Bagworms will start hatching soon. You can find the tiny caterpillars with tiny upright bags anywhere there are bags left from last year. The bagworm is a very common ornamental pest throughout the eastern United States. These pests overwinter as eggs within the mother’s bag. Larvae emerge from the bag during the months of May and June. Once they have emerged, they crawl or drift via a silk strand to nearby foliage where they begin to feed. Bagworms are relatively sedentary during their lifetime, most often remaining on the same tree until they pupate. Adult females are wingless and never leave the tree, while male bagworms pupate and develop into a small brown moth.
Bagworms feed on plant foliage and can cause a significant amount of damage in a relatively short period of time. Some common trees that they infest include maple, sycamore, oak, poplar, and apple while they mostly prefer conifers. The early instar caterpillars produce a silk bag that gradually collects plant tissue debris from them feeding. This creates a leafy bag that camouflages them as plant tissue. Since they don’t move much during their lifetime, they are commonly found in dense populations within the same tree. These dense populations have the potential to kill conifers within one to two seasons due to defoliation. Since they are so discrete and easily mistaken for plant tissue, pest management for these insects can be difficult and/or time-consuming. One of the most effective, yet time-consuming methods of treatment, are handpicking or cutting the female pupae bags from of the branches. Since this may sometimes be impractical or impossible, there are other methods of treatment to be considered. There are chemical control options available that should be applied during the early instar stages of the caterpillars, typically during June and early July. As with many other pest insects, bagworms are susceptible to predation from birds.
Insecticides are effective particularly when applied early when the bagworms are small and relatively sensitive. The following insecticides are labeled for bagworm control in the home landscape.
pesticide (Trade Name) Formulation Amount of Formulation
acephate (Orthene) 9.4 % emulsifiable concentrate 3 tablespoons per gallon of water.
Bacillus thuringiensis B.t.( Biotrol, Dipel) 3.2 to 20 % 1 to 4.5 teaspoons per gallon of water depending on label directions.
carbaryl (Sevin) several formulations on the market; follow label directions.
bifenthrin several formulations on the market; follow label directions.

For more information on bagworms or any gardening questions please contact the Wilson County Extension Master Gardener Volunteers, 252-237-0113, wilsonemgv@hotmail.com.
Recommendations for the use of chemicals included in this article does not imply endorsement nor discrimination against similar products or services not mentioned.