The Box tree moth (Cydalima perspectalis) is an invasive moth species that poses a serious threat to boxwood (Buxus spp.) plants — a commonly planted ornamental shrub used in landscapes and hedges. While not yet confirmed established in Indiana, the pest has been detected in several U.S. states. Introduction via infested nursery stock remains a high risk.
Status: Not detected in Indiana (as of latest information); high-risk invasive species.
- Primary: Boxwood (Buxus spp.) - including common landscape varieties.
- Occasional secondary hosts: Burning bush (Euonymus alatus), Japanese spindletree (E. japonicus), purple holly (Ilex chinensis), and other ornamentals when boxwoods are absent.
Boxwoods are widely used in landscapes across Indiana as hedges and foundation plantings making early detection critical to protecting the industry and landscapes.
The box tree moth has rapidly spread in Europe following its introduction there, severely defoliating and killing boxwood plants where populations establish. In North America, C. perspectalis has been detected in New York, Michigan, Ohio, Massachusetts, and other states — often in association with the movement of infested nursery stock.
Severe outbreaks can:
- Completely defoliate shrubs within weeks.
- Weaken and kill plants if repeated generations infest the same plant.
- Spread quickly by flight and human-assisted movement of nursery stock.
Preventing introduction protects the nursery industry as well as landscapes and gardens statewide.
Look for the following signs in boxwoods and related ornamentals:
- Skeletonized leaves — tissue removed leaving veins intact.
- Webbing and frass (insect droppings) visible among foliage.
- Severe defoliation with little or no green foliage remaining.
- Bark feeding in later stages, potentially girdling branches.
Plants may initially show patchy defoliation progressing to near-complete leaf loss when infestations are heavy.
Box tree moth produces multiple overlapping generations per year. Multiple life stages may be found at the same time. It overwinters as larvae in sheltered leaf and branch crevices.
Adult Moths
- Wingspan ~1.6–1.8 in (40–45 mm).
- Most adults have white wings with a dark brown border, though some can be mostly brown.
- They are strong fliers and active primarily at dusk and night.
Larvae (Caterpillars) — Most Destructive Stage
- Young larvae are light green with black stripes, white spots, and a shiny black head.
- Caterpillars can reach ~1.5 in (35–40 mm) and feed vigorously on boxwood foliage.
- They spin webbing and hide inside bush canopies while feeding.
- Heavy feeding leads to defoliation and bark feeding.
Eggs & Pupae
- Eggs are pale yellow and laid in overlapping clusters on the undersides of leaves.
- Pupation occurs inside silken cocoons within foliage.
- Several generations can occur each season, especially in warmer climates.
If you suspect Box Tree Moth:
- Email: DEPP@dnr.IN.gov
- Call: 866-NO-EXOTIC
- Contact your local nursery inspector
Provide: Photos, location, host plant information, and contact information. Rapid reporting helps protect Indiana’s nursery industry and ornamental plant health.
• USDA APHIS Box Tree Moth Information — regulatory guidance, distribution updates.
• USDA APHIS Box Tree Moth Pest Alert
• National Invasive Species Information Center – Box Tree Moth
Box tree moth larva on boxwood with webbing and frass present.
Several box tree moth larval instars present on a single boxwood stem.
Early instar box tree moth larva.
