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 midge european beech protection larvae diptera fagi galls infested disease infected fagus parasitic blister detail leaves green natural nature mikiola gall insect larva europe leaf summer plant forest environment tree closeup parasite sylvatica red branch cecidomyiidae garden pest insects pathogen damage