Temporal fluctuations and geographic distributions of Leptopilina (Hymenoptera: Figitidae) species in North Carolina: implications for biological control of Drosophila suzukii (Diptera: Drosophilidae).

Abstract

Biological control is an important component of integrated pest management programs. This can include classical biological control agents, but also adventive biological control agents that naturally established. Here, we provide details of the presence and seasonal biology of potential biological control agents for the invasive Drosophila suzukii Matsumura in Southeastern USA blackberry production systems, including a recently established adventive parasitoid wasp species, Leptopilina japonica Novković & Kimura. To better understand the populations of this new species, we compare detection methods and report on temporal fluctuations and geographic distributions in North Carolina blackberry fields. In total, we collected 1,142 specimens from 6 sites including 5 different Leptopilina species: Leptopilina boulardi Barbotin, Carton & Kelner-Pillault, Leptopilina clavipes Hartig, Leptopilina heterotoma Thomson, Leptopilina japonica, and Leptopilina leipsi Lue & Buffington. We confirm previous reports of L. japonica, L. boulardi, and L. heterotoma in North Carolina, but report L. clavipes and L. leipsi in the state for the first time. While several Leptopilina species have now been documented in North Carolina, L. japonica shows the most promise as a biological control agent for D. suzukii. Understanding the when and where each of these parasitoid species is present in crop fields is an important first step in improving D. suzukii management efforts. These data will aid in understanding how best to protect these species and how best to incorporate them into on-farm management plans.