Bagworms are insects that require control as they can defoliate evergreens and sometimes deciduous trees/shrubs. If you can reach the bagworms, handpick as many as you can during the winter and before the eggs hatch in June. Dispose of in soapy water and remove any bagworms from the ground as they may be able to complete their life cycle. If you cannot handpick or multiple trees are involved, you will have to spray. A biological control, Bacillus thuringiensis, often called Bt, is a type of bacteria that only kills certain insects and does not affect humans or animals. Bt must be applied between mid-June and mid-July because it works well only on young bagworms. If your trees are too large to spray, contact a certified arborist as they have the materials to do the job. See our website for more information   http://extension.umd.edu/hgic/bagworms-trees-and-shrubs

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