College of Agriculture & Natural Resources

• Phytophthora root, crown, and collar rot

  Crown and collar rot are often and mistakenly used interchangeably. Collar rot refers to infection that affects the bark tissue of the scion portion of the tree at or just below the soil line, whereas crown rot affects the bark tissue of the rootstock portion of the tree.

• Skeletonizers

  The adults of the skeletonizers are brown and short, with transverse bands on each forewing. The larvae are yellow to pale green with numerous hairy discs on each segment of the body.

• 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.

• Bacterial canker (blossom blast)

  Leaf scars, stomata, and areas of injury are the principal sites of infection. The most conspicuous symptoms are limb and trunk cankers, blossom blast, "dead bud", and leaf spotting; these symptoms may or may not occur together.

• 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.

• Southern blight

  Trees attacked by the fungus show a general decline. In the early phase of disease, a dense mat or web of white mycelium is evident at the base of the tree.

• 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.

• 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.

• 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.

• 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.

• Prionus borers

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

• 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.

• 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.

• Speckled green fruitworm

  The adult is grayish beige with two purplish gray spots on its wings and a hairy thorax. The eggs are laid on the upper surface of the leaves.

• 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.

• European apple sawfly

  The adult looks similar to a small, orange-brown wasp with the ventral side and legs orange in color. It has transparent wings with many veins. The egg, oval and translucent, is inserted into the receptacle of the flower.

• European fruit lecanium (Brown apricot scale)

  The adult female scale is nearly hemispherical and shiny brown, with several ridges along the back. Nymphs are light colored.

• Black peach aphid

  These smooth-looking, pear-shaped insects have long antennae and a pair of cornicles extending from the posterior end of the body.

• Alternaria fruit rot

  The disease appears as velvety dark green to black, circular, sunken lesions on mature fruit; the infected tissue is firm and brown. Disease is typically associated with over-ripe or damaged fruit, or fruit held in storage.