College of Agriculture & Natural Resources

• Green fruit rot

  Both fungi attack the blossoms but rarely invade the twig.

• Green stink bug

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The green stink bug is uniformly grass-green.

• European corn borer

  Adult is a pale yellowish brown moth with irregular darker bands running in wavy lines across wings male is distinctly darker than the female.

• Forbes scale

  Round or elongate gray scale with a raised reddish area in the center, which distinguishes it from the San Jose scale.

• Winter moth

  Adult male has grayish-brown wings; the female has remnants of wings and so cannot fly. This, in combination with the female's large body, makes the legs appear to be long, and gives her the superficial appearance of a spider.

• Apple (Lyonetia) leafminer

  The adult has narrow white forewings with extensive gray-black and brown markings apically wing margins are fringed with long hairs. The larva is whitish and generally concealed within the leaf mine.

• Prionus borers

  Adults are robust, broad, somewhat flattened blackish to reddish brown beetles with antennae roughly half the length of their bodies.

• Sparganothis fruitworm

  Adult is a vivid yellow moth with grayish magenta V-shaped marks on the forewings and reddish orange lace-like markings. Larvae are pale green with yellowish-green head.

• European apple sawfly

  The adult looks similar to a small, orange-brown wasp with the ventral side and legs orange in color. It has transparent wings with many veins. The egg, oval and translucent, is inserted into the receptacle of the flower.

• Alternaria fruit rot

  The disease appears as velvety dark green to black, circular, sunken lesions on mature fruit; the infected tissue is firm and brown. Disease is typically associated with over-ripe or damaged fruit, or fruit held in storage.

• Black peach aphid

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

• Perennial canker of stone fruit

  Small twig infections are usually found around winter-killed buds, leaf scars, and picking and pruning injuries. They appear as sunken discolored areas with alternating zonation lines and may ooze amber gum unless the twig is killed.

• 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.

• Black knot

  Black knot usually develops over two seasons. The disease first appears in late summer or autumn as an olive-green swelling on new shoots. Disease develops rapidly the following summer, forming a characteristic dark, course-textured warty knot.

• Apple seed chalcid

  Adult is a small, dark wasp with a bright green head, thorax and abdomen with coppery or bronze metallic reflections, brownish yellow legs, clear hyaline wings, and a long ovipositor.

• White peach scale

  Adult female is creamy-white to reddish orange, and covered by a round waxy scale that is grayish to brownish white. Adult males are tiny yellow 2-winged insects, and nymphs are oval and white to orange.

• Click beetles

  The click beetle is dark-colored its body is hard and elongated it has a characteristic pair of spurs and sometimes colorful markings on its thorax.

• 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.

• Pear slug (Pear sawfly)

  The adult looks similar to a small, black-bodied wasp with the ventral side and legs yellow in color. The larva is small, fleshy, dark green to orange, slug-like, and slime-covered, with the front part of the body enlarged.