218 - Laboratory and semi-field evaluation of the dried attractive bait station (DABS) against Ae. aegypti mosquitoes

Aedes aegypti is the most important arbovirus vector in the world, but disease prevention is limited by the absence of vaccines against dengue, Zika and chikungunya, and by the increasing development of insecticide resistance of Ae. aegypti. Despite several vector control alternatives have been developed, none of them has been shown to be fully effective against mosquito populations. The application of combined vector control methodologies is essential to tackle the spread of vector populations and thus reduce disease transmission. A recently developed technique that uses the nectar feeding behaviour of mosquitoes has shown promising results in showing killing effects over Ae. aegypti populations, without developing insecticide resistance by the target species. Such is the case of the dried attractive bait station (DABS). This device consists of foamy sheets coated with a mix of sucrose 10% and boric acid. In these experiments, we assessed the optimal concentration of the main killing component, boric acid, under laboratory conditions, by testing 1%, 2% and 4%, against a non-toxic control treatment. Also, we evaluated the optimal size of the device (total exposed surface) as well as the optimal density of devices within rooms under semi-field experiments that were exposed to a fixed number of female Ae. aegypti mosquitoes.  Results indicate that no significant difference was found between different concentrations, thus 1% boric acid was used in further experiments. Experiments on optimal size and density of devices will be finished by December 2023. Upcoming evaluations will consist of field testing in Caguas, Puerto Rico by deploying the optimal device settings to local houses and assessing Ae. aegypti populations before and after implementation in a comparison control trial.