Box Tree Moth in Cincinnati: Why Now is the Best Time to Protect Your Boxwoods
Box tree moths have become a growing concern for homeowners throughout Ohio ever since they were first identified in the state in 2023. This invasive pest can cause significant damage to boxwoods, and many homeowners are already familiar with the telltale signs of an infestation.
Our arborists have recently identified box tree moth activity affecting approximately 150-200 boxwoods across three different properties in Indian Hill, Wyoming, and Amberley Village.
The good news? Boxwoods are capable of recovering from infestation if caught early enough and severe defoliation has not occurred. With winter approaching, October is an important time to inspect your boxwoods and address any signs of box tree moth activity before the pests enter their overwintering stage.
What are Box Tree Moths?
Native to Asia, the box tree moth is an invasive pest that primarily targets boxwood shrubs. Adult moths are relatively small, with blue and brown coloring on their wings, while the larvae, or caterpillars, are responsible for most of the damage.
Adult box tree moths live for 2 to 4 weeks to mate and lay new eggs. The complete life cycle from egg to adult can take approximately 40 to 45 days, allowing multiple generations to develop in one year.
Box tree moth habitats are centered entirely around its host plants, the boxwood plants. Because its survival depends on its food source, the moths can be found in urban, suburban, and residential landscapes where the boxwood plants are typically planted.
Which plants are susceptible?
Boxwoods are popular landscape plants throughout the Cincinnati area, but unfortunately, they can all be vulnerable to box tree moth infestations.
Commonly planted susceptible species include:
Common boxwood
Korean boxwood
Japanese boxwood
Korean boxwood Japanese boxwood Common boxwood
Why October is a Great Time to Treat Boxwoods
October is a critical time to address box tree moth activity on your property. This is because the caterpillars are finishing their final feeding phase of the season before spinning protective, cocooned webbing around themselves to overwinter on boxwood foliage.
By targeting the caterpillars before their overwintering period, you can drastically lower their population by the next spring. Typically, overwintered caterpillars will arise once the temps are above 50 degrees, and they will be ready to devour the new spring growth on your plants.
How to properly inspect your boxwoods
Box tree moth infestations are not always easy to spot. The caterpillars are small and well camouflaged, and early infestations often begin deep within the plant's foliage.
Our tree health professionals at Gregory Forrest Lester, Inc. recommend carefully pulling back the foliage and inspecting the interior of the shrub.
Look for:
Silk webbing around leaves and twigs
Chewed or skeletonized leaves
Yellowing or browning foliage
Small black specks, which are caterpillar droppings
Thin or thinning areas within the foliage
Visible caterpillars
What Should You Do If You Find Box Tree Moths?
If you notice signs of box tree moth activity, it is important to act quickly. Boxwoods can often recover from mild to moderate infestations when properly treated, but severe or prolonged defoliation can significantly weaken the plant and, in some cases, lead to its decline.
With winter approaching, the treatment window is limited. Addressing an infestation before the caterpillars overwinter can help reduce the number of pests that emerge in the spring and protect new growth during the growing season.
At Gregory Forrest Lester, Inc., our plant health care team specializes in identifying and treating a wide range of pests, diseases, and other issues affecting trees and shrubs throughout the Cincinnati area. Our arborists work alongside our plant health care professionals to develop treatment plans tailored to the needs of each property and its plants.
If you're concerned about your boxwoods, now is a great time to have them inspected!
