Surveys of Drosophila suzukii (Diptera: Drosophilidae) and Its Host Fruits and Associated Parasitoids in Northeastern China

SIMPLE SUMMARY: Drosophila suzukii has become a globally invasive pest of thin-skinned berries and stone fruits such as strawberries, blueberries, raspberries, blackberries, and cherries. D. suzukii has caused severe economic losses to the fruit industries in more than 30 countries and has been listed as an important quarantine pest in many countries around the world. To better understand the ecology of this invasive pest for its effective management, it is essential to investigate the occurrence of D. suzukii and its wild host fruits and natural enemies in its native range. Here, we report the occurrence of D. suzukii and its wild host fruits and associated parasitoids in Liaoning, Northeast China for the first time. Four species of wild berries from non-crop habitats were found infested by D. suzukii, and two species of parasitoids (Leptopilina japonica and Asobara japonica) were discovered. Over the survey period from June to October, D. suzukii adult populations increased and peaked in August, and then declined until it was no longer detectable in October. ABSTRACT: Spotted-wing drosophila, Drosophila suzukii (Matsumura), is a worldwide quarantine pest that is currently undergoing a rapid range expansion in the Americas, Europe, and parts of Africa. It feeds and breeds on soft-skinned fruits such as raspberries, blueberries, and cherries, and can cause significant economic losses to fruit production. This study investigated the occurrence of D. suzukii and its wild host fruits and parasitoids in Liaoning, Northeast China for the first time. Sentinel traps were used to monitor D. suzukii adults, and suspected fruits were collected weekly in four different locations (Wafangdian, Faku, Fengcheng, and Shenyang). The results showed that D. suzukii were distributed in the sweet soft-skinned fruit-production areas of Liaoning, and raspberry was the most infested fruit. During the field survey, four species of wild berries from non-crop habitats were found infested by D. suzukii, and two species of parasitoids (Leptopilina japonica and Asobara japonica) were collected. D. suzukii adult-population dynamics throughout the survey period (June to October) were similar in different survey locations; adult fly populations increased and peaked in August, and then declined until the fly was no longer detectable in October.