In East Lansing, Michigan, honeylocust plant bugs Diaphnocoris chlorionis (Say) hatch from overwintering eggs in early May when leaf buds open. They progress through five larval stages by the middle of June. Adults are active in late June and early July. Feeding injury to developing honeylocust foliage occurs throughout the period of larval and adult activity from early May until early July. The leafhopper, Macropsis fumipennis, has a similar life cycle except for the period of adult activity that extends until late July. Cultivars vary considerably in susceptibility to honeylocust plant bug: injury to ‘Halka’ and ‘Skyline’ was far more severe than to ‘Summerlace’ trees in the same randomized planting. Water stress had no effect on honeylocust plant bug, but leafhoppers (M. fumipennis) were less abundant on trees the year following severe water stress.
2Associate Professor, Department of Entomology.
3Associate Professor, Department of Horticulture.