Insects on Boxwoods: Identification and Control

If you're noticing tiny holes or notches on your boxwood leaves, it's likely due to the boxwood leafminer, a common pest that can cause significant damage to your plants. These pests lay their eggs on the underside of leaves, which hatch into larvae that feed on the leaf tissue.

Boxwood psyllids, another type of insect that affects boxwoods, can be identified by their waxy secretions that cover the leaves and stems. This substance can be quite noticeable, especially on sunny days.

To control these pests, it's essential to monitor your plants regularly and catch any infestations early. Regular pruning and maintaining good hygiene practices can also help prevent the spread of these insects.

A unique perspective: Green Velvet Boxwood Bush

Boxwood shrubs are a popular choice for hedges and topiaries, but they're not immune to insect pests. There are three types of insects that attack boxwoods: the Boxwood psyllid, Boxwood leafminer, and Boxwood spider mites.

Recommended read: Boxwood Green Velvet Size

The Boxwood psyllid is a 1/8-inch sucking insect that resembles a cicada and prefers English or common boxwood (Buxus sempervirens 'Suffruticosa'). The Boxwood leafminer is the most common and damaging pest, with one generation per year that prefers American boxwood (Buxus sempervirens 'Arborescens').

Boxwood spider mites overwinter as eggs and tend to feed solely on European, common, and English boxwoods. They're most active in hot, dry summers and can cause a fine stippling of the leaves early in the season.

Boxwood mites are yellowish-green or reddish and 0.5mm long, with yellow eggs that overwinter on the leaves and hatch in April. They breed rapidly and have 5 or 6 generations each summer.

To manage boxwood mites, use a strong spray of water from a hose to dislodge them for light infestations. For large infestations, use a horticultural oil or insecticidal soap spray in the summer following label instructions. Some Buxus microphylla cultivars appear to be more resistant to boxwood mites.

Here are some common boxwood pests and their preferred boxwood varieties:

Boxwood mites are a common problem for boxwood owners. They're tiny, yellowish-green or reddish, and only 0.5mm long.

These spider mites overwinter as eggs on the underside of the leaves, which hatch in April. They breed rapidly and have 5 or 6 generations each summer.

Boxwood mites are most active in hot, dry summers, causing a fine stippling of the leaves early in the season, followed by a general grayish, dingy, unhealthy appearance.

Some Buxus microphylla cultivars appear to be more resistant to boxwood mites. Japanese boxwood is also a bit more resistant.

To treat light infestations, try using a strong spray of water from a hose to dislodge the mites. For larger infestations, use a horticultural oil or insecticidal soap spray in the summer, following label instructions.

For heavy infestations, consider using a biological control option, such as releasing predatory mites that can be purchased from mail-order sources.

Some insecticides used to treat boxwood leafminers may actually exacerbate spider mite problems by killing natural predators of mites.

For another approach, see: Spider Mites on Boxwoods

Here are some common signs of a boxwood mite infestation:

Early treatment is key to controlling boxwood mites, so be sure to inspect your boxwoods regularly and take action as soon as you spot any signs of an infestation.

Leafminers and Psyllids are two common pests that can cause significant damage to boxwoods. The boxwood leafminer, a small fly, is the most detrimental pest of boxwoods, causing blistering and discoloration of the foliage.

Adult boxwood leafminers are about 0.1 inches long and fragile looking, with an orange-yellow to red color. They lay their eggs deep inside the leaf tissue, which hatch into larvae that slowly grow as they munch away on the inside of the leaf.

Some boxwood cultivars have resistance to the boxwood leafminer, including 'Handworthiensis', 'Pyramidalis', 'Suffrutoicosa', 'Varder Valley', and Buxus microphylla var. japonica. If you're dealing with an infestation, reducing the population by pruning prior to adult emergence or after eggs are laid can be an effective control method.

Recommended read: Green Velvet Boxwood Planting

Boxwood psyllid, on the other hand, causes cosmetic damage to boxwoods, including cupping of leaves and affected twig growth. The psyllid overwinters as a tiny, orange egg that hatches in the spring, and the nymphs begin feeding on the plant right away, causing the leaves to cup.

To control psyllids, apply insecticides containing bifenthrin, carbaryl, cyfluthrin, or malathion in early May when the young have hatched.

Leafminer is a common pest that affects boxwood plants, especially in the Mid-Atlantic region of the United States. It's a small mosquito-like insect that emerges in the early spring to mate and lay eggs.

The boxwood leafminer is a small fly that's indigenous to Europe but is now found throughout the United States. Both adults and their larvae cause serious damage to the boxwood foliage in the form of blistering and discoloration.

Adult leafminers are about 0.1 inches long and fragile looking, with an orange-yellow to red color. They mate and then the female lays her eggs deep inside the leaf tissue.

See what others are reading: Can You Keep Boxwoods Small

The larvae become orange-colored pupae and emerge as a fly in May. They're tiny, about 0.125 inch long, and slowly grow as they munch away on the inside of the leaf.

To control boxwood leafminer insects, selecting a more resistant variety initially is a good start. Some cultivars with various resistance are:

If it's a little too late for that, you can reduce the population by pruning prior to adult emergence or after eggs are laid.

The boxwood psyllid is a common insect pest that can cause significant damage to your boxwoods. It's a less serious pest compared to the spider mite, but still worth keeping an eye out for.

The boxwood psyllid, specifically the Cacopsylla busi, can cause cupping of leaves and affected twig growth. This is purely cosmetic damage, but it's still unsightly.

The psyllid afflicts all boxwoods, but the American boxwood is most susceptible. It overwinters as a tiny, orange egg that hatches in the spring when the buds of the plant open.

See what others are reading: How to Prune Boxwoods with Winter Damage

The nymphs begin feeding on the plant right away, causing the leaves to cup. This cupping provides a hiding place for the psyllid as well as protection.

The boxwood psyllid becomes winged adults by early June and then mates. The females lay their eggs between the bud scales of the boxwood to overwinter until the next spring.

There is one population per year, which makes it easier to control. To control psyllids, apply the same insecticides mentioned above in early May when the young have hatched.

Box tree moth is an invasive insect native to eastern Asia, and it's been spotted in several states, including Maryland, Virginia, West Virginia, Pennsylvania, Delaware, Ohio, New York, Michigan, and Massachusetts. The Maryland Department of Agriculture and the USDA Animal and Plant Health Inspection Service confirmed a report of box tree moth in Washington County, Maryland in July 2025.

The larvae of the box tree moth are green and yellow with white, yellow, and black stripes and black spots. They start by chewing on the undersides of leaves, and older larvae can defoliate leaves entirely or leave behind the edges and midvein, creating a "curlicue" leaf appearance.

Take a look at this: Why Are My Boxwoods Turning Yellow

Extensive feeding by the larvae can result in "see-through" brown boxwoods, which can eventually lead to plant death. So far, this insect has only been found feeding on boxwoods (Buxus spp.) in the United States.

If you think you've seen this insect in Maryland, you can send photos to Ask Extension for further assistance. To identify the box tree moth, you can learn more about it on the University of Maryland Extension website.

A different take: Invasive Insects in Maryland

Boxwood shrubs are a popular choice for foundation plantings and formal gardens, but they can be susceptible to certain pests and diseases. Boxwood (Buxus spp.) are broad-leaved evergreen, deer-resistant shrubs.

Leafminers, psyllids, and boxwood mites are the most common pests of boxwood in Maryland. These pests can cause significant damage to your boxwood plants.

Be on the lookout for box tree moth (Cydalima perspectalis), a new potential invasive insect that feeds on boxwoods. If you notice chewing damage on boxwood leaves, it could be a symptom of this moth.

Common diseases of boxwood include Volutella blight and Macrophoma leaf spot.

Broaden your view: Small Boxwoods Shrubs

Boxwoods are a favorite snack of many insects, and it's no surprise why - they're rich in nutrients and easy to access.

Boxwood psyllids are one of the most common insects found on boxwoods, and they're known to cause significant damage to the plant.

These tiny insects feed on the sap of the boxwood, which can lead to curled or distorted leaves.

In addition to psyllids, boxwoods are also susceptible to scale insects, which secrete a sticky substance called honeydew that attracts other insects.

To control these pests, it's essential to understand their biology and life cycle.

Boxwood psyllids, for example, have a complex life cycle that involves multiple stages of development, including egg, nymph, and adult.

Scale insects, on the other hand, have a more straightforward life cycle that involves egg, crawlers, and adults.