Plant Protection and Quarantine

The box tree moth is an invasive pest 

that primarily feeds and completes its 

life cycle on boxwood species (Buxus 

spp). In its native range, it also feeds 

on burning bush (Euonymus alatus),

Japanese spindletree (E. japonicus),

purple holly (Ilex chinensis), 

and orange jessamine (Murraya 

paniculata) once all nearby boxwoods 

are completely defoliated.

Distribution and Spread

The box tree moth is native to 

temperate and subtropical regions in 

Asia. It was first reported in Europe 

in 2007, after which it spread rapidly 

across European countries and into 

Western Asia and Northern Africa. In 

2018, it was documented in Canada, 

and in 2021, the U.S. Department 

of Agriculture (USDA) confirmed the 

presence of the moth in Niagara 

County, NY, near the Canadian border.

The rate of spread for the box tree 

moth has varied since its introduction 

in Europe, with some cases peaking 

at 96 miles per year. Long distance 

movement of the box tree moth 

across Europe occurred primarily 

through the movement of infested 

boxwood plantings. 

Box tree moths are highly mobile 

and are good fliers. Natural spread 

of this moth in Europe is about 3 

to 6 miles per year. One analysis 

from Europe concluded that natural 

dispersal from continental Europe 

to the United Kingdom was possible, 

suggesting sustained adult flights of 

over 20 miles. 

Damage

In 2014, boxwood made up 15 

percent of broadleaf evergreen 

sales in the United States, and the 

estimated value was $126 million 

(USDA-NASS, 2015). Boxwoods are 

Pest Alert

Box Tree Moth (Cydalima perspectalis)

typically planted as ornamentals 

and used for edging, as hedges, 

and/or clipped into different shapes 

to make topiaries. The box tree 

moth can cause heavy defoliation of 

boxwood plants if populations are left 

unchecked. Defoliation of existing 

and new growth can kill the plant. 

If no foliage is available, larvae have 

been observed feeding on the bark, 

which can cause branches or the 

entire plant to die. 

Description

Adult box tree moths generally have 

white bodies with a brown head and 

abdomen. Their wings are white and 

slightly iridescent, with an irregular 

thick brown border spanning 1.6 

to 1.8 inches. Some adults have 

completely brown wings with a small 

white streak on each forewing. Males 

and females show both colorations.

The eggs are pale yellow and average 

0.04 inches in size. They are laid in 

flat clusters of about 5 to 20 on the 

underside of boxwood leaves. As they 

mature, a black spot appears marking 

the larval head. 

Newly hatched larvae have black 

heads and are green to yellow in 

color. As they age, dark brown stripes 

develop on the body. The most 

mature larvae are about 1.6 inches 

long and have thin white and thick 

black stripes and black dots outlined 

in white along the length of the body.

Adult moths (top and bottom left), damage (bottom) 
Credits: Light-colored adult moth, caterpillar, and damage photos courtesy of Matteo Maspero and Andrea Tantardini, Centro MiRT - Fondazione Minoprio [IT]. 

Pupa photo courtesy of Ilya Mityushev, Department of Plant Protection of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. Dark 

brown adult moth courtesy of Colette Walter, www.lepiforum.de/webbbs/images/forum_2/pic13983.jpg.

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APHIS 81-35-040 

Revised March 2022

Pupae develop inside a silk cocoon and 

are 0.6 to 0.8 inches long. They are 

initially green, with black stripes on the 

back, and turn brown as they mature.

Life Cycle

Adult female box tree moths lay their 

eggs singly or in clusters of about 

5 to 20 in a gelatinous mass on the 

underside of boxwood leaves. Box 

tree moths overwinter as larvae. Once 

temperatures rise, overwintering 

larvae emerge and typically begin 

feeding in March, continuing until 

they pupate in late April to early May. 

As they develop, they spin silken 

webs to hold leaves together and 

create protected areas to feed. They 

tend to feed on leaves in the lower 

portion of host plants but reside in the 

upper portion and remain active until 

September or October.

Pupation occurs on the host leaves 

in silk cocoons. If the boxwood host 

is defoliated, pupation may occur 

away from the host plant using leaves 

from the surrounding area. Pupae 

will typically first appear in April or 

May and will be present continuously 

through the summer and into the fall, 

depending on the local climate and 

timing of generations.

Adults first emerge from the 

overwintering generation between 

April and July, depending on climate 

and temperature. Subsequent 

generations are active between June 

and October. Adults typically live for 

2 weeks after emergence.

Where To Look

Signs of damage may not appear 

at the beginning of an infestation 

because young larvae hide 

among twigs and leaves. Larvae 

skeletonize the leaves and feed 

on the bark, causing defoliation 

and dryness, leading to the plant’s 

death. Signs of feeding include 

green-black frass (excrement) 

and webbing.

The female moths lay their eggs 

on the underside of the leaves 

of boxwoods.

Caterpillars, webbing, and frass (top); pupa (bottom left); magnified egg masses (bottom right)

Report Your Findings

If you find an insect that you 

suspect is the box tree moth, 

please contact your local Extension 

office or State Plant Regulatory 

Official to have the specimen 

identified properly.

To locate an Extension specialist 

near you, go to the USDA website at 

www.nifa.usda.gov/Extension. 

A directory of State Plant Regulatory 

Officials is available on the 

National Plant Board website at 

www.nationalplantboard.org/

membership.