B
Bagworms (Thyridopteryx ephemeraeformis)
Bagworms are caterpillars that construct distinctive spindle-shaped bags from silk and plant debris, hanging them from the branches of evergreen and deciduous trees. They feed on foliage from within their protective cases, causing defoliation that can kill heavily infested trees, especially arborvitae, juniper, and spruce. Bags left on trees over winter contain hundreds of eggs ready to hatch in spring. Hand-removal of bags combined with targeted insecticide sprays during early larval activity is the most effective approach.