Submitted to: Journal of Chemical Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/28/2004
Publication Date: 5/23/2005
Citation: Robacker, D.C., Rios, C. 2005. Grapefruit oil enhances attraction of Mexican fruit flies (Diptera: Tephritidae) to a synthetic food-odor lure. Journal of Chemical Ecology. 31(5):1039-1049. Interpretive Summary: The Mexican fruit fly and other fruit flies rank among the most damaging fruit pests in the world. Wherever Mexican fruit flies live or could be introduced, such as Texas, California, and Florida, agricultural agencies must monitor their populations with traps. Research is ongoing in the United States, Mexico, and Central America to improve traps and lures. The recent invention of synthetic protein-odor attractants has greatly improved the lures used in traps. Attempts to increase the attractiveness of the synthetic lures by addition of fruit odors have been unsuccessful to this point. In this work, we demonstrated that grapefruit oil enhances the attractiveness of one of these synthetic protein-odor lures in trapping experiments in citrus orchards. Although only a 20% increase was observed, great improvement may be possible if the chemicals in the oil that is responsible for the effect can be isolated and tested in pure form. This first report of a novel type of attractive effect could signal the beginning of a paradigm shift in our efforts to make better lures for Mexican fruit flies and other species of damaging fruit flies. With more powerful lures, fruit fly infestations will be found sooner following initial introductions, and assessment of populations will be more accurate, leading to faster and cheaper suppression or eradication programs.
Technical Abstract: We investigated attractiveness of grapefruit oil to the Mexican fruit fly. Only high concentrations were attractive in laboratory wind-tunnel bioassays. Experience with grapefruit did not enhance attraction to grapefruit oil. In citrus orchard experiments, undiluted grapefruit oil attracted Mexican fruit flies and enhanced attraction to traps baited with a synthetic food-odor lure emitting ammonia and other nitrogenous chemicals. This is the first demonstration of host fruit odor increasing attraction to another type of attractive blend in Mexican fruit fly. These results suggest differences in the way the flies perceive undiluted grapefruit oil compared with previously tested fruit odors.