Caliroa

Glistening, slug-like sawfly larvae along with their characteristic skeletonizing damage are appearing on oaks belonging to the white oak group in southwest Ohio. The upper leaf surface appears bleached with leave veins remaining apparent. Flipping the leaves over reveals the slug-like culprits stuck to the underside of the leaves.

Skeletonizing damage produced by an oak slug sawfly on oaks belonging to the white oak group is becoming in southwest Ohio. The upper leaf surface appears bleached with leave veins remaining apparent. Flipping the leaves over reveals the slug-like culprits stuck to the underside of the leaves.

I've observed sawfly larvae skeletonizing leaves on the same American bladdernut trees southwest Ohio in 2015, 2017, and again late last week. I've concluded they must cause little harm to the overall health of their bladdernut host because the trees continue to flourish despite providing some great photo ops of sawfly damage over the years!