Jun 20, 2023

BOOR: Spraying for bagworms

Posted Jun 20, 2023 9:00 PM
written by: Alicia Boor - Cottonwood Extension District
written by: Alicia Boor - Cottonwood Extension District

Homeowners looking out into a nicely landscaped yard may wonder whether now is the time to spray for bagworms. The answer is yes.

“Bagworms overwinter as eggs and young larvae usually hatch and emerge during mid- to late- May,” said Ward Upham, Kansas State University horticulture expert.

Bagworms are commonly found in shrubs, cedar, pine and spruce trees to name a few. Many people will begin to see damage during late-July to early-August, but controlling bagworms that are that size can be difficult. “They are much easier to kill while small,” Upham said.

“Now would be a good time to use control measures (because) earlier sprays may miss those who emerge from the bag later than normal,” Upham said.

Before spraying, homeowners should check for miniature versions of the mature bagworms and make sure they are alive because predators and parasites can potentially control this pest.

Upham lists the most common insecticides and brand names used for bagworms:

· Acephate (Orthene).

· Permethrin (38 Plus Turf, Termite & Ornamental Insect Spray; Eight Vegetable, Fruit & Flower Concentrate; Lawn, Garden, Pet & Livestock Insect Spray).

· Bifenthrin (Bug Blaster II, Bug-B-Gon Max Lawn and Garden Insect Killer).

· Lambda-Cyhalothrin (Spectracide Triazicide, Bonide Caterpillar Killer).

· Spinosad – an organic control(Conserve; Natural Guard Spinosad; and Captain Jack’s Dead Bug Brew).

“Thorough spray coverage of foliage is essential for good control with any of these products,” Upham said.

Upham and his colleagues in K-State’s Department of Horticulture and Natural Resources produce a weekly Horticulture Newsletter with tips for maintaining home landscapes. The newsletter is available to view online or can be delivered by email each week.

Interested persons can also send their garden- and yard-related questions to Upham at [email protected], or contact your local K-State Research and Extension office.

Product names used in this article are for identification purposes only, and not intended to be an endorsement or criticism of any specific product.

Alicia Boor is an Agriculture and Natural Resources agent in the Cottonwood District (which includes Barton and Ellis counties) for K-State Research and Extension. You can contact her by e-mail at [email protected] or calling 620-793-1910. K-State Research and Extension is an equal opportunity employer and provider. Kansas State University, County Extension Councils, Extension Districts, and U.S. Department of Agriculture Cooperating.