Lincoln Landscaping is often asked about the little brown bags hanging from customers evergreen trees. This is the common Bag Worm. Gone unnoticed or treated the Bag Worm can kill an adult tree.
The Bag Worm larvae push their head out of their bag and feed on the foliage around it, often stripping the area bare. Because the larvae create their cocoon from the material around them it creates a natural camouflage which protects them from most predators. However, some birds do find the bags with eggs in them. The birds will eat the eggs and pass them, spreading the Bag Worm to other trees.
The removal and treatment process of bag worms should start in early May, while the larvae are hatching. Have any infested trees sprayed with a bag worm insecticide during May to early June. Continue to watch the infected trees to be sure the bag worms have been killed. Next, during the month of September while the female bag worms are producing eggs, spray the infected trees again with the bag worm insecticide.