Expert says webworms shouldn't bug homeowners

August 27, 1999|By JULIE E. GREENE

Tri-State area residents wondering what those webbed nests are on many trees need not fear in most cases, a local horticulture consultant said.

They're not going to lead to gypsy moths, said Sandy Scott, horticulture consultant with the Washington County Cooperative Extension Service.

The nests are fall webworms, a relatively harmless insect whose population peaks for three to five years before disappearing until the next peak cycle, Scott said. They are in their third peak year.

The worms arrive so late in the season that they don't damage older trees much, but homeowners who have them on small or new trees might want to spray them with insecticide, Scott said.

To kill the worms, break open the web and shoot insecticidal soap spray inside, Scott said. Spraying the outside won't work since the spray will drip off or dry and be ineffective.


Normally Scott wouldn't even recommend spraying small trees, but with the drought the trees are under stress.

People should not cut off tree branches to get rid of the worms because that only hurts the tree and may not eliminate the worms, Scott said. Leave the branch and the leaves will grow back next year.

Besides, the worms may already be on another branch or could crawl to another one.

The worms hatch twice a year, but in such small numbers in the spring that they're hardly noticeable, Scott said.

When the worms reach their full size - 1.5 inches to 2 inches long - they will leave the nest and search for a protected area, such as a shutter, to spin a cocoon.

That's happening now with some people in mountainous areas finding the worms all over their houses, Scott said.

Next spring the hairy white worms will hatch as small, white moths.

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