Dr Andrew Weeks , Dr Nancy Endersby

Genetic control methods are under development for pest mosquito populations including the dengue vector, A. aegypti. The eventual success of releases will depend on the population structure of the target species including population size and rates of movement among populations. Here we evaluate the genetic structure of Ae. aegypti populations in Australia and Vietnam and also consider genetic differentiation between these areas and Thailand using microsatellite and EPIC markers. This project is part of a multi-collaborative effort between groups in Australia, Thailand and Vietnam that are investigating the use of the intracellular bacterium Wolbachia as a method to control the spread of dengue in these countries.

Allelic richness and heterozygosities were lower in Australian populations suggesting a past founder effect following colonization. There was isolation by distance across all populations and also within the Australian sample. Overall 5.4% of molecular variation was located among regions and 3.7% among populations within regions. F_ST values were larger among Vietnamese populations than Australian populations and suggest limited movement of Ae. aegypti. The results suggest that releases of modified mosquitoes could target local populations that show a high degree of isolation from surrounding populations, potentially allowing modified organisms to become established initially in one region with eventual dispersal to other regions.