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If you've noticed small, pinecone-like structures on your evergreens, beware — they are not pinecones, they are bagworms. These pests can cause significant damage to your plants if not managed properly. Here's what you need to know about identifying and controlling bagworms.
Bagworms are a type of caterpillar that constructs protective cases around themselves using silk and plant material. These cases resemble small pinecones, leading many to mistake them for harmless debris. During the hot summer months, bagworm larvae hatch, starting as small worms that grow as they consume more foliage.
You can tell these are bagworms if the casings “wiggle” or move slightly, and you may even see the caterpillars come out slightly to feed on your plant. Another sign you may have bagworms is if you notice a portion of your plant dying – this is where they are feeding and killing the foliage.
If left unchecked, a severe infestation can strip your tree or shrub of its leaves, weakening the plant and making it more susceptible to other stresses. Once a large portion of the shrub is dead, they will move on to nearby foliage and can take out several trees or shrubs over the course of even a single season. That’s why it’s very important to mitigate bagworms.
The best way to control bagworms is to take preventative measures before they become a problem.
Mitigation (before the bagworms are present) starts in early spring. You’ll want to spread a product called “Tree and Shrub Drench.” You add this solution to water, where it then moves down through the soil and is absorbed by the roots. Once absorbed, it moves up through the tree or shrub, providing up to 12 months of systemic protection.
If you already have an infestation, you need to try and remove the bagworms ASAP. Here are some steps you can follow:
Manual Removal: If you notice only a few bagworms, manually removing them can be effective. Simply pick off the bags and destroy them to prevent the caterpillars from spreading.
Chemical Treatments: For larger infestations, chemical treatments can be necessary. An effective treatment is Spinosad Soap, which is a natural insecticide that targets bagworms. Spinosad Soap is a safer alternative to traditional chemical treatments and can be used without harming beneficial insects.
You may need to spray a second time about a week after your initial treatment. The casings will still be on your plant, so you’ll have to remove those manually after the worms are eliminated.
Bagworms can pose a serious threat to your plants, but with proper identification and timely control measures, you can protect your plants from these destructive pests. Regular monitoring and early intervention are key to maintaining the health of your plants. Follow these guidelines and you’ll have healthy, bagworm-free trees and shrubs year after year!
Also, come see us for bagworm treatments or worst case, replacement plants.
