Author
LEBLANC, LUC - University Of Hawaii | |
RUBINOFF, DAN - University Of Hawaii | |
Vargas, Roger |
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/30/2009 Publication Date: 10/1/2009 Citation: Leblanc, L., Rubinoff, D., Vargas, R.I. 2009. Attraction of nontarget species to fruit fly (Diptera: Tephritidae) male lures and decaying fruit flies in traps in Hawaii. Environmental Entomology. 38:5, 1446-1461. Interpretive Summary: Synthetic male lures (methyl eugenol and cue-lure) are commonly used to monitor and mass-trap pestiferous fruit flies. However, there has been much dispute as to the non-target impacts of such lures on beneficial and native insects. A University of Hawaii researcher evaluated the non target effects of methyl eugenol and cue-lure in traps in a range of native and non-native forest and commercial orchard sites on Hawaii and Maui Islands. Cue-lure did not attract nontargets, and methyl eugenol attracted low but significant numbers of only 5 species of flower-associated insects (honeybees, syrphid flies, nitidulid beetles, and crambid moths) and 2 endemic Hawaiian species of sciarids and mirids. Most of the previously published records of attraction to methyl eugenol are demonstrated to be actually secondary attraction to decaying fruit flies. Ways of minimizing effects include the use of mineral oil in traps or open bottom traps. Technical Abstract: Synthetic male lures are commonly used to monitor and mass-trap pestiferous fruit flies (Diptera: Tephritidae: Dacinae). However, there has been much dispute as to the non-target impacts of such lures on beneficial and native insects. To evaluate nontarget attraction effects, traps baited with cue-lure and methyl eugenol were maintained and emptied weekly in a range of native and non-native forest and commercial orchard sites on Hawaii and Maui Islands. Lure trap captures were compared against those from unbaited control traps and traps artificially baited with decaying fruit flies, to mimic the effect of accumulation of dead trapped target flies in male lure traps. Cue-lure did not attract nontargets, and methyl eugenol attracted low but significant numbers of 5 species of flower-associated insects (honeybees, syrphid flies, nitidulid beetles, and crambid moths) and 2 endemic Hawaiian species of sciarids (Diptera) and mirids (Heteroptera). Saprophagous nontargets, mostly Diptera, were abundant and diverse in traps baited with decaying flies and in male lure traps where accumulation of dead flies occurred, but not in male lure traps with few or no fruit fly captures. Most of the previously published records of attraction to methyl eugenol are demonstrated to be actually secondary attraction to decaying fruit flies. Endemic non-targets were collected in native and adjacent forest, but almost exclusively invasive species were attracted to traps placed in non-native forests, orchards, farmlands and backyards. Attraction of flower-associated species may be minimized if methyl eugenol traps are placed in trees after flowering season in orchards. |