College of Agriculture & Natural Resources

• Verticillium wilt

  Leaves wilted or browned on one or several branches, often remaining attached; the rest of the tree appears healthy. Young trees are often killed by infection.

• Widestriped green fruitworm

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

• 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.

• Crown gall

  Infected trees are often stunted and produce small, chlorotic leaves. Spherical to elongated swellings along the roots or on the trunk just above the soil line is the primary symptom.

• Apple seed chalcid

  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.

• Dusky stink bug

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The dusky stink bug is dark brown, with sharp shoulder projections.

• Green fruit rot

  Both fungi attack the blossoms but rarely invade the twig.

• Green peach aphid

  These smooth-looking, pear-shaped insects have long antennae and a pair of cornicles extending from the posterior end of the body.

• Green ring mottle virus

  The virus produces symptoms on sour cherry, primarily the variety Montmorency. Apricot, peach, and sweet cherry are symptomless hosts. Yellow mottling with irregularly shaped green islands or rings appear on the leaves of infected trees.

• 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.

• Fall webworm

  Adult is a white moth with dark spots on the wings, which may be less distinct in northern specimens. The pale yellow larva has a dark head and dark tubercles with clumps of hairs.

• Prunus necrotic ringspot

  Individual branches or the entire tree shows delayed budbreak or foliation, stunted wavy leaves, and shortened blossom pedicels in spring. Leaves develop chlorotic spots, lines, or rings as they emerge.

• Pale apple leafroller

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

• Green fruitworm

  Immature larvae of the green fruitworm (GFW) feed on flower buds and new foliage.

• Green June beetle

  The adult is velvet green dorsally with yellow-orange margins on the elytra. Ventrally it is a shiny metallic green mixed with orangish yellow. The larva is a large, C-shaped grub that lives in the soil and is not found in the trees.

• 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.

• Tarnished plant bug

  The adult is brown and the extremities of its wings are translucent with a cream-colored scutellum on its back. The nymph is pale green; from the 3rd nymphal stage, it has five black points on the back.

• 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.

• Plum rust mite

  Plum rust mites (PRM) generally restrict their feeding to new foliage, causing these leaves to brown and roll upward longitudinally

• Sour cherry yellows

  Young leaves develop chlorotic yellow rings or mottle; shot hole may occur in severe cases or as lesions age. These symptoms rarely recur after the first year of infection.