Location: Subtropical Plant Pathology Research2013 Annual Report
1a. Objectives (from AD-416):
1) Study thrips vector biology and behavior relative to virus transmission; 2) Develop and test thrips vector management strategies; 3) Evaluate thrips vector management strategies to determine effect on virus transmission.
1b. Approach (from AD-416):
Field, greenhouse and growth chamber experiments will be used with whole plants and leaf discs to study thrips vector biology and behavior, and virus transmission for Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV) and Tobacco streak virus (TSV). Several common thrips vector species will be examined. These experiments will yield the biological data for development of new and improvement of current thrips vector management strategies. These strategies will be evaluated for thrips and virus management in replicated field trials.
3. Progress Report:
This research relates to inhouse project objectives 1. Characterize ecology, biology, epidemiology, molecular genetics, and vector and host (crop and weed) interactions of domestic, exotic, newly emerging, and re-emerging pathogens; 2. Develop/refine rapid, sensitive reliable detection/sampling methods for pathogens; and 3. Develop or improve comprehensive integrated disease management strategies. Frankliniella cephalica is one of the most common neotropical flower thrips species. In addition to injury to various crops, it is a competent vector of Tomato spotted wilt virus. Its ability to vector other tospoviruses invasive to Florida is not understood. This species is very similar morphologically to the most common flower thrips in Florida, the Florida flower thrips (Frankliniella bispinosa). The adults can be identified competently to species only by a time-consuming and difficult process of museum-quality slide mounting. No method was previously known to determine the species of other life stages. For this reason, it has largely been mis-identified in Florida studies as Frankliniella bispinosa. Consequently, we do not know the pest status of F. cephalica on various crops, nor do we understand its role in vectoring tospoviruses in Florida. We began studies during the past year to determine the geographic and host range of F. cephalica in Florida. We are also investigating the amount of niche overlap between F. cephalica and other common thrips (namely, F. bispinosa) by sampling various plant hosts at 15 to 30 km intervals north to south in Florida from extreme southern Florida in Key West to the northern border near Tallahassee. An objective is to determine how the two species interact competitively. Also, we are developing molecular techniques and additional morphological techniques to identify different life stages and populations of F. cephalica and F.bispinosa. Ultimately, we want to determine the ability of different populations of F. cephalica and F. bispinosa to competently vector Tomato spotted wilt virus, Tomato chlorotic spot virus, Groundnut ringspot virus, and other tospoviruses in Florida. We also began studies to determine the role of flower color in preference of flower thrips and their key natural enemies for ornamental plants. Ultimately we want to develop stimulo-deterrent techniques to manage thrips and tospoviruses by altering flower color. During the past year, we were able to get these projects started. A graduate student, initiated studies as his thesis research. He is coordinating the study to determine the geographic and host ranges of F. cephalica in Florida. He is a full-time employee of the USDA APHIS PPQ located at Miami field station. His tuition and supplies for these studies are paid from a different source. A part-time employee was hired to assist him in sample collection and processing. His salary is paid from the cooperative agreement. We also made progress on the study to determine the role of flower color in preference of flower color on thrips and thrips natural enemies. The part-time employee is also assisting in this study.