Small, two winged, fly-like adults, about three millimetres long overwinter in soil and emerge just as new foliage begins to develop in spring. Females lay microscopic eggs in unfolding leaflets. White to yellow larvae, about six millimetres in length, hatch in one to two days and begin feeding on the leaf surface. After three weeks of feeding, larvae pupate within the pod and adults emerge. There are several generations per season.
Galls dry up and fall resulting in reduced foliage and an unsightly canopy.
Repeated attacks may cause the death of small branches. Honeylocust plantbug overwinters as eggs which have been laid under the bark of two and three year old twigs. Eggs hatch as buds begin to break. Most of the serious damage occurs when the emerging nymphs crawl and begin feeding on developing foliage. They do not have larval and pupal stages as with the podgall midge.