Short- and long-term effects of season-long infestation of Lycorma delicatula trees

Lycorma delicatula White, commonly called spotted lanternfly, is an invasive fulgorid that was first detected in the United States in Pennsylvania in 2014 and has spread across Eastern states. Lycorma delicatula is a phloem feeder, and feeding of persistent populations can cause wilt and dieback in host plants. Vineyards in infested regions have experienced vine loss, where damage has been attributed to L. delicatula. Nymphal and adult lifestages have been observed on cultivated apple and peach trees, but the feeding effects of this pest on these crops have not been quantified. Here, we caged young potted apple and peach trees and infested them with 50 nymphal or 25 adult L. delicatula per plant for 3 months and tracked plant health. Horticultural measurements including trunk diameter, height, leaf drop, and photosynthesis rates were recorded before, during, and after the infestation. To evaluate the long-term effects of infestation, all apple and peach trees were removed from pots and planted in an orchard block where their phenology, growth, and physiology could be evaluated the following growing season. Short- and long-term measurements showed no significant differences in apple tree health between infested and noninfested trees. There was a significant reduction in the growth of trunk diameter in peach trees during exposure to early-instar nymphs; infested peach trees also had significantly increased frost damage to buds the following spring. However, there were no long-term impacts on peach growth and physiology. These results indicate that L. delicatula likely will not be a major threat to these deciduous fruit crops. Keywords: spotted lanternfly, pest status, peach, apple