Watch out for your roses, these little bugs are expanding their diets
Once known almost exclusively for being able to strip juniper and other conifer trees naked, bagworms are back, hungrier than ever, and are expanding their diets to broadleaf plants. It’s vital to act now to protect your yard and garden, according to Dr. Raymond Cloyd, a K-State professor who studies pest management and plant protection.
“These bagworms, which are not strictly specialists in conifers, have a lot of plant material to feed on,” Cloyd said. “It’s not due to climate change or global warming. It’s due to just the advent of different plant material being put in landscapes other than juniper and arborvitae.”
Bagworms feed on deciduous broadleaf trees and shrubs, such as roses, black locust, crab-apple, elm, hackberry, maple, oak, willow and others. They tend to focus on ornamental trees and shrubs, rather than vegetable plants, according to Cloyd.
May and June are the best months for bagworm management.
“Right now they’re out and about so it’s a good idea to be on the lookout for bagworms right now,” Cloyd said. “It’s time to get out there and spray.”
Green-thumbs should be on the lookout for insecticides that have the active ingredient Spinosad when spraying for bagworms, such as Captain Jack’s Deadbug Brew.
“It’s a bacteria-like material and they have to eat it but it’s very non-toxic to humans and some beneficial insects out there,” Cloyd said. “You have to get more than one application and hope for the best. It’s one application once a week for about four to five weeks. As long as they’re out there, keep spraying.”
Bagworms are most susceptible to insecticide when they’re smaller than a 1/4 inch.
“Once they get 3/4 of an inch long, it’s really too late to spray,” Cloyd said. “They are going into reproductive mode and the females can lay up to 1000 eggs.”
If unmanaged, bagworms can cause extensive damage and kill even well-established trees, shrubs and plants.
This story was originally published June 14, 2020 at 7:01 AM.
