Bagworms are a common site in the Midwest, with eggs hatching May through June. After hatching, the larvae emerge to create bags of their own by gradually incorporating materials from crawling around.
Females resemble maggots and cannot fly, nor do they leave their nest, while male moths are black and fuzzy with wing and can fly.
Bagworms feed on over 128 plant species, including juniper, arborvitae, spruce, pine, and cedar but will also attack deciduous trees. Symptoms of bagworm infestation include:
- Brown spotting on foliage
- Bags hanging from branches
- Missing foliage
Small populations of bagworms typically aren’t anything to worry about, but larger infestations need intervention. Here are three ways you can treat your trees for bagworms:
Pick Them Off By Hand
A good way to remove bagworms is to pick them off from your trees by hand and put them in bucket of soapy water to kill the eggs before they hatch. Make sure to leave them in the bucket overnight to make sure that they are dead.
Attract Natural Predators
Sparrows are predators of bagworms, so attracting them to your yard can be a great way to control the pests. To make your property attractive to sparrows and other birds, provide water at ground level (like a low birdbath), a place to build nests, planting seed-bearing flowers, and sunny, dusty areas for bathing.
Have A Professional Apply Pesticides
After hatching, bagworms can be managed with insecticide sprays or injections. This is the best time to treat for them, as they are vulnerable. When they have created their bags, they are much more difficult to target via pesticides.
Always have a professional ISA Certified Arborist inspect your trees before treatment to determine the best course of action for your trees.