Assessing geographic dimensions of biological control for Halyomorpha halys in United States

Biological control is often a key component of management strategies for invasive species. Yet, the effectiveness of biological control can be limited by a poor understanding of natural enemy ecology. To overcome this, habitat suitability models can predict distributions of invasive species and identify areas of potential overlap between invaders and natural enemies to guide biological control. Here we used data from a coordinated national monitoring network and a novel modeling method that incorporates physiology into correlative niche models to predict potential distributions of the brown marmorated stink bug, Halyomorpha halys, and two natural enemies (a parasitoid, Trissolcus japonicus, and a microsporidian, Nosema maddoxi) in current and future climates (2070s). We show all three species have broad similarity in habitat suitability, with especially high overlap in the mid-Atlantic and southeastern US where H. halys populations were first established. Each species will likely expand their range across the northern US in the future, but the overlap between species may decrease. In much of the central and southeastern US, H. halys may decrease its range over time, although natural enemies may be less impacted, and overlap between species may increase. Our study shows that biological control provided by T. japonicus and N. maddoxi could be key for managing H. halys given their overlapping niches, and our models can aid in delineating areas where biocontrol may be most effective. Our method of linking field data with correlative niche models can also be used for other insects.