galls of the gall midge (mikiola fagi) on leaves of common beech (fagus sylvatica)

leaf green plant flower tree nature branch produce shrub insect food invertebrate blossom fruit animal wildflower evergreen galls gall midge mikiola fagi leaves common beech fagus sylvatica infestation procontarinia deciduous phyllocoptes purple cecidia european protection larvae diptera infested disease infected parasitic blister detail natural larva europe summer forest environment closeup parasite red cecidomyiidae garden pest insects pathogen damage sylvatica