• Alternaria blotch

    Disease

    The disease primarily affects the foliage, causing circular, necrotic lesions with a light brown interior that later become surrounded by a darker purplish halo.

  • Alternaria fruit rot

    Disease

    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.

  • American hawthorn rust

    Disease

    Attacks only the leaves of apple and pear; affects the apple varieties McIntosh and Cortland in particular.

  • American plum borer

    Insect

    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.

  • Apple (Lyonetia) leafminer

    Insect

    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.

  • Apple anthracnose

    Disease

    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.

  • Apple latent viruses

    Disease

    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.

  • Apple leaf (curling) midge

    Insect

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

  • Apple maggot

    Insect

    Adults are black flies with three or four white cross bands on the abdomen, a prominent white spot at the posterior end of the thorax, and the wings are marked with black bands in the shape of an "F".

  • Apple mosaic virus

    Disease

    Young leaves develop pale to bright cream-colored spots, blotches, bandings or patterns as they expand in the spring. These turn brown and become necrotic as they age and premature defoliation may occur when infection is severe.

  • Apple pith moth

    Insect

    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.

  • Apple red bug

    Insect

    Adult has head and thorax bright red in color with brown wings.

  • Apple rust mite

    Insect

    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.

  • Apple scab

    Disease

    On leaves, young lesions are velvety brown to olive green with indistinct margins, and will often not be readily noticeable until after petal fall in commercial orchards.

  • Apple seed chalcid

    Insect

    Adult is a small, dark wasp with a bright green head, thorax and abdomen with coppery or bronze metallic reflections, brownish yellow legs, clear hyaline wings, and a long ovipositor.

  • Apple sucker

    Insect

    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.

  • Apple union necrosis and decline

    Disease

    AUND is due to an incompatibility at the graft union where a resistant scion is grafted onto a susceptible, but tolerant rootstock, most commonly MM.106.

  • Armillaria root rot

    Disease

    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.

  • Bitter pit and cork spot

    Disease

    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.

  • Bitter rot

    Disease

    Bitter rot appears on young fruit as small, circular brown lesions. Lesions expand rapidly and radially under wet and warm conditions. As they age, they turn darker brown and become sunken.

  • Black pox of apple (blister canker of pear)

    Disease

    On apple, conical, smooth, shiny black swellings are evident on current season's growth. As lesions age, they become ovoid with raised borders. On leaves, lesions begin as small, circular green spots surrounded by a red halo.

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

    Disease

    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.

  • Blister spot

    Disease

    Lesions begin as small, darkened, water-soaked areas, generally around lenticels and typically on the lower half of the apple.

  • Blue mold

    Disease

    Blue mold enters the fruit through wounds, stem-end invasion, or as a core rot. Infection is first visible as a soft and sunken, yellow to pale-brown circular lesion on the surface of the fruit.

  • Brooks fruit spot

    Disease

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