Introduction: The brown marmorated stink bug, Halyomorpha halys,is an Asian polyphagous species that has become an invasive crop pest in North America and Europe. After its first detection in Switzerland in 2004, it was subsequently found in other European countries such as Italy, where, since 2012, it has rapidly spread in the northern regions, becoming a threat to many crops, especially
in pear and peach orchards.
Results/Conclusion: Overall, most egg parasitism was due to the generalist parasitoid Anastatus sp. (Eupelmidae) and, at a lower level, to various Scelionidae species (e.g. Trissolcus cultratus). In northern Italy, the amount of parasitized eggs ranged from 3.1% in 2014 to 0.9% in 2015 in Emilia Romagna, and from 0.3% on exposed egg-masses to 21.4% on egg-masses collected in a natural habitat in 2015 in Piedmont. Overall parasitism in Switzerland was 4.4% in 2013
