The interactions between parasites and insects are critical to two areas of impact for the Land-Grant University System: 1) Nutrition and Health and 2) Agricultural Systems. Our studies impact Nutrition and Health by advancing understanding of vector insects that transmit human and animal diseases. Our studies impact the sustainability of Agricultural Systems by providing insights into the function of microorganisms that affect the populations of pest insects.
Vector insects transmit several diseases that impact human and animal health. Pest insects affect the profitability, production and sustainability of food and fiber production systems. The issues we study are: 1) how do insects that vector human and animal diseases develop and reproduce, 2) how do parasites and microbes cause disease and how can they be used to control insect pests, and 3) how do microbial symbionts benefit insects that are used to control pest species?
Studies during the past year have focused on three study systems: 1) vector mosquitoes that cause human disease, 2) parasites and microbes that control populations of pest insects, and 3) microbes that promote the survival of beneficial insects that are used to control pest species. The first study system focuses on characterizing the role of microorganisms in mosquito development, reproduction and transmission of human disease organisms. Results this year identified the molecular mechanisms by which microbes in the digestive tract of mosquitoes regulate growth and molting. Studies indicated that gut microbes are required for egg production and affect transmission of Dengue virus and malaria parasites. These studies were conducted in collaboration with Drs. Mark Brown and Kevin Vogel at UGA. The second study system involves several microbial pathogens and insect pest species. Results identified a new bacterium from the field that kills mosquito larvae. Bacterial symbionts associated with aphids were successfully cultured for the first time and multiple strains were genetically characterized, while immune responses of shrimp in aquaculture systems against viral pathogens were characterized. These studies were conducted in collaboration with Dr. Kerry Oliver at UG and collaborators in Thailand. The third study system focused on parasitoid wasps that are used in biological control of several pest insect species, and which rely on viral symbionts to parasitize hosts. Results included issuance of a patent for using genes from viral symbionts as tools for transforming insect cells. Expression studies identified features of viral symbiont genes that control expression in pest insects. These studies were conducted in collaboration with Dr. Gaelen Burke at UGA and collaborators in Europe and China.
Research impacts include new insights on several topics related to insect-microbial interactions, development, and reproduction. Outcomes in 2017 have been published in 9 refereed articles and one book chapter. Educational impacts include training of five graduate students, six post-doctoral associates and multiple undergraduate students. Service impacts include appointments to multiple journal editorial boards, and appointment to a grant evaluation panel at NIH (Vector Biology) for studies of vector insects that transmit human disease. I am PI or co-PI on multiple competitive research grants from NIH and NSF. I serve as co-PI on 2 training grants from NIH, and one Research Experience for Undergraduates (REU) grant from NSF. These awards support undergraduate, graduate student and post-doctoral research at UGA and collaborating institutions. I also serve on two committees for the National Academy of Sciences that are related to the mission of the National Research Council.