Protecting Your Midwest Trees from Bagworm Infestations

Leaving bagworms in your tree could cost you – literally. In some cities across the Midwest, failing to remove these destructive pests can lead to fines. But even if you’re not facing a citation, the real cost is in the damage they cause to your evergreens. Bagworms are aggressive defoliators that can strip trees bare without proper action. Learn more about bagworms and how to protect your property.

Key Takeaways:

• Bagworms are destructive pests that can quickly defoliate up to 50 different species of trees and shrubs in the Midwest, with Eastern red cedar being particularly vulnerable to them.
• These insects create distinctive bag-like shelters from silk and plant material, which can be mistaken for pine cones, and female bagworms can lay up to 1,000 eggs during their brief lifetime.
• While deciduous trees may recover from bagworm damage by producing new leaves, evergreens cannot generate new foliage and may die from severe infestations.
• Prevention methods include keeping trees healthy and stress-free, introducing natural predators, and handpicking bags from late winter to early spring before eggs hatch.
• Professionals treat bagworms using insecticides that remain effective for weeks and are designed to minimize harm to beneficial insects and the environment.

What Are Bagworms?

Bagworms are a type of moth that affect most of Eastern and Midwestern United States. They live in small bags made of silk and pieces of leaves. The larvae grow inside these bags, feeding on leaves and attaching the bags to tree branches with silk threads.

The bags are brown or green and can reach up to 10 centimeters in length. At a glance, it can be easy to confuse these bags with pine cones. The bagworms themselves are small, with adults measuring only a few millimeters in length. When fully grown, the caterpillar bagworm pupates inside the bag and emerges as an adult moth a few weeks later.

What Do Bagworms Turn Into?

Bagworms go through four life stages: egg, larva, pupa, and adult. They start by hatching from eggs inside a bag, usually within two weeks. Once out, the larvae build their own bags and begin feeding on leaves.

As they grow, the larvae add plant material to their bags for protection. Eventually, they pupate – meaning they change into their next stage – inside the bag. After a few weeks, the adult moth emerges.

Adult moths don’t live long – just a few days. But during that short time, females can lay up to 1,000 eggs. With multiple generations possible each year, bagworm damage can quickly get out of control.

How Bagworms Damage Your Trees

According to the USA National Phenology Network, bagworms defoliate up to 50 different species of evergreen and deciduous trees and shrubs. One of the bagworms’ favorite targets is the eastern red cedar, a widespread species in much of the Midwest.

Young bagworms will only do minor damage to leaves or needles, leaving tiny holes in any leaves. As the caterpillars age, they can do more damage to the trees, eating entire needles or leaves.

“Bagworms might not look like much, but they can do a lot of damage in a short amount of time. I’ve seen evergreens stripped bare in just a few days. And it’s not just trees—they can even hit crops like corn and sorghum pretty hard if there’s a big enough infestation.” – Brian Rex, Arbor Masters Arborist Advisor

Deciduous trees can often recover by growing new leaves, just like they do each spring. But evergreens don’t have that ability. Once they lose their needles, they can’t regrow them, making them much more vulnerable to long-term damage or even death.

How to Get Rid of Bagworms

Due to the rapid nature of the damage caused by bagworms, it’s important to take fast action when you notice them or to prevent them from establishing in the first place.

Preventing Bagworm Damage

There are a few primary methods you can use to discourage bagworms from infesting your trees and establishing themselves, such as:

• Keep Trees Stress-Free: An unstressed tree is better able to withstand pest damage. And pests are less likely to attack these trees. To lower tree stress, water them during a drought, keep a layer of mulch under the tree, and fertilize them when there is a nutrient deficiency.
• Introduce Natural Predators: Since these pests are native to our region, they have a few natural predators that reduce their population. You can introduce or encourage natural enemies like birds, mice, and parasitic wasps to hunt bagworms. However, this option will not help when a significant population exists.
• Handpick Any Bags You See: Sometimes, the best way to help your trees is to get your hands dirty. Picking the bags off the trees and squashing them will destroy the eggs and prevent them from hatching. Try to do this from late winter to early spring.

Treatment Options for Bagworms

We have several options for dealing with common Midwest pests like bagworms, webworms, and Japanese beetles. New developments in technology have given us several options for controlling and preventing infestations of these pests, and some even last for an entire year before needing another application.

When we treat your property, we always keep it targeted to protect beneficial insects on your property, especially bees.

Frequently Asked Questions About Bagworms in the Midwest

We’ve answered some common questions to help you better understand bagworms and other pests that endanger trees.

Are bagworms harmful to humans?

No, bagworms are not harmful to humans. However, they can cause significant damage to trees, shrubs, and other plants. If bagworms are a serious problem in your area, you may need to contact a professional pest control company for help.

Are bagworms the only tree pest I need to be concerned about?

No, some other pests that you should keep an eye out for in our area include:

· Wood-boring beetles

· Webworms

· Spider mites

· Emerald ash borer

What should I do if bagworms defoliate my evergreens?

Unlike deciduous trees, which can grow back leaves each spring, evergreens don’t regenerate lost needles. If bagworms cause severe defoliation, the tree may not recover. In that case, it’s important to have a certified arborist inspect the damage. They can determine whether the tree can be saved or if removal is the safest option to prevent further issues.

Worried About Bagworms? Let Arbor Masters Handle It!

Bagworms are an incredibly destructive pest that can quickly defoliate your trees. Early detection, prevention, and identification of an infestation is crucial to ensure your trees survive. When you need professional help with this insect or any others, the team at Arbor Masters can help.

The Arbor Masters team can examine your trees, identify if you have a bagworm problem, and administer insecticides to control their population. We employ ISA Certified Arborists who are experts in tree care and will do everything in their power to save your trees. Call us today at 913-441-8888 or request a quote online for help with bagworms.