Control by Hand Picking
Hand picking makes a sizable dent in most populations of tent caterpillars and can keep them from getting out of hand if you catch the infestation right away. Look for the caterpillars’ white cocoons in late spring on tree trunks, fences, and house siding (especially under ledges and other overhanging surfaces), and hand pick them and destroy them. Egg masses are easy to spot during the winter. They look a little like fat collars and can easily be peeled off and crushed like bits of foam plastic.
Tent caterpillars generally hatch out when the leaves on the cherry and apple trees are just starting to emerge. As soon as you see tents in a tree or shrub, pull them down and pull the tents and caterpillars off the tree and dispose of them in a bucket of soapy water. It is best to do this late in the day or very early in the morning when most of the caterpillars are still in the tent. Tents that are high up in the tree can sometimes be reached by a long pole with a hook on the end to snag the tent material and pull it down. Or, trim any loose twigs off the silky mess, stuff it into a strong black plastic bag, seal it, and leave it in the hot sun before putting it out for the trash man.
Control Using Sticky Band On Trunk
Since tent caterpillars will move off the home tree most days in search of more food, you can thwart their travels by establishing a band of very sticky material around the trunk of the home tree about 3 feet off the ground. This sticky material is not affected by rain or the weather. This band keeps the tent caterpillars already in the tree from getting out into the yard to search for food and it prevents those already outside from getting back to the colony. If the colony is very large, you may still wish to use some form of insecticide to kill it off, but this technique will serve to slow things down if not completely eliminate the problem.
Tip-- To shut off all avenues for the caterpillars , trim back any branches that are touching the house, another tree, or a fence post.