• Oystershell scale

    Insect

    The adult female remains immobile under a small brown scale in the shape of an oyster shell attached to the bark of branches. The white and oval eggs are laid inside the scale and crawlers emerge in the spring during the petal fall stage of apple.

  • Pale apple leafroller

    Insect

    The adult is elongated and dull gray. The larva is creamy white with an amber head, which turns black in the penultimate instar.

  • Pear plant bug (Green apple bug)

    Insect

    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.

  • Pear thrips

    Insect

    Adult is slender and brown, with short antennae and a swelling behind the head; the wings are long and narrow, with fringes of long hairs.

  • Perennial canker of apple and pear

    Disease

    Branch lesions are elliptical, sunken, and orange, purple, or brown in color. A raised layer of callus tissue forms around the infected tissue to isolate the diseased tissue.

  • Periodical cicada

    Insect

    Adults are wedge-shaped, nearly black, with red eyes and red-orange wing veins. The clear wings are held tent-like over the body.

  • Phytophthora root, crown, and collar rot

    Disease

    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.

  • Pistol casebearer

    Insect

    Adult is dark gray with fringed wings. The pistol casebearer appears similar to a cigar casebearer: a small, yellowish larva with a black head that builds and hides in a shelter.

  • Plum curculio

    Insect

    The adult is mottled grayish black and brown. Its head is prolonged into a large but short snout that bears antennae. Each elytron has a series of humps with the 2nd and 3rd pairs separated by a clear transverse band.

  • Potato leafhopper

    Insect

    All leafhopper species feed on the undersides of leaves, puncturing cells and sucking out the contents. In general, juice grape (labrusca) varieties are much more tolerant of leafhoppers than hybrid or vinifera varieties.

  • Powdery mildew of apple and pear

    Disease

    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.

  • Prionus borers

    Insect

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

  • Quince rust

    Disease

    Attacks only the fruit of apple and pear. Symptoms begin as a purplish lesion, usually appearing on the calyx end of the fruit. As the disease progresses, the entire calyx end becomes blistered and deformed. Tube-like structures eventually form and produce powdery, bright orange spores.

  • Redbanded leafroller

    Insect

    The adult's forewings are grayish brown with a subtle dark red and brown oblique band. The larva is pale green with a yellow or green head.

  • Redhumped caterpillar

    Insect

    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.

  • Replant disorders

    Disease

    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.

  • Root-lesion nematode

    Disease

    Root-lesion nematodes are microscopic, migratory endoparasites that feed on the root systems of many crops. Affected trees appear stunted, may exhibit chlorosis or yellowing of the leaves, and have poor yields; young trees may be killed.

  • Rose chafer

    Insect

    The rose chafer is a light tan beetle with a darker brown head and long legs. It is about 12 mm long. There is one generation per year.

  • Rosy apple aphid

    Insect

    Populations arise from the overwintered stem mothers, which are wingless and purplish in color, and form into colonies of rosy-purple nymphs with dark cornicles.

  • Roundheaded appletree borer

    Insect

    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.

  • San Jose scale

    Insect

    Adult males are minute, winged insects about 1 mm long and golden brown with a reddish tinge. Scales may be either disk-shaped or oval, and are composed of concentric rings of gray-brown wax radiating from a tiny white knob.

  • Shothole borer

    Insect

    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.

  • Silver leaf

    Disease

    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.

  • Skeletonizers

    Insect

    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.

  • Snowy tree cricket

    Insect

    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.