• Last modified 764 days ago (Aug. 16, 2018)


It's in the bag - worms, that is

Staff writer

If you’ve noticed strange, small structures hanging from your trees, they may be tiny homes for bagworms.

District forester Howard Freerksen said many trees were heavily infested.

If a tree has been stripped of its leaves, look around for the culprit. Three signs of infestation include stripped leaves, insect manure, and what appears to be a dangling, brown ornament.

“The bagworm defoliates trees. The tree probably won’t die, but with this years’ drought being so bad, it makes it worse for the tree to fight off, especially if it’s already stressed by other factors,” Freerksen said.

Infestations are cyclical. Some years there is little to no damage, and others when they severely affect the trees’ growth and sustainability can be severely affected.

In the fall, insects use their silk and pieces of the tree to create a camouflaged, cocoon-looking bag, which they fill with up to 1,000 eggs.

Control options are hand removal and biological and chemical solutions.

Hand removal and destroying caterpillars is the most economical, safe, and natural control.

In spring, as soon as eggs hatch and the young emerge, the trees can be sprayed with Bt, a biological bacterium that causes larvae to become sick, stop feeding, and die.

Chemicals are designed to be applied when worms are in their caterpillar stage. If treated later, the bag is too dense, and spray can’t get through, Freerksen said.

Although bagworms prefer evergreens, Freerksen said, they will dine on whatever is available.

Last modified Aug. 16, 2018