Buckeye Petiole Borer

There have been numerous reports thus far this season of damage to trees and shrubs attributed to the deep diving temperatures that occurred in December during Christmas week. However, wilted, darkened buckeye (Aesculus glabra) leaves appearing randomly among healthy leaves isn’t winter injury; it’s the handiwork of the Buckeye Petiole Borer (Zeiraphera claypoleana, family Tortricidae).

The title of this Alert isn’t referring to last year’s shocking November surprise in that State Up North.  Curtis Young (OSU Extension, Van Wert County) reported during yesterday’s BYGL Zoom Inservice that the handiwork of the Buckeye Petiole Borer is appearing on its namesake host in northwest Ohio. Likewise, I’ve been finding damage on wild understory buckeyes in the southwest part of the state.

Round one turned beautiful magnolia blooms into brown mush in southwest Ohio. Impacts from this second round are yet to be determined but it’s likely some trees and shrubs suffered frost/freeze damage that will eventually be revealed with symptoms ranging from blasted flowers to wilted, blackened leaves, to twig dieback. However, wilted buckeye leaves may not be related to low temperatures.

A number of trees and shrubs in Ohio suffered frost/freeze damage this spring with symptoms ranging from blasted flowers to wilted, blackened leaves, to twig dieback. Wilted leaves on buckeyes may mimic frost/freeze damage, but a close look at the petioles will reveal the true culprit: the buckeye petiole borer.

Buckeye and horsechestnut tree canopies tend to be remarkably free of insect pest damage except for the depredations of some general defoliators. However, if you're cruising Ohio woodlands this spring, you may run across three types of leaf damage. None of the damage appears to cause serious harm to overall tree health, but the symptoms can be obvious.

The handiwork of the Buckeye Petiole Borer is now becoming evident on its namesake host in southern Ohio. Individual caterpillars of this tiny native moth bore into leaf petioles to disrupt vascular flow causing leaves to droop, wilt, and turn dark green to black. Damaged leaves will eventually detach producing mild defoliation. Symptoms may superficially resemble frost or freeze damage.

Wilting buckeyes may sound like an Ann Arbor dream, but I'm not talking about our beloved Silver Bullets. I'm referring to the symptoms caused by the Buckeye Petiole Borer (Zeiraphera claypoleana) on its namesake host.