Inside each pod gall, two to eight cream-colored larvae or pupae may be found. After the adult midges emerge, the galls drop leaving bare leaf stalks. The honeylocust podgall midge has multiple annual generations, being most active from the time of first shoot growth through mid-summer.
Infestations occasionally can be severe enough to temporarily destroy all new growth.
Leaflets that have already expanded are not injured by the insect. All commonly planted honeylocust varieties appear to be susceptible to honeylocust podgall midge. Natural honeylocust podgall midge controls include severe weather and a small parasitic wasp that attacks young midge larvae. Heavy midge infestations often collapse when new growth ceases and the trees are no longer attractive to the egg-laying adult midges. In the absence of suitable egg-laying sites, the adult midges apparently go into an inactive diapause stage, renewing activity the following spring.