Survey of Peristenus spp. (Hymenoptera: Braconidae) parasitoids in the Monterey Bay region of California

Two European parasitoids, Peristenus relictus and Peristenus digoneutis, were introduced into California to improve the management of Lygus hesperus. While P. relictus quickly established, P. digoneutis has only rarely been recovered. After a renewed release effort, a field survey was conducted in an attempt to recover P. digoneutis. Collections of Lygus hesperus nymphs were made from strawberry production areas and associated alfalfa trap crops in the Monterey Bay region in 2023. Parasitoid larvae recovered from dissected nymphs were identified using species-specific molecular markers. All successfully assayed specimens were confirmed as P. relictus. Furthermore, all reared parasitoids from similarly collected Lygus nymphs were identified as P. relictus. This survey corroborates previous findings indicating that P. relictus is the primary nymphal parasitoid in California and fails to provide evidence that P. digoneutis has established on the central coast.