Climate change impacts on the invasive brown marmorated stink bug and Japanese beetle: The good, the bad and the ugly

Climate change is expected to exacerbate agricultural losses from invasive insect pests by increasing growing degree-days, reducing over-wintering mortality, and altering their geographic distribution. In this talk, I will discuss the potential positive and negative impacts of climate change on two invasive polyphagous insect pests: the brown marmorated stink bug, (Hemiptera: Pentatomidae) and Japanese beetle, Popillia japonica (Coleoptera: Scarabaeidae). CLIMEX, a process-based bioclimatic niche modeling package, was used to examine the potential global distribution of P. japonica and H. halys under both current climatic conditions and possible future climate scenarios. Simulated changes in growing degree-days for both insects were also examined. Under the possible future climate scenarios explored here, the non-native North American range of both H. halys and P. japonica expanded northward into Canada and contracted from its southern temperature range limits due to increased heat stress. For H. halys, projected prolonged periods of warm temperatures resulted in longer growing seasons. Under the worst-case future emission scenario, P. japonica’s cumulative growing degree-days increased, thereby reducing the probability of two-year life cycles in northern latitudes where they are commonly observed, including Hokkaido, Japan, and northeastern portions of the USA. The results of these models highlight several regions of increasing and emerging risk from both pests that should be considered in ongoing biosecurity and pest management programs. Since climate change is already altering global insect abundance and geographic distribution, inter-disciplinary research teams and international collaborations are warranted to help reduce economic and environmental impacts of newly emerging invasive pests.