Bagworms love junipers, arborvitae and many types of evergreens. When the bagworms are hungry, they will move to all kinds of trees, bushes and other plants. Bagworms are nasty pests that form a cocoon from tree needles that looks like a pinecone. However, it is really filled with 500 to 1,000 eggs that will hatch into hungry little worms that devour tree needles and move on to other bushes and trees. During their growing season, the bagworm cocoons are green. In late summer the cocoons turn brown and are easier to see. These cocoons are dormant from September to May and can be removed from the trees by hand. This is the most effective method to control bagworms. The only time insecticides work is when the tiny worms are growing usually in June through August.

If you find a few of these pinecone-looking bagworms on your trees, remove them by hand, seal them in a zip-lock bag and dispose of them. Do not let any cocoons lay on the ground, since they will find their way back to your trees in early summer. If the bagworms are left on a tree for a few years, they will multiple and seriously affect the health of the tree. The worms do not fly. Instead, they hang by silk threads on branches, and the wind carries them to new trees. Keep an eye on your trees to help them stay healthy.

These bagworms are in Miller. The garden volunteers were working at the Father Marquette Statue Garden in Marquette Park and discovered the bagworms on the big beautiful juniper trees. We even found some cocoons on the St. John’s Wort bushes near the trees! We have already removed buckets full of them. The high branches need help from someone kind enough to climb a ladder and lend us a hand. Let us know if you can help.