Bagworms On Juniper

Photo By Julie Martens Forney

Bagworm

Bagworms are the larval form of a moth that attacks evergreens and other trees. The worm inside each bag feeds on the evergreen bush or tree, building a case around itself for protection from predators. The case is made from bits of the plant the insect is feeding on and slowly enlarges over time as the insect grows. Females lay eggs in the bags in late fall. The best control, if you only have a few bagworms, is to handpick the bags and drop them into soapy water or put them out with the trash. Predatory insects including wheel bugs or insect-eating birds will attack these insects, even inside their bags. You can also spray traditional or bioinsecticides. Follow directions carefully on timing. Once larvae are more mature and tucked into thicker bags, the chances of a spray reaching the worm itself are small.