Here We Go Again! Forest Tent Caterpillar Outbreak Continues for Fifth Year

by | Jun 5, 2019

The forest tent caterpillar strikes again! Just after getting them this spring, trees along the Roanoke River, Chowan River, and Lake Waccamaw once again lost their leaves. The very hungry caterpillar responsible for this defoliation, the forest tent caterpillar, is nothing new to us. This is the fifth year that outbreaks have occurred in the region.

Some areas on the Roanoke River were heavily defoliated by the forest tent caterpillar. Trees look gray now without their leaves, but will soon re-leaf. Image: K. Oten, N.C. Forest Service.

The forest tent caterpillar is about two inches long, covered in fuzz-like hair, and is commonly described as having a line of penguin shapes or white footprints running down its back. Despite sounding cute, the defoliation they cause is not cute at all. Forest tent caterpillar attacks bottomland hardwood trees such as maple, sweetgum, and water tupelo. This year, they seemed to prefer water tupelo.

During an aerial survey in May, N.C. Forest Service surveyors could see from the air just how expansive this year’s outbreak is.  An estimated 105,000 acres were defoliated along the Roanoke and Chowan Rivers. Some areas were extensively defoliated, with the most impacted area in the crook of the river just north of Jamesville. Most other areas suffered more minor defoliation.

Forest tent caterpillar are cyclical pests, meaning outbreaks regularly occur but die down on their own. History tells us that outbreaks typically last 3-6 years before subsiding. Natural enemies eventually catch up and the populations are once again managed. Leaf loss can cause growth reduction and some branch loss, but long-term tree health is seldom affected.

Trees are already re-leafing and soon, you won’t even know anything happened. Luckily, the worst is behind us… for now.

Jim Slye, Forest Health Specialist with the N.C. Forest Service, assesses forest tent caterpillar defoliation from the air. Image: K. Oten, N.C. Forest Service.