Forms a c. 4mm blister on the upper surface of the leaf which may show a central depression in old galls. Often several per leaf. The white gall midge larva escapes through a hole in the lower surface. Reliable separation of the galls of Polystepha malpighi and P. quercus requires breeding.
Wherever the host plants are found.
Univoltine, hibernation in the ground.
Leicestershire & Rutland Map
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