• Western flower thrips and flower thrips

  Western flower thrips and Flower thrips are indistinguishable without a microscope. Adults are slender and yellowish, with short antennae; the wings are long and narrow, and held over the abdomen.

• 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.

• Assassin bugs

  The head is narrow and elongate with the portion behind the eyes neck-like. Sometimes a sculptured crest may be found on the pronotum. The front legs are specialized for hunting.

• 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.

• White apple leafhopper

  Adults are creamy white with short antennae, translucent wings, and a long wedge-shaped body. Usually found on the underside of leaves, they jump and fly with great agility. Nymphs are yellowish, wingless and very mobile; they generally move in a back-and-forth motion.

• Rosy apple aphid

  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.

• X-Disease

  This disease is caused by a mycoplasma and infects many varieties of stone fruits. On cherry, infected trees tend to develop a dieback and a generally unthrifty appearance. Infected trees decline, but the rate of decline is dependent on the rootstock.

• Rhizopus rot

  Although the rot is predominantly a postharvest problem, symptoms may also develop in the field. Rotted fruit appears similar to brown rot, but Rhizopus-affected fruit appears slightly darker, the skin may slip away from decaying flesh underneath, or the fruit may be very leaky.

• Apple leaf (curling) midge

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

• Cigar casebearer

  Adult is dark gray with fringed wings. The small yellowish larva of the cigar casebearer has a black head and builds and hides in a cigar-shaped shelter that it carries with it while feeding or attaches to leaves and branches of apple trees.

• 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.

• Fusicoccum canker (constriction canker)

  On new shoots, small, reddish brown to dark, oval cankers centered on infected buds or leaf scars, or at the base of current season's twigs are found in early spring.

• 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.

• Perennial canker of stone fruit

  Small twig infections are usually found around winter-killed buds, leaf scars, and picking and pruning injuries. They appear as sunken discolored areas with alternating zonation lines and may ooze amber gum unless the twig is killed.

• Gypsy moth

  The adult male is brownish and marked with blackish zigzag lines. The adult female is whitish with brown transverse zigzag stripes and does not fly. The masses of oval and yellow eggs are laid on the trunk of trees and covered with hair left by the female.

• Codling moth

  The adult's forewings are striped with fine brown-gray lines and a distinctive bronze to brown-black oval spot at the tip. Eggs are laid on the leaves or fruit.

• Pear psylla

  Adults resemble very small cicadas and can be reddish brown or tan to light brown. Smaller, wingless nymphs are yellow with red eyes, flat and oval in shape, and develop within a clear honeydew drop.

• Brown marmorated stink bug

  Brown marmorated stink bug adults are shield-shaped, with mottled brown coloration on the upper and lower surface. They can be distinguished by lighter bands on antennae and they have darker bands on the membrane part of the front wings.

• Peach scab

  On fruit, lesions begin as small, greenish circular spots that gradually enlarge and darken as spore production begins. These spots appear when fruit are half grown and are most common on the stem end of the fruit, but can occur over the whole surface.

• Brown rot

  Infected flowers turn brown, wither, and either become fixed to twigs as a gummy mass or drop like unpollinated flowers.