College of Agriculture & Natural Resources

• Bitter pit and cork spot

  Small, green to purplish to light brown, slightly sunken lesions appear on the surface of mature fruit. Individual lesions on the fruit surface are dry and do not extend deep into the fruit; however, cutting into the fruit can reveal numerous internal lesions.

• Stigmaeid/"Yellow" mites

  Agistemus fleschneri is the principal species found in QC and northern ON orchards, while Zetzellia mali predominates in the US, southern ON and the maritime provinces.

• 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.

• Climbing cutworms

  Adults are dark brown or grayish colored moths. Larvae tend to be smooth caterpillars with few hairs, brown or black head capsules, and bodies a dull gray-brown background color with stripes, spots, or dark brown, black, yellow or white splotches.

• Apple latent viruses

  Latent viruses are viruses that survive in their host without causing symptoms. These viruses are transmitted when a virus-infected scion is grafted onto a susceptible rootstock.

• Powdery mildew of apple and pear

  The fungus overwinters in leaf buds and sometimes flower buds. Mycelium develops rapidly on unfolding leaves and appears as white, felt-like patches or as a solid mat on the upper or undersurface of the leaf.

• Tufted apple bud moth

  Adult is an inconspicuous moth, varying from mottled gray at the wing base to brown at the wing tip, with a lighter colored margin along the wing's leading edge. Two or three groups of tufted scales can be seen on the top of the wings.

• Twospotted spider mite

  Adult and nymphal mites are yellowish to pale green with a dorsal pair of apparent dark "spots". Males are smaller than females and have a pointed abdomen. The female takes on an orange tinge in the fall.

• Brown stink bug

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The brown stink bug is brown to grayish-brown and slightly speckled.

• 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.

• 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.

• Shothole borer

  The adult is stocky with a hard black body and antennae, leg segments and tips of elytra reddish brown; its head is not visible from above.

• Lesser peachtree borer

  Adult is a clear-winged, metallic-blue moth that has two or more yellow bands across the abdomen, giving it a wasp-like appearance.

• Apple pith moth

  Head of adult is covered with white scales; forewings are narrow, mostly black or dark brown with white marks and usually with an irregular faint, rusty yellow line in the middle, and with two prominent black scale tufts.

• Eyespotted bud moth

  Adult forewings are bluish gray with a central cream-colored band and black spots. The chocolate brown larva has a black head and thoracic shield.

• Prionus borers

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

• Mullein plant bug

  Adult is grayish green with black spots on the legs. The nymph resembles an apple aphid or a white apple leafhopper and is solitary, very mobile and lacks cornicles.

• Fire blight

  Blossom blight occurs in the spring. Infected blossoms first exhibit a water soaking, followed by wilting and their eventually turning brown on apple and nearly black on pear. Individual flowers or the entire cluster may be affected.

• 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 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.