College of Agriculture & Natural Resources

• Gray mold

  Lesions usually start at the calyx or stem end of the fruit or at wound sites as small water-soaked areas. As lesions age, they enlarge, turning from grayish-brown to light brown, and eventually to a darker brown.

• 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.

• Green Apple Aphid

  Green apple aphid nymphs and adults prefer to feed on the underside of leaves on growing shoot tips and stems.

• 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.

• 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.

• Silver leaf

  Silvering of the foliage is the characteristic symptom. At first, silvering may be associated with only one or two major branches, but eventually the entire tree becomes silvery in appearance. When infection is severe the leaves may curl upward.

• European earwig

  The European earwig is dark brown with an elongated body, equipped with pincer-like forceps at the rear of the abdomen. The short elytra do not entirely cover the abdomen.

• Replant disorders

  In general, trees suffering from replant disease show slow and uneven growth within the first three years of planting. Both specific and non-specific replant disorders are known.

• Pear plant bug (Green apple bug)

  The adult pear plant bug is brownish yellow with two dark bands on the thorax and the extremities of its anterior wings are yellowish in color.

• Sooty blotch

  Sooty blotch and flyspeck are found together on the same fruit and affect only the epidermal layer of the fruit. Sooty blotch appears as various shades of olive-green on the surface of the fruit.

• 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 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.

• Black rot (Blossom end rot, Frogeye leaf spot)

  Fruit infections that occur early in the season appear at the calyx end and typically develop into blossom end rot that may not appear until the fruit begin to mature.

• 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.

• American plum borer

  The adult is a light grayish brown moth with reddish brown forewings marked by wavy black and brown vertical bands about two-thirds the distance from the base.

• 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.

• Phytoseiid mites

  A dark mark in the form of an "H" sometimes appears within their body. This mark is red when they feed on European red mites and yellow when they feed on twospotted spider mites. They move very rapidly on the leaves.

• Spirea aphid

  The eggs are oval and shiny black. The adults and nymphs are olive-green with brown-black legs, antennae, and cornicles. They live in colonies.

• Snowy tree cricket

  Adult somewhat resembles a field cricket, but is pale green in color and has a longer, more slender body and smaller head. Antennae are much longer than the body; males have stiff veins in their flat wings.

• White peach scale

  Adult female is creamy-white to reddish orange, and covered by a round waxy scale that is grayish to brownish white. Adult males are tiny yellow 2-winged insects, and nymphs are oval and white to orange.