Research Project
8829373
? DESCRIPTION (provided by applicant): Vector control remains the only means to combat many important mosquito-borne pathogens, including the viruses responsible for West Nile, Dengue and Chikungunya. A key deficiency of existing vector control methods is the inability to affect cryptic breeding sites, which provide refugia to immature mosquitoes and allow for the rapid recovery of mosquito populations following conventional control efforts. The self-delivering method known as 'auto-dissemination' promises to address this deficiency by using mosquitoes as the vehicle to deliver powerful larvicides to cryptic breeding sites. However, current auto-dissemination methods rely upon the indigenous mosquito population to become contaminated at a device that is attractive to mosquitoes and then to transmit the larvicide as they encounter breeding sites; thus models predict that a robust mosquito population is required for the method to work effectively, i.e., without mosquitoes to act as vehicles, the larvicide will not leave the introduced/attractive device. The auto-dissemination approach is based on an active ingredient classified as a 'reduced risk pesticide' by the US EPA. It is potent: 1/1,000th of the dry weight o a mosquito adult is adequate to treat a 200ml breeding site, and there is no resistance in mosquitoes. A novel paradigm shift to the auto-dissemination approach is employing as the larvicide vehicle: mass- produced, larvicide-treated adult male mosquitoes, which do not bite or transmit disease. We refer to this approach as Auto-Dissemination Augmented by Males (ADAM). By no longer relying on the indigenous mosquito population, the ADAM approach can be used as a preventative tool, i.e., treating cryptic sites in advance of the normal population increase (e.g., in early spring). Furthermore, using the ADAM approach, the number of introduced larvicide treated males can be sustained despite a reduced indigenous population. Preliminary data from laboratory tests show that males in the ADAM approach can (1) contaminate females with dosages that are subsequently lethal to larvae ('Sexually Transmitted Larvicide') and (2) directly deliver larvicide to breeding sites. The outcome of a small field tria demonstrates that introduced oviposition sites experienced significant larval mortality relative to control sites, up to 150m from a release site that received ADAM male introductions at a rate of 4,500/week over four weeks. Methods for the mass manufacturing of adult male mosquitoes are previously developed as part of an ongoing Wolbachia-biopesticide project at MosquitoMate. In the proposed work (Aims 1-3), we will examine the feasibility of the ADAM approach against Culex pipiens, Aedes aegypti and Ae. albopictus, first in laboratory trials and subsequently under field conditions. In Aim 4, we will prepare for a pre-registration meeting with the US EPA, toward obtaining an Experimental Use Permit required for large-scale, Phase 2 trials.
