|BIONDI, ANTONIO - Universita Di Catania
|DAANE, KENT - University Of California
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2019
Publication Date: 10/7/2019
Citation: Wang, X., Biondi, A., Daane, K.M. 2019. Functional responses of three candidate Asian larval parasitoids evaluated for classical biological control of Drosophila suzukii. Journal of Economic Entomology. https://doi.org/10.1093/jee/toz265.
Interpretive Summary: Spotted wing drosophila has become a key invasive pest of soft- and thin-skinned fruit crops in Europe and Americas, where locally occurring natural enemies are generally not effective for the suppression of this pest or largely absent. Three parasitic wasps that attack spotted wing drosophila larvae were collected from its native range in Asia and are under consideration for release in North America to help control this pest. As a part of systematic evaluations of these candidate agents, we compared the capacity of these parasitic wasps to locate and attack hosts in response to changes in host density. One species was more efficient than other two species in terms of the searching efficiency. The results from this study will help to develop effective mass rearing methods of these candidate parasitoids and guide the selection of natural enemies to be released for the control of this invasive pest.
Technical Abstract: Drosophila suzukii has become a key invasive pest of soft- and thin-skinned fruit crops in its invaded regions in Europe and Americas, where locally-occurring natural enemies are generally not effective for the suppression of this pest or are largely absent, such as larval-attacking parasitoids. As a part of systematic evaluations of candidate agents for classical biological control of this invasive pest, we evaluated the functional responses of three Asian-native larval hymenopteran parasitoids, Asobara japonica (Braconidae), Ganaspis brasiliensis and Leptopilina japonica (both Figitidae) to D. suzukii or D. melanogaster (A. japonica only) larvae. Host larval densities were 5, 10, 15, 20, 25, 30, 35 or 40 larvae per test for A. japonica and 3, 6, 9, 12, 18, 24, 30, 36 or 42 larvae per test for G. brasiliensis or L. japonica. Host larvae were provided in standard artificial diet in tubes for a 24-h exposure to individual female parasitoids under the quarantine conditions (23°C). All three parasitoids showed a linear (type I) functional response to the tested host densities. Host species (for A. japonica only) did not affect the number of hosts parasitized or the functional response. Asobara japonica was more efficient than either figitid in terms of the searching efficiency, while L. japonica performed slightly better than G. brasiliensis under the tested conditions. The results are discussed with respect to the selection of parasitoid species to be released in North America and Europe to suppress D. suzukii.