College of Agriculture & Natural Resources

• Pear psylla

  Adults resemble very small cicadas and can be reddish brown or tan to light brown. Smaller, wingless nymphs are yellow with red eyes, flat and oval in shape, and develop within a clear honeydew drop.

• Skeletonizers

  The adults of the skeletonizers are brown and short, with transverse bands on each forewing. The larvae are yellow to pale green with numerous hairy discs on each segment of the body.

• Replant disorders

  In general, trees suffering from replant disease show slow and uneven growth within the first three years of planting. Both specific and non-specific replant disorders are known.

• Apple maggot

  Adults are black flies with three or four white cross bands on the abdomen, a prominent white spot at the posterior end of the thorax, and the wings are marked with black bands in the shape of an "F".

• Root-lesion nematode

  Root-lesion nematodes are microscopic, migratory endoparasites that feed on the root systems of many crops. Affected trees appear stunted, may exhibit chlorosis or yellowing of the leaves, and have poor yields; young trees may be killed.

• Redbanded leafroller

  The adult's forewings are grayish brown with a subtle dark red and brown oblique band. The larva is pale green with a yellow or green head.

• Silver leaf

  Silvering of the foliage is the characteristic symptom. At first, silvering may be associated with only one or two major branches, but eventually the entire tree becomes silvery in appearance. When infection is severe the leaves may curl upward.

• Crown gall

  Infected trees are often stunted and produce small, chlorotic leaves. Spherical to elongated swellings along the roots or on the trunk just above the soil line is the primary symptom.

• Green peach aphid

  These smooth-looking, pear-shaped insects have long antennae and a pair of cornicles extending from the posterior end of the body.

• Flatheaded appletree borer

  The adult is a short-horned beetle, flattened above, with short antennae and large conspicuous eyes. The upper surface of the body is dark metallic brown with slightly patterned wing covers.

• Prunus necrotic ringspot

  Individual branches or the entire tree shows delayed budbreak or foliation, stunted wavy leaves, and shortened blossom pedicels in spring. Leaves develop chlorotic spots, lines, or rings as they emerge.

• X-Disease

  This disease is caused by a mycoplasma and infects many varieties of stone fruits. On cherry, infected trees tend to develop a dieback and a generally unthrifty appearance. Infected trees decline, but the rate of decline is dependent on the rootstock.

• Tarnished plant bug

  The adult is brown and the extremities of its wings are translucent with a cream-colored scutellum on its back. The nymph is pale green; from the 3rd nymphal stage, it has five black points on the back.

• Spirea aphid

  The eggs are oval and shiny black. The adults and nymphs are olive-green with brown-black legs, antennae, and cornicles. They live in colonies.

• Pearleaf blister mite

  The adults are very small and cannot be seen without a 15X hand lens; the body is white and elongate oval in shape, like a tiny sausage.

• Brown stink bug

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The brown stink bug is brown to grayish-brown and slightly speckled.

• Gypsy moth

  The adult male is brownish and marked with blackish zigzag lines. The adult female is whitish with brown transverse zigzag stripes and does not fly. The masses of oval and yellow eggs are laid on the trunk of trees and covered with hair left by the female.

• Brown rot

  Infected flowers turn brown, wither, and either become fixed to twigs as a gummy mass or drop like unpollinated flowers.

• Codling moth

  The adult's forewings are striped with fine brown-gray lines and a distinctive bronze to brown-black oval spot at the tip. Eggs are laid on the leaves or fruit.

• Cherry fruitworm

  The adult is a small, brownish gray moth with a median gray band on the forewings and a dark spot at the base of the hind wings. Although whitish gray with a black head when young, the larva eventually becomes pink tinted, with a brownish tan head.