Key to Nearctic species of Trissolcus Ashmead (Hymenoptera, Scelionidae), natural enemies of native and invasive stink bugs (Hemiptera, Pentatomidae)

Trissolcus japonicus (Ashmead) and T. cultratus (Mayr), comb. rev. are under study as classical biological agents to control the brown marmorated stink bug Halyomorpha halys (Stal) in North America. Here we present diagnoses for all Nearctic species of Trissolcus, including T. japonicus and T. cultratus comb. rev., and identification keys to enable separation of these species from the existing fauna. Trissolcus cultratus comb. rev, is removed from synonymy with T. flavipes. Two new species are described, Trissolcus valkyria sp. n. and T. zakotos sp. n. A neotype is designated for T. brochymenae and a lectotype is designated for T. basalis.