The ocellate gall midge causes an ocellate (single-spotted), pale green to yellow, often bright red-margined gall. This creep is most often found on  red maples.  Galls appear in May and contain a single larva. After the larva matures it falls to the ground, and over-winters as a pupa.  In spring it appears to mate, and a new round of galls is formed.  These creeps are something to look at, and don’t cause much harm to the tree at all.

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