Fall Webworm

Fall webworms are especially abundant this year, particularly in the western part of the county around Myersville, Middletown, and Wolfsville. Fall Webworm (Hyphantria cunea)) is a native Lepidopterous insect that becomes a moth at adulthood. The larval stage of this insect builds the nest and feeds on a wide range of tree foliage, preferring black walnut and hickory. The larvae become active, spinning their nests and feeding in early August, and continue until about mid-September when they will pupate and emerge as adults. Eggs are laid and hatch within about 10 days. The small larvae will over winter in bark crevices or in leaf litter beneath the tree.

Credit: frederick.forestryboard.org - Mike Kay

Fall web worms are considered more of an eyesore than a serious threat to tree health. It is not very often that these insects are found in large enough numbers to defoliate a tree. Like many leaf eating insects that appear in the fall, the damage they inflict does not seriously impact deciduous trees that are getting ready to drop their leaves anyway. Fall web worm was first identified in Hungary in 1940, and has become a serious insect pest across much of Europe over the years. The fact that this imported pest does not have any natural predators in Europe results in larger damaging populations. Fall web worm is an example of one of our native insects that has become a problem overseas.

Article by FCFCDB member

Nature note for 10/2/2021