Have you noticed browning leaves in the canopies of mature trees in your lawn or around the Kansas City area lately? If so you might think the leaves are browning due to a lack of adequate hydration, but a closer look could reveal those leaves covered in webs, which are fall webworms.
While the evidence of fall webworms appear on our trees in late summer to early fall, they actually begin their attack on trees much earlier in the year. According to the Ohio State University Extension Fact Sheet on fall webworms, this tree pest overwinters in what is called the pupal stage. Fall webworm pupae are generally found in the ground, but they can also be located in old nest remains, in leaf litter, or under loose bark. Adults appear in late May to early June and lay their eggs on the undersurface of leaves.
The mass of eggs laid on a leaf will hatch about a week after the eggs were laid, and then “the small mass of caterpillars web over single leaves and feed by skeletonizing. As the caterpillars grow, they web over additional leaves and finally are able to eat the entire leaf.”
Fall webworms feed on many trees in the U.S., including pecan, walnut, American elm, hickory, and some maple trees. While fall webworms mainly cause damage to the appearance of trees, a major outbreak can be more problematic.
If you think webworms could be a problem with the trees in your yard, contact the certified arborists at Cartwright Tree Care at 816-965-6758. They can accurately identify the problem and recommend the best treatment option for your trees.
Photo credit: Ag.utah.gov