Question
My Hyland,
I have what it looks like web-like bags in my tree. In the bag it appears that the leaves are dying. Is it a spider or a bag worm? Also, how do I get rid of it without hurting my tree? Thank you!

Answer
Sounds like fall Webworm.
The fall webworm, Hyphantria cunea (Drury), is most often discovered when the unsightly, light gray, silken webs on the trees in late summer and early fall are observed. Webworms enclose leaves and small branches in their nests, unlike the tent caterpillars which make a smaller nest in the crotch of branches.

This pest is native to North America and is common from Canada into Mexico. It is one of the few American insect pests that has been introduced into Europe and Asia.

Chemical Control - Standard Insecticide Sprays - Most applicators attempt to "blow" the nest out of the tree with a strong jet of insecticide mix. While this generally works, more material is often used than is needed. Locate nests early and merely wet the nest and cover nearby foliage. As the larvae walk on the nest surface or incorporate new foliage, they will contact the insecticide. Second applications may be needed if additional generations occur. Sprays can be used for control but they must be applied with sufficient pressure to penetrate the silk tent and reach the leaves within. Appropriate insecticides include Bt, diazinon, Orthene or Sevin. Read and follow label directions.



Chemical Control - Use Systemic Insecticides - Extensive nests may occur in tall trees which are difficult to spray with ground equipment. These trees can often be treated with translocated systemics applied to the soil for root uptake or injected.