Getting rid of Bagworms-Organic


Bagworms are caterpillars that build a protective sack around themselves using their silk and the leaves and twigs of the plants they have invaded.  The teardrop-shaped brown bags reach 1-2 inches in length and look like little cones or seedpods.  Don’t let their small size fool you, these little creatures can tear apart a tree in no time.  They can defoliate their host plant, causing them to weaken, look unattractive and worst, even die.  Several organic treatments exist to treat bagworms without harming the environment.

Bagworms will feed on about 130 plant species, but their favorite foods are the junipers such as red cedars and Leyland cypress trees.   Adult bagworm males are black, fuzzy moths with 1/2-inch wingspans, but the adult females are flightless, worm-like creatures that reach about 1 inch in length and never leave their bags. They lay between 500 and 1,000 eggs inside of the bags before dying. The eggs hatch once warm weather arrives in the spring, and the blackish caterpillars emerge and promptly start feeding on their host plants.

Handpick Bags

You can typically control small or localized bagworm populations by handpicking and destroying the bags, but you must do so no later than early spring to prevent the eggs from hatching. Drop the bags into a pail of soapy water instead of just letting them fall to the ground. This ensures the caterpillars don’t return to their host plants. After you remove the sacks, cut the silk bands that attach the bags to the branches. If you don’t, this sturdy silk can girdle limbs and cause branch dieback in just a few years.

 Attract Natural Enemies

Bagworms have plenty of natural enemies, including parasitic wasps and birds. Attract the predatory beneficial insects by planting daisy and aster family members near affected trees. Shasta daisies (Leucanthemum X superbum) and Frikart’s asters (Aster x frikartii) both work as great attractants.  Placing birdbaths, feeders, and birdhouses near bagworm-infested trees will help attract the right birds to eliminate the bagworms.

Spray With Btk

Control young bagworms by using a pesticide containing Bacillus thuringiensis var. kurstaki (Btk), a natural soil bacterium that makes caterpillars quit feeding and die within just a few days. You must start spraying Btk on your plants when the bags are still smaller than 1/2-inch long and the larvae are actively feeding, generally from late May through the end of June. Carefully read and follow the mixing and application instructions on the product’s label. One Btk-based pesticide recommends mixing 4 teaspoons of product for every 1 gallon of water. Using a handheld garden sprayer, thoroughly saturate all foliage surfaces, including the tops and undersides of leaves. Repeat applications every seven days until you achieve control.  Below is our recommendation for this type of attack on your bagworms.

Apply Spinosad

Spinosad is a microbial pesticide made from soilborne bacteria. It poisons caterpillars that eat or touch it, effectively killing bagworms within 48 hours. Follow the directions on the manufacturer’s label since instructions will vary. One product recommends mixing 4 tablespoons of product for every 1 gallon of water in a handheld sprayer. Spray the affected tree until you thoroughly cover the tops and bottom surfaces of the host plant’s foliage. If bagworm populations persist, apply more spinosad solution in seven to 14 days.  Again, here is our recommendation for using this method.

Spinosad Warning

Spinosad is very toxic to honeybees for about three hours following application. Spray in the early morning or late evening to avoid harming the pollinating insects. Spray Btk- or spinosad-based products only on calm days when no rain is expected for at least 24 hours. Reapply pesticide after a heavy rain. Although Btk and spinosad offer organic bagworm control, even these natural ingredients can still cause eye or skin irritation. Protect yourself from exposure by wearing goggles, a facemask, waterproof gloves, shoes with socks, long sleeves and long pants. Keep family members and pets out of the treatment area until the spray dries.  Below is our recommendation for personal protective equipment, remember these are only recommendations and must be used properly by the user for maximum protection.

Thanks for reading and perhaps you have gained some knowledge of bagworms.  Please comment below.

What are your thoughts on bagworms?  Have you had any luck getting rid of them using any other method of attack then what is mentioned?  Please let us know.

4 thoughts on “Getting rid of Bagworms-Organic

  1. Thanks for educating me on a new subject. I’ve never heard of bagworms before but these little pests sound like they can potentially cause a lot of damage to a tree, with their numbers, if not controlled. Is this species of caterpillar only found in North America? Because I live in the UK and this has intrigued me now.

    1. Thanks for stopping by my site.
      Yes, these bagworms can kill a whole lot of trees if let go without treatment. I am not sure if these are outside of the US. I would think they would be everywhere.
      Thanks. Please stop by anytime for more information.

  2. Thanks for this very interesting article Bob. We also have these caterpillars in France, they are not called bagworms though, we call them “pine processionary caterpillars”, and I have seen some complete forests of pines destroyed by them. The problem is that in France it is totally forbidden to use pesticides now. I see that you promote organic product for that which I think is acceptable in France. But some people place trap to collect them naturally and relocate them, I am not sure that this is really a solution though.

    What do you think about that Bob? Should me preserve them or destroy them?

    Best wishes,

    John ツ

    1. Thanks for stopping by my site.
      Sounds to me that without using some form to destroy this pesky pest, it may be very difficult to rid yourself of them. Using some kind of pesticide may be the best method to achieve this but if you cannot, then that seems to present a problem. How do you get rid of other types of bugs without using a pesticide? Tough call.
      If I went to the trouble to trap them or pick them off the tree, I would really have a hard time transporting them somewhere else. I have stepped on many a bagworm.
      I do know people have had luck pulling or picking them off but that to sounds like a lot of work, but sometimes we must do what it takes to save our trees.
      Thanks again for stopping by. Good luck with getting rid of bagworms in your country.

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