Box Tree Moth Updates? - Ask Extension
Looking forward to Spring 2026, and currently browsing the MSU extension site to see if there is any updated guidance on the treatment/prevention of t...
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Box Tree Moth Updates? #924639
Asked February 16, 2026, 11:29 AM EST
Looking forward to Spring 2026, and currently browsing the MSU extension site to see if there is any updated guidance on the treatment/prevention of the Box Tree Moth for the upcoming season. Should I plan to continue treating with the BTK, has there been any updated product recommendations, should this winter have negatively impacted the population of the BTM? Thank you for any help you can provide.
Wayne County Michigan
Expert Response
BTM is not going away anytime soon. If there are healthy boxwoods and you know of BTM damage in the area, I would recommend treating the plants. Current best practices are applications of BT every 2 weeks or twice annual applications of other conventional pesticides (July and Sep). There are reports of BTM damage appearing in May, and a 3rd treatment could be necessary earlier if symptoms of BTM damage are spotted in Spring.
Our winter temperatures will not have had any meaningful impact on BTM populations. If temperatures remain cooler than average through Spring, we may see delayed arrival of BTM emergence and symptoms on plants.
Our winter temperatures will not have had any meaningful impact on BTM populations. If temperatures remain cooler than average through Spring, we may see delayed arrival of BTM emergence and symptoms on plants.
David,
Thank you for the reply. Last year at my house I observed (have photos if you are able to accept photos) the BTM at various stages of life on 6/18, 7/7, 7/18, 8/27, and 9/20. Most if not all of those dates I observed eggs, webbing, and adult caterpillars all at the same time. I’m concerned if I only treated in July & September I would see a ton of damage.
Thanks again
Jason
On Feb 18, 2026, at 9:02 AM, Ask Extension wrote:
How frequently you apply depends on the insecticide used. The products in the first table (in link below) provide 2 - 3 weeks of protection. The products in the second table are likely to provide a longer period of protection. Always check the label to determine the frequency of repeat applciations.
https://bygl.osu.edu/node/2339
https://bygl.osu.edu/node/2339
