Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2000
Publication Date: 10/15/2000
Citation: AYYAPPATH, R., POLAVARAPU, S., MCGUIRE, M.R. EFFECTIVENESS OF THIAMETHOXAM-COATED SPHERES AGAINST BLUEBERRY MAGGOT FLIES (DIPTERA: TEPHRITIDAE). JOURNAL OF ECONOMIC ENTOMOLOGY. 2000. v. 93(5). p. 1473-1479. Interpretive Summary: The blueberry maggot is an insect that can cause millions of dollars of damage to blueberries in the eastern and northeastern U.S. if left uncontrolled. Currently, control is accomplished by the application of chemical insecticides via sprayers. Public concerns over misuse of pesticides has led to the Food Quality and Protection Act which will affect the number of pesticides available for use on fruit and the number of applications allowable to control insect pests. A new strategy is to deploy starch-based, biodegradable spheres that attract and kill adult blueberry maggot flies before they lay eggs. The spheres are deployed only around the edge of the blueberry orchard and contain very small amounts of pesticide. Thus, no pesticide comes in contact with the fruit. We found that fruit damage was not different between plots treated with standard chemical insecticides and plots protected by the new spheres. This information will be of use to scientists involved in fruit fly research and by fruit producers and consumers.
Technical Abstract: Studies were conducted to evaluate the mortality of blueberry maggot flies, Rhagoletis mendax Curran. exposed to thiamethoxam- and imidacloprid-coated biodegradable red spheres under both laboratory and field conditions. Laboratory studies with spheres coated with 0.1-2.0% (AI) of thiamethoxam indicated that they are effective against R. mendax; however, no dose-dependent response was observed. Studies on the effect of visitation time on thiamethoxam-coated spheres on the mortality of R. mendax showed a reduction in fly mortality as the visitation time on treated spheres decreased from 60 s to 10 s. Under field conditions, significantly more flies were captured on plexiglas panes below the 2% (AI) thiamethoxam-coated spheres when compared with similar panes below untreated spheres. In field evaluations of thiamethoxam- and imidacloprid-coated spheres, imidacloprid- coated spheres (2.0% AI) were found to be significantly more effective than thiamethoxam-coated spheres (0.5-4.0% AI). Field trials to characterize the levels of mortality associated with aging pesticide-coated spheres revealed that the attractiveness of treated spheres decreased with increasing age of sphere, and this reduction in effectiveness is greater in thiamethoxam-coated spheres than in imidacloprid-coated spheres. The results support the potential for using thiamethoxam-coated spheres for control of blueberry maggot flies.