How can I get rid of the tent worms I have in northwestern Montana?
You may want to use several methods in the war against tent worms. You could try removal, which means taking the nests and caterpillers and smashing the worms or dropping them into a strong solution of salt water or kerosene. If you do this little job at night or early morning, you’ll catch most of the caterpillars in their nest. You could try importing some predators and beneficials, such as bluebirds, chickadees, ground beetles, and praying mantises, all of which eat tent worms. Be cautious about using praying mantises, however, because they’ll be happy to eat your ladybugs as well. You could plant butterfly milkweed and members of the carrot family (celery, dill, parsnips, and Queen Anne’s lace), all of which host parasites that can eventually kill or reduce your tent worm population. You could try trapping the worms, using burlap wrapped around the trunk of an infected tree. This can trap the mature larvae, which you’ll need to remove and destroy daily. Finally, you could try biological control, spraying with Bacillus thuringiensis (BT). Several applications may be necessary. To prevent investations, destroy the egg bands that are visible on tree trunks, fences, and house siding during the winter.