First report of Trissolcus japonicus parasitizing Halyomorpha halys in North American agriculture

Summary Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug, an invasive agricultural pest in America and Europe, is reaching a global distribution. In the US, the first detection of H. halys was in the mid-1990s, and it has become a serious pest in multiple crop systems. In 2014, an exotic egg parasitoid, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), was documented parasitizing sentinel H. halys egg masses in a wooded habitat in Beltsville, Maryland, USA. The parasitoid has since been reported in several other locations in the eastern and western US, and its population appears to be expanding in geographic range. However, there have been no reports of T. japonicus parasitizing H. halys egg masses within cultivated crops in the US. Whereas attack of H. halys in non-agricultural habitat may provide important biological control services in the landscape, if T. japonicus is not able to successfully forage for H. halys eggs within crops, its impact as a biological control agent may be limited. Here we report on successful parasitism of egg masses deployed in 2 peach orchards in New Jersey, USA. Egg masses were deployed as part of an experiment investigating the efficacy of an integrated pest management (IPM) strategy utilizing border insecticide sprays in apple and peach. While overall egg parasitism was low, the majority of successfully developing parasitoids (97.4% of total adult parasitoids emerging, and from 75% of successfully parasitized sentinel egg masses) were T. japonicus. © 2018 Florida Entomological Society. All rights reserved.