More than 1,000 species of gall-forming midges have been described in North America. These differ from gall wasps in that the adults are tiny (1 to 3 mm), mosquitolike flies, not wasps. Trees that frequently support gall midges include oak, willow, elm, maple, walnut, hickory, pine and honey locust. Gall midges can induce rounded stem and leaf galls or ridgelike vein galls.
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|Birch midge galls - 29K||Birch midge damage - 28K|
|Honeylocust midge damage - 24K||Honeylocust midge cross section of damaged area - 26K|