EAB parasitoid persistence across a climate gradient

The Emerald Ash Borer (Agrilis planipennis) is a well-known invasive insect in the U.S. that has wreacked havoc on native Ash trees (Fraxinus spp.). The USDA has identified and released four parasitoid wasps of EAB larva and eggs across the country. However, the ability of these parasitoids to persist in an area across multiple years is variable across a temperature gradient. Our research tracks the persistence of these parasitoids across a region from Duluth, MN, USA to Poplar Bluff, MO, USA to measure the success and survival of each species in different climates. Thus far, we have found that colder climates are perferrable to the parasitoids as more EAB larva overwinter as 4th instars in colder regions. In warmer climates, EAB tend to overwinter as "J-larva," which may lead to a decline in parasitoid populations in southern states and a need to release parasitoids yearly.