Development of a novel gel bait for the control of mosquitoes in urban environments

Project Summary Mosquito-vectored disease outbreaks are on the rise in the USA (4,858 in 2004 to 47,461 in 2016, CDC: National notifiable disease surveillance system). The increased incidents of the human cases of dengue virus, West Nile virus, and chikungunya virus among urban populations indicate the role of expanding urbanization in facilitating the production of disease-transmitting mosquitoes. Our proposal aims to develop a novel semiochemical-based, blood-substitute gel bait to improve monitoring and control strategies for a variety of mosquito species in our nation's urban communities. Bait has become the preferred method of control against many urban insect pests due to its economic cost, ease of deployment, and superior efficacy coupled with minimal impact on public health, environment, and non-target species. Despite this, bait technologies targeting mosquitoes are lacking, as their unique feeding behavior makes the use of typical solid baits difficult. Even the highly investigated attractive toxic sugar baits (ATSB) targeting adult mosquitoes have failed to yield an effective commercial product. This SBIR project proposes the development of a blood substitute gel bait that will exploit both the blood and sugar-feeding behavior of mosquitoes instead of only sugar feeding behavior as in ATSB baits. Specifically, we hypothesize that a bait matrix based on a combination of blood and sugar meal components, combined with attractants, phagostimulants, and insecticides could effectively overcome many of the pitfalls of current chemical control methods and result in an effective commercial product that can be used in the urban setting for mosquito control. Our research team recently reported that a prototype blood-substitute gel bait containing attractants, phagostimulants, and insecticides outperforms the only commercially available mosquito ATSB product in head-to-head mosquito attraction and mortality comparisons. Accordingly, we predict that targeting the blood-feeding behavior of mosquitos by incorporating long-distance attractants and reduced risk insecticide in gel bait formulations would be highly successful in reducing mosquito populations in urban settings. We propose three specific aims to test the technical feasibility of this approach for mosquito control. In aim 1, we will determine if the addition of long-distance attractants can further increase mosquito attraction to the gel bait. In aim 2, we will evaluate the performance of boric acid and spinosad as reduced risk bait insecticides against three different species of mosquito. In aim 3, we will test the efficacy of prototype bait containing newly identified attractants and insecticide (from aim 1 and 2) in semi-field test and determine the environmental stability of gel bait to access indoor and outdoor field life of this product. The results of our work will build on Apex Bait Technologies' recent accumulated research on host attractants and blood phagostimulants as well as on decade-long experience in research, development, and commercialization of bait technologies for urban pests.