Population Dynamics of the Yellow Fever Mosquito, Aedes aegypti

Chemical, biological, source reduction and novel methods involving transgenic refractory mosquitoes have all been used or proposed to reduce vectorborne disease transmission. However, a thorough understanding of mosquito vector dynamics is needed to increase the success of these interventions which is applied to interrupt pathogen transmission. My first aim (Aim 1A) was to examine how the population structure of Aedes aegypti mosquitoes varies around individual human domiciles, in addition to dengue (DENV-2) susceptibility. Ae. aegypti is generally regarded as a weak flier and tends to remain active within a small geographic area throughout its lifetime. This behavior can have profound effects dengue virus transmission. The results indicated that population structure determined from microsatellites can vary significantly from house to house within a small geographic area. Furthermore, DENV-2 susceptibility was highest during the wet season. Related to this (Aim 1B) I examined anthropogenic urban landscapes can potentially influence Ae. aegypti dispersal. Here we assessed whether there was evidence of adult mosquitoes crossing a major urban highway in Trinidad using a combination of microsatellite and mitochondrial DNA sequencing. My second aim was to examine whether quantitative trait loci (QTL) influencing DENV-2 susceptibility in Ae. aegypti that have been identified in laboratory studies could be recovered using mosquitoes collected from the field. Two QTL influencing DENV-2 dissemination were recovered on chromosomes 1 and 3. Both of which have been previously reported as influencing DENV infection in Ae. aegypti. My third aim examined how abiotic factors (ammonium, nitrate, soluble reactive phosphorus, and water temperature influence the presence or absence of Ae. aegypti larvae in 50 gallon water storage drums. There was no indication that the micronutrients assayed influenced the presence of mosquito larvae. However, there was a difference in water drum infestation when maximum water temperatures climbed over 32Ìâå¡ Celsius.