Horned Oak Gall

Horned Oak Galls "Pop"

The physical emergence of the "horns" that give horned oak galls their common name is such a short-lived event I've only witnessed it one other time in 26 years. I've commonly observed fully extended horns, but seeing them in the process of breaking through the gall surface is a rare treat and it's happening right now in southwest Ohio.
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Authors
Joe Boggs

Horned Oak Gall Leaf Galls

When most people think of horned oak galls, they visualize the gnarled, woody stem galls that form on the twigs and small branches of pin oaks.  This is understandable since the gall-making wasp, Callirhytis cornigera (Family Cynipidae) that's responsible for directing the growth of the stem galls spends 33 months developing inside individual chambers within these very obvious galls.

The galls grow larger in size with each season.  In early spring, as the immature wasps near the completion of their development, the whitish-tan, cone-shaped “horns” that give this gall its...

Published on
Authors
Joe Boggs