New Pest from Eurasia Attacks Boxwoods

Near the end of May, AmericanHort learned that the Canadian Food Inspection Agency (CFIA) had confirmed the presence of box tree moth (Cydalima perspectalis) in a St. Catharines, Ontario, Canada nursery. On May 26, USDA imposed a federal order (FO) prohibiting the importation of all Buxus, Ilex, and Euonymus spp. plants from anywhere in Canada until further notice. By the end of last week, APHIS and state cooperators had initiated “trace-forwards” to U.S. customers that had received plants from the nursery. 

Box Tree Moth

If you are not familiar with the pest, box tree moth is a Eurasian native moth. The larvae are voracious defoliators of Buxus. The pest has become established in western Europe, where it has been extremely damaging to boxwood in the landscape. Roughly two years ago, it was found in an urban Toronto neighborhood. There are ongoing efforts to suppress and contain it, and a nursery surveillance program using pheromone traps has been undertaken during adult flight seasons.

APHIS officials have briefed AmericanHort and Horticultural Research Institute (HRI) on the objectives and status of the emergency program. The overarching objective is eradication. Inspections are underway targeting 26 customer facilities (mostly retail) in seven U.S. states (MI, OH, NY, CT, MA, SC and TN). The list may change. APHIS reported that the pest has been found associated with these plants in at least three of the states where inspections are underway. Accordingly, plants from the Canadian source that are found at retail will be placed on hold and destroyed. At least some of the plants have been sold to consumers, there will be efforts to trace forward to the consumer. We also preliminarily discussed industry strategies to replace consumers’ plants, which may facilitate the effectiveness of the trace/inspect/destroy initiative.  

How to ID Box Tree Moth

Click here to view a preliminary document on pest ID and potential treatment tools for nursery and landscape professionals (not appropriate for consumers).

Finally, click here for a Canadian blog post with good pest ID and other information.

Box tree moth is considered a high-consequence defoliating pest of boxwood, with other possible hosts. We fully support the efforts of federal and state regulators to prevent this pest from establishing in the U.S. AmericanHort and HRI proactively worked to get several major research projects funded to get “ahead of the curve” on this threat. We are hopeful that the regulatory response efforts are successful, giving more time for the ongoing research agenda to better equip the industry with tools to manage the pest if it establishes in the U.S. in the future. 

AmericanHort and HRI continue to monitor this situation and will share additional updates as it unfolds. For more information about boxwood health matters, visit www.hriresearch.org.