College of Agriculture & Natural Resources

• 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.

• Fall webworm

  Adult is a white moth with dark spots on the wings, which may be less distinct in northern specimens. The pale yellow larva has a dark head and dark tubercles with clumps of hairs.

• 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.

• Roundheaded appletree borer

  Adult has a hard, elongated body, with white and brown longitudinal stripes and long antennae. The larva is a fleshy, cream-colored legless grub with a dark brown head, blackish mandibles.

• 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.

• 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.

• 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.

• 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.

• Hawthorn dark bug

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

• American brown rot

  American brown rot is common on apricot, peach, nectarine, plum and cherry.

• 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.

• 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".

• Minute pirate bug

  Adults are very similar in size to the mullein plant bug (Campylomma varbasci), but their head is narrower and their wings are colored contrasting white and black.

• European brown rot

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

• Powdery mildew of cherry

  The fungus attacks young leaves and shoots and tends to cause more damage on sour cherry than sweet cherry. Infections appear as white circular lesions or patches of powdery growth on either side of the leaf or on the terminal ends of shoots.

• Apple rust mite

  The vermiform adult has two pairs of legs at the front of its body. Brownish yellow in color, they are invisible to the naked eye, requiring a minimum magnification of 15X to be observed.

• European red mite

  Adult female European red mites are less than 0.5 mm and dark red with eight legs. Adult males are smaller than the females and have a pointed abdomen. Males are usually dull green to brown.

• Apple red bug

  Adult has head and thorax bright red in color with brown wings.

• 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.