Native to East Asia, this pest has been spotted in Cincinnati

The Box tree moth is an invasive pest that can significantly damage and potentially kill boxwood plants if left unchecked. The caterpillars are ravenous feeders, and heavy infestations can completely defoliate host plants. After the leaves are gone, they feed on the bark which eventually kills the plant. Originally native to East Asia, this moth has spread to various parts of Europe and North America, and we've seen them in our yards here in Cincinnati.

What to look for

• Appearance: The adult moth has a wingspan of about 3-4 cm and is characterized by its white wings with a distinct dark brown or black border.

• Larvae: The caterpillars are green with a yellow stripe along their sides and can grow up to 5 cm long.

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Life Cycle

• Eggs: Females lay eggs on the underside of boxwood leaves.

• Larval Stage: The larvae hatch and begin feeding on the leaves, often causing significant damage.

• Pupation: After several weeks of feeding, they pupate in silken cocoons.

• Adults: The adult moths emerge to continue the cycle.

  

Impact on Boxwood Plants

The Box Tree Moth can cause severe defoliation, leading to the decline of boxwood health and, in some cases, plant death. This pest is particularly problematic in our ornamental gardens and landscapes where boxwoods are commonly planted.

Management Strategies

• Monitoring: Regularly inspect boxwood plants for signs of infestation.

• Cultural Practices: Maintain plant health through proper watering and fertilization to enhance resilience against pests.

• Treatment: In some cases, consider using targeted insecticides with residual effect. Also, pruning out affected branches, and hand-picking caterpillars for small infestations can help prevent spread

• Replacement: In areas with severe or recurring infestations, replacing boxwood with alternative species like holly or thuja may be advisable.

Conclusion

Effective management of the Box Tree Moth involves a combination of monitoring, cultural practices, and, if necessary, chemical controls. Early detection and intervention are crucial to minimizing the impact of this invasive pest on boxwood plants.