Is Drosophila suzukii as susceptible to entomopathogenic nematodes as Drosophila melanogaster?

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is the major invasive pest of small, soft-skinned and stone fruits, with a wide range of hosts. This study aims to test the susceptibility of this insect to entomopathogenic nematodes (EPNs) and their efficacy on infested fruits from first instar larvae to adult emergence. Drosophila suzukii and D. melanogaster (Meigen) (Diptera: Drosophilidae) were susceptible to Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), S. feltiae (Filipjev) (Rhabditida: Steinernematidae), Steinernema sp. (glaseri group) (Filipjev) (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora (Poinar) (Rhabditida: Heterorhabditidae) on two substrates (filter paper and agar). The greater efficacy against D. suzukii was achieved by S. feltiae and S. carpocapsae (94 and 84%, respectively) with equal efficacy than that obtained using D. melanogaster as host (93.37 and 92.88%, respectively). The EPNs infected and could reproduce inside D. suzukii larvae. In contrast, pupae of both species were not infected by them. Nematodes proved to be able to reduce adult emergence of D. suzukii (up to 35% by S. feltiae) on strawberry fruit under laboratory conditions. These results show that D. suzukii is as susceptible as D. melanogaster to EPNs, confirming the potential of these nematodes as biological control agents against this important pest.