Disrupting oviposition behavior of spotted-wing drosophila, <i>Drosophila suzukii</i> (Diptera: Drosophilidae) in blueberries with volatile blends

Drosophila suzukii (Matsumura), spotted-wing drosophila, is an invasive pest native to East Asia that causes significant economic losses in soft-skinned high-value fruit like blueberries. Current management strategies heavily rely on insecticide applications, raising concerns about resistance and sustainability. This study evaluated the efficacy of plant-derived volatile blends, including Decoy Attract and Kill (A&K) (Batch no. 24026021), Combi-protec (Batch no. SP2211XXUS), Decoy (Batch no. 42022121, 10% citric acid), and fermentation-based volatiles of Scentry experimental blend (SEB) (Batch no. SBI2024200-005), and Droski drink (acetic acid) as potential behavioral disruptors that reduce D. suzukii oviposition without insecticide use. These five volatile blends, except Decoy and Droski drink have undisclosed active ingredients. Three concentrations of Decoy A&K (0.5, 2, and 5 mM) and four other blends were tested using Drosophila activity monitor (DAM), electroantennography (EAG), laboratory behavioral trials, and exclusion cage semi-field oviposition trials. DAM quantified positional preference and dwell time to blends, while EAG measured antennal responses to Decoy A&K. Laboratory behavioral trials assessed oviposition and dwelling behaviors, while exclusion caged semifield trials evaluated oviposition behavior alone. Decoy A&K, Combi-protec, and Decoy significantly increased dwell time and reduced oviposition on blueberries, both in controlled and semi-field conditions. EAG responses showed that D. suzukii can detect Decoy A&K volatiles through olfaction, likely mediating the observed behavioral results. These findings highlight the potential of selected volatile blends as tools for behavioral disruption, supporting their application in integrated pest management strategies, including push-pull or attract-and-kill systems for D. suzukii.