FIELD TRIALS OF SPINOSAD AS A REPLACEMENT FOR NALED, DDVP, AND MALATHION IN METHYL EUGENOL AND CUE-LURE BUCKET TRAPS TO ATTRACT AND KILL MALE ORIENTAL FRUIT FLIES AND MELON FLIES (DIPTERA: TEPHRITIDAE) IN HAWAII

Authors: Vargas, Roger; Miller, Neil; STARK, JOHN - WASHINGTON STATE UNIV

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2003
Publication Date: 12/15/2003
Citation: Vargas, R.I., Miller, N., Stark, J.D. 2003. Field trials of spinosad as a replacement for naled, ddvp, and malathion in methyl eugenol and cue-lure bucket traps to attract and kill male oriental fruit flies and melon flies (diptera: tephritidae). Journal of Economic Entomology. 96(6):1780-1785.

Interpretive Summary: Four economically important fruit flies have been introduced accidentally into the Hawaiian Islands. These fruit flies jeopardize development of a diversified tropical fruit and vegetable industry in Hawaii, cause exported fruits to undergo expensive quarantine treatment and provide a reservoir for introduction into the mainland United States. Environmental concerns over the use of malathion insecticide make it necessary to emphasize alternative methods of control. In the present report we examine the substitution of an environmentally acceptable male annihilation treatment containing the novel insecticide, spinosad. The development of integrated approaches that include the use of both male annihilation dispensers and protein bait sprays without organophosphates has important application to suppression of fruit flies not only in Hawaii but also throughout the south and western Pacific, Australia, and tropical Asia where Bactrocera are serious economic pests. Furthermore, the development of environmentally-sound area-wide IPM procedures has important applications to eradication of accidental introductions of fruit flies into the U.S. mainland.

Technical Abstract: Plastic bucket traps with cotton wicks were used as dispensers for methyl eugenol (4-allyl-1, 2-dimethoxybenzene-carboxylate) and cue-lure [4-(p-acetoxyphenyl)-2-butanone] to evaluate suppression of Bactrocera dorsalis (Hendel), oriental fruit fly, and B. cucurbitae (Coquillett), melon fly, respectively, under Hawaiian climatic conditions. Spinosad was compared to three organophosphate insecticides (naled, ddvp and malathion) and a synthetic pyrethroid (permethrin) as a killing agent in the dispensers. During the first 20 wk trial with methyl eugenol traps, naled was in the highest rated group during all four evaluation periods on the basis numbers of B. dorsalis captured per trap per day. Spinosad was equal to naled in oriental fruit fly captures up to 10 wk (2nd test period). During the second 20 wk trial naled was in the top rated group during all 4 evaluation periods. Spinosad was equal to naled in B. dorsalis captures up to 10 wk. Spinosad compared favorably with malathion during all test periods. Bactrocera dorsalis captures were lowest with permethrin. During the 1st 20 wk trial with cue-lure traps, naled and malathion were in the top group during all four evaluation periods. Spinosad was equal to naled in B. cucurbitae captures up to 5 weeks. During the second 20 wk trial with cue-lure traps spinosad and naled were both in the top grouping during 3 of the 4 test periods. The use of male lure traps with methyl eugenol or cue-lure had no effect on the attraction of females into the test area with respect to methyl eugenol or cuelure. Our results suggest that spinosad is a promising substitute for organophosphate insecticides in male annihilation bucket traps for control of oriental fruit fly and melon fly in Hawaii and will be tested further in an area-wide pest management program for fruit fly suppression.