Single and Combined Release of Trichopria drosophilae (Hymenoptera: Diapriidae) to Control Drosophila suzukii (Diptera: Drosophilidae).

To further the use of local parasitoids to control the spotted wing drosophila suzukii (Matsumura) in Mexico, three treatments were implemented by sextuplicate in commercial berry fields of Colima and Jalisco from June 2017 to May 2018: single release of Trichopria drosophilae Perkins (pupal parasitoid), combined release of T. drosophilae + Leptopilina boulardi Barbotin, Carton & Kelner-Pillault (larval parasitoid), and a no release control. Compared with the no release sites, parasitism by T. drosophilae increased 4 and 4.1-fold at the single and combined release sites, respectively, and parasitism of L. boulardi increased 2.8-fold at the sites where it was evaluated. Additionally, it was registered a 50 and 55% reduction of D. suzukii at the sites with single and combined releases, respectively; in other words, supplementing T. drosophilae with L. boulardi provided little benefit compared with the release of T. drosophilae alone. These results indicate that single release of local T. drosophilae is a more cost-effective option to reduce D. suzukii populations, and that such activity can contribute significantly to the phytosanitary management of this invasive pest.