College of Agriculture & Natural Resources

• 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.

• 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.

• 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.

• 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.

• Cherry leaf spot

  Lesions begin as small, circular red to purplish spots on the upper leaf surface. Spots enlarge as they grow older, typically coalescing and turning brown. Lesion centers may eventually drop out to give the leaf a "shot-hole" appearance, particularly on plum.

• Japanese beetle

  Japanese beetles can be present from June through September. Japanese beetle adults are metallic green or greenish bronze with reddish wing covers and several white spots near the abdomen tip and along the sides. Larvae are larger C-shaped grubs that live in the soil.

• Fruittree leafroller

  The adult is red-brown with mottling. The translucent green caterpillar has a reddish to dark brown head and an amber to pale green thoracic shield edged with brown.

• 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 ring mottle virus

  The virus produces symptoms on sour cherry, primarily the variety Montmorency. Apricot, peach, and sweet cherry are symptomless hosts. Yellow mottling with irregularly shaped green islands or rings appear on the leaves of infected trees.

• 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.

• Assassin bugs

  The head is narrow and elongate with the portion behind the eyes neck-like. Sometimes a sculptured crest may be found on the pronotum. The front legs are specialized for hunting.

• Apple leaf (curling) midge

  The adult is a tiny dark brown fly, and the larva is a yellow-white maggot with a reddish tinge.

• Comstock mealybug

  Adult females and nymphs are generally similar in appearance, having an elongate-oval shape, no wings, a many-segmented body and well-developed legs.

• Woolly apple aphid

  The colonies of reddish brown adults and nymphs produce waxy secretions, which resemble small tufts of wool or cotton batting. The aphids are without cornicles, possessing only abdominal pores.

• European brown rot

  Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits.

• Hawthorn dark bug

  The young adult is black with red wing markings, which disappear a few days after it metamorphoses into an adult.

• Green pug

  The adult is a grayish moth with mottled or scalloped dark striations toward the wing margins. The larva is a green inchworm with a dark head and a dark reddish brown dorsal mid-line present in later instars.

• European fruit scale

  The female is immobile and covered with a circular waxy shell that becomes dark gray over time and is elevated at the center. The adult male is brownish red with an elongated abdomen, long antennae and wings.

• Periodical cicada

  Adults are wedge-shaped, nearly black, with red eyes and red-orange wing veins. The clear wings are held tent-like over the body.