Natural transovarial dengue virus infection rate in both sexes of dark and pale forms of Aedes aegypti from an urban area of Bangkok, Thailand.

Transovarial dengue virus infection status of two forms of adult Aedes aegypti (dark or Ae. aegypti type form and pale or form queenslandensis), reared from field-collected larval and pupal stages, was determined by one-step RT-PCR and dengue viral serotype by nested-PCR. Natural transovarial transmission (TOT) of dengue virus was detected in the two Ae.

Biology of Culex sitiens, a predominant mosquito in Phang Nga, Thailand after a tsunami.

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.

Cavernicolous species of phlebotomine sand flies from Kanchanaburi Province, with an updated species list for Thailand.

During 2008-2009 2,401 Phlebotomine sand flies were collected in 14 limestone caves in Kanchanaburi Province, Thailand to determine the prevalence and type of cavernicolous species that have the potential to be leishmaniasis vectors. Twenty species belonging to the genera Chinius, Nemopalpus, Phlebotomus and Sergentomyia were identified. An additional man-biting species, P.

Prospective field study of transovarial dengue-virus transmission by two different forms of Aedes aegypti in an urban area of Bangkok, Thailand.

A prospective field study was conducted to determine transovarial dengue-virus transmission in two forms of Aedes aegypti mosquitoes in an urban district of Bangkok, Thailand. Immature Aedes mosquitoes were collected monthly for one year and reared continuously until adulthood in the laboratory. Mosquitoes assayed for dengue virus were processed in pools and their dengue virus infection status was determined by one-step RT-PCR and nested-PCR methods.

Mosquito fauna of "Toh Daeng" swamp forest, Thailand.

Entomological surveys (2001-2005) were carried out in Narathiwat Province to determine mosquito fauna of the peat swamp forest. Fifty-four species belonging to 13 genera were identified from 837 larval specimens and 3,982 adult mosquitoes. These included the major vectors for Brugian fillariasis: Mansonia annulata, Ma.

Insecticide susceptibility of mosquitoes invading tsunami-affected areas of Thailand.

In order to control the mosquitoes invading tsunami-affected areas of Thailand, the insecticide susceptibility status of field larvae and mosquitoes (Anopheles sundaicus and Culex sitiens) was tested under laboratory conditions. Larval bioassay tests were conducted using the WHO standard method. Three larvicides: temephos, malathion, and plant extract (ethanolic extract of the Southeast Asian long pepper.

Surveys for natural host plants of Mansonia mosquitoes inhabiting Toh Daeng peat swamp forest, Narathiwat Province, Thailand.

Surveys were carried out monthly from April-October 2002 to examine 68 sampling sites around "Toh Daeng" peat swamp forest in Narathiwat Province, Thailand, of which 38 were known Mansonia-positive habitats and 30 were Mansonia-negative sites. The present larval surveys were qualitative owing to features of the host plants (location, distribution, and abundance), difficulties in locating and selecting the host plants in the swamp forest, and time constraints. Twenty attempts were made for each species for larvae.

Bionomics studies of Mansonia mosquitoes inhabiting the peat swamp forest.

The present study was conducted in the years 2000-2002 to determine the bionomics of Mansonia mosquitoes, vectors of nocturnally subperiodic Brugia malayi, inhabiting the peat swamp forest, "Phru Toh Daeng", Narathiwat Province, Thailand. Fifty-four species of mosquitoes belonging to 12 genera were added, for the first time, to the list of animal fauna in the peat swamp forest. Mansonia mosquitoes were the most abundant (60-70%) by all collection methods and occurred throughout the year with a high biting density (10.

Laboratory colonization of Mansonia mosquitoes with an emphasis on Ma. annulata and Ma. bonneae.

The present study records the first successful colonization of Mansonia annulata and describes colony maintenance with modification of rearing medium and host plants. Three species of Mansonia mosquitoes (Ma. uniformis, Ma.

The relationship between the abundance of Mansonia mosquitoes inhabiting a peat swamp forest and remotely sensed data.

The present study aimed to demonstrate the relationship of some environmental factors, vegetation greenness index (NDVI) and land surface temperature (LST), with the seasonal variations of Mansonia bonneae and Ma. uniformis in Khosit Subdistrict, Narathiwat Province. It was found that the Mansonia population lagged one month behind but correlated positively to NDVI, LST and rainfall.

Comparative susceptibility to oral infection with dengue viruses among local strains of Aedes aegypti (Diptera: Culicidae) collected at different seasons of the year.

The vector competence of Aedes aegypti (L.) mosquitoes, collected during the hot, rainy and cool seasons from different localities in Thailand, was tested for a correlation with a seasonal cyclic pattern of dengue incidence. Under laboratory conditions, some groups of mosquitoes exhibited differences in susceptibility to oral infection but showed no correlation to dengue cases that peak during the rainy season.

Application of GIS to the characterization of filariasis transmission in Narathiwat Province.

The geographical information system (GIS) and available survey data (both from the Filariasis Annual Reports, 1985-1999 and from the published literature) for the microfilarial infection rates are used to develop the first subdistrict-level endemicity maps of lymphatic filariasis in Narathiwat Province. The maps demonstrated the subdistrict-level geographical distribution of filariasis and the subdistricts at varied degrees of infection rate. The maps also indicate that, since 1985, there was a marked decrease in endemicity at the subdistrict level and in some areas, the infection rates were zero.