Project Number: 8042-32000-008-000-D
Project Type: In-House Appropriated
Start Date: Nov 5, 2014
End Date: Oct 27, 2019
Objective 1: Design and synthesize novel chemicals such as toxicants, repellents, and attractants that can be used to mitigate the impact of blood-feeding arthropods. Objective 2: Determine physiological and molecular mechanisms involved in the detection of attractants, repellents, and feeding deterrents by mosquitoes in order to facilitate discovery of novel behavior-modifying chemicals. Sub-objective 2.A: Characterize gustatory receptors (GRs) and other chemosensory genes in the major gustatory appendages of Aedes aegypti, localize their expression and relative abundance, and determine their function through heterologous expression studies. Sub-objective 2.B: Determine the specificity of gustatory receptor neurons (GRNs) expressing identified GRs with emphasis on detection of feeding stimulants and repellents, and their role in Ae. aegypti feeding and avoidance behavior. Objective 3: Develop improved surveillance and control techniques for bed bugs. Sub-objective 3.A: Identify and elucidate the role of chemicals involved in the behaviors of dispersal (repellency) and aggregation (attractancy), and develop new detection techniques. Sub-objective 3.B: Develop new chemical or biological control agents to reduce or eliminate bed bug infestations. Objective 4: Discover and develop new tools for the control of ticks affecting humans, and evaluate their effectiveness at a range of conditions associated with climate change. Sub-objective 4.A: Develop new tick repellents/formulations and characterize the physiological mechanisms involved in repellent detection by ticks. Sub-objective 4.B: Determine if certain abiotic and biotic factors affect the responses of deer ticks to repellents.
New toxicants, repellents and attractants will be synthesized using quantitative structure-activity relationship analyses. This component will also focus on the development of novel inhibitors of detoxifying enzymes that are found in insects. Candidate compounds obtained from existing chemical libraries and commercial sources will be screened for bioactivity against blood-sucking arthropods. Gustatory receptors and genes in the appendages of the yellow fever mosquito Aedes aegypti will be characterized. Molecular studies will also determine the specificity of gustatory receptor neurons with emphasis on feeding stimulants and repellents. Chemicals that attract and repel bed bugs will be identified, and their role elucidated. To develop new monitoring devices, behavioral studies will use a photographic tracking system to monitor bed bug responses to behavior-altering compounds. New chemical and biological control agents will also be developed under this objective to mitigate the impact of this blood-sucking pest. New tick repellents and formulations will be developed and the mechanism of repellent detection by ticks characterized. This will involve the optimization of an in vitro feeding system for ticks, as well as the use of electrophysiological techniques to characterize tick responses to repellents and antifeedants. The effect of pathogen infection status, temperature, humidity, and geographic origin of ticks will also be investigated with regard to repellents.