College of Agriculture & Natural Resources

• Blister spot

  Lesions begin as small, darkened, water-soaked areas, generally around lenticels and typically on the lower half of the apple.

• Buffalo treehopper

  The pale green adult exhibits a large thorax with two "horns" and a long posterior wedge-shaped body. The cream-colored eggs are laid in a groove on the tree bark, where they overwinter.

• White rot

  Fruit lesions become visible 4–6 weeks before harvest, and appear as small, circular, slightly sunken tan to brown spots, sometimes surrounded by a red halo on yellow-skinned fruit.

• Pear midge

  The adult resembles a very small mosquito or gnat; the body is brown and the wings transparent with simple veins. The larva is a white maggot with no legs or visible head; the posterior end is blunt, and the front end tapers to a point.

• 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.

• 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.

• 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.

• Leafhoppers, about

  Potato leafhopper (PLH) can be differentiated from white apple leafhopper by color and by observing movement and feeding habits.

• Hover flies

  The adult is a fly that mimics the coloration of wasps; it often hovers during flight. It is found among aphid colonies, often co-existing with other predators such as the gall midge.

• 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.

• 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.

• 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".

• Pistol casebearer

  Adult is dark gray with fringed wings. The pistol casebearer appears similar to a cigar casebearer: a small, yellowish larva with a black head that builds and hides in a shelter.

• Calyx end rot

  Symptoms begin at the calyx end of the fruit, causing a reddish discoloration at the site of infection. The rot is at first soft, but eventually dries out, turning tan to brown with a red border.

• Forbes scale

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

• Perennial canker of apple and pear

  Branch lesions are elliptical, sunken, and orange, purple, or brown in color. A raised layer of callus tissue forms around the infected tissue to isolate the diseased tissue.

• 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.

• Leaf weevils

  Leaf weevils are green or brown curculios with a metallic appearance. Their antennae are borne on the snout.