The invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a pest of growing economic importance in the United States, the control of which currently relies on pesticide applications. Biological control could provide sustainable and long-term control but classical biological control agents have not yet been approved at the federal level. Adventive populations of a potential biological control agent, the Samurai wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), have been found in the United States, first in Maryland in 2014, expanding its range west to Ohio by 2017. Trissolcus japonicus is a highly effective parasitoid of H. halys eggs, but its redistribution and augmentative releases are restricted to states where it has been detected in the wild. To assess the presence of T. japonicus in Michigan and attack rates on H. halys by native natural enemies we deployed 189 H. halys egg masses at ten sites in lower Michigan between May and October in 2018. In addition, we deployed 51 native stink bug egg masses at the same sites to evaluate potential non-target effects of T. japonicus in the field, which were shown to occur in laboratory studies. We found T. japonicus in a single H. halys egg mass, which constitutes the first record of this Asian parasitoid in Michigan. Native predators and parasitoids caused minimal mortality of H. halys eggs and we did not find evidence of non-target effects of T. japonicus on native stink bug species. These findings open the door to initiation of a classical biological control program using an efficient, coevolved parasitoid from the native range of H. halys.