Pest Alert – Fall Webworm

— Written By
en Español / em Português

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.


Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


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 ▲

What the heck is this web stuff in my tree? A giant spider? No, it’s the Fall webworm.

Fall Webworms

The fall webworm, Hyphantria cunea, is a common pest of trees in Henderson County. The caterpillar attacks more than 88 different kinds of plants, including many fruit, nut, and ornamental trees and shrubs. They especially like sourwoods. The webs can be so numerous they weigh down branches and cause them to break.

Fall webworms are notorious for the large conspicuous webs they produce. Heavy infestations are unsightly but rarely fatal. If the caterpillars attack the same tree repeatedly over several years, they can stress the plant make it more susceptible to drought, disease or other insect pests.

The fall webworm is a caterpillar; the larval stage of a small white moth. Full-grown caterpillars are approximately 1-inch long, pale green or yellow, and covered with tufts of long, white and black hairs.

Fall webworms often cover entire branches with their webs. In extreme infestations whole trees may be covered. Larvae feed within the web, eating leaf tissue between the leaf veins. When cooler temperatures herald the coming of fall, the larvae begin to enclose themselves in cocoons. They spend the winter as pupae in these silken cocoons on the ground or on tree bark. In the spring, the moths emerge from their cocoons, disperse and mate. Female moths deposit their eggs on the undersides of the leaves of plants they like to eat.

Soon after webworm eggs hatch the larvae begin to build a web. As larvae consume leaves within the web, they expand the web to take in more and more foliage. The nest grows as acquire more leaves.

Scouting for Fall webworms on trees that have experienced previous infestations is recommended. Remove any old nests and leaves from under the tree to reduce the amount of pupae that will emerge in the spring. Locate, remove and destroying any leaves that contain egg masses.

The caterpillars can be controlled without insecticides. Larvae may be knocked out of lower branches with a stick or broom. Many birds and beneficial insects attack the egg and larval stages of fall webworm. You can help these predators and parasites get to their fall webworm prey by tearing open the webs. Webs can also be pruned from smaller branches; dispose of nests in the trash.

Fall webworms do not kill trees. Remember that insecticides usually kill all insects. So give the beneficial insects and birds a chance to do their job and avoid applying chemicals.