Physiological status of Drosophila suzukii (Diptera: Drosophilidae) affects their response to attractive odours

Authors: WONG, JESSICA - Oregon State University; WALLINGFORD, ANNA - Cornell University; LOEB, GREG - Cornell University; Lee, Jana

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2018
Publication Date: 2/9/2018
Citation: Wong, J., Wallingford, A., Loeb, G., Lee, J.C. 2018. Physiological status of Drosophila suzukii (Diptera: Drosophilidae) affects their response to attractive odours. Journal of Applied Entomology. 142(5):473-482. https://doi.org/10.1111/jen.12497.
DOI: https://doi.org/10.1111/jen.12497

Interpretive Summary: The spotted wing drosophila is a serious pest infesting small fruits and cherries. Traps are placed in the field to help growers detect when the fly is present and start treatment programs. Mass trapping, the use of many traps to trap out the fly, is another potential way to control the pest as an alternative to insecticides. While numerous studies have examined baits for attracting spotted wing drosophila, we don't know what kind of flies are being captured. Flies can vary by status, specifically by: age, whether they are hungry or fed, mated or virgin, with or without eggs to lay, with or without previous opportunities to lay eggs, and physically adapted for summer or winter conditions. We conducted a series of experiments to examine how flies of different status are trapped in fermenting or fruit-based odors. Starved flies were trapped at greater rates compared to fed flies; virgin flies were trapped more often than mated flies; flies deprived of egg laying opportunities were trapped more frequently than flies given egg laying opportunities. Flies with many eggs in their ovary were most attracted to fruit odors. The type of bait chosen in traps should consider the objective of trapping and the time of year.

Technical Abstract: A comprehensive understanding of the biology of the invasive pest, Drosophila suzukii, is critical for the development of effective management strategies. Trapping is one technique used both for detection and control, however the efficacy of trapping can vary depending on the target insect’s physiological state, its behavioral priorities, and the type of attractant used in the trap. We conducted a series of no-choice experiments and a greenhouse experiment to investigate the effects of D. suzukii feeding status, age, mating status, ovipositional status, and seasonal morph type on the capture rate of traps baited with fermentation odors. A choice experiment investigated the relationship between female reproductive status and attraction to fermentation or fruit odors. Starved flies were trapped at greater rates compared to fed flies; virgin flies were trapped more often than mated flies; flies deprived of an oviposition substrate were trapped more frequently than flies given an oviposition substrate; and fermentation odors were attractive to flies regardless of their reproductive status, while fruit odors were most attractive to flies with many eggs. It is less apparent whether age or seasonal morphology affect trap response. D. suzukii physiology should be considered when choosing which types of attractants to use with traps or when developing new lures. The type of bait chosen in traps should take into consideration the objective of trapping and the time of year.