Location: Horticultural Crops ResearchTitle: Attractiveness of fermentation and related products to spotted wing Drosophila (Diptera: Drosophilidae)) Author
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2014
Publication Date: 2/15/2014
Citation: Kleiber, J.R., Lee, J.C., Qian, M., Unelius, C.R., Suckling, D.M., Bruck, D.J. 2014. Attractiveness of fermentation and related products to spotted wing Drosophila (Diptera: Drosophilidae). Environmental Entomology. 43:439-447. Interpretive Summary: Spotted wing drosophila (SWD) is an invasive pest causing huge economic losses in small fruit and cherry industries. Currently, the monitoring trap is not very sensitive and improvements are needed such that the trap can be used to detect flies early in the season and predict crop risk. Apple cider vinegar is a commonly used bait for SWD. We compared 17 compounds that are fermentation products for their attractiveness to SWD: including alcohols, acids, phenethyl esters, and acetates. The 17 compounds were first screened in greenhouse cages. The ones that were attractive within cages were further tested in the field by adding them to standard apple cider vinegar traps. The compounds determined to be attractive in the greenhouse bioassay include methanol, ethanol, propanol, formic acid, acetic acid, ethyl acetate, propyl acetate, phenethyl acetate, phenethyl propionate, and phenethyl butyrate. None of the compounds added into vinegar traps significantly increased the attractiveness. Captures from the same treatments were also compared during peak fruit ripeness and post-harvest, and treatments performed consistently during both periods.
Technical Abstract: Laboratory screening bioassays and field trapping experiments of spotted wing Drosophila flies, Drosophila suzukii were conducted to determine the attractiveness of 17 potentially attractive compounds as well as compare attractant efficiency during peak fruit ripeness and postharvest captures late in the season. Compounds structurally similar to each of the fermentation products acetic acid, ethanol, ethyl acetate and 2-phenethyl alcohol were screened for attractiveness in greenhouse cage bioassays. The compounds determined to be attractive in the greenhouse bioassay (methanol, ethanol, propanol, formic acid, acetic acid, ethyl acetate, propyl acetate, phenethyl acetate, phenethyl propionate, phenethyl butyrate) were subsequently tested individually in the field as a volatile supplement to apple cider vinegar (ACV) or neutralized apple cider vinegar (NACV) (pH~7) bait traps as well as in combination in NACV. The numbers of captures in ACV traps were not increased by the addition of any of the compounds tested, although differences in catches between supplemented compounds were observed. Compounds that are most prevalent in wine and vinegar (methanol, ethanol, acetic acid, ethyl acetate) as well as phenethyl propionate and phenethyl butyrate had less of a negative impact on the captures in ACV traps than other compounds tested in the field. Captures from the same treatments were also compared during peak fruit ripeness and postharvest late in the season when no fruit hosts were available or overripe. Although the total number of flies captured late in the season was lower, the trends in treatment performance were similar. This is promising if trap users can expect a consistent performance of baits from peak fruit ripeness through postharvest.