SUMMARY OBJECTIVES To assess the risk of transmission of viral haemorrhagic fevers in northern Ghana. DESIGN A two-year cross-sectional entomological study was carried out in four communities in the northern part of Ghana. Standard WHO methods were used to collect adult and larvae of Aedes mosquitoes to estimate man-vector contact rates and larval indices. RESULTS A total of 2804 households...

Solubilized crystals of Bacillus thuringiensis var. israelensis were 7000 times less toxic to Aedes aegypti larvae than intact crystals, presumably because mosquito larvae are filter feeders and selectively concentrate particles while excluding water and soluble molecules. A procedure is described whereby soluble toxins are adsorbed to 0.8-micrometer latex beads, with retention of toxicity. The...

Allochthonous leaf litter is often the main resource base for invertebrate communities in ephemeral water-filled containers, and detritus quality can be affected by hydrologic conditions. The invasive mosquito Aedes albopictus utilizes container habitats for its development where it competes as larvae for detritus and associated microorganisms with the native Aedes triseriatus. Different hydrol...

Univoltine Aedes mosquito larvae infected lsy Romanonterrnrs sp. were found at 2 localities in Yellowstone National Park, Wyoming. Aedes neuad.ensis, Ae. impiger, Ae. pullntus and Ae. punctor were the predominant host species. Only Ae. neuadensis was common to all sites. Rates of parasitism rangedfrom 55 to 93Vo and differed significantly between localities. Significant annual variation in the ...

Living fossils” refers to plants that are similar to extinct ones. One classic example –Cycads, prominent in the Jurassic and Cretaceous period but recently the cycads have started to disappear. Cycas circinalis L. commonly known as Queen Sago is an endemic restricted to the Western Ghats, was investigated for larvicidal activity. The fourth instar larvae of Aedes aegypti and Culex quinquefasci...

Female mosquitoes use abiotic and biotic factors, such as the presence of heavy metals or parasites, to determine the acceptability of oviposition sites. Some biotic factors can originate from mosquito larvae. When mosquito larvae are starved or infected with trematode metacercaria, they render associated water unacceptable to ovipositioning females. Internal symbiotes are common in wild mosqui...

The hexanolic extract of Dennellia tripetala was tested for acute toxicity on 3 Instar larvae of Aedes aegypti reared in the Laboratory at the Department of Zoology, University of Ibadan,. Six sets of graded concentrations 30pprn, 50ppm 60pprn 70pprn, 80ppm and 90ppm were tested for acute toxicity on the 3 instar larvae of Aedes agypti and total percentage mortalities recorded at intervals of 1...

Trees with larvicidal activity may be found in Thailand. We conducted this study to evaluate the efficacy and length of efficacy of Thai neem (Azadirachta siamensis) oil emulsion and an alginate bead of Thai neem oil formulation against early fourth stage Aedes aegypti larvae using a dipping test. The Thai neem oil emulsion had significantly greater larvicidal activity than the alginate bead fo...

The relative suitability of two colonies established from local strains of Aedes albopictus (Wilmington and Rockingham) and a local (Raleigh) and laboratory (Liverpool) strain of Ae. aegypti to support development of Dirofilaria immitis was investigated. High levels of mortality occurred 1-2 days after mosquitoes fed on a heavily microfilaremic (28,617 microfilariae/ml) dog but not when mosquit...