Submitted to: Hawaiian Entomological Society Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2006
Publication Date: 12/1/2006
Citation: Uchida, G.K., Mackey, B.E., Vargas, R.I., Beardsley, J.W., Hardy, D.E., Goff, M.L., Stark, J.D. 2006. Response of nontarget insects to methyl eugenol, cue-lure, trimedlure, and protein bait on Kauai Island, Hawaiian Islands. Hawaiian Entomological Society Proceedings. 38:41-71.
Interpretive Summary: A nontarget insect (insects other than fruit flies) study was conducted on the island of Kauai, Hawaiian Islands, to determine if plastic bucket traps in combination with fruit fly attractants, methyl eugenol, cue-lure, trimedlure, protein bait, and naled (killing agent) were attractive to endemic and introduced insects. We found that both endemic and introduced nontarget insects were attracted to each attractant-trap and naled-trap combination. However, based on available knowledge discoverd by other researchers and our study, nontarget insects are positively attracted to decaying B. dorsalis in traps and not to methyl eugenol. Thus, methly eugenol can be used for fruit fly control (i.e. male annihilation) without affecting nontarget insects provided that decaying insects in the traps are eliminated or the odors emanating from decaying insects are subdued. The problem of captured decaying insects in traps, which are attractive to nontarget insects, can be mitigated by making proper changes to these traps, such as removing or cutting holes in trap bottoms, or addition of mineral to slow down escape of decaying odors from captured nontarget insects. For the present, monitoring traps which have bottoms should be used sparingly in environmentally sensitive habitats until future research comes up with modified trap designs that will capture fewer species and individuals as traps currently being used in area-wide programs in the Hawaiian Islands.
Technical Abstract: Responses of nontarget insect species to bucket traps baited with different tephritid fruit fly attractants were examined in primarily native habitats at three localities on Kauai Island. Traps were made according to a previous design and no effort was made to control the odors given off by collected decaying insects or to sterilize the traps. Significantly greater (P = 0.05) than water control catch rates were observed across different attractant trap types: methyl eugenol (five species and two morphospecies), cue-lure (two species), trimedlure (three species and one morphospecies), and protein bait trap (one species and one morphospecies). Control traps (5% naled) collected significantly greater numbers of three species than methyl eugenol, cue-lure, trimedlure, and protein bait traps, more of one species in cue-lure, trimedlure, and protein baits and more of one morphospecies in methyl eugenol traps. Our findings suggest that nontarget insects are attracted to combined effect of plastic bucket traps baited with methyl eugenol, cue-lure, trimedlure, protein bait, or naled (control). However, based on available data and results herein, nontarget insects are positively attracted to decaying B. dorsalis in traps and not to methyl eugenol. Thus, methyl eugenol can be used for fruit fly control (i.e. male annihilation) without any impact to nontarget insects as long as decaying insects in traps are eliminated or volatiles emanating from collected decaying insects are subdued. The problem of nontarget insects being attracted to collected insects in a trap can be mitigated through proper modification of trap (removing or cutting holes in trap bottoms) or addition of mineral to slow down escape of volatiles from collected decaying insects. For the present, monitoring traps which have bottoms should be used sparingly in environmentally sensitive habitats until more research can be done to devise traps with altered physical characteristics that capture fewer species and individuals as the traps currently being used in areawide programs in the Hawaiian Islands.