I have had a worm dangling from a silk tread that has been eating the foliage...
I have had a worm dangling from a silk tread that has been eating the foliage on my oak, dogwood and wild cherry trees for the last 2 springs. The trees affected have since died. Can you tell what they are and how to control them? Mechanicsville
St. Mary's County Maryland
We can't say for sure what pest you are having trouble with, and if you would send us a digital photo attached to one of these emails next spring, we can give you a positive identification.
However, it sounds like cankerworms. These are common on oaks, though not so much on wild cherry or dogwood. They are a native insect, however and feed on many native trees. Their populations spike some years (not every year) and they can seriously defoliate a tree. Usually a tree can bounce back from one year of defoliation, but several years in a row will kill them surely.
Cankerworms are the larvae of a beetle. The best way to handle them is to spray Bt (Bacillus thuringiensis) in the spring when the leaves of the trees are 1/2 unfurled. Bt is an ingredient found in several products. If your trees are very large, your best bet is to hire a tree service company to spray them. Bt is a great pesticide because it does not harm your beneficial insects--which in turn eat your cankerworms.
You can also spray the trees while dormant with a dormant oil to kill eggs before they hatch.