1a.Objectives (from AD-416):
To devise innovative methods for the suppression of insects that transmit diseases to U.S. military deployed abroad.
1b.Approach (from AD-416):
Identify and test compounds with insecticidal activity that makes them especially beneficial in the rapid control of mosquitoes, flies, and other arthopods responsible for carrying disease agent. Devise innovative means of applying control agents especially suited for use in combat or deployment conditions. Identify and test new classes of topical and area repellents for use by troops.
Toxicity bioassays of several novel compounds provided by ARS chemists and several essential oils were completed. Development of a feeding bioassay to test the repellency and/or antifeedant effects of these compounds was initiated. Additional essential oils were obtained from collaborators in Brazil and Iowa State University for evaluation against P. papatasi sand flies as new toxicants, repellents, and/or antifeedants. Two insecticide target genes, sodium channel and acetylcholinesterase, were cloned and sequenced, setting the foundation for discovery of gene mutations that may be associated with insecticides. Examination for the presence of a gene mutation that results in resistance to pyrethroids was initiated on sand flies from Iraq collected to support the Deployed Warfighters Program. DNA from 100 individual flies was purified and sequenced. Bioinformatic analysis is ongoing to determine if insecticide resistance-associated gene mutations exist. If a mutation is found, a DNA-based diagnostic assay will be developed for rapid analysis of resistance genotype in these flies. Efforts were made to obtain field sand flies from the Middle East. A sand fly import permit was obtained in 2011, and a shipment of sand flies from Egypt was received in November 2011. More ethanol-preserved sand fly samples from Egypt are expected to arrive in next few months. These field sand fly samples will be used in a molecular study to search for gene mutations that may confer insecticide resistance.