The non-native Box Tree Moth (BTM) (Cydalima perspectalis, family Crambidae) has been in the news owing to the announcement that a BTM quarantine is now in place for parts of S.W. Ohio. Maps of the quarantined region in Ohio as well as BTM quarantined areas elsewhere in the U.S. can be viewed by clicking this hotlink:
https://go.osu.edu/btm-quarantinemap
Home gardeners may ask what they can spray to kill the BTM caterpillars. There are several things to consider before providing guidance on insecticides targeting BTM.
1. BTM has only been confirmed in parts of S.W. Ohio. However, there may be undiscovered infestations elsewhere in the state. The BYGL Alert titled, “Box Tree Moth (BTM) Update #1,” provides guidance on what to look for with BTM. You can read the Alert by clicking on this hotlink:
Photo: Joe Boggs
The Ohio Department of Agriculture (ODA) has developed a user-friendly online reporting tool for BTM. The reporting tool requires a picture, so make certain you take clear, in-focus pictures to upload with your report.
Here is the hotlink to the ODA reporting tool:
https://survey123.arcgis.com/share/1b36dd2cf09e4be0a79776a6104ce1dc
2. Insecticides should only be applied to boxwoods with an identified BTM infestation, or to boxwoods close to an identified BTM caterpillar infestation such as in a neighboring landscape. Preventative insecticide applications outside the locations where BTM has been found and confirmed are not justified.
Making unwarranted insecticide applications wastes money, presents environmental risks, and can have unintended consequences including producing secondary pest outbreaks. For example, many “caterpillar insecticides” will also kill predatory mites that help keep Boxwood Spider Mites (Eurytetranychus buxi) in check. This mite has been on the rise over the past several years.
3. Below are lists of over-the-counter caterpillar insecticides that are available to home gardeners and labeled for use on outdoor woody ornaments, ornamental trees and shrubs, herbaceous or woody plants, etc. The primary source for the products listed is a compilation titled, “Insecticides Labeled for Box Tree Moth Registered in New York State” prepared by Jared Dyer and Dan Gilrein, Cornell Extension of Suffolk County, and reviewed by Mike Helms, Cornell Pesticide Saftey Education Program. Additional insecticides that can be used in Ohio are also included.
* “Biorational” is generally defined as insecticides with relatively low mammalian toxicity and few environmental side effects. However, it does not mean they will not kill non-target organisms. For example, although pyrethrins are derived from a botanical source, the concentration is much higher in the products than in nature. Also, “biorational” does not mean the products are compatible with organic practices as approved by the Organic Materials Review Institute (OMRI). Products that are approved by the OMRI can be found on their website:
The complete compilation titled “Insecticides Labeled for Box Tree Moth Registered in New York State” is available on the Cornell College of Agriculture and Life Sciences (CALS), New York State Integrated Pest Management program website at:
NOTE: The information provided in both tables above is presented with the understanding that no product discrimination is intended and no endorsement of any product mentioned or criticism of unnamed products is implied. Labeling, registrations, and uses can change. The label is the law: applicators are responsible for reading and following all label directions.