DESCRIPTION
Adult midges are small black flies about 3 mm long. Larvae are whitish-yellow worms about 6 mm long. They are found inside leaflet galls.

DAMAGE
Several varieties of Honeylocust (Gleditsia) are affected. Larvae cause leaflets to form into a pod which often turns reddish in colour and sometimes drops prematurely. Smaller branches often die and even though trees are not greatly distressed, their ornamental value is lessened.

LIFE CYCLE
Insects overwinter as adults, although it is not known where. Adults fly and lay lemon coloured eggs in spring when new growth begins. Larvae emerge in 1 or 2 days and immediately begin to feed, causing the leaflet to develop around them into a pod. Larvae pupate inside the pod and emerge as adult midges. There are several generations per year, appearing at 3 to 4 week intervals.

CONTROLS
• Inspect plants frequently for adult midges (yellow sticky traps may help) and leaflet galls (larvae).
• Prune off and destroy gall infested branch tips. Pesticide application is only moderately effective.
• The best results are obtained when midges are flying, larvae are newly hatched and leaflets are opening in spring, before the galls are formed.
• Keep a pest journal recording the number of generations observed and timing of sprays.

PESTICIDES
• Chemical-Latox at label rate, repeat in 14 days if necessary.
• Alternative-Pyrethrin, Safer’s Soap, Trounce or Rotenone at label rates every 3 days whenever midges are flying.

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