Bagworms in the “dunce cap” stage. B. t. and Conserve provide good control at this stage.
Bagworm infestation with bags already drooping down.
Damage from bagworm feeding (Photo by: T. Simms).
Bag with green foliage incorporated into it suggests a live caterpillar inside the bag. Insect growth regulators (Dimilin or Confirm), Acelepryn, Conserve (depending on bag/caterpillar size and population density) pyrethroids, acephate or carbaryl provide good control against larger caterpillars. Caterpillar feeding is usually finished by mid-August, consequently hand picking in September – May is a good method to reduce next season’s populations. Photos provided by: Brian Kunkel, University of Delaware