Pests in the US

Asian Longhorned Beetle

The Asian longhorned beetle (Anoplophora glabripennis or ALB) is a large distinctive-looking insect growing to 1.5” long. The body is shiny jet black with irregular white spots. Antennae are typically longer (up to 2 ½ times longer) than the body and banded black and white. It has six legs sometimes with bright blue on the legs and feet.

Larvae are large, light cream-colored and do not have legs or a distinct head. Larvae live entirely within the wood of trees and are the most damaging stage of the beetle.

Box Tree Moth

The box tree moth, Cydalima perspectalis, was detected in Niagara County, New York in July of 2021. These insects attack a variety of boxwood species, commonly used in landscape plantings and for hedges and topiaries. While non-destructive in its native East Asian region, the larvae feed extensively on the leaves of boxwoods in nonnative regions, weakening and desiccating the plants. Dense moth populations often result in complete defoliation and death.

Brown Marmorated Stink Bug

Brown marmorated stink bug (Halyomorpha halys or BMSB) adults are shield shaped and about dime-sized. They are a mottled tan, with two white bands on their antennae, rounded shoulders, and alternating dark and light bands around the perimeter of their abdomen. Eggs are light green and elliptical, with tiny spines in a ring around the tip of the egg; once nymphs hatch, the eggs are white with a black triangle where the nymphs emerged.

Emerald Ash Borer

The emerald ash borer (Agrilus planipennis or EAB) is an invasive wood boring beetle. Despite their flashy color these beetles are difficult to spot in the wild! Adult EAB are bright, metallic green, about 1/2″ long and 1/8” wide with a flattened back. An adult EAB fits on the head of a penny.

EAB larvae are flattened and creamy white, worm-like with nested bell-shaped segments. It is the larvae that does all the harm to ash trees. The larvae tunnel under the bark and disrupt the tree’s systems that transport food and water, eventually killing it.

European Gypsy Moth

The European gypsy moth (Lymantria dispar dispar or EGM) is a relatively large moth and easy to identify from native moths. The sexes are distinct in both appearance and behavior. The males moths are brownish and can be seen flying during the day. Males have a wingspan of about 1 ½”. Female European gypsy moths do not fly and are a bit larger and creamy white in color. Both sexes have a characteristic mark on the forewings which consists of a blackish arc and an accompanying dot near the apex of this arc.

Giant African Snail

Giant African snail (GAS) refers to several snail species from East Africa. One species, Lissachatina fulica, can grow almost eight inches long. This species has a long, conical shell which usually consists of 7–9 whorls. The largest whorl can measure five inches in diameter which is about the size of an average adult’s fist. Shell color can vary depending on the snail’s diet but usually consists of brown and tan stripes with variations of light brown and cream. Often the tip of the shell is lighter or white.

GAS are very prolific and just two snails can produce an infestation in a relatively

Hemlock Woolly Adelgid

The hemlock woolly adelgid (Adelges tsugae or HWA) is a very small, aphid-like insect that feeds at the base of hemlock needles. Adults are red to purple-black and about 1mm long; nymphs are about the size of the period at the end of this sentence. HWA is most visible towards the end of adulthood, when they cover themselves in a white, cottony wax where they lay up to 300 eggs. Eggs hatch into nymphs which crawl or are moved by wind, birds and other animals to another hemlock needle, where they feed on the starches the needle needs to live.


Huanglongbing (HLB), previously called citrus greening, is one of the most threatening diseases to citrus plants in the U.S. and worldwide. The bacteria that causes HLB is spread by the tiny, invasive Asian citrus psyllid and may infect a wide range of citrus and closely related species. The disease is fatal, and presently there is no known cure.

Laurel Wilt

Laurel wilt is a deadly disease of redbay and other native plants in the laurel family. The disease is caused by the fungus, Raffaelea lauricola, which is introduced into host trees by a non-native insect, the redbay ambrosia beetle, Xyleborus glabratus. The fungus quickly plugs the water-conducting cells of an affected tree and causes it to wilt.

This insect vector attacks healthy trees. These beetles can be difficult to identify so a specialist should be consulted for positive identification.

Light Brown Apple Moth

The light brown apple moth (Epiphyas postvittana or LBAM) is a small, rather nondescript moth in the tortricid (Tortricidae) family. In North America there are approximately 1200 species of tortricid moths many of which are pest species. As its common name implies, this species is generally light brown but coloration and markings are highly variable making identification difficult for the casual observer. Unfortunately most tortricid moths are small and brown so dissections by a tortricid taxonomist are typically necessary to identify this moth.
The small green larvae roll and web leaves

Oak Wilt

Oak wilt is caused by the fungus, Bretziella fagacearum. It was first identified in 1944 and its origin is still uncertain. The fungus grows in the vascular tissue of the tree—this cuts off the supply of water and causes the tree to wilt and die. As the fungus grows it spreads below ground through natural root grafts to infect healthy oak trees. Once the fungus has killed a tree it may produce a mat of fungal spores under the bark. When pressure builds in this spore mat it causes the bark to split.

Phytophthora ramorum

Phytophthora ramorum is a water mold pathogen which causes two types of diseases. On trunk hosts it causes the disease known as sudden oak death, a forest disease that has resulted in widespread dieback of several tree species in California and Oregon. On understory plants P. ramorum is a foliar and twig disease which infects but does not kill a wide variety of ornamental plants; on foliar hosts P. ramorum is referred to as ramorum blight or ramorum dieback.

Spotted Lanternfly

Spotted lanternfly (SLF), an invasive insect native to China, India, and Vietnam, threatens U.S. agricultural, logging, and tourism industries. First detected in Berks County, PA in 2014, the pest demonstrated its detrimental impact upon plant growth and fruit production as its populations exponentially increased and spread in 2017.

Red hidwings, striped with white and tipped in black, faintly saturate the semitranslucent, spotted, gray forewings of this 1" long adult leafhopper. Young nymps are black with white spots becoming more red as they mature.

Thousand Cankers

Thousand cankers disease (TCD) results from the combined activity of two organisms; a newly described fungus, Geosmithia morbida, and the walnut twig beetle (WTB), Pityophthorus juglandis. Trees are eventually killed by overwhelming attacks of the walnut twig beetle and subsequent cankers that girdle branches.
WTB are tiny yellowish-brown bark beetles, about the size of a small flea or a broken piece of lead from a mechanical pencil. See image gallery.