Fall Webworms Are Back

— Written By and last updated by
en Español

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.

English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

This article was written by Gail Griffin, Extension Master Gardener Volunteer with North Carolina Cooperative Extension in Lee County.

Those pesky fall webworms are making their rounds in our landscape again. The webs of these native insects can be found on hundreds of species of trees and shrubs. In our area, trees such as sourwood, persimmon and pecan are mostly affected. Unlike eastern tent caterpillars that build their webs in spring near the trunks of trees, fall webworms locate their webs on the ends of branches.

Fall webworm, Hyphantria cunea, over winters in mulch and soil as pupa surrounded by a cocoon. It emerges in spring as a snow-white moth. After mating, females lay eggs (up to 900) on the undersides of leaves. They hatch into tiny, light colored caterpillars that begin feeding on leaves, usually between the leaf veins and start to form their web as protection from predators. As they mature, they grow into dark, 1 1/2 inch caterpillars and begin to consume the entire leaf. Webs can contain hundreds of caterpillars and  expand as more and more leaves are needed for these voracious feeders. After 4 to 5 weeks of feeding, they crawl down to the ground and pupate in the soil where they will spend the winter months. The webs remain in the tree until they are weathered away.

Because of the timing of infestations of fall webworms, they rarely cause any real damage. Trees have had time to store food before the caterpillars become abundant in mid to late summer. The unsightly webs contain leaf residue, waste material and shed skins from the process of molting. Probably some nice digs if you are a webworm. If controls are necessary, tear open the webs if they areFall Webworms within reach with a pole or other device and expose the caterpillars to predators like birds, stink bugs and wasps. Insecticides are not effective if applied directly on the web, but instead must be used on foliage adjacent to it. For recommendations, contact your local extension office and be sure to follow label instructions. To learn more, view our Webworm Factsheet.

Since the damage to trees from fall webworms is mostly cosmetic, there is no need to stress over their appearance. After several weeks, the webs will be vacated and mature caterpillars will be making their way back into the soil. Cooler temperatures are on the horizon. Days will soon grow shorter and leaves will begin to change over to their glorious fall colors. And that will be a welcome sight after a long, hot summer.

Gail Griffin is an Extension Master Gardener Volunteer with North Carolina Cooperative E

Extension in Lee County.