Submitted to: Annals of the Entomological Society of America
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/25/2004
Publication Date: 9/20/2004
Citation: Miller, N.W., Vargas, R.I., Prokopy, R.J., Mackey, B.E. 2004. State-dependent attractiveness of protein bait and host fruit odor to bactrocera cucurbitae (diptera: tephritidae) females. Annals of the Entomological Society of America. 94:5 p. 1063-1068(6). Interpretive Summary: Melon flies were first discovered in Hawaii in 1898 and have since become a major pest of vegetable crops including melons, cucumbers, squash and tomatoes. Historically melon fly has been controlled with bait sprays containing contact poisons applied to border crops. Recently the USDA has begun an Area-wide control program for fruit flies which focuses on control of melon fly on Hawaii Island. Spinosad, a new environmentally friendly pesticide, has been introduced for control of melon fly. This pesticide must be mixed with attractive substances and ingested by the fly to have its maximum effect. We conducted tests of female melon flies, both with and without eggs, to attractants including various host fruit juices and protein baits. Choice tests were conducted on both types of female flies between protein and host fruit juice. We found that females with and without eggs were equally attracted to odor of host fruit, but that flies without eggs were much more attracted to odor of protein than flies with eggs. Several types of host fruit and proteinaceous odor were quantified as more or less attractive. Our findings suggest that some egg-carrying melon fly females might bypass/insecticide baits, enter field, and lay eggs in cultivated crops.
Technical Abstract: We evaluated responses of protein-deprived and protein-fed mature (26-30 days old) female melon flies, Bactrocera cucurbitae (Coquillett), to odor of host fruit and of proteinaceous baits using 1 x 1 x 1 m cages containing non-host plants. Protein-deprived and protein-fed females were equally attracted to odor of host fruit. For both types of females, odor of cucumber, kabocha pumpkin, and cantaloupe was more attractive than odor of zucchini squash, bitter melon or tomato. Our findings suggest that some feral host-seeking melon fly females that have fed recently on natural sources of protein and carry mature eggs might by pass proteinaceous baits, reducing the effectiveness of current approaches to melon fly management.