2007 Annual Report
1a.Objectives (from AD-416)
This study proposes to investigate attraction and effects on non-target organisms of ME, CL, GF-120 protein bait and BioLure bait.
1b.Approach (from AD-416)
A - Short interval studies in traps in different habitats, where traps are cleared daily to avoid attraction of saprophagous organisms to the dead fruit flies. Documents SCA with U of HI. Formerly 0500-00044-007-08S; 03/2005. B - Direct application of attractants to potential treatment areas: evaluation with tree leaves treated with attractant and fixed to sticky boards on sticky traps and untreated controls, and direct attractant application onto plants, with observations on feeding. Habitats to be covered by the above sampling should follow gradients that include a diversity of habitats such as native forests, exotic forests, ecotone areas (eg. strawberry guava invading a native forest), agricultural farmlands, fruit production orchards, residential areas and riparian habitats. Study sites will cover the main fruit-producing islands (Hawai'i, Maui, Oahu, and Kauai) C - Possibility of rearing in laboratory, if feasible, several native Hawaiian insects (especially Drosophilidae) or biological control agents, and the application of attractant treatments to confirm and further investigate the nature of attraction. D - Identification of native areas potentially impacted by area-wide fruit fly suppression/eradication methods (GF-120 and male annihilation treatments).
3.Progress Report
This report documents research conducted under a specific cooperative agreement # 58-5320-4-0501, between ARS and the University of Hawaii. Additional details of research can be found in the report for the parent CRIS 0500-00044-016-00D, Areawide Management of Fruit Flies in Hawaii. Traps baited with female attractants and male lures were setup in native, mixed native and non-native forests, farmlands, orchards and residential areas. Traps were maintained for 10-12 weeks and emptied weekly at 35 sites on Hawaii Island (2005) and 46 sites on Maui (2006). Trap catches were compared against catches from unbaited control traps. To isolate the effect of decaying fruit flies that frequently accumulate in traps and may secondarily attract non-targets, propylene glycol was used as a liquid preservative in all traps, and additional traps artificially baited with decaying flies were maintained at most sites. Most of FY07 was spent processing samples, with every specimen counted and identified to species level whenever possible. The preliminary results and implications are as follows. Male lures (cue-lure, methyl eugenol) failed to attract insects other than target fruit flies, except for a weak attraction to methyl eugenol for flower-associated insects, one or several species of possibly endemic fungus gnats, and possibly endemic plant bugs. Again numbers of non-targets were very low. Non-target insects were abundant in traps baited with decaying flies, and the same species were also observed in male lure traps with large accumulations of dead trapped fruit flies. Protein attractants (solulys, torula yeast), BioLure and decaying flies attracted large numbers of mostly Dipteran non-targets. Endemic species were attracted to traps set up in invasive forests, orchards, farmlands and backyards. Details of the geographic range of non-target attraction are forthcoming. Attraction of Medfly and non-target to 2-component and 3-component BioLure and its individual components was thoroughly investigated in native forest and orchards. Ammonium acetate was found to be the most attractive componenet to both target Medflies and non-target insects. Also, the putrescine component is not a necessary component in BioLure traps because it did not add significant extra attraction to Medflies, compared to using only two components. Comprehensive literature reviews on past studies of non-target effects of male lures were compiled as technical support to the lure registration application packages to EPA. The reviews critically assessed all published records of possible lure attraction. and concluded that cue-lure attracts only target fruit flies, only a few species of non-targets are attracted in small numbers to methy eugenol, and most published records of methyl eugenol attraction were actually attraction to decaying Oriental fruit flies accummulating in traps. Progress was monitored through regular meetings with cooperator and an annual meeting held each April. A detailed progress report was received from the cooperator.
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