Target Pests

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.

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. Freshly emerged nymphs are black with orange abdomens and a black pattern in the center of the back; as they grow they become darker with small orange patterns, and the oldest instars closely resemble adults only without the wings. Older nymphs have spines, which are not present on the adult. Nymphs tend to feed on leaves and stems of plants, while adults feed on fruit and seeds in addition to leaves and stems. This causes stippling on leaves, dead spots on fruit and offers an invasion pathway for pathogens. In fruits like apples, the damage creates a characteristic pattern called “cat facing”, which renders the fruit unmarketable as a fresh product.

Eggs are laid in late spring and summer; nymphs grow to adulthood in the fall, and find overwintering sites in structures or standing dead trees. Adults emerge in mid-spring to feed on a host list that includes many economically important species.

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. This arc-dot combination is diagnostic of Lymantria and easily separates them from native moths. Females lay furry, buff to cream colored egg masses on tree trunks, outdoor furniture and other outdoor items and will be visible through winter.

Newly hatched larvae are black with long hairs. Older larvae are distinguishable from all native caterpillars by the presence of five pairs of blue raised “bumps” or spots followed by six pairs of raised brick-red spots along their backs. They are very hairy.

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 short time. Each snail contains both male and female reproductive organs and can produce up to 1200 eggs/year.

Adult snails are typically nocturnal—feeding at night and seeking shelter during the day time. They become more active during damp or humid weather. Juvenile snails may feed during the day. In heavy infestations, snails will be visible in the open, any time of day and are considered a nuisance.

Immature snails are smaller and may resemble some native snails. It is best to contact an expert if you suspect a large snail could be a giant African snail.

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. The adelgid stays in that spot for the rest of its life. Although many eggs are produced, mortality of the nymphs can be as high as 90% since their dispersal method is mainly dependent on chance. HWA has two generations a year so populations can build rapidly.

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 together or on top of fruit where they feed protected from predators. For this reason they are known as leaf-rollers. When fully grown the larvae are less than an inch in length. As with the adults, LBAM larvae are not distinguishable from many native tortricid larvae and require careful examination, rearing to adulthood, or even DNA tests to accurately identify them.

Oak Wilt

Oak wilt is caused by the fungus, Ceratocystis 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. Several species of sap beetles are attracted to the strong fruity odor produced by the spore mats. The beetles feed on and tunnel through the mats they get covered with spores. Disease spreads when beetles covered in oak wilt spores transfer these spores to new host trees. The spore mats are especially common in infected red oaks.

Sudden Oak Death

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.

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.