College of Agriculture & Natural Resources

• 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.

• 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.

• 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.

• Lesser appleworm

  The adult is a small gray moth with distinct small orange bands or patches on the wings; some blue is also evident in newly emerged specimens.

• Redhumped caterpillar

  The adult is a grayish brown moth. The larva is yellow with a red head and is lined longitudinally with orangish, black, and white stripes.

• Rhizopus rot

  Although the rot is predominantly a postharvest problem, symptoms may also develop in the field. Rotted fruit appears similar to brown rot, but Rhizopus-affected fruit appears slightly darker, the skin may slip away from decaying flesh underneath, or the fruit may be very leaky.

• White apple leafhopper

  Adults are creamy white with short antennae, translucent wings, and a long wedge-shaped body. Usually found on the underside of leaves, they jump and fly with great agility. Nymphs are yellowish, wingless and very mobile; they generally move in a back-and-forth motion.

• Armillaria root rot

  The bark at the crown and roots sloughs off easily, exposing the dense white growth of the fungus. The growth extends in a fan-like pattern underneath the bark. Black shoestring-like strands may be obvious on the surface of the bark.

• American brown rot

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

• 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.

• 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.

• Peach bark beetle

  Adult's body is brown with many punctures, from which arise yellowish hairs. The larva is a small, legless grub.

• Rose chafer

  The rose chafer is a light tan beetle with a darker brown head and long legs. It is about 12 mm long. There is one generation per year.

• Plum rust mite

  Plum rust mites (PRM) generally restrict their feeding to new foliage, causing these leaves to brown and roll upward longitudinally

• Dock sawfly

  The adult is bluish black with red legs. The larva is a smooth velvety green worm with white legs and a dark head.

• Rosy apple aphid

  Populations arise from the overwintered stem mothers, which are wingless and purplish in color, and form into colonies of rosy-purple nymphs with dark cornicles.

• Apple sucker

  Adult resembles a miniature cicada, greenish yellow to yellow in color but sometimes containing reds or browns, with eyes pale green to reddish brown, and long slender antennae; wings are transparent and iridescent.

• 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.

• Dogwood borer

  The adult is bluish black with yellow bands and has clear wings, resembling a wasp. Larva is creamy white to pink with a sclerotized reddish head.

• Variegated leafroller

  Adult is grayish magenta with dark brown bands on the middle and end of the forewing. Larvae are pale green with yellowish green heads.