Two Asian egg parasitoids of Halyomorpha halys (Stål) (Hemiptera, Pentatomidae) emerge in northern Italy: Trissolcus mitsukurii (Ashmead) and Trissolcus japonicus (Ashmead) (Hymenoptera, Scelionidae)

Abstract

Halyomorpha halys (Stål) is a severe agricultural pest that is spreading worldwide from its original distribution in Asia. Egg parasitoids from Asia, which play a key role in the population dynamics of H. halys, are following its host along global pathways. We present the first records of Trissolcus mitsukurii in Europe, and of Trissolcus japonicus in Italy. Both discoveries were made in northern Italy, where H. halys is widely present and has reached extremely high population densities in some areas. Given the availability of their host, the distributions and populations of these exotic egg parasitoids are expected to expand, even in the absence of human intervention.