Potential Threats

The spotted lanternfly (Lycorma delicatula) is an invasive pest that impacts a wide range of plants as it feeds throughout the growing season. This non-native leafhopper was first identified in Pennsylvania back in 2014 and has since spread to 10 other states. It was first found in Illinois in fall of 2023 and efforts are underway to discover its population and prevent further spread. 

The elm zigzag sawfly (Aproceros leucopoda) is an invasive pest of elm trees (Ulmus spp.) that was first detected in Illinois in July 2024 in Busse Woods, Cook County. Native to parts of China and Japan, this species became established in Europe in 2003 and was first detected in the U.S. in Virginia in 2021. Elm zigzag sawflies are primarily problematic because the larvae defoliate elm trees. Adult elm zigzag sawflies can extend their range by 28–56 miles per year, a rapid expansion attributed to their strong dispersal capabilities.