“Over the past week we have received an increase in calls to the Urban Forest Management Division from residents who are concerned about large webby tents in tree branches," said Joan Allen, Chief, Forest Pest Branch, Urban Forest Management Division, Public Works and Environmental Services. These webs are caused by fall webworm. This is a native caterpillar that spins webs over leaves of deciduous trees. There is a very noticeable increase in fall webworm in the area compared to recent years. Population levels for this pest are cyclical and it is not unusual to see population levels rise and fall over a span of a few years. This insect does not pose a serious risk to trees and native trees are well adapted to this pest. This publication from Virginia Tech has more information on fall webworm.
For more information about trees, call the Urban Forester of the Day at 703-324-1770, TTY 711.
