MSU Extension Integrated Pest Management

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  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.

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  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.

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  American hawthorn rust

  Disease

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

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  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.

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  Angular leaf scorch

  Disease

  Lesions are initially yellow or reddish and confined by major veins. They later become necrotic and surrounded by yellow or red margins. Late-season infections may look like freckled spots and can cause premature defoliation. Infected flower clusters dry up. Unlike Botrytis blight, this disease infects only the berry stems, not the rachis. The pathogen overwinters in fallen infected leaves. The disease may seem absent in most years but can be severe in years with prolonged rainy weather.

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  Annual Bluegrass

  Weeds

  Annual bluegrass is unique among weeds. There is probably no other weed that is so widely adapted to variations in mowing height, site conditions and cultural practices.

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  Anthracnose

  Disease

  Lesions start as small, circular, tan to brown spots on mature or nearly mature fruit. Lesions expand rapidly, with a tendency to form concentric rings that may or may not be sunken.

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  Ants

  Insect

  A column of ants on a vine during the summer may be tending mealybugs because ants feed on the secreted honeydew.

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  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.

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  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.

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  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.

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  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.

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  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".

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  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.

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  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.

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  Apple red bug

  Insect

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

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  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.

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  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.

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  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.

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  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.

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  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.

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  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.

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  Assassin bugs

  Beneficial

  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.

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  Ataenius and Aphodius

  Insect

  Aphodius beetles are active on golf courses mostly in May, while Ataenius beetles are active in June. Ataenius and Aphodius beetles are virtually identical to the naked eye and require an expert with a microscope to identify the species. Turf damage from Aphodius grubs occurs in June while damage from Ataenius grubs occurs in July. The adults are small black beetles, 3/16th of an inch long.

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  Bacterial blossom blast of pear

  Disease

  The most common symptoms are wilting followed by browning or blackening of blossoms, often spreading through the entire blossom truss and killing the fruiting spur.

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  Bacterial canker (blossom blast)

  Disease

  Leaf scars, stomata, and areas of injury are the principal sites of infection. The most conspicuous symptoms are limb and trunk cankers, blossom blast, "dead bud", and leaf spotting; these symptoms may or may not occur together.

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  Bacterial spot

  Disease

  Bacterial spot appears on apricot, peach, nectarine, plum and prune.

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  Bacterial spot

  Disease

  On leaves, lesions are small, tan to brown in color, eventually becoming necrotic, and usually surrounded by a yellow halo. There are often numerous lesions on a leaf and they tend to be restricted to areas between veins, which gives them an angular appearance.

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  Bacterial Wilt

  Disease

  Bacterial wilt is characterized by tiny red-copper-colored spots first appearing about the size of a dime. As more plants die, spots become larger. Small, yellow leaf spots, streaked tan to dark brown spots, dark green, water soaked lesions, shriveled blue to dark green leaves, and yellow elongated leaves are all symptoms that have been associated with bacterial wilt.

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  Banded grape bug

  Insect

  The banded grape bug has piercing-sucking mouthparts that it inserts into plant tissue to suck out plant sap. It completes one generation per year on grapes and is active in vineyards from shortly after bud break to early July.

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  Bees and bumble bees

  Beneficial

  Principal species are honey bees and bumble bees. Bumble bees have a robust black body covered with hair of variable colors (yellow, orange, black, and white). Honey bees are more delicate; they are golden brown with yellow rings on the abdomen, and have a hairy body.

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  Bermudagrass

  Weeds

  Bermudagrass is a warm-season perennial that spreads by stolons (above ground runners). Bermudagrass is a not widely considered to be cold tolerant, however, several selections exist that can overwinter in Michigan.

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  Billbug

  Insect

  Adult bluegrass billbugs are a small dark gray to black weevil approximately 5/16 of an inch long. Individuals are typically found in small numbers in most lawns. They have a single generation per year with adults becoming active in May.

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  Birdsfoot Trefoil

  Weeds

  Birdsfoot trefoil is a common perennial broadleaf plant in under-fertilized, minimal maintenance turfgrass sites. It is well distributed across Michigan and the Great Lakes Region.

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  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.

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  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.

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  Black cherry aphid

  Insect

  Adults and nymphs are shiny black soft-bodied insects; adults may or may not have wings. Nymphs are smaller, but generally similar in appearance to the adults.

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  Black hunter

  Beneficial

  The adult is a slender, sharply pointed, blue-black insect with silvery wings, which are held over the abdomen.

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  Black knot

  Disease

  Black knot usually develops over two seasons. The disease first appears in late summer or autumn as an olive-green swelling on new shoots. Disease develops rapidly the following summer, forming a characteristic dark, course-textured warty knot.

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  Black Medic

  Weeds

  Black medic is a low-growing creeping weed that is well adapted to many lawn situations. In particular, black medic can be an indication of low soil nitrogen. It is most common to find medic in full sun , low maintenance situations. Black medic and white clover grow in similar situation and are often found growing together.

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  Black peach aphid

  Insect

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

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  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.

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  Black rot

  Disease

  Black rot can affect all new growth – leaves, petioles, shoots, tendrils and berries – but it is most destructive to fruit clusters. Fruit infections occur from bloom until the berries become naturally resistant (about 3 to 5 weeks after bloom in most varieties). The first symptom, a whitish dot within a rapidly expanding brown area, appears 10 to 14 days after infection. Within a few days, the berry starts to shrivel and becomes a hard, blue-black mummy. If berries are infected close to the onset of natural resistance, lesions remain localized. The fungus over-winters in mummies within the vine or on the ground. Ascospores are released shortly after bud break until about 2 weeks after bloom and are dispersed by wind and rain. Infected tissues can also yield conidia, which are dispersed by rain splash and cause secondary infections. The optimum temperature for disease development is 80°F (27°C). At this temperature, the wetness period required for infection is only 6 hours (see table below). Number of wetting hours required for black rot infection at various temperatures. Ave. temp. (F) / Hr. of leaf wetness 50 / 24 55 / 12 60 / 9 65 / 8 70 / 7 75 / 7 80 / 6 85 / 9 90 / 12

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  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.

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  Blister spot

  Disease

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

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  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.

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  Botrytis bunch rot

  Disease

  Botrytis bunch rot is a fruit rot, but it can also affect other plant parts. In spring, buds and young shoots may be infected and turn brown. In late spring, V-shaped or irregular brown patches may appear on leaves. Inflorescences may become blighted and wither away. Some flower infections remain latent until veraison. Once infections become activated, they spread rapidly from berry to berry. Compact clusters, powdery mildew infection, hail and insect damage, high nitrogen content and rain cracking can predispose grapes to infection. The disease is favored by temperatures of 59 to 68ºF (15 to 20ºC) and spreads rapidly during rainy periods, especially close to harvest. In certain cultivars, slow developing late-season infections are termed “noble rot” because they contribute to the production of exceptionally sweet wines. The fungus overwinters in mummified fruit and other infected plant parts.

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  Braconid and chalcid parasitic wasps

  Beneficial

  Brown or black, these wasp species are small and difficult to differentiate from one another, except that chalcids have greatly enlarged hind femora (third leg segment). They have two pairs of membranous wings, segmented antennae, and a very distinct head, thorax and abdomen.

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  Broadleaf Plantain

  Weeds

  Broadleaf plantain is probably the second most common broadleaf weed of turf after dandelion. It is extremely well adapted to most sites including dry or wet conditions, heavy soils and very low mowing heights.

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  Brooks fruit spot

  Disease

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

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  Brown marmorated stink bug

  Insect

  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.

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  Brown Patch

  Disease

  Brown patch appears as circular patches, ranging from a few inches to several feet in diameter.

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  American brown rot

  Disease

  American brown rot is common on apricot, peach, nectarine, plum and cherry.

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  Brown rot

  Disease

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

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  European brown rot

  Disease

  Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits.

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  Brown stink bug

  Insect

  Stink bug adults have a broad, flattened, shield-shaped body and a narrow head. The brown stink bug is brown to grayish-brown and slightly speckled.

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  Buckhorn Plantain

  Weeds

  Buckhorn plantain is a narrow-leaved perennial that forms a rosette. The 3-10 inch long leaves are less than 1 inch wide and arise from a thick, shallow tap root. Buckhorn plantain is very common in maintained turf but will also survive in meadows and waste areas.

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  Buffalo treehopper

  Insect

  The pale green adult exhibits a large thorax with two "horns" and a long posterior wedge-shaped body. The cream-colored eggs are laid in a groove on the tree bark, where they overwinter.

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  Bull Thistle

  Weeds

  Bull thistle is a clumping biennial that forms a thick taproot in its first growing season. The leaves of bull thistle are covered with 'soft' hairs and needle-like spines on the margin.

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  Calyx end rot

  Disease

  Symptoms begin at the calyx end of the fruit, causing a reddish discoloration at the site of infection. The rot is at first soft, but eventually dries out, turning tan to brown with a red border.

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  Canada Thistle

  Weeds

  Canada thistle is a creeping perennial that always colonizes in patches. Plants can reach 1-3 feet high. Canada thistle has an extremely well developed creeping root system that can grow several feet deep.

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  Carolina Geranium

  Weeds

  Carolina geranium is an uncommon weed of low or no-maintenance areas such as fence rows. The leaf shape is very similar to common mallow, except that the leaves are more finely dissected. Pink, inconspicuous flowers are produced within the canopy. Plants typically do not persist after flowering.

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  Cedar apple rust

  Disease

  On leaves, the disease appears on the upper surface as small, faint, yellow spots shortly after the appearance of active cedar galls found on the alternate host for this fungus, the red cedar.

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  Cherry fruit flies

  Insect

  The adult cherry fruit fly is somewhat smaller than the house fly, with a yellowish brown head and legs, and white crossbands on the abdomen. The black cherry fruit fly is slightly larger and its abdomen is entirely black.

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  Cherry fruitworm

  Insect

  The adult is a small, brownish gray moth with a median gray band on the forewings and a dark spot at the base of the hind wings. Although whitish gray with a black head when young, the larva eventually becomes pink tinted, with a brownish tan head.

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  Cherry leaf spot

  Disease

  Lesions begin as small, circular red to purplish spots on the upper leaf surface. Spots enlarge as they grow older, typically coalescing and turning brown. Lesion centers may eventually drop out to give the leaf a "shot-hole" appearance, particularly on plum.

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  Cherry leafminer

  Insect

  The adult is a small, bronzy tan-colored moth, with a wavy darkish brown to black band at the outer third of the forewings.

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  Chicory

  Weeds

  Chicory is a simple (unbranched) perennial with a jagged fleshy taproot. The coarsely-toothed basal leaves are 6-8" long and form a rosette.

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  Chinch Bug

  Insect

  The chinch bug does not have a pupal stage and the immatures look very much like the adult, but are black and lack wings.

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  Cigar casebearer

  Insect

  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.

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  Click beetles

  Insect

  The click beetle is dark-colored its body is hard and elongated it has a characteristic pair of spurs and sometimes colorful markings on its thorax.

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  Climbing cutworms

  Insect

  Adults are dark brown or grayish colored moths. Larvae tend to be smooth caterpillars with few hairs, brown or black head capsules, and bodies a dull gray-brown background color with stripes, spots, or dark brown, black, yellow or white splotches.

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  Codling moth

  Insect

  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.

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  Common Chickweed

  Weeds

  Primarily a winter annual, common chickweed is frequently found growing in the mulch skirts of shade trees. In general, common chickweed prefers shaded sites with moist soils. The vegetation forms mounds that are 3-7 inches tall. The delicate white-to-pink flowers appear early in the spring. Plants can persist in protected areas well after flowering.

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  Common Lambsquarters

  Weeds

  Like many other summer annual broadleaf weeds, common lambsquarters is generally considered an 'establishment weed.' Common lambsquarters needs cultivation (bare, loose soil) to establish.

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  Common Mallow

  Weeds

  Common mallow most often establishes along culverts, fencelines and near foundations. Common mallow forms a clump whorled branches that do not root where they touch the ground.

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  Common Milkweed

  Weeds

  Milkweed is easily identified by its upright growth habit and large (entire) leaves. All plant parts will exude a milky white latex when broken.

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  Common Mullein

  Weeds

  Large oblong densely-hairy leaves growing from a rosette in the first year. Leaves have alternate arrangement in second year. Mullein is commonly found in headlands and boundary areas.

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  Common Purslane

  Weeds

  Common purslane is a mat-forming summer annual that thrives in all soil types. Common purslane has multi-branched red stems with thick fleshy leaves that cluster at the end of the branches.

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  Comstock mealybug

  Insect

  Adult females and nymphs are generally similar in appearance, having an elongate-oval shape, no wings, a many-segmented body and well-developed legs.

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  Constriction disease of Stanley plum (Brown line)

  Disease

  Brown line disease is due to an incompatibility at the graft union when Stanley plum and some other European or hybrid plum varieties are grafted onto Myrobalan rootstock. Asian plums are not affected. Infected trees show a general decline and bear small, pale green leaves.

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  Corn Speedwell

  Weeds

  Corn speedwell is an upright, clumping winter annual that produces small purple flowers in the spring. The lower, non-flower, portion of the plant has leaves that are round-to-oblong with rounded teeth on the margin in an opposite arrangement.

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  Cranefly

  Insect

  The insect generally has a single generation per year. The adults, which resemble giant mosquitos, begin to fly in August. The two species are difficult to distinguish from each other, and can also be confused with several species of native craneflies that do not harm turfgrass. The most destructive of the two European species (European cranefly and common cranefly) is the European cranefly.

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  Creeping Bentgrass

  Weeds

  Creeping bentgrass is a spreading cool-season perennial grass that is commonly used for golf course greens, tees and fairways. Like other grasses, bentgrass can be considered a weed when it is present in another species.

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  Creeping Speedwell

  Weeds

  Creeping speedwell is a low growing perennial that prefers shade, moist soils, good fertility and a low mowing height.

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  Creeping Woodsorrel

  Weeds

  Creeping woodsorrel is a spreading perennial weed with a reddish-purple color that frequently roots at the nodes.

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  Crown gall

  Disease

  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.

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  Crown Rot Anthracnose

  Disease

  Anthracnose can occur as both a foliar infecting and crown infecting disease.

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  Curly Dock

  Weeds

  Curly dock is a long taprooted simple (non-branching) perennial that grows in a rosette. The 6-8" long elliptical or lance-shaped leaves of curly dock have entire but wavy margins (not toothed). The youngest leaves smooth margins that get progressively more rippled as the leaf matures. The appearance of the mature leaves resembles leaf lettuce (very curly).

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  Cutworm

  Insect

  The adults are nondescript brown or grey moths. There are several species that can be a problem on turf. The insect does not overwinter in Michigan (see notes section) and flies in on wind currents in the spring.They can go through several generations per year, so damage can occur at different times over the summer.

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  Dandelion

  Weeds

  Common dandelion is a simple perennial (no branching) with a basal rosette that has deeply lobed leaves that generally point back towards the center of the rosette. Probably the most common weed in maintained turf.

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  Dock sawfly

  Insect

  The adult is bluish black with red legs. The larva is a smooth velvety green worm with white legs and a dark head.

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  Dogwood borer

  Insect

  The adult is bluish black with yellow bands and has clear wings, resembling a wasp. Larva is creamy white to pink with a sclerotized reddish head.

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  Dollar Spot

  Disease

  Dollar spot is characterized by round, bleached-out or straw-colored spots, ranging from the size of a quarter to the size of a silver dollar. Spots appear as sunken areas in the turf, especially low mown turfgrass.

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  Downy mildew

  Disease

  Downy mildew is a widespread, serious disease of grapevines. Initial leaf symptoms are light green to yellow spots, called “oil spots” because they appear greasy. Under humid conditions, white, downy spore masses can be seen on the lower leaf surface. These spores are wind dispersed. The lesions eventually turn brown as the infected tissue dies. Severely infected leaves drop prematurely, which can reduce winter hardiness of the vine. Infected flower clusters dry up or become covered with white spores under humid conditions. Infected berries turn a mottled dull green or reddish purple and readily fall from the cluster. Although berries become resistant to infection within 3 weeks after bloom, the rachis remains susceptible for several weeks longer. The pathogen overwinters in infected leaves on the ground. In spring, spores are carried by rain splash to new leaves, where they require a film of water for infection. Lesions appear 5 to 17 days after infection. The disease can spread rapidly under warm conditions with frequent rain or dew. Use the 10-10-10 rule to decide when to start scouting for downy mildew: at least 10 cm (4 in.) of shoot growth, 10 mm (0.4 in.) rainfall and temperatures of 10 degrees Celsius (50 F) during a 24-hour period.

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  Dry eye rot (blossom end rot)

  Disease

  Symptoms begin at the calyx end of the fruit, causing a reddish discoloration at the site of infection. The rot is at first soft, but eventually dries out, turning tan to brown with a red border.

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  Dusky stink bug

  Insect

  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.

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  Earthworm

  Insect

  They become active when the ground thaws and will have multiple generations per season. Activity will slow down in late October as the ground temperature decreases.

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  Eastern tent caterpillar

  Insect

  The adult is reddish brown with two white, transverse-parallel bands. Masses of shiny black eggs are laid in a ring around twigs. Larvae have long silky hairs on their body and a yellow line on their back.

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  English Daisy

  Weeds

  English Daisy is an escaped ornamental plant that can sometimes be found in lawns and pastures. Prefers heavy, moist, fertile soil and can tolerate mowing heights down to 1 inch.