Diaphnocoris chlorionis (Say) The Honeylocust plant Bug, became a pest in the 1950’s and 1960’s with the introduction of the thornless cultivars. It easily escapes detection because the color of the nymph and adult closely matches that of new plant growth. If the infestation is extensive, complete defoliation can occur.

As its name suggests, the honeylocust plant bug attacks the honeylocust tree. Yellow-leaved cultivars, such as the popular "Sunburst," appear to be more susceptible to honelocust plant bug damage than green-leaved cultivars.

Both the nymph and adult feed on the foliage of the plant, although the most serious damage is caused by the nymph, early in the season. Damage includes severe leaf distortion, discoloration and dwarfed leaflets. Severe defoliation weakens the tree and increases its susceptibility to invasion by secondary insect and disease pests. Complete defoliation of the host plant is possible.