Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 7, 2006
Publication Date: December 20, 2006
Citation: Yee, W.L. 2006. Feeding history effects on feeding responses of rhagoletis indifferens (dipt., tephritidae) to gf-120 and nulure. Journal of Applied Entomology. 130(9-10), 538-550. Interpretive Summary: Western cherry fruit fly is a serious pest of cherry in the Pacific Northwest, and knowledge about the biology of flies is needed to manage the fly. Personnel at the Yakima Agricultural Research Laboratory in Wapato, WA, are determining the role of prior feeding by flies on their attraction to and feeding on protein baits (GF-120 and Nulure) mixed with insecticides that are used to manage the flies. Flies that were kept on protein (yeast and sugar) fed less on GF-120 and Nulure than flies kept on sugar alone. A longer period of protein deprivation resulted in greater feeding responses. After 16 hours of starvation, responses in flies kept on sugar were greater than those in flies kept on yeast and sugar. The results of this study are important in that they indicate cherry fruit fly feeding on baits may be reduced by prior feeding on protein foods. This suggests that development of baits that entice even protein-fed flies to feed may increase the effectiveness of baits for fly management.
Technical Abstract: The effects of feeding history on feeding responses of western cherry fruit fly, Rhagoletis indifferens Curran, to the commercial protein baits GF-120 and Nulure were determined in the laboratory. Flies were kept on 5% sucrose alone or on yeast extract and sucrose (Y + S) for 3-7 or 14-16 days and exposed to 24-hour old GF-120 or Nulure drops on artificial leaves the following day. Numbers and durations of feeding events on leaves and durations of non-feeding events were recorded over a 1-hour observation period. Experiments were also conducted to determine the effects of Y + S feeding sequences on responses to Nulure and the effects of starvation after sucrose or Y + S feeding on responses to Nulure. Protein-deprived flies consistently fed more times on GF-120 and Nulure than protein-fed flies and fed longer because protein-fed flies either did not feed or few fed. Infrequent exposure to Y + S or 16 hours of starvation after exposure to sucrose caused greater feeding on Nulure than frequent exposure to Y + S or 16 hours of starvation after exposure to Y + S, but no differences existed in durations of non-feeding events on leaves among treatments. However, durations of non-feeding events on leaves were generally not different in protein-deprived and protein-fed flies (across 4 experiments). Responses of 4-6-day old flies kept on sucrose to 0- and 24-hour old GF-120 or Nulure were not different. Overall, results show that complete protein deprivation, long periods of protein deprivation, and starvation after sucrose feeding increased fly feeding responses to GF-120 and Nulure. The general lack of differences in durations of non-feeding events on leaves with sucrose or GF-120 or Nulure in protein-deprived and protein-fed flies suggests that protein-deprived flies found baits through normal movement in addition to attraction to them. However, it is unclear how feeding affected subsequent durations spent on leaves, and field studies are needed to confirm this hypothesis.