplied to GM mosquitoes, although less frequently. Participants wanted to see evidence that GM mosquitoes can reduce malaria prevalence without negative consequences for human health and the environment. For several participants, a mosquito control programme was preferred; however a transgenic release that satisfied certain requirements was usually acceptable. Conclusions Although there were some dissenters, the majority of participants were pragmatic towards a release of GM mosquitoes. An array of social and cultural issues associated with malaria, mosquitoes and genetic engineering became apparent. If these can be successfully addressed, then social acceptance among the populations surveyed seems promising.

Famenini Shannon

2010-05-01

245

Botanicals as Mosquito Larvicides  

Directory of Open Access Journals (Sweden)

Full Text Available Methanol extracts of 19 indigenous plants were evaluated as mosquito larvicide. Among these, pericarp of Zanthoxylum limonella was found to have the most promising larvicidal properties against Aedes(s albopictus and Culex quinquefasciatus with LC90 values at 0.47 ppm and 0.73 ppm, respectively. The extract of Piper nigrum was also found very effective (LC90 on the larvae of both the species at 6.8 ppm and 8.4 ppm, respectively. The extracts of the remaining plant parts showed LC90 values at above 100 ppm concentration. Extract of Calotropis gigantea was found to be the least effective ( LC90 values at 962.8 ppm and 1091.8 ppm against the larvae of both the species. However, plant extracts were found more effective against Aedes(s albopictus larvae than against Culex quinquefasciatus larvae.

D.R. Nath

2006-10-01

246

Genetic methods for control of mosquitoes and biting flies  

International Nuclear Information System (INIS)

The earliest research efforts on using genetic methods for the control of mosquitoes and biting flies concentrated on the evaluation of the sterile insect technique (SIT). Several successful, but generally small scale, research efforts with mosquitoes clearly documented that either chemosterilized or radiation sterilized males were effective in causing a level of genetic load that would be sufficient for the reduction or eradication of natural populations of several species. Genetic sexing strains of several species of mosquitoes have been assembled, and this aspect of breeding specialty strains is not a limiting factor in the implementation of SIT. In the largest field experiment, conducted with Anopheles albimanus in El Salvador during the 1970s, a genetic sexing strain was used operationally in a factory that produced one million sterile males per day over a one year period. Technical problems that would require extensive research of a practical nature before the implementation of SIT for mosquito control involve primarily better means for the rearing, sterilization and distribution of the insects. A successful experiment was conducted to eliminate the stable fly on the island of St. Croix, the United States Virgin Islands, and since this work in the 1970s, genetic sexing strains have been developed. A considerable amount of effort was expended on the synthesis of chromosome aberrations for the control of mosquitoes. Although the results of experimental trials indigh the results of experimental trials indicated that aberration bearing insects could effectively inject a genetic load into the natural population, no large scale tests have ever been conducted to evaluate fully the real effectiveness of induced chromosomal aberrations. More recently, most of the research work in genetic control has been aimed at the use of recombinant DNA techniques for the development of new technology. All of these topics and an assessment of their value are discussed. (author). 30 refs

247

Native Pig and Chicken Breed Database: NPCDB.  

Science.gov (United States)

Indigenous (native) breeds of livestock have higher disease resistance and adaptation to the environment due to high genetic diversity. Even though their extinction rate is accelerated due to the increase of commercial breeds, natural disaster, and civil war, there is a lack of well-established databases for the native breeds. Thus, we constructed the native pig and chicken breed database (NPCDB) which integrates available information on the breeds from around the world. It is a nonprofit public database aimed to provide information on the genetic resources of indigenous pig and chicken breeds for their conservation. The NPCDB (http://npcdb.snu.ac.kr/) provides the phenotypic information and population size of each breed as well as its specific habitat. In addition, it provides information on the distribution of genetic resources across the country. The database will contribute to understanding of the breed's characteristics such as disease resistance and adaptation to environmental changes as well as the conservation of indigenous genetic resources. PMID:25178289

Jeong, Hyeon-Soo; Kim, Dae-Won; Chun, Se-Yoon; Sung, Samsun; Kim, Hyeon-Jeong; Cho, Seoae; Kim, Heebal; Oh, Sung-Jong

2014-10-01

248

Emperor penguins breeding on iceshelves.  

Science.gov (United States)

We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species. PMID:24416381

Fretwell, Peter T; Trathan, Phil N; Wienecke, Barbara; Kooyman, Gerald L

2014-01-01

249

A geographic information system approach to evaluating the effects of the endangered species protection program on mosquito control.  

Science.gov (United States)

The purpose of this study was to assess what impacts on organized mosquito control the implementation of an Endangered Species Protection Program for the Houston toad might have in Chambers and Harris counties, Texas. The study was also intended to demonstrate the value of using geographic information system (GIS) techniques and methodologies in making such assessments to those in mosquito control who are unfamiliar with GIS and its applications. Using the GIS, Geographical Analysis Support System (GRASS), databases were developed on the habitats and patterns of mosquito control insecticide usage occurring in Chambers and Harris counties. These databases were then employed by means of various utilities associated with GRASS and computer-supported, rule-based reasoning processes to create maps depicting the amount and locations of toad habitat and the areas treated annually with insecticides by districts in Chambers and Harris counties. This map information was then used via other GRASS utilities to identify and depict zones of overlap or coincidence between toad habitat and areas treated with insecticides for mosquito control in the 2 counties. As compared to existing maps for toad habitat, our resulting GIS-generated maps gave more precise, easy-to-use information that could be used to make decisions as to how to protect the toad in the zones of coincidence in each county without causing undue disruption to mosquito control activities in these zones. PMID:9673913

Spradling, S L; Olson, J K; Coulson, R N; Lovelady, C N

1998-06-01

250

Larvicidal activity of neem oil (Azadirachta indica) formulation against mosquitoes  

Science.gov (United States)

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 sites under natural field conditions provided 98.1% reduction of Anopheles larvae on day 1; thereafter 100% reduction was recorded up to week 1 and more than 80% reduction up to week 3, while percent reduction against Culex larvae was 95.5% on day 1, and thereafter 80% reduction was achieved up to week 3. The formulation also showed 95.1% and, 99.7% reduction of Aedes larvae on day 1 and day 2 respectively; thereafter 100% larval control was observed up to day 7. Conclusion The neem oil formulation was found effective in controlling mosquito larvae in different breeding sites under natural field conditions. As neem trees are widely distributed in India, their formulations may prove to be an effective and eco-friendly larvicide, which could be used as an alternative for malaria control. PMID:19500429

Dua, Virendra K; Pandey, Akhilesh C; Raghavendra, Kamaraju; Gupta, Ashish; Sharma, Trilochan; Dash, Aditya P

2009-01-01

251

Cubiertas de auto abandonadas como sitios de cría de Culex eduardoi (Diptera: Culicidae en el Parque Provincial Pereyra Iraola, Provincia de Buenos Aires Discarded car tires as breeding sites of Culex eduardoi (Diptera: Culicidae in the Pereyra Iraola Provincial Park, Buenos Aires Province  

Directory of Open Access Journals (Sweden)

Full Text Available El conocimiento sobre la fauna de mosquitos que se cría en cubiertas de auto es realmente escaso en Argentina. El objetivo de este estudio fue caracterizar una población de inmaduros de Culex eduardoi Casal & Garcia en una acumulación de cubiertas abandonadas en un bosque suburbano de la Provincia de Buenos Aires. Entre noviembre 2009 y mayo 2010, se recolectaron mensualmente larvas de mosquitos en 27 cubiertas de auto abandonadas en un sector boscoso del Parque Provincial Pereyra Iraola. Se recolectaron en total 1.009 larvas del tercer y cuarto estadio de Cx. eduardoi, y el índice de contenedores (IC global fue 66,3% (106/160. Culex eduardoi estuvo presente durante todos los meses, aunque el IC difirió significativamente (x²(6 = 15,11; p The knowledge about tire-breeding mosquitoes is truly scarce in Argentina. The objective of this study was to characterize a population of immatures of Culex eduardoi Casal & Garcia, from a pile of abandoned tires located in a suburban forest of Buenos Aires Province. Between November 2009 and May 2010, mosquito larvae were monthly collected in 27 abandoned tires within a woody area of the Parque Provincial Pereyra Iraola. A total of 1009 third and fourth instar larvae of Cx. eduardoi were collected, and the overall container index (CI was 66.3% (106/160. Culex eduardoi was collected every month but the CI differed significantly (x²(6 = 15.11; p < 0.05, reaching maximum values in November and December (76 and 92.5% respectively. In spring, the relative abundance of larvae was also the highest, and the mean number of larvae collected per habitat was 9.5 (min. 3.5 in March; max.15.1 in November. Other mosquito species such as Cx. pipiens Linneo and Toxorhynchites theobaldi Dyar & Knab were also found in the studied containers. The present findings contribute with novel knowledge on culicids of tires in Argentina.

Alejandra Rubio

2011-06-01

252

Biology of Culex sitiens, a Predominant Mosquito in Phang Nga, Thailand after a Tsunami  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A tsunami affected area in Phang Nga province, Thailand was explored randomly as some freshwater sites had changed into brackish-water sites. A survey of four areas found Culex sitiens to be the most dominant mosquito species.This mosquito prefers to breed in putrefied water with garbage and it was found in almost every stagnant, brackish-water site in full sunlight. The larval density was more than 300 larvae/dip/250 ml water. Its biting cycle, determined by human landing catch, was nocturna...

Prummongkol, Samrerng; Panasoponkul, Chotechuang; Apiwathnasorn, Chamnarn; Lek-uthai, Usa

2012-01-01

253

Chemicals of predatory mosquitofish (Gambusia affinis) influence selection of oviposition site by Culex mosquitoes.  

Science.gov (United States)

Ovipositing insects may avoid aquatic sites where there is high predation risk to their offspring, but the proximate mechanisms that mediate avoidance behavior are poorly resolved. We conducted an experiment to determine whether mosquitoes would reduce oviposition rates in pools containing chemicals of the mosquitofish (Gambusia affinis), a voracious predator that is widely employed to control mosquitoes. Experimental treatments consisted of outdoor pools that contained known concentrations of fish chemicals (low, medium, or high) or no fish chemicals (control). The pools were arranged in a randomized block design, and the number of mosquito larvae in each pool served as the response variable to estimate relative oviposition rate. Members of the Culex pipiens complex were the main colonizers of the pools. The mean number of larvae per pool differed among treatments (P = 0.026) and was about three times greater in control pools compared with those receiving medium and high concentrations of fish chemicals. Pairwise comparisons indicate that only medium and high treatments differed significantly from controls, suggesting that a threshold concentration exists below which mosquitoes cannot reliably detect predators. Our data suggest that the effectiveness of Gambusia affinis in controlling mosquitoes may be compromised if adult mosquitoes respond to fish stocking by shifting to nearby breeding sites that lack fish. We discuss issues conceming the use of Gambusia in biological control programs within the context of these new findings. PMID:12035927

Angelon, Kim A; Petranka, James W

2002-04-01

254

Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.  

Science.gov (United States)

The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue. PMID:24252487

Lees, Rosemary Susan; Knols, Bart; Bellini, Romeo; Benedict, Mark Q; Bheecarry, Ambicadutt; Bossin, Hervé Christophe; Chadee, Dave D; Charlwood, Jacques; Dabiré, Roch K; Djogbenou, Luc; Egyir-Yawson, Alexander; Gato, René; Gouagna, Louis Clément; Hassan, Mo'awia Mukhtar; Khan, Shakil Ahmed; Koekemoer, Lizette L; Lemperiere, Guy; Manoukis, Nicholas C; Mozuraitis, Raimondas; Pitts, R Jason; Simard, Frederic; Gilles, Jeremie R L

2014-04-01

255

Fluctuaciones estacionales y temporales de la densidad larvaria de Anopheles darlingi Root (Diptera: Culicidae) y familias de insectos asociados al hábitat en El Granzón, Parroquia San Isidro, municipio Sifontes del estado Bolívar, Venezuela / Seasonal and temporal fluctuations of larval densites of Anopheles darlingi Root (Diptera: Culicidae) and insects associated to the habitat in San Isidro Parish, Sifontes municipality, Bolívar state, Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Anopheles darlingi Root ha sido considerado en condiciones naturales como el principal vector de la malaria humana en América del sur y también en Venezuela, principalmente en los estados Bolívar y Amazonas, donde se produce el 90% de la malaria del país. Durante un mes (Junio de 1999) se realizaron [...] muestreos en criaderos de mosquitos en siete localidades del área minera de San Isidro municipio Sifontes, estado Bolívar. Los sitios de muestreo fueron clasificados a priori en cuatro tipos de hábitat larvario: quebradas, lagunas, ríos, pantanos (herbáceo o arbóreo). En cada criadero se tomaron 30 muestras con un cucharón para colectar larvas de Anopheles. Simultáneamente al muestreo de larvas se midieron cuatro variables físico-químicas del criadero: pH, oxígeno disuelto, temperatura y profundidad del criadero. Asimismo, en un criadero de An. darlingi (quebrada con sombra), ubicado en la localidad de El Granzón, se llevó a cabo un estudio longitudinal, durante un año entre Julio de 1999 y Junio del 2000. En dicho criadero, se colectaron mensualmente larvas de An. darlingi e insectos acuáticos asociados. Las correlaciones entre la precipitación acumulada, la abundancia de estos insectos y la abundancia de larvas de An. darlingi, se establecieron mediante el análisis no paramétrico de correlación de Spearman (Spearman rank correlation). En el hábitat seleccionado, los resultados del análisis revelaron la presencia de una correlación negativa y significativa entre la abundancia de larvas de An. darlingi y la precipitación acumulada el mes anterior a la colecta. En esa misma localidad, la precipitación acumulada el mes anterior a la colecta, se correlacionó positivamente con la abundancia de la familia Naucoridae (Hemiptera). Asimismo, la abundancia de larvas de An. darlingi presentó una correlación negativa y significativa con la abundancia de la familia Naucoridae. En este hábitat (quebrada del Granzón), la densidad de larvas An. darlingi fue mayor en los meses de menor precipitación, aunque tanto en la época de menor precipitación como en la temporada lluviosa, hubo presencia de larvas de esta especie. Por otro lado, el criadero típico de An. darlingi, donde éste presentó su mayor abundancia y hubo presencia de larvas durante todo el año, fue clasificado como “Quebrada con sombra”. Esta presentó mucha sombra (90-100%), abundante materia orgánica sumergida o flotante (hojarasca, palitos, hojas, semillas), profundidad promedio de 65,22 cm, un pH promedio de 6,16, contenido medio de oxigeno disuelto de 6,40 g/L y una temperatura promedio del agua de 26ºC. Abstract in english Anopheles darlingi Root has been considered under natural conditions as human malaria’s principal vector in South America. In Venezuela, Amazonas and Bolivar States, it is responsible for 90 % of malaria cases reported in the country. Field surveys and mosquito larvae sampling of mosquito breeding s [...] ites in mining areas, were carried out in seven localities of Sifontes county, Bolívar state during one month, between 2 and 29 June 1999. The breeding sites were a priori classified into four larval habitat categories: lagoons, streams, rivers and herbaceous swamps. At each breeding site, 30 dips for mosquito larvae samples were made. Simultaneously with mosquito larvae sampling, four selected variables of water were measured: temperature, dissolved oxygen, pH and water depth. On the other hand, a longitudinal study was carried out in the typical An. darlingi breeding site (shaded streams) in El Granzón (Sifontes county). Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding site over a one-year period (July, 1999 to June, 2000). At this breeding site, Anopheles larvae and aquatic insects were collected monthly. During the study, 12 samples were taken from this larval habitat of An. darlingi. Seasonal and temporal variations of An. darlingi larvae and aquatic insects were determined. Rel

Jesús, Berti-Moser; Julio, González-Rivas; Edith, Navarro.

2008-12-01

256

Effects of insect growth regulators on the mosquito-parasitic nematode Romanomermis iyengari.  

Science.gov (United States)

Pyriproxyfen, a juvenile hormone analogue, diflubenzuron, a chitin synthesis inhibitor, and azadirachtin, an ecdysone agonist, are three insect growth regulators (IGRs) considered as selective and effective insecticides for mosquitoes. Romanomermis iyengari (Welch) is a mosquito-parasitic mermithid that can provide biological control against many medically important mosquito species. The compatibility of these two control tactics was tested by evaluating the sublethal effects of exposure to IGR on nematode developmental stages (preparasitic, parasitic, and preparasitic + parasitic) using Culex pipiens larvae as the host. Sublethal concentrations of IGRs were 90 % emergence inhibition of host mosquito. Preparasitic exposure to pyriproxyfen, azadirachtin, and diflurbenzuron had no effect on infectivity, parasite load, sex ratio, or male size but reduced nematode female length and increased male sex ratio at one parasite/larva. When IGRs treatments were made against the parasitic and preparasitic + parasitic stages, pyriproxyfen and azadirachtin reduced R. iyengari infectivity, parasite load, and male nematode length, whereas pyriproxyfen exposure increased male sex ratio and reduced the female R. iyengari length. Thus, IGRs have significant negative impacts on different stages of mosquito mermithid that can destabilize the balance of host-parasite population interaction. Therefore, IGRs should be used with caution in mosquito habitats where these parasites have established. PMID:23180130

Suman, Devi Shankar; Brey, Christopher W; Wang, Yi; Sanad, Manar; Shamseldean, Muhammed S M; Gaugler, Randy

2013-02-01

257

Habitat heterogeneity and prey selection of Aplocheilus panchax: an indigenous larvivorous fis  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: The ability of the native larvivorous fish Aplocheilus panchax (Hamilton, 1822 (Cyprinodontiformes:Aplocheilidae as predator of mosquito larvae was assessed under laboratory conditions using multiple prey andhabitat conditions.Methods: The consumption of larvae of the mosquito Culex quinquefasciatus Say 1823 (Diptera: Culicidae byA. panchax was evaluated in the presence of tubificid worms and chironomid larvae under complex and simplehabitat conditions. The number of mosquito larvae consumed in comparison to other prey types was noted andan index of prey selectivity was used to evaluate the preference for mosquito larvae.Results: Aphlocheilus panchax consumed 53 to 65 mosquito larvae in a three hour feeding bout contrast to 29–38 tubificid worms and 43–62 chironomid larvae depending on the habitat conditions. The prey consumptiondiffered significantly between the habitats and the prey type. The index of prey selectivity was positive for Cx.quinquefasciatus larvae over other alternative prey in all the habitat conditions.Conclusion: It is apparent from the study that the larvivorous fish A. panchax can be employed for biologicalregulation of mosquitoes in rice-fields and similar wetlands where the multiple prey choices are available undercomplex habitat conditions. However, field studies including other prey species will be required to substantiatethis finding

Barnali Manna , Gautam Aditya & Samir Banerjee

2011-09-01

258

Understanding the Habitat Needs of the Declining Western Yellow-Billed Cuckoo  

Science.gov (United States)

The western yellow-billed cuckoo, once common along the streams and rivers of the American West, is now a candidate for protection under the Endangered Species Act. Most of the remaining breeding pairs are found in Arizona, California, and New Mexico. Research to understand the cuckoos' habitat needs by U.S. Geological Survey (USGS) and Northern Arizona University scientists has shown that cuckoos in Arizona prefer breeding habitat dominated by native tree species, especially cottonwood-willow habitat bordered by mesquite bosque habitat. This research also revealed that the size of habitat patches matters - breeding cuckoos were found only in large, continuous areas of riparian habitat. These findings and the development of spatially explicit habitat models by USGS scientists will help resource managers conserve and manage riparian habitats needed to ensure the survival of the western yellow-billed cuckoo.

Johnson, Matthew J.

2009-01-01

259

Genetic diversity of European cattle breeds highlights the conservation value of traditional unselected breeds with high effective population size.  

Science.gov (United States)

In times of rapid global and unforeseeable environmental changes, there is an urgent need for a sustainable cattle breeding policy, based on a global view. Most of the indigenous breeds are specialized in a particular habitat or production system but are rapidly disappearing. Thus, they represent an important resource to meet present and future breeding objectives. Based on 105 microsatellites, we obtained thorough information on genetic diversity and population structure of 16 cattle breeds that cover a geographical area from the domestication centre near Anatolia, through the Balkan and alpine regions, to the North-West of Europe. Breeds under strict artificial selection and indigenous breeds under traditional breeding schemes were included. The overall results showed that the genetic diversity is widespread in Busa breeds in the Anatolian and Balkan areas, when compared with the alpine and north-western European breeds. Our results reflect long-term evolutionary and short-term breeding events very well. The regular pattern of allele frequency distribution in the entire cattle population studied clearly suggests conservation of rare alleles by conservation of preferably unselected traditional breeds with large effective population sizes. From a global and long-term conservation genetics point of view, the native and highly variable breeds closer to the domestication centre could serve as valuable sources of genes for future needs, not only for cattle but also for other farm animals. PMID:19659482

Medugorac, Ivica; Medugorac, Ana; Russ, Ingolf; Veit-Kensch, Claudia E; Taberlet, Pierre; Luntz, Bernhard; Mix, Henry M; Förster, Martin

2009-08-01

260

[Genetic analysis of malaria mosquitoes of Anopheles maculipennis (Diptera, Culicidae) complex from Armenia].  

Science.gov (United States)

The results of morphological, cytogenetic, and molecular genetic analyses of malaria mosquitoes from Armenia have indicated that two representatives of the maculipennis complex, such as An. maculipennis s.s. and An. sacharovi, inhabit in the blotopes under study. The predominant species is An. maculipennis that is present in all the examined habitats. This species accounts for 15.5% of all the mosquitoes of the maculipennis complex. An. sacharovi has been found only in the Ararat valley where its proportion varies from 25 to 91.7%. Morphological, cytogenetic, and molecular genetic criteria are shown to be used to determine the warrior species of the maculipennis complex in Armenia. PMID:19827512

Keshish'ian, A; Gordeev, M I; Bezzhonova, O V; Goriacheva, I I; Zvantsov, A B; Davidiants, V A; Ezhov, M N

2009-01-01

 
 
 
 
261

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish 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. Abstract in english 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 Venezuela. A longitudinal study was carried out in the coastal areas of th [...] e Paria Peninsula, Sucre state. The larval habitats of A. aquasalis were classified as: 1- Brackish mangrove, and 2- Freshwater herbaceous swamp. Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding sites over a one-year period, between January and December 1999. At each site, 30 samples of Anopheles larvae and aquatic insects were taken monthly. Simultaneously with mosquito larvae sampling, five selected variables of water were measured: conductivity, salinity, dissolved oxygen, temperature and pH. Seasonal and temporal variations of A. aquasalis larvae and aquatic insects were determined in the two larval habitats. For the entire study period, the abundance of larvae was higher in the mangrove. Correspondence analysis showed a strong relation between some chemical factors of water and larval abundance. The abundance of A. aquasalis larvae in both seasons, was positively correlated with water salinity, pH and conductivity, and negatively with dissolved oxygen in the dry season. The presence of larvae was positively correlated with the presence of Avicenia germinans. In the mangrove there was a positive association between larvae abundance and Scirtidae family abundance and a negative correlation between larvae abundance and monthly precipitation (Spearman), as well as a significant negative correlation between Gerridae abundance and monthly precipitation. In the herbaceous swamp, there were not significant associations between A. aquasalis larvae abundance and abundance of others aquatic insects associated to habitat. Rev. Biol. Trop. 58 (2): 777-787. Epub 2010 June 02.

Jesús, Berti; Julio, González; Edith, Navarro-Bueno; Evelin, Zoppi; Elizabeth, Gordon; Laura, Delgado.

262

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

Directory of Open Access Journals (Sweden)

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 Venezuela. A longitudinal study was carried out in the coastal areas of the Paria Peninsula, Sucre state. The larval habitats of A. aquasalis were classified as: 1- Brackish mangrove, and 2- Freshwater herbaceous swamp. Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding sites over a one-year period, between January and December 1999. At each site, 30 samples of Anopheles larvae and aquatic insects were taken monthly. Simultaneously with mosquito larvae sampling, five selected variables of water were measured: conductivity, salinity, dissolved oxygen, temperature and pH. Seasonal and temporal variations of A. aquasalis larvae and aquatic insects were determined in the two larval habitats. For the entire study period, the abundance of larvae was higher in the mangrove. Correspondence analysis showed a strong relation between some chemical factors of water and larval abundance. The abundance of A. aquasalis larvae in both seasons, was positively correlated with water salinity, pH and conductivity, and negatively with dissolved oxygen in the dry season. The presence of larvae was positively correlated with the presence of Avicenia germinans. In the mangrove there was a positive association between larvae abundance and Scirtidae family abundance and a negative correlation between larvae abundance and monthly precipitation (Spearman, as well as a significant negative correlation between Gerridae abundance and monthly precipitation. In the herbaceous swamp, there were not significant associations between A. aquasalis larvae abundance and abundance of others aquatic insects associated to habitat. Rev. Biol. Trop. 58 (2: 777-787. Epub 2010 June 02.

Jesús Berti

2010-06-01

263

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish 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. Abstract in english 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 Venezuela. A longitudinal study was carried out in the coastal areas of th [...] e Paria Peninsula, Sucre state. The larval habitats of A. aquasalis were classified as: 1- Brackish mangrove, and 2- Freshwater herbaceous swamp. Field surveys of mosquito larvae and aquatic insects were carried out in the same breeding sites over a one-year period, between January and December 1999. At each site, 30 samples of Anopheles larvae and aquatic insects were taken monthly. Simultaneously with mosquito larvae sampling, five selected variables of water were measured: conductivity, salinity, dissolved oxygen, temperature and pH. Seasonal and temporal variations of A. aquasalis larvae and aquatic insects were determined in the two larval habitats. For the entire study period, the abundance of larvae was higher in the mangrove. Correspondence analysis showed a strong relation between some chemical factors of water and larval abundance. The abundance of A. aquasalis larvae in both seasons, was positively correlated with water salinity, pH and conductivity, and negatively with dissolved oxygen in the dry season. The presence of larvae was positively correlated with the presence of Avicenia germinans. In the mangrove there was a positive association between larvae abundance and Scirtidae family abundance and a negative correlation between larvae abundance and monthly precipitation (Spearman), as well as a significant negative correlation between Gerridae abundance and monthly precipitation. In the herbaceous swamp, there were not significant associations between A. aquasalis larvae abundance and abundance of others aquatic insects associated to habitat. Rev. Biol. Trop. 58 (2): 777-787. Epub 2010 June 02.

Jesús, Berti; Julio, González; Edith, Navarro-Bueno; Evelin, Zoppi; Elizabeth, Gordon; Laura, Delgado.

2010-06-01

264

Do traditional mosquito repellent plants work as mosquito larvicides?  

Science.gov (United States)

Plant derived larvicides were evaluated in Kamhororo, an area of Zimbabwe. Twenty five third and fourth instar An. gambiae s.s mosquito larvae were used per test according to the method of WHO. All larvicides were effective against the An. gambiae s.s mosquito larvae and were comparable to studies done in Tanzania using Orange peel extracts. The extracts of the plant Ocimum canum (LC50 = 54, 94 x 10(3) ug/ml) were more effective in killing the larvae than Lippia javanica (LC50 = 125,34mg x 10(3) ug/ml). These concentrations are higher when considering commercial larvicides. PMID:7859271

Lukwa, N

1994-11-01

265

Mosquito Infection Responses to Developing Filarial Worms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in tr...

Erickson, Sara M.; Xi, Zhiyong; Mayhew, George F.; Ramirez, Jose L.; Aliota, Matthew T.; Christensen, Bruce M.; Dimopoulos, George

2009-01-01

266

HERBAL CONTROL OF MOSQUITO LARVAE  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquitoes are the vectors for the dreadful diseases of mankind. For control of larval stages of mosquito, herbal plant extracts/ botanical insecticides are being tried. In the present study aqueous extract of some traditional medicinal herbal plants i.e. Neem (Azadirechta indica, Tobacco (Nicotiana tabacum, Turmeric (Curcuma longa, Tulasi (Ocimum santum, and Ginger (Zingiber officinale were tested for their Larvicidal activity. The successful attempt is made to kill the larvae, the premature stage of mosquitoes by using safe and socio-economical herbal plant extract mixtures. Ginger+Tobacco, Neem+Tobbaco and Ginger Neem, Turmeric, Tobacco and Tulasi showed highest larvicidal activity. The results obtained show that this plant material exhibited larvicidal activity and could be considered as potent natural larvicidal agent without any toxic effects.

Chaudhari Priyanka S, Chaudhari SV* Jangam Sampada, Shinde JS, Wankhede Sneha

2013-04-01

267

Geostatistical evaluation of integrated marsh management impact on mosquito vectors using before-after-control-impact (BACI design  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In many parts of the world, salt marshes play a key ecological role as the interface between the marine and the terrestrial environments. Salt marshes are also exceedingly important for public health as larval habitat for mosquitoes that are vectors of disease and significant biting pests. Although grid ditching and pesticides have been effective in salt marsh mosquito control, marsh degradation and other environmental considerations compel a different approach. Targeted habitat modification and biological control methods known as Open Marsh Water Management (OMWM had been proposed as a viable alternative to marsh-wide physical alterations and chemical control. However, traditional larval sampling techniques may not adequately assess the impacts of marsh management on mosquito larvae. To assess the effectiveness of integrated OMWM and marsh restoration techniques for mosquito control, we analyzed the results of a 5-year OMWM/marsh restoration project to determine changes in mosquito larval production using GIS and geostatistical methods. Methods The following parameters were evaluated using "Before-After-Control-Impact" (BACI design: frequency and geographic extent of larval production, intensity of larval production, changes in larval habitat, and number of larvicide applications. The analyses were performed using Moran's I, Getis-Ord, and Spatial Scan statistics on aggregated before and after data as well as data collected over time. This allowed comparison of control and treatment areas to identify changes attributable to the OMWM/marsh restoration modifications. Results The frequency of finding mosquito larvae in the treatment areas was reduced by 70% resulting in a loss of spatial larval clusters compared to those found in the control areas. This effect was observed directly following OMWM treatment and remained significant throughout the study period. The greatly reduced frequency of finding larvae in the treatment areas led to a significant decrease (~44% in the number of times when the larviciding threshold was reached. This reduction, in turn, resulted in a significant decrease (~74% in the number of larvicide applications in the treatment areas post-project. The remaining larval habitat in the treatment areas had a different geographic distribution and was largely confined to the restored marsh surface (i.e. filled-in mosquito ditches; however only ~21% of the restored marsh surface supported mosquito production. Conclusion The geostatistical analysis showed that OMWM demonstrated considerable potential for effective mosquito control and compatibility with other natural resource management goals such as restoration, wildlife habitat enhancement, and invasive species abatement. GPS and GIS tools are invaluable for large scale project design, data collection, and data analysis, with geostatistical methods serving as an alternative or a supplement to the conventional inference statistics in evaluating the project outcome.

Dempsey Mary E

2009-06-01

268

Surplus Killing by Predatory Larvae of Corethrella appendiculata: Prepupal Timing and Site-Specific Attack on Mosquito Prey.  

Science.gov (United States)

Surplus or 'wasteful' killing of uneaten prey has been documented in the fourth larval instar of various species of the mosquito genus Toxorhynchites that occur in treeholes and other phytotelmata. Here we document surplus killing by the predatory midge Corethrella appendiculata, which in Florida cohabits treeholes and artificial containers with larvae of Toxorhynchites rutilus. Provided with a surfeit of larval mosquito prey, surplus killing was observed only in the fourth instar of C. appendiculata, peaking in intensity in the final 24 h prior to pupation, as observed for Toxorhynchites spp. Attack sites identified from videotaped encounters with mosquito prey were divided among head, thorax, abdomen, and siphon. Consumed mosquito larvae (n = 70) were attacked primarily on the head (46%) or siphon (34%), but surplus-killed prey (n = 30) were attacked predominantly on the thorax (83%). Despite its independent evolution among different insect species in aquatic container habitats, the functional significance of prepupal surplus killing remains unclear. PMID:19081802

Lounibos, L P; Makhni, S; Alto, B W; Kesavaraju, B

2008-03-01

269

Exploiting mosquito sugar feeding to detect mosquito-borne pathogens.  

Science.gov (United States)

Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO(2)-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations. PMID:20534559

Hall-Mendelin, Sonja; Ritchie, Scott A; Johansen, Cheryl A; Zborowski, Paul; Cortis, Giles; Dandridge, Scott; Hall, Roy A; van den Hurk, Andrew F

2010-06-22

270

Biodiversidade de mosquitos (Diptera: Culicidae) nos parques da cidade de São Paulo I / Mosquito (Diptera: Culicidae) survey in parks of São Paulo City I  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Diante da escassez de informações sobre mosquitos (Diptera: Culicidae) na cidade de São Paulo, foi proposto um projeto para estudar esse grupo de insetos nas áreas verdes representadas pelos parques municipais da cidade. Foram investigados 35 desses parques distribuídos nas regiões sul, norte e cent [...] ro-oeste da cidade, entre outubro de 2010 e fevereiro de 2011 em período diurno. Os imaturos foram coletados dos criadouros por meio de conchas entomológicas e bomba de sucção e os adultos foram capturados em seus abrigos por aspirador elétrico (bateria de 12V). A identificação e catalogação de espécimes foram feitas no Laboratório de Entomologia da Faculdade de Saúde Pública, Universidade de São Paulo. Nesta primeira fase do projeto, coletou-se um total de 5.129 espécimes distribuídos em 11 gêneros e 41 categorias taxonômicas. Culex (Cux.) quinquefasciatus foi a espécie mais abundante. O gênero Aedes foi representado principalmente por Ae. (Och.) fluviatilis e Ae. (Ste.) albopictus. Ae. (Ste.) aegypti e Ae. (Och.)scapularis também foram frequentes em alguns parques. Os demais gêneros apresentaram-se pouco abundantes. Dos parques, 25,7% apresentaram mais de dez grupos, com destaque para o Anhanguera com 26; em contrapartida, 57,1% apresentaram cinco ou menos grupos. Apesar da pressão antrópica sobre esses ambientes, diversas espécies de culicídeos se utilizam destes habitats para a manutenção e refúgio de suas populações. É recomendado que estes ambientes estejam sob constante vigilância epidemiológica, visto que algumas das espécies coletadas possuem importância em saúde pública como vetoras de patógenos à população humana. Abstract in english Given the scarcity of information on mosquitoes (Diptera: Culicidae) in the city of São Paulo, led the authors to propose a project to investigate this group of insects in some of the green areas, represented by municipal parks. The captures were undertaken in 35 municipal parks in the south, north [...] and central-west of the city, between October 2010 and February 2011, during daylight. Immature forms were collected from breeding places with entomological ladles and suction pumps and adults from resting places with electric aspirators (12V battery). The identification of the specimens was undertaken in the Culicid laboratory of the Faculdade de Saúde Pública, Universidade de São Paulo. In this first phase of the project, a total of 5,129 specimens distributed in 11 genera and 41 taxonomic categories were captured. Culex (Cux) quinquefasciatus was the most abundant species. The genus Aedes was represented mainly by Ae. (Och) fluviatilis and Ae. (Ste) albopictus. Ae. (Ste) aegypti and Ae. (Och) scapularis were frequent in some parks. Other genera were less abundant. Of the parks investigated, 25.7% presented more than ten groups of species, notably the Anhanguera with 26; on the other hand, 57.1% had five or fewer groups. Despite the anthropic pressure on these environments, several culicid species make use of these habitats as refuges. It is recommended that these environments be kept under constant epidemiological surveillance as some of the species collected constitute public health threats as pathogen vectors to the human population.

Antônio Ralph, Medeiros-Sousa; Walter, Ceretti-Junior; Paulo Roberto, Urbinatti; Delsio, Natal; Gabriela Cristina de, Carvalho; Marcia Bicudo de, Paula; Aristides, Fernandes; Maria Helena Silva Homem de, Mello; Rosane Correia de, Oliveira; Lilian Dias, Orico; Elisabeth Fernandes Bertoletti, Gonçalves; Mauro Toledo, Marrelli.

2013-03-01

271

Transcription profiling of resistance to Bti toxins in the mosquito Aedes aegypti using next-generation sequencing.  

Science.gov (United States)

The control of mosquitoes transmitting infectious diseases relies mainly on the use of chemical insecticides. However, resistance to most chemical insecticides threatens mosquito control programs. In this context, the spraying of toxins produced by the bacteria Bacillus thuringiensis subsp. israelensis (Bti) in larval habitats represents an alternative to chemical insecticides and is now widely used for mosquito control. Recent studies suggest that resistance of mosquitoes to Bti toxin may occur locally but mechanisms have not been characterized so far. In the present study, we investigated gene transcription level variations associated with Bti toxin resistance in the mosquito Aedes aegypti using a next-generation sequencing approach. More than 6 million short cDNA tags were sequenced from larvae of two strains sharing the same genetic background: a Bti toxins-resistant strain and a susceptible strain. These cDNA tags were mapped with a high coverage (308 reads per position in average) to more than 6000 genes of Ae. aegypti genome and used to quantify and compare the transcription level of these genes between the two mosquito strains. Among them, 86 genes were significantly differentially transcribed more than 4-fold in the Bti toxins resistant strain comparatively to the susceptible strain. These included gene families previously associated with Bti toxins resistance such as serine proteases, alkaline phosphatase and alpha-amylase. These results are discussed in regards of potential Bti toxins resistance mechanisms in mosquitoes. PMID:22115744

Paris, Margot; Melodelima, Christelle; Coissac, Eric; Tetreau, Guillaume; Reynaud, Stephane; David, Jean-Philippe; Despres, Laurence

2012-02-01

272

Rehydration driven RNAi: a novel approach for effectively delivering dsRNA to mosquito larvae.  

Science.gov (United States)

The soft bodies and aquatic habitats of mosquito larvae pose a challenge for applying standard RNA-interference techniques to silence expression of target genes. Here we describe a novel technique for delivering double-stranded RNA into mosquito larvae by exploiting the larva's dehydration tolerance. Larvae were dehydrated in a NaCl solution and then rehydrated in water containing double-stranded RNA. Using larvae of Culex pipiens (L.) we demonstrated the principle by knocking down expression of the gene encoding heat shock protein 90. The knockdown persisted through the pupal stage and into adulthood, with a knockdown of approximately 77% still evident on the third day of adult life. We anticipate that this relatively simple procedure will prove useful for knocking down expression of other genes as well, in larvae of this mosquito and in others. PMID:22308791

Lopez-Martinez, Giancarlo; Meuti, Megan; Denlinger, David L

2012-01-01

273

[Quantitative distribution of malaria (Anopheles maculipennis Meigen, 1818 species complex) mosquito larvae in different microhabitat types].  

Science.gov (United States)

Anopheles mosquito larvae very much demand the environmental conditions of the water reserves that are their habitat. Aquatic plant communities play an environment-forming role, by acting as a microhabitat and leveling or enhancing the influence of external factors; there is a clear topical arrangement of malaria mosquito preimaginal hemipopulations to the aquatic plant communities. The largest number of malaria mosquito larvae is found in the phytocenoses, the mandatory components of which are elodeids and amphibiids, the latter being occupied by the larvae to a greater extent than elodeids. Larval abundance center motion is to a greater degree characteristic for natural conditions. Under urbanized conditions, the larval abundance center becomes more dispersed and stable. Moreover, its more or less close arrangement to amphibiids is observed. PMID:20614527

Kolpakov, A D

2010-01-01

274

Field evaluation of four spatial repellent devices against Arkansas rice-land mosquitoes.  

Science.gov (United States)

Four commercially available spatial repellent devices were tested in a rice-land habitat near Stuttgart, AR, after semi-field level assessments had been made at the Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, US Department of Agriculture in Gainesville, FL. OFF! Clip-On(metofluthrin), Mosquito Cognito (linalool), No-Pest Strip (dichlorvos), and ThermaCELL (d-cisltrans allethrin) were selected for this study from >20 candidate products. The units based on metofluthrin, linalool, or d-cisltrans allethrin significantly reduced captures of 1 or more of the mosquito species at surrogate human sites (unlit Centers for Disease Control and Prevention traps with CO2 and octenol). Among the mosquito species analyzed statistically (Anopheles quadrimaculatus, Culex erraticus, and Psorophora columbiae), there were significantly different responses (up to 84% reduction) to individual products, suggesting that combinations of certain spatial repellents might provide significantly greater protection. PMID:24772674

Dame, David A; Meisch, Max V; Lewis, Carolyn N; Kline, Daniel L; Clark, Gary G

2014-03-01

275

Insecticide-resistant mosquitoes and malaria control.  

Science.gov (United States)

The emergence of insecticide-resistant mosquitoes strongly challenges the fight against mosquito-borne diseases, in particular malaria. In this paper, we formulate a system of nonlinear difference equations for malaria transmission cycle. Our model incorporates compartments for insecticide-resistant mosquitoes, where mutation is the only evolutionary force involved in the occurrence of resistant allele in the mosquito population. By deriving an epidemiological threshold, the global stability of the disease and the resistance-free fixed point is established for reduced recruitment rates of resistant mosquitoes. Furthermore, by employing numerical techniques, we showed that the mosquito-human transmission cycle of malaria and its prevalence could be impacted by mutation rate, the personal protection of hosts and the density of mosquitoes. Our results highlight that given a large mosquito population, the presence of even a small number of resistant mosquitoes to an insecticide could make the insecticide ineffective for malaria control. This suggests the need for effective insecticide management strategy, alternate mosquito control approaches, educating the public about personal protection and reduction of mosquito population in a given environment. PMID:24657875

Blayneh, Kbenesh W; Mohammed-Awel, Jemal

2014-06-01

276

Microsporidia parásitos de larvas de mosquito de la Costa Pacífica del Chocó  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Zuluaga Juan S.; Weiser Jaroslav; Rojas William; Orduz Sergio

1993-01-01

277

Rural buyers' perception about mosquito repellants  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito repellants prevent mosquito bites and prevention of "man-mosquito contact" is a critical factor in transmission and spread of any disease through mosquitoes particularly in rural area. There has been a long standing 'bias' towards rural buyers. The rural markets are considered rigid in the nature but it is not the case in real sense. Marketing to rural buyers is not only a challenge to the marketers but to the manufacturers, communicators, national planners and economists as well. That is why it has been necessary to understand the various aspects of selected rural areas and consumption pattern for such a fast growing market i.e. mosquito repellants and rural buyers’ perception towards such urban products. The present paper aims to find out the factors influencing the purchase decisions of rural buyers for mosquito repellants and to study the perceptions of present and potential rural buyers' of selected mosquito repellant brands.

D. MEHTA

2010-06-01

278

Mosquitocidal and water purification properties of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus leaf extracts against the mosquito vectors.  

Science.gov (United States)

Ethanolic extracts of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus were tested for their toxicity effect on the third-instar larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The leaves of C. dactylon, A. vera, H. indicus and C. amboinicus were collected from natural habitats (forests) in Western Ghats, Tamil Nadu, India. A total of 250 g of fresh, mature leaves were rinsed with distilled water and dried in shade. The dried leaves were put in Soxhlet apparatus and extract prepared using 100% ethanol for 72 h at 30-40°C. Dried residues were obtained from 100 g of extract evaporated to dryness in rotary vacuum evaporator. Larvicidal properties of ethanolic leaf extracts showed that the extracts are effective as mosquito control agents. The larval mortality was observed after 24 h exposure. No mortality was observed in the control. The median lethal concentration (LC(50)) values observed for the larvicidal activities are 0.44%, 0.51%, 0.59% and 0.68% for extracts of C. dactylon, A. vera, H. indicus and C. amboinicus, respectively. The observed mortality were statistically significant at P?extracts) taken from the different breeding sites of mosquitoes. Water colour, turbidity and pH were reduced significantly after treatment with C. dactylon (13 HU, 31.5 mg/l and 6.9), H. indicus (13.8 HU, 33 mg/l and 7.1), A. vera (16 HU, 33.8 mg/l and 7.4) and C. amboinicus (21 HU, 35 mg/l and 7.5) extracts. The study proved that the extracts of C. dactylon, A. vera, H. indicus and C. amboinicus have both mosquitocidal and water sedimentation properties. PMID:21947308

Arjunan, Nareshkumar; Murugan, Kadarkarai; Madhiyazhagan, Pari; Kovendan, Kalimuthu; Prasannakumar, Kanagarajan; Thangamani, Sundaram; Barnard, Donald R

2012-04-01

279

Mapping of zones potentially occupied by Aedes vexans and Culex poicilipes mosquitoes, the main vectors of Rift Valley fever in Senegal.  

Science.gov (United States)

A necessary condition for Rift Valley fever (RVF) emergence is the presence of Aedes (Aedimorphus) vexans and Culex (Culex) poicilipes mosquitoes carrying the arbovirus and responsible for the infection. This paper presents a detailed mapping in the Sahelian region of Senegal of zones potentially occupied by these mosquitoes (ZPOMs) whose population density is directly linked to ecozones in the vicinity of small ponds. The vectors habitats and breeding sites have been characterized through an integrated approach combining remote sensing technology, geographical information systems, geographical positioning systems and field observations for proper geo-referencing. From five SPOT-5 images (approximately 10 m spatial resolution) with appropriate channels, a meridional composite transect of 290 x 60 km was first constructed at the height of the summer monsoon. Subsequent ZPOMs covered major ecozones from north to south with different hydrological environments and different patterns pond distributions. It was found that an overall area of 12,817 ha +/- 10% (about 0.8% of the transect) is occupied by ponds with an average ZPOM 17 times larger than this (212,813 ha +/- 10% or about 14% of the transect). By comparing the very humid year of 2003 with 2006 which had just below normal rainfall, the ZPOMs inter-annual variability was analyzed in a sandy-clayey ecozone with an important hydrofossil riverbed within the Ferlo region of Senegal. Very probably contributing to an increased abundance of vectors by the end of August 2003, it was shown that the aggregate pond area was already about 22 times larger than in August 2006, corresponding to an approximately five times larger total ZPOM. The results show the importance of pin-pointing small ponds (sizes down to 0.1 ha) and their geographical distribution in order to assess animal exposure to the RVF vectors. PMID:19021110

Tourre, Yves M; Lacaux, Jean-Pierre; Vignolles, Cecile; Ndione, Jacques-André; Lafaye, Murielle

2008-11-01

280

Mosquito immatures in bamboo internodes in eastern Santa Catarina State, South Brazil (Diptera: Culicidae  

Directory of Open Access Journals (Sweden)

Full Text Available Since mosquito immatures had been previously reported found in bamboo internodes in the Brazilian state of Santa Catarina, a study was conducted from January to March 2011 to evaluate the mosquito fauna associated with artificially drilled bamboos in eight localities in the eastern region of this state. Ninety-one mosquitoes of the following species were recorded: Aedes albopictus (Skuse, 1894 (1.1%, Culex soperi Antunes & Lane, 1937 (11.0%, Onirium personatum (Lutz, 1904 (6.6%, Sabethes aurescens (Lutz, 1905 (38.5%, Sa. identicus Dyar & Knab, 1907 (16.5%, Sa. intermedius Lutz, 1904 (3.3%, Sa. purpureus (Theobald, 1907 (1.1%, Trichoprosopon pallidiventer Lutz, 1905 (6.6%, Trichoprosopon soaresi Lane & Cerqueira, 1942 (2.2% and Wyeomyia limai Lane & Cerqueira, 1942 (24.2%. The finding of Ae. albopictus in perforated bamboos and the diversified mosquito fauna, whose biology is mostly poorly known, indicates the need of more detailed studies. Bamboo internodes constitute an important breeding place or mosquitoes of several species in the studied area. Sabethes intermedius and Culex soperi are reported for the first time in the state.

Gerson Azulim Müller

2014-03-01

 
 
 
 
281

Habitat Observations  

Science.gov (United States)

In this outdoor activity, learners discover the wonders of the habitat surrounding them. After reading "The Empty Lot," a picture book by Dale Fife, learners observe and record in writing what happens in the natural environment around them. Spending time outdoors observing nature can help learners better understand and appreciate the world in which we live.

Aquariums, Association O.

2009-01-01

282

A new larval tray and rack system for improved mosquito mass rearing.  

Science.gov (United States)

The requirement for efficient mosquito mass rearing technology has been one of the major obstacles preventing the large scale application of the Sterile Insect Technique against mosquitoes. At the Food and Agriculture Organization/International Atomic Energy Agency (FAO/ IAEA) Insect Pest Control Laboratories we developed a larval rearing unit based on the use of a stainless steel rack that operates 50 thermoformed ABS plastic trays and is expected to be able to successfully rear 140,000-175,000 Anopheles arabiensis (Patton) adult mosquitoes per rack. The mechanized rearing unit is simple to handle, maintains minimal water temperature variation and negligible water evaporation and allows normal larval development. The mosquito mass-rearing tray was designed to provide a large surface area of shallow water that would closely mimic natural breeding sites. The trays stack into a dedicated rack structure and filling and draining were easily performed. The close stacking of the trays in the rack and the possibility to tightly line up several racks makes this rearing unit a valid solution for maximal use of the space thus reducing construction, heating, and cooling costs. The low amount of labor required to operate the system also reduces labor costs that represent one of the main expenditures in any mass rearing facility operation. Preliminary experiments performed on Aedes albopictus (Skuse) also confirm the possibility of successfully extending the use of this technology to other mosquito species. Our larval rearing unit could enhance any mosquito control strategy in which large-scale releases of mosquitoes are needed to suppress or replace natural populations. PMID:22679867

Balestrino, F; Benedict, M Q; Gilles, J R L

2012-05-01

283

The Zumba mosquito trap and BG-Sentinel trap: novel surveillance tools for host-seeking mosquitoes.  

Science.gov (United States)

In a periurban habitat located in Northern Virginia, this study used 13 replicates of a 4 x 4 Latin square to evaluate the efficacy of 2 novel mosquito traps, the Zumba mosquito trap and the BG-Sentinel trap, against 2 existing host-seeking mosquito traps [Centers for Disease Control and Prevention (CDC) miniature light and CDC Fay-Prince]. All traps were baited with the BG-Lure and CO2. The Zumba trap, baited with the BG-Lure and CO2 (Zumba trap combination) was the most productive and diverse trap, averaging 35.51 mosquitoes and 4.16 species per trapping period. It collected 19 times as many Culexpipiens/restuans, which will be referred to as Cx. pip/res, as the other traps and was the only trap to collect West Nile virus (WNV)-infected host-seeking Cx. pip/res in the study area. The BG-Sentinel trap, baited with the BG-Lure and CO2 (BG-Sentinel trap combination) collected 7 times as many female Aedes albopictus as the CDC miniature light or Fay-Prince traps. The Zumba trap combination collected 4 times as many female Ae. albopictus as the CDC miniature light or Fay-Prince traps. The WNV infection rate of Cx. pip/res and Ae. albopictus collected by the Zumba trap combination was consistently greater than the infection rates for these species collected in the Fairfax County program's routine CDC miniature light traps and comparable to the infection rate found in the Cx. pip/res collected in the program's routine gravid traps. Both the Zumba and BG-Sentinel trap combinations collected WNV-infected Ae. albopictus in the study area. PMID:19653494

Bhalala, Hina; Arias, Jorge R

2009-06-01

284

Categorization of potential breeding sites of dengue vectors in Johor, Malaysia.  

Science.gov (United States)

This cross-sectional study was to compare and categorize potential breeding sites of dengue vectors, Aedes aegypti and Aedes albopictus at three different places, namely, an urban (Taman Permas Jaya, Johor Bahru, Johor), a suburban (Kg. Melayu Gelang Patah, Johor Bahru, Johor) and a rural (Felda Simpang Waha, Kota Tinggi, Johor) habitats in Malaysia. Larval surveys were conducted once in every two months at each habitat over a period of 11 months from August 2000 until June 2001. There was a significant difference between the three study sites in terms of potential breeding sites inspected (psuburban (29.35)>urban habitat (16.97). Both breeding sites and potential breeding sites were the nominator and the total number of containers inspected as the denominator in the formula of PCI, thus the latter could be a potential indicator to initiate anti-dengue campaign at the community level to rid off potential Aedes breeding sites. The three most common potential breeding sites of Aedes species were similar for urban and suburban habitats (flower pots, pails and bowls respectively). However, flower pots, vases and tyres were the three most common potential breeding sites for the rural habitat. Another finding in this study was that various types of larval habitats were found indoors and outdoors for both species. PMID:20562811

Nyamah, M A; Sulaiman, S; Omar, B

2010-04-01

285

Cattle Breed Identification  

Science.gov (United States)

How many of you all grew up on a cattle farm? This is a diagram that we will use to tell some advantages and disadvantages about beef cattle as we study different beef breeds. Diagram Advantages and Disadvantages of beef cattle breeds The first website that we will look at for the identification of beef cattle breeds is The Beef Site. Choose three breeds and look for some advantages ...

Harbour, Mr.

2012-04-04

286

Roles of spatial partitioning, competition, and predation in the North American invasion of an exotic mosquito.  

Science.gov (United States)

Invasion success and species coexistence are often mediated by species interactions across patchily distributed habitats and resources. The invasive mosquito Aedes japonicus japonicus has established in the North American range of the competitively superior resident congener, Aedes albopictus, and the predatory native mosquito Toxorhynchites rutilus. We tested predictions for two hypotheses of invasion success and species coexistence: keystone predation and spatial partitioning. We tested competition between A. japonicus japonicus and A. albopictus with or without T. rutilus in laboratory microcosms, and measured abundances of A. japonicus japonicus, A. albopictus, other resident competing mosquito species, and the presence of T. rutilus among tree holes and tires in metropolitan Washington, DC. In laboratory microcosms, A. albopictus was competitively dominant over A. japonicus japonicus, which is consistent with the few prior studies of competition between these two Aedes species. T. rutilus predation severely lowered performances of both Aedes species but more severely lowered A. japonicus japonicus performance than A. albopictus performance when all three species co-occurred, thus yielding no evidence for keystone predation. Consistent with the spatial partitioning hypothesis, A. japonicus japonicus was negatively correlated and independently aggregated with A. albopictus and all combined resident mosquito competitors and was not associated with T. rutilus among field containers. These results suggest that predation from T. rutilus and competition from A. albopictus are barriers to the spread of A. japonicus japonicus, but that A. japonicus japonicus may escape these interspecific effects by utilizing spatially partitioned container habitats. PMID:24569942

Freed, T Z; Leisnham, P T

2014-06-01

287

Mosquito species geographical distribution in Iraq 2009  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: Mosquitoes transmit diseases to >700 million people annually. Malaria kills threemillion persons every year, including one child every 30 sec. Worldwide there are >3000 mosquito species.In Iraq, 37 species have been identified in different surveys over several decades. We conducted an entomologicalsurvey to determine the mosquito species and their distribution in Iraq in 2009.Methods: Between January 20 and December 31, 2009, mosquitoes in houses in 12 Iraqi provinces werecollected and speciated. Five to 10 villages were selected randomly in each province and in each village 10houses were selected randomly to collect mosquitoes and the density of mosquitoes per room was calculated.Kits for entomological investigation were used and the collected mosquitoes were sent to the vector bornedisease section laboratory for classification using the Naval Medical Research Unit 3 standard classificationkey.Results: A total of 29,156 mosquitoes were collected, representing two genera: Anopheles (n=13,268, or 46%of the total collected and Culex (n=15,888, or 54% of the total collected. Four Anopheles (An. pulcherrimus,An. stephensi, An. superpictus, and An. sacharovi and one Culex (Cx. pipiens species were identified. Anophelespulcherrimus was found in 11 provinces, An. stephensi in 7, An. superpictus in 2 and An. sacharovi in oneprovince, while Cx. pipiens was found in all the 12 provinces. Two peaks of mosquito density were found: thefirst from April–June and the other from September–October.Interpretation & conclusion: There are clear differences in Anopheles mosquito species geographical distributionand density among Iraqi provinces, while Cx. pipiens mosquitoes are distributed all over Iraq. All mosquitogenera show clear seasonal density variation. The study highlights that the manual mosquito classification isnot enough to identify all the species of mosquitoes in Iraq

Haidar A. Hantosh, Hameeda M. Hassan, Bushra Ahma & Ali Al-fatlawy

2012-03-01

288

A five-year integrated mosquito control project in Kavala (N. Greece)  

International Nuclear Information System (INIS)

Full text: The plain of the Nestos River is a coastal area of 25,000 ha of agricultural land irrigated by the day-regulated waters of the Nestos River. Rice fields (600 individual parcels of 1,900 ha of total surface) represent the most important breeding sites during summer (five larvicide applications on average). Abandoned agricultural land (over 200 fields of 900 ha) receiving occasionally irrigation water constitutes the second most productive mosquito-breeding site (1-2 applications). Approximately 1-2% of the total surface of 6,500 ha of corn cultivation fields is poorly drained and thus about 100 ha produce at least one generation of mosquitoes during the summer. Along its 25 kilometers of seashore, the area of Nestos comprises the lagoons of Kavala (extensive aquaculture), and the last part of the delta of the Nestos River, 11,500 ha of protected wetlands under the Ramsar convention. About 2,000 ha of these wetlands harbours plants such as Arthr. fruticosum, Sal. europea, Ael. littoralis, Ju. maritimus, Sc. maritimus, representing highly productive mosquito breeding sites (1-2 generations during the summer). Ecological mapping involved 3,200 individual vegetation polygons organised in 311 different sampling stations. Larvae sampling protocol was followed on a weekly basis for the individual and/or groups of parcels in the agricultural and natural environment. All the above information was systematically monitored and transferred to an ArcView (8.3)-GIS (Geographical Information System) database for further exploitation. In addition, mosquito breeding sites were recorded in the urban environment: within 9 villages, 2,300 individual residences were monitored and 1,070 cesspools were recorded, out of which more than 50% were producing mosquitoes (1-2 applications). In total 8,500 ha were treated with larvicides by using temephos and diflubenzuron (agricultural land), Bti (natural environment) and MMF-Agnique (urban environment). 70% of the applications were made by air using a spraying helicopter (Hiller) and a specially modified ultra-light motorized (Delta type) equipped with GPS (Geographical Positioning System). During the five years of application of the project, 17 species of mosquitoes have been identified, the most important being Ochlerotatus caspius and Anopheles spp. (human bait and CO2 traps). Nuisance has been considerably reduced since the beginning of the operations, when 1,000 bites/hour were not unusual. Evaluation of the project was made twice through 200 questionnaires in year 2000 and 180 questionnaires in year 2004. Local community is fully supporting the project: 90% of the people are willing to participate financially for the continuation of the project. (author)

289

Wash resistance and repellent properties of Africa University mosquito blankets against mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of permethrin-treated Africa University (AU mosquito blankets on susceptible female Anopheles gambiae sensu lato mosquitoes was studied under laboratory conditions at Africa University Campus in Mutare, Zimbabwe. Wash resistance (ability to retain an effective dose that kills ?80% of mosquitoes after a number of washes and repellence (ability to prevent ?80% of mosquito bites properties were studied. The AU blankets were wash resistant when 100% mortality was recorded up to 20 washes, declining to 90% after 25 washes. Untreated AU blankets did not cause any mortality on mosquitoes. However, mosquito repellence was 96%, 94%, 97.9%, 87%, 85% and 80.7% for treated AU blankets washed 0, 5, 10, 15, 20 and 25 times, respectively. Mosquito repellence was consistently above 80% from 0-25 washes. In conclusion, AU blankets washed 25 times were effective in repelling and killing An. gambiae sl mosquitoes under laboratory conditions.

M. Zimba

2013-04-01

290

Hyperspectral analysis of columbia spotted frog habitat  

Science.gov (United States)

Wildlife managers increasingly are using remotely sensed imagery to improve habitat delineations and sampling strategies. Advances in remote sensing technology, such as hyperspectral imagery, provide more information than previously was available with multispectral sensors. We evaluated accuracy of high-resolution hyperspectral image classifications to identify wetlands and wetland habitat features important for Columbia spotted frogs (Rana luteiventris) and compared the results to multispectral image classification and United States Geological Survey topographic maps. The study area spanned 3 lake basins in the Salmon River Mountains, Idaho, USA. Hyperspectral data were collected with an airborne sensor on 30 June 2002 and on 8 July 2006. A 12-year comprehensive ground survey of the study area for Columbia spotted frog reproduction served as validation for image classifications. Hyperspectral image classification accuracy of wetlands was high, with a producer's accuracy of 96 (44 wetlands) correctly classified with the 2002 data and 89 (41 wetlands) correctly classified with the 2006 data. We applied habitat-based rules to delineate breeding habitat from other wetlands, and successfully predicted 74 (14 wetlands) of known breeding wetlands for the Columbia spotted frog. Emergent sedge microhabitat classification showed promise for directly predicting Columbia spotted frog egg mass locations within a wetland by correctly identifying 72 (23 of 32) of known locations. Our study indicates hyperspectral imagery can be an effective tool for mapping spotted frog breeding habitat in the selected mountain basins. We conclude that this technique has potential for improving site selection for inventory and monitoring programs conducted across similar wetland habitat and can be a useful tool for delineating wildlife habitats. ?? 2010 The Wildlife Society.

Shive, J.P.; Pilliod, D.S.; Peterson, C.R.

2010-01-01

291

Behavioural cues surpass habitat factors in explaining prebreeding resource selection by a migratory diving duck  

Science.gov (United States)

Prebreeding habitat selection in birds can often be explained in part by habitat characteristics. However, females may also select habitats on the basis of fidelity to areas of previous reproductive success or use by conspecifics. The relative influences of sociobehavioural attributes versus habitat characteristics in habitat selection has been primarily investigated in songbirds, while less is known about how these factors affect habitat selection processes in migratory waterfowl. Animal resource selection models often exhibit much unexplained variation; spatial patterns driven by social and behavioural characteristics may account for some of this. We radiomarked female lesser scaup, Aythya affinis, in the southwestern extent of their breeding range to explore hypotheses regarding relative roles of habitat quality, site fidelity and conspecific density in prebreeding habitat selection. We used linear mixed-effects models to relate intensity of use within female home ranges to habitat features, distance to areas of reproductive success during the previous breeding season and conspecific density. Home range habitats included shallow water (?118 cm), moderate to high densities of flooded emergent vegetation/open water edge and open water areas with submerged aquatic vegetation. Compared with habitat features, conspecific female density and proximity to successful nesting habitats from the previous breeding season had greater influences on habitat use within home ranges. Fidelity and conspecific attraction are behavioural characteristics in some waterfowl species that may exert a greater influence than habitat features in influencing prebreeding space use and habitat selection within home ranges, particularly where quality habitat is abundant. These processes may be of critical importance to a better understanding of habitat selection in breeding birds.

O'Neil, Shawn T.; Warren, Jeffrey M.; Takekawa, John Y.; De La Cruz, Susan E. W.; Cutting, Kyle A.; Parker, Michael W.; Yee, Julie L.

2014-01-01

292

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

Science.gov (United States)

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 < 0.05) preferred anopheline habitat water to the culicine one. Peak oviposition activity was not delayed when the mosquitoes were exposed to the less preferred oviposition substrate (culicine habitat water). However, culicine water influenced negatively (P < 0.05) not only the number of eggs oviposited by the mosquitoes during peak oviposition time but also the overall number of gravid mosquitoes that laid their eggs on it. The differences in mosquito feeding times did not affect the daily oviposition patterns displayed. 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. PMID:15596009

Sumba, Leunita A; Okoth, Kenneth; Deng, Arop L; Githure, John; Knols, Bart Gj; Beier, John C; Hassanali, Ahmed

2004-12-13

293

Experimental harvest reveals the importance of territoriality in limiting the breeding population of Svalbard rock ptarmigan  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Svalbard rock ptarmigan (Lagopus muta hyperborea) is an endemic subspecies of rock ptarmigan inhabiting the high Arctic archipelagos of Svalbard and Franz Josefs Land. This ptarmigan species exists at low population densities, with little interannual variations in population numbers, and limited habitat for breeding with less than 5 % of the land area in Svalbard constituting medium to high quality breeding habitat. Unander and Steen (1985) hypothesized, based on a descriptive study, that...

Pedersen, A?shild Ønvik; Soininen, Eeva M.; Unander, Sigmund; Willebrand, Maria Ho?rnell; Fuglei, E.

2013-01-01

294

Plant extracts as potential mosquito larvicides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain an...

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-01-01

295

Distribution and occurrence of mosquito species in the municipal areas of Imo State, Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available A study of the ecology of drainage - breeding mosquito vectors was conducted in the three urban centers (Owerri, Orlu and Okigwe of Imo State, Nigeria. Four drainage sites located around markets, residential, stream and hotel premises were selected in each urban centre. Dipping method of sampling was employed and a total of 8,820 mosquitoes comprising eight species namely; Aedes aegypti, Aedes vittatus, Culex quinquefasciatus, Culex tigripes, Culex horridus, Culex cinereus, Culex annuliorus and Anopheles gambiae were encountered; in Owerri and Orlu with Cx. cinereus being completely absent in Okigwe. Cx. quinquefasciatus was predominantly present in all drainage sites with the highest occurrence of 4,474(50.74% followed by Aedes aegypti 1814 (20.57%, An .gambiae 945(10.71%, Cx. tigripes 484 (5.48% Ae. vittatus 420 (4.76%, Cx. horridus 264 (02.99%, Cx. cinereus 261 (2.96%, Cx. annuliorus 159 (1.88%. Of all sites sampled, market drainages had the highest abundance of mosquitoes which was significantly higher than (ANOVA, P? 0.05 those found in the residential, streams and hotel premises. Residential drainages recorded the second highest density followed by stream/vegetation drainages and hotel drainages which had the least. The abundance and distribution of mosquitoes in Owerri (130.06 the State Capital was significantly higher (ANOVA, P? 0.05 than those for Orlu (93.44 and Okigwe (52.13. The mosquito species identified in this study are of public health importance and there is an urgent need to desilt and clean up these drainages for free flow of water. This will not only rid these species of breeding sites but also free the State of the diseases associated with these organisms.

Ifeyinwa Celestina MGBEMENA

2012-05-01

296

Entomopathogenic fungi for mosquito control: A review  

Directory of Open Access Journals (Sweden)

Full Text Available Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis.

Ernst-Jan Scholte

2004-06-01

297

Mosquitoes (Diptera: Culicidae) of metropolitan Hamburg, Germany.  

Science.gov (United States)

In Europe, mosquito-related public health concerns are growing due to the increasing spread of invasive mosquito species and the recent emergence of mosquito-borne arboviruses. A vital backbone in the assessment of these issues is detailed knowledge of the mosquito fauna, i.e. regional mosquito inventories. It was therefore decided to intensify nationwide investigations on the occurrence and distribution of mosquitoes in Germany in order to update old records and to detect possible faunal changes. This paper is focussing on a densely populated metropolitan region, the federal state of Hamburg and its adjacent environs, taking two historical baseline inventories into consideration, spanning almost 100 years of mosquito research in Hamburg. In the period between 2010 and 2014, more than 10,000 juvenile, neonate and adult mosquito specimens were sampled and trapped at 105 sites in Hamburg and its environs, of which about 60% have been identified to species level, resulting in a total of 33 recorded species. Of these, Anopheles algeriensis, Culex modestus, Ochlerotatus caspius, Ochlerotatus nigrinus and Ochlerotatus sticticus are new to the area. The most common species in Hamburg are Culex pipiens/torrentium and Ochlerotatus annulipes/cantans. In contrast, two previously common species, Anopheles atroparvus and Ochlerotatus excrucians, were not detected. Despite substantial environmental changes due to reconstruction, urbanisation and renaturation in the Hamburg metropolitan region in recent decades, there has been remarkably little change within the mosquito fauna during the last century. PMID:24870250

Krüger, A; Börstler, J; Badusche, M; Lühken, R; Garms, R; Tannich, E

2014-08-01

298

Efficacy of Mosquito Traps for Collecting Potential West Nile Mosquito Vectors in a Natural Mediterranean Wetland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO2 traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO2 and attractants are as effective as CDC-CO2 traps for Culex mosquito species, Ochlero...

2012-01-01

299

Terrestrial vegetation and aquatic chemistry influence larval mosquito abundance in catch basins, Chicago, USA  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background An important determinant of mosquito-borne pathogen transmission is the spatial distribution of vectors. The primary vectors of West Nile virus (WNV in Illinois are Culex pipiens Linnaeus (Diptera: Culicidae and Culex restuans Theobald. In urban environments, these mosquitoes commonly oviposit in roadside storm water catch basins. However, use of this habitat is inconsistent, with abundance of larvae varying significantly across catch basins at a fine spatial scale. Methods We tested the hypothesis that attributes of the biotic and abiotic environment contribute to spatial and temporal variation in production of mosquito vectors, characterizing the relationship between terrestrial vegetation and aquatic chemistry and Culex abundance in Chicago, Illinois. Larvae were sampled from 60 catch basins from June 14 to October 3, 2009. Density of shrubs and 14 tree genera surrounding the basins were quantified, as well as aquatic chemistry content of each basin. Results We demonstrate that the spatial pattern of Culex abundance in catch basins is strongly influenced by environmental characteristics, resulting in significant variation across the urban landscape. Using regression and machine learning techniques, we described landscape features and microhabitat characteristics of four Chicago neighborhoods and examined the implications of these measures for larval abundance in adjacent catch basins. The important positive predictors of high larval abundance were aquatic ammonia, nitrates, and area of shrubs of height Culex during the fruit-bearing periods and early senescent periods in August and September. Conclusions This study identifies environmental predictors of mosquito production in urban environments. Because an abundance of adult Culex is integral to efficient WNV transmission and mosquitoes are found in especially high densities near larval habitats, identifying aquatic sites for Culex and landscape features that promote larval production are important in predicting the spatial pattern of cases of human and veterinary illness. Thus, these data enable accurate assessment of regions at risk for exposure to WNV and aid in the prevention of vector-borne disease transmission.

Gardner Allison M

2013-01-01

300

Mosquito Surveillance Revealed Lagged Effects of Mosquito Abundance on Mosquito-Borne Disease Transmission: A Retrospective Study in Zhejiang, China  

Science.gov (United States)

Mosquito-borne diseases (MBDs) are still threats to public health in Zhejiang. In this study, the associations between the time-lagged mosquito capture data and MBDs incidence over five years were used to examine the potential effects of mosquito abundance on patterns of MBDs epidemiology in Zhejiang during 2008–2012. Light traps were used to collect adult mosquitoes at 11 cities. Correlation tests with and without time lag were performed to investigate the correlations between MBDs incidence rates and mosquito abundance by month. Selected MBDs consisted of Japanese encephalitis (JE), dengue fever (DF) and malaria. A Poisson regression analysis was performed by using a generalized estimating equations (GEE) approach, and the most parsimonious model was selected based on the quasi-likelihood based information criterion (QICu). We identified five mosquito species and the constituent ratio of Culex pipiens pallens, Culex tritaeniorhynchus, Aedes albopictus, Anopheles sinensis and Armigeres subalbatus was 66.73%, 21.47%, 6.72%, 2.83% and 2.25%, respectively. The correlation analysis without and with time lag showed that Culex mosquito abundance at a lag of 0 or 1 month was positively correlated with JE incidence during 2008–2012, Ae. albopictus abundance at a lag of 1 month was positively correlated with DF incidence in 2009, and An. sinensis abundance at a lag of 0–2 months was positively correlated with malaria incidence during 2008–2010. The Poisson regression analysis showed each 0.1 rise of monthly mosquito abundance corresponded to a positive increase of MBD cases for the period of 2008–2012. The rise of mosquito abundance with a lag of 0–2 months increased the risk of human MBDs infection in Zhejiang. Our study provides evidence that mosquito monitoring could be a useful early warning tool for the occurrence and transmission of MBDs. PMID:25393834

Guo, Song; Ling, Feng; Hou, Juan; Wang, Jinna; Fu, Guiming; Gong, Zhenyu

2014-01-01

 
 
 
 
301

Mourning Dove nesting habitat and nest success in Central Missouri  

Science.gov (United States)

Previous Mourning Dove (Zenaida macroura) nesting studies conducted in areas containing a mixture of edge and continuous habitats have focused on edge habitats. Consequently, little is known about the potential contribution of continuous habitats to dove production. In this study we evaluated the relative importance of these two extensive habitat types by monitoring the habitat use and nest success of 59 radio-marked doves during 1990-1991 in central Missouri. Of 83 nests initiated by our marked sample, most (81.9%) were located in edge habitats. Although continuous habitats were selected less as nest sites, the proportion of successful nests did not differ significantly from that in edge habitats. Our data indicate that continuous habitats should not be considered marginal nesting habitat. If the intensity of use and nest success that we observed are representative regionally or nationally, continuous habitats could contribute substantially to annual Mourning Dove production because of the high availability of these habitats throughout much of the Mourning Dove breeding range.

Drobney, R.D.; Schulz, J.H.; Sheriff, S.L.; Fuemmeler, W.J.

1998-01-01

302

Immature mosquitoes (Diptera: Culicidae on the bromeliad Nidularium innocentii in ombrophilous dense forest of Santa Catarina Island, Florianópolis, Santa Catarina State, southern Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Immature forms of mosquitoes (Diptera: Culicidae were collected from bromeliads Nidularium innocentii var. paxianum in dense ombrophilous forest of Santa Catarina Island, state of Santa Catarina. Two hundred and eleven mosquitoes were collected; 37.44% Culex (Microculex albipes, 19.91% Cx. (Mic. davisi, 0.95% Anopheles (Kerteszia cruzii and 0.47% Wyeomyia (Phoniomyia tripartita. Correlation between the quantities of collected mosquitoes and mean temperatures was significantly positive, but that between the quantities and the rainfall was not. The quantity of anophelines was much smaller than that reported by other workers in the same region. Even considering the small quantity of anophelines collected, the great density of this bromeliad in the area indicates the need for of attention to it as a breeding ground for these mosquitoes.

Carlos Brisola Marcondes

2007-06-01

303

[Pathogenic effect of the nematode parasite Romanomermis iyengari(Nematoda: Mermithidae) in Aedes aegypti mosquito larvae (Diptera: Culicidae) under laboratory conditions in the state of Oaxaca, Mexico].  

Science.gov (United States)

Laboratory tests with waters from Aedes aegypti Linneaus (1762) breeding places were made to determine the pathogenic effect of the mermithid nematode Romanomermis iyengari Welch 1964 in mosquito larvae of this species. According to the results obtained, the administration of a dosage of 10:1 (10 preparasitics per mosquito larvae) showed levels of parasitism of 90, 93, 91, and 85% in mosquito larvae in the I, II, III, and IV stage, respectively. With the highest dosage of 20:1 (20 preparasitics per mosquito larvae) there were obtained levels of parasitism with values of 98, 97, 93 and 89% among larvae in the I, II, III, and IV stage, respectively. Generally, the values of the physical and chemical parameters such as pH, conductivity, oxygen, and chlorides calculated in these waters did not affect apparently the infective capacity of the preparasitics of R. iyengari. PMID:9842260

Santamarina Mijares, A; Pérez Pacheco, M C

1998-01-01

304

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

Directory of Open Access Journals (Sweden)

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

Schaffner Francis

2012-11-01

305

Diversidad larval de mosquitos (Diptera: Culicidae) en contenedores artificiales procedentes de una comunidad urbana de San José, Costa Rica / LARVAL DIVERSITY OF MOSQUITOES (DIPTERA: CULICIDAE) IN ARTIFICIAL CONTAINERS FROM AN URBAN COMMUNITY OF SAN JOSÉ, COSTA RICA  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Se realizó una encuesta larval por mosquitos urbanos en contenedores artificiales intra y peridomiciliares en la comunidad "La Carpio", San José, Costa Rica. "La Carpio" es una comunidad que sufrió un brote de dengue en los últimos meses de la estación lluviosa de 2002. En 2003, fueron visitadas 369 [...] viviendas durante la estación seca y 582 en la lluviosa, para identificar los potenciales sitios de multiplicación de mosquitos. 1.160 contenedores fueron identificados y 152 de ellos (13,0%) estuvieron positivos por larvas de al menos una especie de mosquitos. La presencia de larvas de dos especies de mosquitos en un mismo contenedor fue observada en 9 contenedores (0,78%). Con el fin de estimar la diversidad larval de mosquitos, se calculó un índice de infestación por especie para cada tipo de contenedor. Cinco especies de larvas de mosquito fueron identificadas: Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator y Limatus durhamii. Ae. aegypti fue la especie que se encontró con mayor frecuencia y fue la que mostró los índices de diversidad más altos para los contenedores identificados (p Abstract in english A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood "La Carpio", San José, Costa Rica. "La Carpio" is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 hous [...] es were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0%) were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78%) of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii) was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p

OLGER, CALDERÓN-ARGUEDAS; ADRIANA, TROYO; MAYRA E, SOLANO.

2004-07-01

306

Diversidad larval de mosquitos (Diptera: Culicidae en contenedores artificiales procedentes de una comunidad urbana de San José, Costa Rica LARVAL DIVERSITY OF MOSQUITOES (DIPTERA: CULICIDAE IN ARTIFICIAL CONTAINERS FROM AN URBAN COMMUNITY OF SAN JOSÉ, COSTA RICA  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó una encuesta larval por mosquitos urbanos en contenedores artificiales intra y peridomiciliares en la comunidad "La Carpio", San José, Costa Rica. "La Carpio" es una comunidad que sufrió un brote de dengue en los últimos meses de la estación lluviosa de 2002. En 2003, fueron visitadas 369 viviendas durante la estación seca y 582 en la lluviosa, para identificar los potenciales sitios de multiplicación de mosquitos. 1.160 contenedores fueron identificados y 152 de ellos (13,0% estuvieron positivos por larvas de al menos una especie de mosquitos. La presencia de larvas de dos especies de mosquitos en un mismo contenedor fue observada en 9 contenedores (0,78%. Con el fin de estimar la diversidad larval de mosquitos, se calculó un índice de infestación por especie para cada tipo de contenedor. Cinco especies de larvas de mosquito fueron identificadas: Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator y Limatus durhamii. Ae. aegypti fue la especie que se encontró con mayor frecuencia y fue la que mostró los índices de diversidad más altos para los contenedores identificados (p A larval survey of mosquitoes was performed in artificial containers from indoor and outdoor enviroments in the neighborhood "La Carpio", San José, Costa Rica. "La Carpio" is a community that suffered a dengue outbreak during the last months of the rainy season in 2002. During 2003, 582 and 369 houses were visited in the dry and rainy season, respectively, and the potencial mosquito breeding sites were searched for larvae. Of 1160 water containers identified, 152 (13.0% were positive for at least one species of mosquito larvae and two mosquito species were found in 9 (0.78% of the containers. In order to estimate the mosquito diversity, an infestation index by species (Ii was calculated for each kind of container. Aedes aegypti, Culex quinquefasciatus, Cx. restuans, Cx. coronator, and Limatus durhamii were identified. Ae. aegypti was the most common species, and it showed the highest infestation index for all the containers (p < 0.05. In addition to Ae. aegypti, the presence of other species of Culicidae could mask the success of campaigns for prevention of dengue. This is also an important factor to consider in order to prevent the ocurrence of emerging vector borne diseases such as West Nile Virus Encephalitis.

OLGER CALDERÓN-ARGUEDAS

2004-07-01

307

Tritium breeding in fusion reactors  

International Nuclear Information System (INIS)

Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements

308

Free flight of the mosquito Aedes aegypti  

CERN Document Server

High speed video observations of free flying male Aedes aegypti mosquitoes, the dengue and yellow fever vector, along with custom measurement methods, enable measurement of wingbeat frequency, body position and body orientation of mosquitoes during flight. We find these mosquitoes flap their wings at approximately 850 Hz. We also generate body yaw, body pitch and wing deviation measurements with standard deviations of less than 1 degree and find that sideways velocity and acceleration are important components of mosquito motion. Rapid turns involving changes in flight direction often involve large sideways accelerations. These do not correspond to commensurate changes in body heading, and the insect's flight direction and body heading are decoupled during flight. These findings call in to question the role of yaw control in mosquito flight. In addition, using orientation data, we find that sideways accelerations are well explained by roll-based rotation of the lift vector. In contrast, the insect's body pitch...

Iams, S M

2012-01-01

309

Relevant microclimate for determining the development rate of malaria mosquitoes and possible implications of climate change  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The relationship between mosquito development and temperature is one of the keys to understanding the current and future dynamics and distribution of vector-borne diseases such as malaria. Many process-based models use mean air temperature to estimate larval development times, and hence adult vector densities and/or malaria risk. Methods Water temperatures in three different-sized water pools, as well as the adjacent air temperature in lowland and highland sites in western Kenya were monitored. Both air and water temperatures were fed into a widely-applied temperature-dependent development model for Anopheles gambiae immatures, and subsequently their impact on predicted vector abundance was assessed. Results Mean water temperature in typical mosquito breeding sites was 4-6°C higher than the mean temperature of the adjacent air, resulting in larval development rates, and hence population growth rates, that are much higher than predicted based on air temperature. On the other hand, due to the non-linearities in the relationship between temperature and larval development rate, together with a marginal buffering in the increase in water temperature compared with air temperature, the relative increases in larval development rates predicted due to climate change are substantially less. Conclusions Existing models will tend to underestimate mosquito population growth under current conditions, and may overestimate relative increases in population growth under future climate change. These results highlight the need for better integration of biological and environmental information at the scale relevant to mosquito biology.

Imbahale Susan S

2010-07-01

310

Microsporidia parásitos de larvas de mosquito de la Costa Pacífica del Chocó  

Directory of Open Access Journals (Sweden)

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.

Zuluaga Juan S.

1993-12-01

311

Tritium breeding materials  

Energy Technology Data Exchange (ETDEWEB)

Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved.

Hollenberg, G.W.; Johnson, C.E.; Abdou, M.

1984-03-01

312

Tritium breeding materials  

International Nuclear Information System (INIS)

Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved

313

moss habitat sheet10 special habitats  

...four special habitat types: ? Buffer zone - nutrient management of non-ASSI...the sensitive ASSI habitats. ? Buffer zone - wildlife corridors: these are permanently...MOSS for special habits: Buffer zone - nutrient management of non-ASSI...

314

Field evaluation of mosquito control devices in southern Louisiana.  

Science.gov (United States)

The effect of 2 mosquito traps and 2 repellent systems on the catch of adult mosquitoes in American Biophysics Corporation (ABC) light traps was evaluated over a 14-month period at 3 locations in Louisiana. Devices evaluated included 1) ABC Mosquito Magnet with dry ice and octanol; 2) the BioSensory 500 cc Dragonfly Biting Insect Trap with CO2, octenol, and Mosquito Cognito, which uses Conceal inhibitor; 3) the SC Johnson OFF! Mosquito Lantern; and 4) the ThermaCell cordless mosquito repellent system. The number of adult mosquitoes caught in the ABC light traps, at the SC Johnson OFF! Mosquito Lantern, and ThermaCell cordless mosquito repellent treatment sites was significantly lower than the number collected at the ABC Mosquito Magnet or the Dragonfly/Mosquito Cognito trap system sites. When the 2 repellent devices were placed in combination with the ABC traps, mosquito numbers were significantly reduced when compared with sites with ABC traps alone. These data indicate that the SC Johnson OFF! Mosquito Lantern and ThermaCell cordless mosquito system may reduce attack from biting mosquitoes due to the reduction in their numbers. In the same study, the mosquito counts of the trapping devices also were reported. PMID:17067044

Collier, Brett W; Perich, Michael J; Boquin, Gerardo J; Harrington, Scott R; Francis, Mike J

2006-09-01

315

Green Nanoparticles for Mosquito Control  

Science.gov (United States)

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. PMID:25243210

Soni, Namita; Prakash, Soam

2014-01-01

316

Green nanoparticles for mosquito control.  

Science.gov (United States)

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. PMID:25243210

Soni, Namita; Prakash, Soam

2014-01-01

317

Survivorship of immature stages of Anopheles gambiae s.l. (Diptera: Culicidae) in natural habitats in western Kenya highlands.  

Science.gov (United States)

We examined the survivorship of Anopheles gambiae s.l. Giles (Diptera: Culicidae) larvae and habitat productivity in three major habitat types in the western Kenya highlands. The age-specific distribution was determined for larvae and pupae, and survivorship curves were constructed. Larval-to-pupal survivorship was 6.8% in drainage ditches, 4.3% in cow hoofprints, and 1.8% in disused goldmines, respectively. High mortality rates were observed in all developmental stages. The estimated daily survival rate was highest in drainage ditches (0.74), followed by cow hoofprints (0.71), and it was lowest in disused goldmines (0.62). Productivity of emerging An. gambiae adults was generally low in these larval habitats (1.35, 1.55, and 1.84 mosquitoes per m2 per wk in drainage ditches, disused goldmines, and cow hoofprints, respectively). In total, seven families of larval mosquito predators were identified from the larval habitats, including Hydrophilidae, Dytiscidae, Corixidae, Nepidae, Notonectidae, Belostomatidae, and Cordulidae. Predator density in disused goldmines was significantly higher than that of other habitat types. Determination of the relative importance of predation, habitat stability and food contents on natural mosquito habitat productivity would help to design cost-effective vector control methods specifically targeted at the productive habitats. PMID:17915505

Munga, Stephen; Minakawa, Noboru; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

2007-09-01

318

A malaria transmission-directed model of mosquito life cycle and ecology  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Malaria is a major public health issue in much of the world, and the mosquito vectors which drive transmission are key targets for interventions. Mathematical models for planning malaria eradication benefit from detailed representations of local mosquito populations, their natural dynamics and their response to campaign pressures. Methods A new model is presented for mosquito population dynamics, effects of weather, and impacts of multiple simultaneous interventions. This model is then embedded in a large-scale individual-based simulation and results for local elimination of malaria are discussed. Mosquito population behaviours, such as anthropophily and indoor feeding, are included to study their effect upon the efficacy of vector control-based elimination campaigns. Results Results for vector control tools, such as bed nets, indoor spraying, larval control and space spraying, both alone and in combination, are displayed for a single-location simulation with vector species and seasonality characteristic of central Tanzania, varying baseline transmission intensity and vector bionomics. The sensitivities to habitat type, anthropophily, indoor feeding, and baseline transmission intensity are explored. Conclusions The ability to model a spectrum of local vector species with different ecologies and behaviours allows local customization of packages of interventions and exploration of the effect of proposed new tools.

Eckhoff Philip A

2011-10-01

319

Biocontrol efficiency of odonate nymphs against larvae of the mosquito, Culex quinquefasciatus Say, 1823.  

Science.gov (United States)

An estimation of the predatory efficiency of the nymphs of five coexisting odonate species Aeshna flavifrons, Coenagrion kashmirum, Ischnura forcipata, Rhinocypha ignipennis and Sympetrum durum using the fourth-instar larvae of Culex quinquefasciatus as prey, was made under laboratory and semi-field conditions. The daily feeding rate varied among the odonate species, at laboratory conditions. The mean number of IV instars Cx. quinquefasciatus larvae killed per day, ranged between 14 and 64 (64 mosquito larvae for I. forcipata, 57 for A. flavifrons, 45 for R. ignipennis, 25 for S. durum and 14 for C. kashmirum). The prey consumption was linearly related to the number of predators and prey available but inversely related with space. It was also noted that the feeding rates varied significantly between dark and light conditions, in all the odonate species. The presence of nymphs in semi-field conditions significantly lowered the mosquito larval density in dipper samples after 15 days from the introduction, followed by a significant increase of larval mosquito density after 15 days from the withdrawal of the nymphs. The results of the present observations are suggestive of the use of odonate nymphs in temporary pools or larger habitats where they can be a potential biological resource in regulating the larval population of the vector and pest mosquitoes. PMID:18378207

Mandal, S K; Ghosh, A; Bhattacharjee, I; Chandra, G

2008-05-01

320

Spatial evaluation of larvae of Culicidae (Diptera) from different breeding sites: application of a geospatial method and implications for vector control / Avaliação espacial de formas larvais de Culicidae (Diptera) em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Avaliação espacial de formas larvais de Culicidae (Diptera) em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores. Este estudo investiga a distribuição espacial da fauna urbana e de Culicidae e informa o monitoramento entomológico de espécies que usam [...] recipientes artificiais como habitat larval. Coletas de larvas de mosquitos foram realizadas no município paulista de Santa Bárbara d' Oeste entre os anos de 2004 e 2006, durante visitas casa-a-casa. Um total de 1.891 amostras foi considerado, com nove espécies diferentes coletadas. A distribuição das espécies foi avaliada através do método de krigagem estatística extrapolando as divisões administrativas do município. O método de coleta adotado no presente estudo está de acordo com os métodos sugeridos aos serviços de saúde municipais pelo Ministério da Saúde e pode, portanto, ser adotado pelas autoridades públicas de saúde no controle da doença e delimitação das áreas de risco. Além disso, este tipo de levantamento e análise pode ser empregado como vigilância entomológica de espécies de mosquitos vetores que usam recipientes artificiais como habitat larval em áreas urbanas. Abstract in english Spatial evaluation of Culicidae (Diptera) larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers a [...] s larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.

Rafael, Piovezan; Thiago Salomão de, Azevedo; Cláudio José, Von Zuben.

 
 
 
 
321

Spatial evaluation of larvae of Culicidae (Diptera from different breeding sites: application of a geospatial method and implications for vector control Avaliação espacial de formas larvais de Culicidae (Diptera em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores  

Directory of Open Access Journals (Sweden)

Full Text Available Spatial evaluation of Culicidae (Diptera larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.Avaliação espacial de formas larvais de Culicidae (Diptera em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores. Este estudo investiga a distribuição espacial da fauna urbana e de Culicidae e informa o monitoramento entomológico de espécies que usam recipientes artificiais como habitat larval. Coletas de larvas de mosquitos foram realizadas no município paulista de Santa Bárbara d' Oeste entre os anos de 2004 e 2006, durante visitas casa-a-casa. Um total de 1.891 amostras foi considerado, com nove espécies diferentes coletadas. A distribuição das espécies foi avaliada através do método de krigagem estatística extrapolando as divisões administrativas do município. O método de coleta adotado no presente estudo está de acordo com os métodos sugeridos aos serviços de saúde municipais pelo Ministério da Saúde e pode, portanto, ser adotado pelas autoridades públicas de saúde no controle da doença e delimitação das áreas de risco. Além disso, este tipo de levantamento e análise pode ser empregado como vigilância entomológica de espécies de mosquitos vetores que usam recipientes artificiais como habitat larval em áreas urbanas.

Rafael Piovezan

2012-09-01

322

Spatial evaluation of larvae of Culicidae (Diptera) from different breeding sites: application of a geospatial method and implications for vector control / Avaliação espacial de formas larvais de Culicidae (Diptera) em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Avaliação espacial de formas larvais de Culicidae (Diptera) em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores. Este estudo investiga a distribuição espacial da fauna urbana e de Culicidae e informa o monitoramento entomológico de espécies que usam [...] recipientes artificiais como habitat larval. Coletas de larvas de mosquitos foram realizadas no município paulista de Santa Bárbara d' Oeste entre os anos de 2004 e 2006, durante visitas casa-a-casa. Um total de 1.891 amostras foi considerado, com nove espécies diferentes coletadas. A distribuição das espécies foi avaliada através do método de krigagem estatística extrapolando as divisões administrativas do município. O método de coleta adotado no presente estudo está de acordo com os métodos sugeridos aos serviços de saúde municipais pelo Ministério da Saúde e pode, portanto, ser adotado pelas autoridades públicas de saúde no controle da doença e delimitação das áreas de risco. Além disso, este tipo de levantamento e análise pode ser empregado como vigilância entomológica de espécies de mosquitos vetores que usam recipientes artificiais como habitat larval em áreas urbanas. Abstract in english Spatial evaluation of Culicidae (Diptera) larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers a [...] s larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.

Rafael, Piovezan; Thiago Salomão de, Azevedo; Cláudio José, Von Zuben.

2012-09-01

323

Composição, uso de hábitat e estações reprodutivas das espécies de anuros da floresta de restinga da Estação Ecológica Juréia-Itatins, sudeste do Brasil / Species composition, habitat use and breeding seasons of anurans of the restinga forest of the Estação Ecológica Juréia-Itatins, Southeastern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Apresentamos aqui dados sobre a composição de espécies, o uso de hábitat e as estações reprodutivas dos anuros da floresta de restinga da Estação Ecológica Juréia-Itatins, sudeste do Brasil. Entre fevereiro e dezembro de 1993, foram realizadas visitas mensais à área de estudo, com permanência de trê [...] s ou quatro dias, totalizando 28 dias de trabalhos de campo. Três poças pré-selecionadas foram investigadas diariamente entre 18:00 e 22:30 horas, quando foi estimado o número de machos vocalmente ativos nas agregações observadas, tentando-se localizá-los visualmente em seus substratos característicos de vocalização. A fauna é composta por 20 espécies, a maior riqueza já registrada em um ambiente de restinga do Brasil. De acordo com os critérios da IUCN, oito dessas espécies possuem populações em declínio, devido principalmente à perda de hábitat. Onze espécies apresentaram machos em atividade de vocalização e reprodução nas poças monitoradas mensalmente durante todo o período de estudo; a maioria dos hilídeos apresentou segregação vertical em seus sítios de vocalização sobre a vegetação marginal. Scinax hayii e S. littoralis foram consideradas de reprodução contínua, mas o período reprodutivo da maior parte das espécies mostrou-se associado à estação chuvosa. A alta riqueza de espécies observada na área e a indicação de declínios populacionais de algumas espécies em outras regiões sugerem que a região da Juréia apresenta uma grande relevância como área de preservação de anuros. Abstract in english Herein we present data on species composition, habitat use, and calling seasons of anurans from the Restinga forest of the Estação Ecológica Juréia-Itatins, Southeastern Brazil. The study site was visited monthly (3 to 4 days) between February and December 1993, a total of 28 days of field work. Thr [...] ee previously selected puddles were searched for anurans between 6:00 and 10:30 PM, when the number of calling males of each species was estimated and the positions of their calling sites were recorded. Anuran fauna is composed by 20 species, the highest richness ever recorded in a Brazilian restinga habitat. According to IUCN criteria, eight of these species have populations declining mainly due to habitat loss. Eleven species showed calling males in the three pools monitored during the study period; most hylids showed some vertical segregation on the marginal vegetation used as calling sites. Scinax hayii and S. littoralis were considered continuous breeders, but the calling and breeding period of most species was associated to the rainy season. The high species richness recorded and the indication of declining populations for some species outside the area suggest the E.E. Juréia-Itatins has a high potential to preserve anuran fauna.

Patrícia, Narvaes; Jaime, Bertoluci; Miguel Trefaut, Rodrigues.

2009-06-01

324

Studies on habitat preferences and territory structures of the Savi's Warbler (Locustella luscinioides) in Lake Tåkern  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Savi’s Warbler (Locustella luscinioides) is a recently established bird species in a few reedy shallow lakes of southern Sweden and has only been found nesting for the last twenty years. Little is known about the species' habitat preferences, breeding biology and demands for specific territory structures at breeding sites in Sweden. Knowledge of a newly established species’ habitat requirements is essential to maintain a viable population and design action plans. This study, the first...

Bergner, Adam

2012-01-01

325

Plant extracts as potential mosquito larvicides.  

Science.gov (United States)

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-05-01

326

Rodent malaria-resistant strains of the mosquito, Anopheles gambiae, have slower population growth than -susceptible strains  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Trade-offs between anti-parasite defence mechanisms and other life history traits limit the evolution of host resistance to parasites and have important implications for understanding diseases such as malaria. Mosquitoes have not evolved complete resistance to malaria parasites and one hypothesis is that anti-malaria defence mechanisms are costly. Results We used matrix population models to compare the population growth rates among lines of Anopheles gambiae that had been selected for resistance or high susceptibility to the rodent malaria parasite, Plasmodium yoelii nigeriensis. The population growth rate of the resistant line was significantly lower than that of the highly susceptible and the unselected control lines, regardless of whether mosquitoes were infected with Plasmodium or not. The lower population growth of malaria-resistant mosquitoes was caused by reduced post blood-feeding survival of females and poor egg hatching. Conclusion With respect to eradicating malaria, the strategy of releasing Plasmodium-resistant Anopheles mosquitoes is unlikely to be successful if the costs of Plasmodium-resistance in the field are as great as the ones measured in this study. High densities of malaria-resistant mosquitoes would have to be maintained by continuous release from captive breeding facilities.

Taylor Pam J

2009-04-01

327

Mutation breeding in Japan  

International Nuclear Information System (INIS)

The achievements made in mutation breeding in Japan over the past 40 years are outlined from the viewpoint of practical breeding. Fifty-four varieties of 23 crops were obtained by direct use of induced mutants. These include 12 cereal mutant varieties, five food legumes, nine industrial crops, seven vegetables and 18 ornamentals. Ten varieties were obtained by national breeding institutes, 14 by prefectural stations and 30 by universities or private firms. The varieties produced by the national breeding programme were registered and released with Norin numbers. In most cases, ionizing radiation was used. Forty additional mutant varieties were developed through cross-breeding using induced mutants as the gene sources. Of the 33 rice varieties in this category, 21, including six national varieties, resulted from crosses involving Reimei, a semi-dwarf mutant variety. Another semi-dwarf mutant parent was used to breed two more national varieties. Three early heading mutants were also integrated into cross-breeding programmes and produced three national and two prefectural varieties. A large grain mutant produced three varieties for sake brewing. A new recessive resistant mutant allele to the soil borne virus (BaYMV) was induced in barley. One variety was bred using this mutant as a parent. Another promising disease resistant clone was induced by chronic irradiation in a gamma field in the leading Japanese pear variety Nijisseiki, which is susceptible to black spot disease caused by Alternaria alternata (Fr.) Keissler. This mutant clone maintained all the superior qualities of the original variety. The significant role of the Institute of Radiation Breeding as a core in mutation breeding is mentioned briefly. (author). 10 refs, 2 figs, 6 tabs

328

Can mosquitoes fly in the rain?  

CERN Document Server

Collisions with raindrops are one of many obstacles insects face during flight. In this fluid dynamics video, we present a series of high-speed films of impacts between mosquitoes and raindrops. We also present drop impacts upon insect mimics, which are unsupported styrofoam balls of the same mass as mosquitoes. High-speed videography and particle tracking during collision are employed to determine the insect position versus time. We determine the magnitude of acceleration by considering the momentum transfer and impact duration. Experiments with live mosquitoes indicate a surprising ability to quickly recover flight post-collision, despite accelerations of 30-300 gravities over durations of 1 ms.

Dickerson, Andrew; Madhavan, Nihar; Hu, David

2011-01-01

329

California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation  

Science.gov (United States)

Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

Fellers, G.M.; Kleeman, P.M.

2007-01-01

330

Efficacy of Mosquito Traps for Collecting Potential West Nile Mosquito Vectors in a Natural Mediterranean Wetland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO2 traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO2 and attractants are as effective as CDC-CO2 traps for Cule...

Roiz, David; Roussel, Marion; Mun?oz, Joaqui?n; Ruiz, Santiago; Soriguer, Ramo?n C.; Figuerola, Jordi

2012-01-01

331

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

Directory of Open Access Journals (Sweden)

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

Futami Kyoko

2008-07-01

332

Developing operational algorithms using linear and non-linear squares estimation in Python for the identification of Culex pipiens and Culex restuans in a mosquito abatement district (Cook County, Illinois, USA).  

Science.gov (United States)

In this research, community level spatial models were developed for determining mosquito abundance and environmental factors that could aid in the risk prediction of West Nile virus (WNv) outbreaks. Adult Culex pipiens and Culex restuan mosquitoes and multiple habitat covariates were collected from nine sites within Cook County, Illinois, USA, to provide spatio-temporal information on the abundance of WNv vectors from 2002 to 2005. Regression analyses of the sampled covariates revealed that the adult Culex population was positively associated with temperature throughout the sampling frame. The model output also indicated that precipitation was negatively associated to mosquito abundance in 2002, 2003 and 2005 (P system method were able to evaluate stream flow direction and accumulation for identification of terrain covariates associated with the sampled habitat data. These results demonstrate that remotely sensed operational indices can be used to identify parameters associated with field-sampled Cx. pipiens and Cx. restuans aquatic habitats. PMID:19440960

Jacob, Benjamin J; Gu, Weidong; Caamano, Erik X; Novak, Robert J

2009-05-01

333

breeding birds paw leaflet  

...breeding birds Who is PAW NI? The Partnership for Action against...Crime in Northern Ireland (PAW NI) is comprised of various organisations...in wildlife law enforcement. PAW NI members are from both non...

334

Mutation breeding manual  

International Nuclear Information System (INIS)

The Atomic Energy Commission of Japan with the cooperation from the Japan Atomic Industrial Forum, Inc. (JAIF) held the first international conference for nuclear cooperation in Asia in 1990 to enhance cooperation in the nuclear field with neighboring Asian countries and as a result, a consensus was to implement regional nuclear cooperation in the field of radioisotopes and radiation utilization for agriculture among other areas, and plant mutation breeding was approved as a common field of cooperation; and due to vast information generated by the group in the succeeding roundtable discussions of each workshop, it was held as a consensus that a database of plant mutation breeding - FNCA be established; a mutant stock repository be set up, and that a bench-top mutation breeding manual be published as a guide for the aspiring radiation mutation breeding novice

335

Mosquitos Culicidae como vetores emergentes de infecções / Culicidae mosquitoes as emerging vectors of diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Apresenta-se sucinta revisão do relacionamento entre as chamadas infecções emergentes e o conceito de vetores emergentes. Estes são entendidos não apenas no que concerne aos que são descritos como tais, de forma nova, mas também aqueles com acentuadas mudanças de comportamento. Os fatores específico [...] s que propiciam esse fenômeno identificam-se à poderosa influência humana sobre o ambiente. Assim, aquele construído pelo homem e conhecido como antrópico representa a função de pressão seletiva que induz as populações vetoras a se adaptarem às novas circunstâncias. Nelas inclui-se fatores ecológicos ambientais, ou demográficos, que incrementam o contato com os novos comportamentos vetoriais. Relata-se o encontro de criadouros anômalos de mosquitos Culicidae nas Américas. A interpretação desses encontros é feita visando à vigilância epidemiológica. O significado dessa emergência ou reemergência pode se traduzir no aparecimento de problemas epidemiológicos. Sugere-se que, em sendo assim, a vigilância epidemiológica deva ser feita em grau global. Abstract in english A review is presented of the relationships between the so-called emerging infectious diseases and what may be defined as emerging vectors. These include not only those that have recently appeared but also those that present remarkable behavioral changes. Specific factors leading to that emergence ca [...] n be associated with the powerful human influence on the environment. So the man-made, i.e. anthropic environment, exercises a selective pressure inducing vector populations to adapt to new circumstances. These may arise from ecological, environmental, or demographic factors that increase contact with the new vector. With this in mind, data on anomalous Culicidae breeding places in the Americas are reported. An interpretation of these findings is offered in the light of epidemiological surveillance. The question is whether vector emergence or re-emergence may constitute an epidemiological problem. Thus it is suggested that plane for all inclusive surveillance be prepared.

Oswaldo Paulo, Forattini.

336

Mosquitos Culicidae como vetores emergentes de infecções / Culicidae mosquitoes as emerging vectors of diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese Apresenta-se sucinta revisão do relacionamento entre as chamadas infecções emergentes e o conceito de vetores emergentes. Estes são entendidos não apenas no que concerne aos que são descritos como tais, de forma nova, mas também aqueles com acentuadas mudanças de comportamento. Os fatores específico [...] s que propiciam esse fenômeno identificam-se à poderosa influência humana sobre o ambiente. Assim, aquele construído pelo homem e conhecido como antrópico representa a função de pressão seletiva que induz as populações vetoras a se adaptarem às novas circunstâncias. Nelas inclui-se fatores ecológicos ambientais, ou demográficos, que incrementam o contato com os novos comportamentos vetoriais. Relata-se o encontro de criadouros anômalos de mosquitos Culicidae nas Américas. A interpretação desses encontros é feita visando à vigilância epidemiológica. O significado dessa emergência ou reemergência pode se traduzir no aparecimento de problemas epidemiológicos. Sugere-se que, em sendo assim, a vigilância epidemiológica deva ser feita em grau global. Abstract in english A review is presented of the relationships between the so-called emerging infectious diseases and what may be defined as emerging vectors. These include not only those that have recently appeared but also those that present remarkable behavioral changes. Specific factors leading to that emergence ca [...] n be associated with the powerful human influence on the environment. So the man-made, i.e. anthropic environment, exercises a selective pressure inducing vector populations to adapt to new circumstances. These may arise from ecological, environmental, or demographic factors that increase contact with the new vector. With this in mind, data on anomalous Culicidae breeding places in the Americas are reported. An interpretation of these findings is offered in the light of epidemiological surveillance. The question is whether vector emergence or re-emergence may constitute an epidemiological problem. Thus it is suggested that plane for all inclusive surveillance be prepared.

Oswaldo Paulo, Forattini.

337

Slow Death by Many Mosquito Bites  

CERN Document Server

We study the dynamics of a single diffusing particle (a "man") with diffusivity $D_M$ that is attacked by another diffusing particle (a "mosquito") with fixed diffusivity $D_m$. Each time the mosquito meets and bites the man, the diffusivity of the man is reduced by a fixed amount, while the diffusivity of the mosquito is unchanged. The mosquito is also displaced by a small distance $\\pm a$ with respect to the man after each encounter. The man is defined as dead when $D_M$ reaches zero. At the moment when the man dies, his probability distribution of displacements $x$ is given by a Cauchy form, which asymptotically decays as $x^{-2}$, while the distribution of times $t$ when the man dies asymptotically decays as $t^{-3/2}$, which has the same form as the one-dimensional first-passage probability.

Redner, S

2014-01-01

338

Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Car tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance. Results Spinosad treatments at 1 or 5?ppm (mg a.i./liter provided 6–8?weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments. Conclusion The present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes.

Marina Carlos F

2012-05-01

339

An innovative mosquito trap for testing attractants.  

Science.gov (United States)

We describe a simple trap modification for testing volatile attractants to collect flying mosquitoes. The trap uses a standard Centers for Disease Control and Prevention trap modified for release of test chemicals. Test chemicals and other materials can be added and removed easily without spills or cross contamination. In preliminary studies using lactic acid and octenol, modified traps collected 40% more mosquitoes than controls (n = 164 and n = 117, respectively). Modifications cost less than $2.00 per trap. PMID:22533089

Dees, William H; Sylvester, Terry L; Clark, Benjamin M; Canning, Linda D; Schultz, George W; Kline, Daniel L

2012-03-01

340

MODELING AND BIOLOGICAL CONTROL OF MOSQUITOES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Models can be useful at many different levels when considering complex issues such as biological control of mosquitoes. At an early stage, exploratory models are valuable in exploring the characteristics of an ideal biological control agent and for guidance in data collection. When more data are available, models can be used to explore alternative control strategies and the likelihood of success. There are few modeling studies that explicitly consider biological control in mosquitoes; however...

Lord, Cynthia C.

2007-01-01