Attraction of Hawaiian Ground Litter Invertebrates to Protein Hydrolysate Bait

Abstract

This study addressed the potential effects on Hawaii's unique fauna of protein bait sprays used in fruit fly eradication programs. We sampled the ground litterinhabiting invertebrates attracted to protein hydrolysate-baited pitfall traps at six localities on the island of Kauai. Twenty-two taxa and possibly 30 species were found in significantly higher numbers in treatment than in control traps. A diverse fauna, including species of land snails (Gastropoda), isopods (Isopoda), millipedes (Diplopoda) and insects (nine families), was attracted to the bait. Flies in the family Drosophilidae may be particularly susceptible to bait sprays, with at least eight species demonstrating attraction. Traps in high-elevation native forest attracted the highest number of species (20) and the most native species (11). The number of native species attracted to the bait decreased with elevation and the proportion of native vegetation, so that no native species were recovered from the two low-elevation agricultural areas. The potential effect of using protein hydrolysate bait sprays for alien fruit fly control in Hawaii is discussed.

Attraction ofCeratitis capitata(Diptera: Tephritidae) and Endemic and Introduced Nontarget Insects to BioLure Bait and Its Individual Components in Hawaii

“…The same species of Dyscritomyia were equally drawn (2.7 per trap per day) to traps baited with decaying fruit ßies (Leblanc et al 2009b). Outside native forest, only introduced Calliphoridae were trapped, and in very small numbers (0.002Ð 0.009 per trap per day), consistent with results of Asquith and Messing (1992).…”

“…Species attracted to BioLure largely belong to families whose larvae are scavengers on decaying plant or animal matter (Drosophilidae, Chloropidae, Lonchaeidae, Neriidae, Otitidae, Phoridae, Anthomyidae, Calliphoridae, Muscidae, Sarcophagidae, and Nitidulidae). Most of these families were also dominant in BioLure (Thomas 2003) and protein hydrolysate (Hardy 1952, Asquith andMessing 1992) traps in other studies and are attracted to decaying fruit ßies that accumulate inside male lure traps (Leblanc et al 2009b). …”

“…Nontarget attraction to liquid and sticky protein bait traps has been reported in literature for decades (Hardy 1952, Moore 1969, Neuenschwander et al 1981, Asquith and Messing 1992, Thomas 2003. Although most nontargets were saprophagous Diptera, substantial numbers of beneÞcial Tachinidae (Moore 1969, Thomas 2003 and honeydew-feeding Chrysopidae (Neuroptera) (Neuenschwander et al 1981) were captured.…”

Trapping and the Detection, Control, and Regulation of Tephritid Fruit Flies

“…Corn protein hydrolysate was found to be very effective in capturing C. capitata (Gothilf and Levin 1987;, whereas yeast hydrolysate was more effective for Anastrepha species . Liquid protein baits capture a higher percentage of females but also large numbers of non-target organisms, including ground invertebrates (Asquith and Messing 1992) and flying insects , which is a serious weakness of these attractants (as further discussed below).…”

“…The attraction of non-target insects to fruit fly traps has been widely studied (Asquith and Messing 1992;Uchida et al 2004;Tschorsnig et al 2011), and several authors pointed out the importance of reducing the number of non-target insects in traps that are intended for use over long periods of time (Uchida et al 2004). In studies on Bactrocera male attractants, although the higher number of non-target captures were saprophagous insects (mostly Diptera) attracted to traps baited with decaying flies (Leblanc et al 2009), some flower-associated insects (honey bees, syrphid flies, nitidulid beetles, and endemic crambid moths) were also trapped.…”