Evaluating fruit protection and mortality outcomes of attract-and-kill disruptors for managing Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii is a destructive pest of soft-skinned fruits, driving the need for more sustainable and behaviorally targeted pest control strategies. This study had two objectives: (1) to assess the compatibility of malathion and spinosad with two attractants, Combi-Protec® and Decoy®, based on D. suzukii mortality and oviposition across five droplet volumes (0, 2, 6, 10, and 14), and (2) to compare adult mortality patterns between Attract-and-Kill (A&K), full-cover spray, and untreated control (UTC) treatments over 24 hours. Oviposition was significantly suppressed with ≥6 droplet applications. Spinosad reduced egg-laying by 26% (Combi-Protec®) and 61% (Decoy®), while malathion achieved 68% and 66% reductions, respectively. Mortality also increased significantly with droplet volume, with 6, 10, and 14 droplets producing consistently higher adult mortality for both insecticides. Among all treatments, malathion with Decoy® showed the strongest combined suppression of oviposition and adult survival. In time-course trials, A&K achieved 85.4% mortality within 5 hours, substantially higher than full-cover spray (33.9%) and UTC (0%), and maintained superior efficacy through 20 and 24 hours. These results indicate that A&K systems using malathion or spinosad paired with Decoy®, especially at ≥6 droplet levels, can rapidly and effectively reduce D. suzukii populations. This strategy offers a promising, selective, and scalable alternative to full-cover sprays and supports the adoption of environmentally responsible approaches within integrated pest management programs.