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Home > Bugs > Bugs of Trees and Shrubs > Fall Webworm

Fall Webworm—Hyphantria cunea

The most notable aspect of this pest is the unsightly silken web that it produces. Many times, there are many of these webs per tree. These webs are started near the tips of the branches and gradually are extended down the branch towards the trunk. Although not considered a serious forest pest, the ugliness of the webs can cause them to be considered a significant pest of nurseries and landscapes.

tree with many fall webworm webs fall webworm web with many caterpillars fall webworm caterpillar up close
Webworms enclose leaves and small branches in their nests, unlike the tent caterpillars which make a smaller nest in the crotch of branches. Webs start small, but the caterpillars enlarge them every few days as they grow and consume the leaves within.  Webs contain many hairy caterpillars that hatched from one egg mass. Caterpillars are slightly more than 1 inch long and covered with long, pale, gray hairs. The body color ranges from yellow to brown with dusky, mottled areas along the sides and two rows of black dots along the back.

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[Photos, left to right: Ronald F. Billings, Texas Forest Service, Bugwood.org; Steven Katovich, USDA Forest Service, Bugwood.org; James B. Hanson, USDA Forest Service, Bugwood.org]

 
It is the policy of the State of Maine to minimize reliance on pesticides. The Maine Department of Agriculture and the Maine IPM Council encourage everyone to practice integrated pest management and to use pesticides only as a last resort. The mention of pesticides in the fact sheets linked to these pages does not imply an endorsement of any product. Be sure that any product used is currently registered and follow all label directions.