• Necrotic leaf blotch

  Medium to large, irregular necrotic lesions occur on the foliage of mature leaves during mid- to late summer. The remaining green tissue generally turns yellow shortly after the appearance of symptoms.

• 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.

• 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.

• 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.

• 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.

• Peach bark beetle

  Adult's body is brown with many punctures, from which arise yellowish hairs. The larva is a small, legless grub.

• 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.

• 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.

• Bitter rot

  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.

• Shothole borer

  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.

• Widestriped green fruitworm

  The adult has bluish or steel gray wings marked with inconspicuous mottled patches.

• Spiders: Foliage Hunters

  The body of a spider is divided into two regions, the cephalothorax and abdomen. The cephalothorax bears the eyes (various numbers and arrangements), mouthparts, pedipalps and legs (four pairs), and the unsegmented abdomen bears the genital structures, spiracles, anus and spinnerets (silk-spinning structures).

• 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.

• 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.

• 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.

• 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.