jumping oak gall

Jumping oak galls are caused by a very tiny, native, stingless wasp (Neuroterus sp.) which lays eggs in leaf buds. As the leaf develops, pinhead-size galls, also referred to as abnormal plant growths, form on the undersides of the leaves. Each round, button-like gall contains one wasp larva.

  Oak leaf blister, a fungal disease caused by Taphrina caerulescens, is widespread this year on a range of oak species, both in the white oak and red oak groups. Symptoms include raised, blistered, greenish-yellow spots on upper leaf surfaces and darker, corresponding sunken spots on lower leaf surfaces, though sometimes the raised and sunken aspects may be obscured. Fungal growth can sometimes be seen on undersurfaces of leaves.

 

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