Controlled-release dispenser and dry trap developments for Drosophila suzukii detection

Authors: LARSON, NICHOLAS - Towson University; Strickland, Jaime; SHIELDS, VONNIE - Towson University; Zhang, Aijun

Submitted to: Frontiers in Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2020
Publication Date: 3/6/2020
Citation: Larson, N.R., Strickland, J.A., Shields, V., Zhang, A. 2020. Controlled-release dispenser and dry trap developments for Drosophila suzukii detection. Frontiers in Ecology and Evolution. https://doi.org/10.3389/fevo.2020.00045.
DOI: https://doi.org/10.3389/fevo.2020.00045

Interpretive Summary: The fruit fly, spotted wing drosophila (SWD), is an exotic insect pest from Southeast Asia, which was introduced to the United States in 2008. It attacks a wide variety of fruits and has become a devastating pest of soft-skinned fruit crops. Due to the rapid spread of SWD across the United States and European countries, specific and efficient SWD detection tools are urgently needed so that growers/farmers can deliver timely management interventions to meet market demands. In our previous study, the liquid trap baited with a quinary blend had been established for effective SWD attraction. In present study, a dry trap baited with an optimized controlled-release dispenser has been developed. New trapping system demonstrated earlier SWD detection compared to the conventional liquid traps that have been currently used in orchards/farms. Due to the simplicity of the dry trap design with controlled release dispenser, it has provided growers/farmers an efficient, convenient, and easy processing tool for SWD infestation detection.

Technical Abstract: Asia and has invaded many American and European countries. This devastating pest has caused severe damage on soft-skinned fruit crops, which has resulted in large economic losses. Although many D. suzukii detection devices have been developed and used by growers/farmers in orchards, most of them did not meet their expectation. More simple, convenient, and efficient detection tools are still urgently needed so that growers/farmers can make timely management decision. In our previous study a quinary blend, containing acetoin, as a long-range, and ethyl octanoate, as a short-range attractant for SWD, had been identified. In this study, a controlled-release polyethylene dispenser containing five identified attractants: acetoin, ethyl octanoate, ethyl acetate, penethyl alcohol, and acetic acid, was tested in laboratory conditions for release rates, as well as in a blueberry field and an adjacent wooded area for trapping activity. Release of the most D. suzukii attractants from the polyethylene dispenser was constant. In the laboratory, release rates of ethyl acetate (0.3 g/day over 14 days), phenethyl alcohol (0.0054 g/day over 36 days), and acetic acid (0.13 g/day over 36 days) followed zero order kinetics. Acetoin and ethyl octanoate were blended together and had a varied release rate. In the field, dry and liquid traps baited with the optimized controlled-release dispenser were evaluated and compared with liquid traps baited with apple cider vinegar (ACV). During blueberry harvest season in 2018, the liquid traps containing drowning solution baited with the optimized controlled-release dispenser caught both male and female D. suzukii two weeks earlier and had significantly higher selectivity than that of ACV traps in the field. Additionally, in 2019 field tests, dry traps baited with the controlled-release dispenser demonstrated earlier detection compared to the ACV traps. Due to the simplicity of the dry trap design and easy processing, it has great potential to be an efficient and convenient D. suzukii detection tool for growers/farmers.