Dasineura gleditchiae

Honeylocust pod gall midge damage. Photo: Whitney Cranshaw, Colorado State University, Bugwood.
Scientific Name: Dasineura gleditchiae
Common Name: Honeylocust Pod Gall Midge
Growing Degree Days (GDD's): 192–299 GDD's, Base 50F, March 1st Start Date (Source: Cornell Cooperative Extension.)
Host Plant(s) Common Name (Scientific Name)
Honeylocust (Gleditsia triacanthos)
Insect Description:

Honeylocust pod gall midge flies first appear in the spring when new growth is forming on the trees. Females lay tiny, kidney-shaped and lemon colored eggs in the young leaflets of honeylocust. Larvae hatch from their eggs in a couple of days and begin feeding. The feeding larvae cause leaves to develop into a pod shape. Within each pod, one or several tiny, white-yellow, 6 mm long larvae can be found. Larvae mature and pupate within these pods, and emerge as small, delicate flies or midges that are approximately 3 mm long. Male flies are black in color, similar to the females, with the exception that the adult female also has a red abdomen. In Connecticut, 5-7 generations of the honeylocust pod gall midge have been recorded each year. Overwintering is thought to occur as an adult, somewhere outside of the pod (Johnson and Lyon, 1991) however there may be some disagreement on this as sources from points south of Massachusetts indicate that the insect may overwinter as a pupa in the soil. 
Damage to Host:

Causes distortion of new leaflets. Attracted to newly growing foliage. Galled leaflets may dry up and drop from trees prematurely. Repeated feeding may cause the death of small branches, and sometimes new shoots form at the base of dead twigs. Trees are typically not killed, but aesthetic damage may be an issue for some. 
Monitoring:

Sticky traps may be used to monitor for adult midges. Black midges may also be seen on buds at budbreak. As leaflets expand, monitor for developing pod galls. 
Cultural Management:

The cultivar 'Sunburst' may be particularly susceptible to honeylocust pod gall midge injury. Keep this in mind when selecting plantings.
Natural Enemies & Biological Control:

Parasites and predators of the honeylocust pod gall midge are noted. These include but are not limited to parasitic wasps such as Aprostocetus epicharmus, Eupelmus urozonus, and Torymus chloromerus as well as predators such as Orius horvathi, O. minutus, and O. niger (Invasive Species Compendium; CABI). The efficacy of natural enemies at managing honeylocust pod gall midge populations in managed landscapes is not fully understood.
Chemical Management:

Azadirachtin (NL)

Cyfluthrin (NL)

Deltamethrin (L)

Flonicamid+cyclaniliprole (N)

Gamma-cyhalothrin (L)

Imidacloprid (L)

Lambda-cyhalothrin (L)

Spinosad (NL)

Thiamethoxam (N)
Notes:

Applications, if necessary, may be made in the spring before adults finish laying eggs.

Active ingredients that may be applied systemically include: azadirachtin (injection, soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022, neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: September 27, 2024. To check current product registrations in Massachusetts, please visit the MA Department of Agricultural Resources Pesticide Product Registration page and click on "Search Pesticide Products Registered in Massachusetts - Kelly Solutions".