College of Agriculture & Natural Resources

• 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.

• Green stink bug

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The green stink bug is uniformly grass-green.

• 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.

• 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.

• 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.

• 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.

• 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.

• Nectria canker

  Cankers are often associated with nodes, often appearing as elliptical sunken areas. Sometimes callus production stops fungal invasion and cankers die by season's end.

• Red velvet mites

  Balaustium is a large, bright red mite with a tick-like shape and a dense velvet-like covering of dorsal setae.

• Green June beetle

  The adult is velvet green dorsally with yellow-orange margins on the elytra. Ventrally it is a shiny metallic green mixed with orangish yellow. The larva is a large, C-shaped grub that lives in the soil and is not found in the trees.

• Brooks fruit spot

  Appears as irregular, slightly sunken dark green lesions on immature fruit.

• 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.

• 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.

• Apple leaf (curling) midge

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

• Peach bark beetle

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

• Oriental fruit moth

  The adult is a small moth with dark gray mottled wings that lighten somewhat at the outer edges. The larva is dirty white to pinkish with a reddish brown head and an anal comb.

• Leafhoppers, about

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

• Apple anthracnose

  Branch lesions first appear as small, circular spots that are purple or red when wet. As lesions enlarge, they become elliptical, sunken and turn orange to brown. A distinct margin develops between healthy and diseased tissue, which eventually causes the bark to crack around the infected area.

• 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.