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Tag: bagworms

Now is the Time to Scout for Bagworms

Article derived from KSRE News Story: Now is the Time to Scout for Bagworms

Patience and persistence is key when trying to manage bagworms. Begin scouting in early May, and depending on weather conditions – through early summer.

Once caterpillars emerge, they begin feeding on the host tree or shrub, creating their protective bags. In addition to emergence over time, young bagworms can ‘blow in’ – called ‘ballooning’ – from neighboring plants on silken threads, which increases the importance of treating multiple times during the growing season. Watch both conifers and deciduous trees and shrubs. Although defoliation of deciduous trees and shrubs don’t typically affect long-term health of trees and shrubs, extreme defoliation of conifers can cause stress or kill conifers outright.

Bagworm feeding on plant foliage, photo by Raymond Cloyd

Hand removing and destroying bagworm bags is an option for smaller infestations. For larger infestations, the bag provides protection from insecticide treatments, so it’s important to apply applications when the bagworms are young. Apply insecticides weekly when young bagworms are present, up to 5 weeks. Treat windbreaks, Christmas trees, and ornamental landscape trees as soon as bagworms are present to prevent bagworms from causing substantial plant damage. Thorough coverage is important, including penetration into the interior plant canopy and upper branches.

Bagworm bags hanging from a tree branch, photo by Raymond Cloyd

Many insecticides are labeled for bagworms, but timing of application and thorough coverage will ensure the effectiveness of insecticides in managing bagworms. When bagworm caterpillars are small (1/8 to 1/4 of an inch long), products containing Bacillus thuringiensis subspecies kurstaki (Btk) or spinosad as the active ingredient can be effective. These insecticides have minimal direct impact on beneficial insects compared to broad-spectrum insecticides, which could lead to outbreaks of spider mites or scale insects that can cause damage to treated trees and shrubs.

If insecticides are not applied when bagworm caterpillars are small (1/8 to 1/4 of an inch in length) then broad-spectrum insecticides, including those containing malathion, acephate, or cyfluthrin as the active ingredients can be applied. Be sure to read the product label and follow directions.

For more information on controlling bagworms, reference the publication, Bagworm: Insect Pest of Trees and Shrubs, written by Dr. Raymond Cloyd.

1, 2, 3…..look for bagworms!

By Brooke Garcia

The June 11, 2021 issue of the Extension Entomology Newsletter featured a recent post on Bagworms. The cool weather may have slowed the development of these landscape insect pests, but they are still going to be present this summer in the Kansas landscape on broadleaf and evergreen trees and shrubs.

Learn more in the Entomology Newsletter here: https://entomology.k-state.edu/doc/extension-newsletters/2021/KSInsectNewsletter%2010.pdf

Photo by: William Fountain at the University of Kentucky

Landscape and Garden Bugs

(Posted by Jared Hoyle, KSU Turfgrass Research and Extension)

K-State Horticultural Entomologist Raymond Cloyd covers a variety of insects now at work in home lawns, landscapes in gardens, including bagworms infesting evergreens, emerald ash borers attacking ash trees, and squash bugs feeding on garden cucurbit crops.

Click the link below for K-State Research and Extension Agriculture Today Radio Program hosted by Eric Atkinson.