Vomiting caterpillar dining on SC oaks

COLUMBIA, SC (WMBF) - Caterpillars of the common oak moth are making a dinner out of trees across South Carolina, and now the South Carolina Forestry Commission is advising the destructive bug could show up in anyone's back yard.

Since late April, homeowners have been reporting sightings of Phoberia atomaris feeding on post oaks and other white oak trees across Anderson, Chapin and Irmo.

"This is a native pest which leaves a yucky calling card," Laurie Reid said, insect and disease specialist with the SCFC. "At one residence, the caterpillars were found wandering from the host tree onto the porch and into the garage, leaving a long trail of rusty-colored vomit."

The common oak moth occurs sporadically through the eastern U.S., from Massachusetts to Florida, and towards Texas and Kansas.

SCFC officials say there is only one generation of the caterpillar per year. Early in the spring before buds break, adults emerge from the pupa and mate. Female moths lay eggs and the caterpillars binge no the newly emerging tree leaves.

The tattered foliage or completely defoliated trees, caterpillar waste material, and wandering caterpillars can be a nuisance to homeowners, the SCFC's Reid warns.

"However, there is no long-term affect for most healthy trees and most trees will put out another flush of leaves," she added.

Typically, trees which have been defoliated by this oak moth caterpillar for many years in a row and which happen to be stressed by other factors may experience some damage such as limb loss, or in the worst cases, tree mortality.

Natural enemies usually keep the caterpillar numbers in check and, according to Reid, the experience won't last too long anyway.

"Luckily for homeowners, in the next few weeks the caterpillars will form an underground pupa where they will remain for the rest of the summer and through the winter," Reid said.

Copyright 2010 WMBF News. All rights reserved.