Question
I live in Olathe KS, yesterday during the high winds, there were many little green worms [3/4"] that blew out of my hybrid ash trees.  Are they bag worms and what should I do about them? I have never seen them like this in the 40 years I have lived here.  Thank you

Answer
It is not the bag worm sounds like one of the inch worm type. A picture would help id the caterpillar. Most of the inch worm type caterpillars emerge in the early spring and really do not cause that much damage. They can if the population is large enough eat most of the leaves from the tree. BUT hardwood have the capability to leaf out again and the inch worm caterpillars have only one life cycle per year so once the do their thing they will not be back until next year. Usually these type of caterpillars have so many natural predators that if you have a large population one year the next you will see no caterpillars. We have a caterpillar on sweetgum here in Alabama that shows up about every ten 15 years in populations large enough to defoliate trees.
I really do not think there is a worry since what is defoliate is about over and the caterpillar will not kill the tree. The only damage maybe some growth loss but you will not be able to detect this.

These trees are too tall to spray and since the damage IF any will be slight I would not worry about these. IF you can not live with this you can treat the soil around the tree with an insecticide called Bayer Advanced Tree and shrub insect control. This is applied to the soil around the tree and the roots will carry it to the foliage and when the caterpillar feed on the leaves they are killed. Here is a web link to this product--you can find it at a nursery or garden type store. http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect