Adult beetles are large, distinctive-looking insects measuring 1 to 1.5 inches in length with long antennae. Their bodies are black with small white spots, and their antennae are banded in black and white. Females can lay up to 90 eggs in their lifetime. Within 2 weeks, the egg hatches, and the white larva bores into the tree, feeding on the living tissue that carries nutrients and the layer responsible for new growth under the bark. After several weeks, the larva tunnels into the woody tree tissue, where it continues to feed and develop over the winter.

In the United States the beetle prefers maple species (Acer spp.), including boxelder, Norway, red, silver, and sugar maples. Other preferred hosts are birches, Ohio buckeye, elms, horse chestnut, and willows. Occasional to rare hosts include ashes, European mountain ash, London planetree, mimosa, and poplars. A complete list of host trees in the United States has not been determined.

Chewed round depressions in the bark of the tree, pencil-sized, perfectly round tree exit holes, excessive sawdust near tree bases, unseasonable yellowed or dropping leaves. Signs of ALB start to show about 3 to 4 years after infestation, with tree death occurring in 10 to 15 years depending on the tree’s overall health and site conditions. Infested trees do not recover, nor do they regenerate.

• Pest Alert ( pdf)
• US FS - Northern Research Station ( html)
• Missouri Department of Conservation ( html)
• USDA APHIS ( html)

If you see signs or symptoms of infestation, follow the reporting directions on the MDC website .

The Emerald Ash Borer is rapidly expanding its range and is killing ash trees by the millions. This valuable hardwood tree is prized for baseball bats and tool handles and provides critical ecosystem functions in riparian areas.

Ash

Canopy thinning and dieback, epicormic sprouting (growing new branches and leaves wherever they can), woodpecker damage, d-shaped exit holes, s-shaped galleries and splitting bark

• Emerald Ash Borer Information Network ( html )
• Pest Alert ( pdf)
• US FS - Northern Research Station ( html)
• Missouri Department of Agriculture ( html)
• USDA APHIS ( html)

If you see signs or symptoms of infestation, report it immediately by calling 573-751-5505.

Oaks are the preferred host species for feeding caterpillars, but apple, sweetgum, basswood, gray and white birch, poplar, willow and many others serve as hosts. Spongy moths avoid ash, yellow -poplar, sycamore, black walnut, catalpa, locust, American holly, and shrubs such as mountain laurel, rhododendron and arborvitae. Older larvae will also feed on a number of conifers such as hemlock, pines, spruces and southern white cedar.

While they prefer oak trees, spongy moth may feed on many species of trees and shrubs, both hardwood and conifer. In the eastern US, the spongy moth prefers oaks, aspen, apple, sweetgum, speckled alder, basswood, gray, paper birch, poplar, willow, and hawthorns, amongst other species.

Teardrop-shaped egg masses are tan to yellowish and may possibly be hairy in appearance. Caterpillar can be up to 2 and 3/4 inches long with hairy black or brown bodies with five pairs of blue bumps toward the front and six pairs of red bumps towards the back. Adults show up in the middle of summer, the males are brown, have antennae and fly. Women are larger, cream colored and don't fly. Damage ranges from light leaf damage to branches stripped bare of leaves to a tree’s complete defoliation.

• Pest Alert ( pdf)
• US FS - Northern Research Station ( html)
• Missouri Department of Agriculture ( html)
• USDA APHIS ( html)

If you see signs or symptoms of infestation, report it immediately by calling 573-751-5505.

Japanese beetles have a one year life cycle and are most common from early June through late August.

Adults can feed on over 350 different species of plant, and are especially fond of flowers, overripe fruit, grapes, corn silks and soybeans.

Adults feed on leaves, buds and flowers of many plants. On leaves they eat between the veins. On flowers they eat the petals. Larvae feed on roots of grasses and damage is not immediately visible.

• Pest Alert ( html)
• APHIS ( html)
• Missouri Department of Conservation ( html)

The sirex woodwasp was introduced through imported wood products. It feeds on healthy pine trees and sires as a vector for a fungus that kills pine trees.

Pine species, including jack, red and white. Spruce, fir, larch, and Douglas Fir.

This pest is attracted to stressed trees. The problem is not the sirex woodwasp directly, but its association with the pathogenic fungus, Amylostereum areolatum, which kills the tree, making it a more suitable host for the larva. Symptoms include wilting needles, which turn downward and eventually turn red or brown. Egg laying causes the tree to produce resin flow or beading. As adults emerge, they chew round exit holes that vary from 1/8 to 3/8 inch in diameter.

• USDA Forest Service - Research and Development ( html)
• USDA APHIS ( html)

Butternut, also called white walnut, nuts are an important food source for wildlife. When butternut develops a canker, an oblong-shaped abscess that oozes, the wounds eventually cut off the trees nutrient supply and it dies.

• Northern Research Station ( HTML)
• Purdue University ( PDF)
• APHIS ( HTML)

Chestnut blight is caused by Cryphonectria parasitica. The blight fungus causes cankers, dieback and ultimately death of the aboveground portions of the tree. The first sign of the disease is cankers.

• APHIS ( HTML)
• Cornell ( pdf)

If you see signs or symptoms of infestation, report it immediately by calling 1-866-253-7189 or email badbug@pa.gov.

Oak wilt is caused by Ceratocystis fagacearum. White oak is more resistant to oak wilt than red or bur oak, but can still be killed if infected. American, Chinese, and European chestnuts, tanbark oak, and bush chinquapin are also susceptible. Susceptible trees will die within a few weeks of infection, while trees with some resistance will decline slowly for two to three years.

Signs of infection include leaf tips turning brown, wilting and falling off while still green. The die-off progresses down the tree, twigs and branches will die off. A fungal mat develops under the bark, sap-feeding and bark beetles will feed on the fungal mat and spread spores to other trees.

• USDA Forest Service Northeastern Area State and Private Forestry ( pdf)
• Missouri Department of Conservation( HTML)

If you see signs or symptoms of infestation, report it immediately by calling 1-866-253-7189 or email badbug@pa.gov.

HRD is most damaging in plantation-grown conifers (especially pine and spruce) where stumps of trees that were cut down offer a place for infection to start. Once a stump is infected, HRD spreads to other living trees through root contact underground.

• Wisconsin Department of Natural Resources ( HTML)

A phenomenon known as Sudden Oak Death was first reported in 1995 in central coastal California. Since then, tens of thousands of tanoaks (Lithocarpus densiflorus), coast live oaks (Quercus agrifolia), and California black On these hosts, the fungus causes a bleeding canker on the stem. The pathogen also infects Rhododendron spp., huckleberry (Vaccinium ovatum), bay laurel (Umbellularia californica), madrone (Arbutus menziesii), bigleaf maple (Acer macrophyllum), manzanita (Arctostaphylos manzanita), and California buckeye (Aesculus californica). On these hosts the fungus causes leaf spot and twig dieback.

• Pest Alert ( pdf)
• APHIS ( HTML)

Beefsteak is often planted as an ornamental, but easily escapes cultivated areas and has become a problematic invasive plant.

A plant in the mint family, beefsteaks can grow anywhere from 18 - 30 inches tall. The leaves are a dark green, oval shape and smell like mint. The flowers are white and purple, small and bell-shaped.

Usually establishes along riparian areas of streams and rivers, gravel bars, forest edges, roadsides, right of ways, pastures, or other disturbed areas where soils are alluvial and dry.

• USDA Plants Database ( HTML)
• Invasive.org ( PDF)
• Purdue ( html

Can grow up to 15 - 20 feet tall with white flowers from May to June, and red berries starting in September. The bark is a grayish brown and older branches are often hollow.

Adaptable to many soil types and all light levels.

• USDA FS State and Private Forestry ( HTML
• USDA Plants Database ( HTML)
• MDC ( PDF)

A pear tree, it can grow up to 50 feet in height. Often has thorns and a large number of seeds. The fruit is small, round and olive brown, appearing in May or June.

Heavy clay soils, drought prone areas, in full sun to partial shade. Spreads in open, disturbed habitats.

• Missouri Invasive Plant Task Force ( HTML)
• USDA Plants Database ( HTML)
• MDC ( HTML)

Unlike most other species, though, garlic mustard moves from disturbed areas into healthy forest. There it forms dense patches which dominate and displace native wildflowers, tree seedlings, and other native plant species of intact forests. The reduced plant diversity that comes with garlic mustard monoculture means less resources for wildlife, and, ultimately, no new trees.

In addition, the roots of garlic mustard are thought to produce a toxin that kills soil fungi many plants depend on. The seeds are about the size of a grain of mustard and can move around easily. Combine that with these seeds surviving several years in the soil and you have a plant that’s difficult to manage.

A biennial herb that grows 5 to 46 inches. First-year plant forms a rosette with kidney-shaped leaves which are green through winter. The second year, a flowering stem holds sharply toothed, triangular-shaped leaves. Crushed leaves emit a garlic-like odor. Flowers bloom in a cluster at stem’s end. Each flower has four white petals and blooms from May to June. Fruits are green capsules that turn brown as seeds mature.

Most frequent in upland and floodplain forests, savannas and along roadsides. Invades shaded areas, especially disturbed sites and open woodland. Grows in dense shade and occasionally occurs in areas receiving full sun. Spreads easily through contact; brush clothes and wash vehicles to avoid accidental transference.

• Michigan State University ( HTML)
• Cornell Cooperative Extension ( pdf)
• USDA Forest Service Northern Research Station ( pdf)
• USDA Plants Database ( HTML)

introduced to the US in 1806 on Long Island, New York as an ornamental, Japanese honeysuckle is one of the most recognizable and well established NNIS in the US. It is adapted to a wide variety of habitats and can be found from the coast of the Atlantic as far west as Wisconsin and Texas, and north to south from Maine to Florida.

A fast-growing vine that twines around stems of shrubs, herbaceous plants and other vertical supports. The leaves are paired and oval shaped up to 3 inches long. The flowers turn from white to yellow and are very fragrant. Fruits are black and appear in the fall.

Runners are prolific in open sun and will root where they touch the soil. Can be found in shade, but is not as prolific in partial to full shade. Can be found in thickets, fencerows, forest openings, rocky slopes, ditches and along roads.

• Missouri Department of Conservation ( HTML)
• National Invasive Species Information Center ( HTML)
• USDA Plants Database ( HTML)

Because of its rapid and dense growth, it alters light and moisture regimes and likely affects seed germination of other plants, creating a monoculture that is sometimes acres in size.

has thin, pale green, lance-shaped leaves, about 3 inches in length, that grow alternately along a branched stalk. The leaves have a silvery stripe of reflective hairs down the center of the upper leaf surface. The flowers bloom along a delicate spike that emerges from the stalk tips in late summer and early fall. The seeds mature in mid to late fall, and can remain viable for more than five years in the soil.

Plants are found in a range of habitats, from wetlands to early successional fields and forested uplands. Although it is a shade adapted species, it also grows in full sunlight, especially in disturbed habitats such as roadsides, powerline right-of ways, ditches, agricultural lands, lawns and gardens.

• Missouri Department of Conservation ( HTML)
• National Invasive Species Information Center ( HTML)
• USDA Plants Database ( HTML)

Sericea Lespedeza is an introduced legume native to eastern Asia. Sericea was planted in the past to control soil erosion, provide forage for livestock, and provide cover and food for wildlife. Animal movement and contaminated hay has caused it to spread into prairies, shrublands, forests and pastures where it out-competes native grasses and plants.

A perennial that can reach from 3 to 6 feet in height. Leaves alternate and are comprised of numerous three leaflet clusters. Leaves are small, green topped with white underneath and a gray-green stem

Found in forest openings and dry to wet sites. It is flood tolerant. The species spreads from plantings and seeds can remain viable for years. Dense stands are formed by sprouting from roots.

• Missouri Department of Conservation ( HTML)
• Wisconsin Department of Natural Resources ( HTML)
• USDA Plants Database ( HTML)

Spotted knapweed is a very aggressive species that can quickly infest large areas. Knapweed infestations increase production costs for farmers, degrade wildlife habitat, decrease plant diversity, increase soil erosion rate and pose wildfire hazards.

It’s a biennial or perennial growing to 5 feet with a stout tap root. It is hairy and rough, with a somewhat woolly appearance. Plants start as a rosette (cluster of radiating leaves) of deeply lobed leaves the first year and then produce flowering stems.

It can be found in meadows, pastures, rocky areas, roadsides, railroads, airports, vacant lots, hayfields, forest clearing, and near streams and rivers. It has no preference for where it takes over, and it can spread rapidly, with each plant producing up to 1,000 seeds a year, and seeds being viable for up to eight years.

• Michigan State University ( HTML)
• USDA Forest Service Rocky Mountain Research Station ( HTML)
• APHIS ( pdf)
• USDA Plants Database ( HTML)

Kudzu is a highly aggressive invasive plant which is extremely difficult to control once established. Kudzu is so aggressive it covers and smothers all other plants in its path, resulting in solid single species stands eliminating native species.

Deciduous leaves are alternate and compound, with three broad leaflets up to 4 inches across. Vines may grow as long as 98 feet. A single root crown may produce as many as 30 vines which become somewhat woody and expand out in all directions.

Kudzu grows best in well-drained degraded or eroded land or in disturbed, sandy, deep loam soils in full sun. It will, however, invade well-drained acid-soil forests as well as the floor of a closed canopy forest.

• USDA Forest Service Northeastern Area State and Private Forestry ( HTML)
• APHIS ( pdf)
• Pennsylvania Department of Conservation and Natural Resources ( pdf)
• USDA Plants Database ( HTML)

Rosa multiflora is a multi-stemmed, thorny, perennial shrub that grows up to 15 ft. (4.6 m) tall. The stems are green to red arching canes which are round in cross section and have stiff, curved thorns.

It forms impenetrable thickets in pastures, fields, and forest edges. It restricts human, livestock, and wildlife movement and displaces native vegetation. And it tolerates a wide range of conditions allowing it to invade habitats across the United States.

• APHIS ( HTML)
• USDA Plants Database ( HTML)
• Invasive.org ( PDF)

A rapidly growing deciduous tree with pale gray bark, light brown twigs and large pinnately compound leaves arranged alternately on the stem (one leaf per node). Resembles sumacs (Rhus. spp.), poison-sumac (Toxicodendron vernix) and walnuts (Juglans spp.), but differs by having two teeth at the base of each leaflet, versus many teeth in sumac and walnut, and no teeth in poison sumac. Teeth are substantially thicker than the rest of the leaflet. Crushed foliage has a distinct, unpleasant odor, not easily confused with odor of walnut leaves.

The tree of heaven is a prolific seed producer and can thrive in even the most unfavorable conditions with little management. Its rapid growth also means it can crowd out nearby native plant species, and its aggressive root system can cause damage to pavement, sewers and building foundations. It has the potential to become dominant in second growth stands in rural areas. Allelopathic compounds suppress the growth of native wildflowers and competing native trees nearby.

• APHIS ( HTML)
• USDA Plants Database ( HTML)
• Invasive.org ( PDF)

All four Asian carps were imported to North America to assist with pest control in aquaculture facilities, and have since escaped into the wild. Grass carp also are sold in parts of the United States to help control aquatic vegetation in lakes and ponds.

The primary threat from Asian carps is competition with other fish for food resources, and the likely ability of these invaders to outcompete native desirable fishes.

There are four species of Asian Carp in the US. All four Asian carps grow to large sizes approaching or exceeding 100 lbs and four feet in length. Bighead carp and silver carp feed on small plants and animals floating in the water, called plankton. Grass carp feed on rooted plants in shallow water areas. Black carp feed primarily on snails and mollusks.

Since escaping into the wild, the Asian carps have moved northward through the Mississippi River basin toward Lake Michigan and the other Great Lakes. Bighead and silver carps are now within 47 miles of Lake Michigan.

• National Invasive Species Information Center ( HTML)
• USGS ( HTML)
• US Fish and Wildlife Service ( pdf)

Brought to the US in the late 19th century as a potential food source, they have spread to many locations. In the spring the snails will give birth to young, fully developed snails.

Adult snails are over 1 ½ inches in length (snail shell length is measured from the lip of the shell to the tip of the whorl). Shell color varies from olive green to brown to reddish brown. The shell has 6-7 whorls and no banding. They have an operculum (trapdoor), which seals off the snail from adverse water conditions.

Chinese Mystery Snails achieve very high densities and adversely affects aquatic food webs. It competes with native snails for food and habitat and may contribute to their decline. They may also transmit parasites and diseases. This species also clogs screens on any size water-intake pipe, making them an economic nuisance in addition to an ecological threat.

• USGS ( HTML)
• US Fish and Wildlife Service ( html)
• Missouri Department of Conservation ( html)

All starlings are descendants of 100 birds that were let loose in Central Park (New York City) in the early 1890’s by a group of Shakespeare lovers. Today there are over 200 million starlings and they are considered a pest in many areas where it competes with bluebirds and Red-headed woodpeckers for nesting sites.

A stocky black bird with a short tail, triangular wings and long, pointed bills. Glossy in summer, developing white spots during the winter.

Cities, parks, farms, open groves, fields. Most numerous in farm country and in suburbs and cities, but inhabits almost any kind of disturbed habitat.

• Cornell Lab of Ornithology ( HTML)
• Audubon Field Guide ( HTML)
• USDA FS Research and Development ( HTML)

Wild boars look like ridge-backed, coarsely hairy dark gray-to-brown pigs. Ranging from 35 to 65 inches long and 20 to 40 inches tall, with straight 10-inch tails, and four continually growing tusks, they weigh 110 to 770 pounds. Males are larger than females. Wild boars often form herds of 20 or more animals. Wild boars are mainly active at dusk, dawn and night.

Typically moist forest, scrubland, and especially oak forest. Wild boars are sensitive to cold (less than 50 degrees F) temperatures, and are limited in travel and food finding by deep snow. Home ranges vary from 250 to 1,000 acres. Male territories are twice as large as females’. Populations can exceed 80 animals per square mile.

• Pest Alert ( pdf)
• Mark Twain National Forest ( html)
• Missouri Department of Conservation ( html)

Because the rusty crayfish are able to avoid predators fairly well, their population in aquatic ecosystems was able to grow extremely quickly and within twenty years the rusty crayfish population had exploded and become an invasive species

Unlike most freshwater crayfish, the rusty crayfish will fight back when fish attempt to eat it. The predator fish are not used to dinner fighting back, so the aggressive stance of the rusty crayfish causes the would-be predators to be scared away.

A large, aggressive, fresh water crayfish.

• USGS ( HTML)
• National Invasive Species Information Center ( html)
• Missouri Department of Conservation ( html)

One of the most widespread invasive freshwater animals in the world. Average yearly economic damage from this small bivalve is estimated at over one billion dollars a year.

In addition to filtering large quantities of microscopic algae, which impacts other aquatic species that obtain nutrition from algae, zebra mussels will smother other mollusks, causing mass mollusk extinctions. Boaters are familiar with them from buildup on boat motors and hulls, freshwater homeowners from zebra mussels building up and clogging pipes. Zebra mussels have also caused damage to water treatment and electrical plants, clogging intake valves/pipes.

Small, at only 1/4 to 1 1/2 inch-long, they have a D or wedge-shaped shell, often marked with alternating brown or yellow bands. Each mussel is male or female. Females release up to 500,000 eggs a year, which, once released into the water and fertilized, are spread by wind and water. Zebra mussels are capable of reproduction starting at 12 - 18 months.

A small fresh water mussel found in lakes, streams and ponds.

• USGS ( HTML)
• National Invasive Species Information Center ( html)
• Missouri Department of Conservation ( html)

The USDA-APHIS defines a weed as any plant that poses a major threat to agriculture and/or natural ecosystems within the United States. Although this is more specific than a typical dictionary definition (i.e. a plant growing in an undesired location), it more accurately portrays the economic and ecological impact weeds can cause on our landscapes and on the natural ecosystems we manage.

A species introduced and occurring in locations beyond its known historical range. This includes introductions from other continents, bio-regions, and also those not native to the local geographic region. Executive Order (E.O.), Invasive Species, February 3, 1999 more narrowly defines an alien species and ties the definition to an occurrence outside a native ecosystem. An "alien species means, with respect to a particular ecosystem, any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem,"(E.O., Invasive Species). Synonyms for alien species include exotic, non-native, non-indigenous, and introduced species. Of the thousands of plants that have been introduced to the United States intentionally for cultivation or by accident, approximately 4000 of these alien plant species now occur outside of cultivation. However, only about 400 of these are considered problematic with respect to adverse effects on agricultural or our native biota.

As defined in E.O., Invasive Species, February 3, 1999, a "native species means, with respect to a particular ecosystem, a species that, other than as a result of an introduction, historically occurred or currently occurs in that ecosystem." Accordingly, a species can not be considered native to a geographic region or habitat merely because it occurs natively somewhere within the continental United States. For example, White Pine ( Pinus strobus) occurs natively in the northeastern United States, and although it is planted widely in many states, it is not a native species in several of those states.

A species that demonstrates rapid growth and spread, invades habitats, and displaces other species. Species that are prolific seed producers, have high seed germination rates, easily propagated asexually by root or stem fragments, and/or rapidly mature predispose a plant to being an invasive. Alien species that are predisposed to invasiveness have the added advantage of being relatively free from predators (herbivores, parasites, and disease) and can; therefore, expend more energy for growth and reproduction.

Any living stage (including but not limited to seeds and reproductive parts) of any parasitic or other plant of a kind, or subdivision of a kind, which is of foreign origin, is new to or not widely prevalent in the United States, and can directly or indirectly injure crops, other useful plants, livestock, or poultry or other interests of agriculture, including irrigation, or navigation or the fish and wildlife resources of the United States or the public health (1974 Federal Noxious Weed Act). For example, Spotted Knapweed ( Centaurea stoebe) was accidentally introduced, through contaminated seed or ballast, into the United States in the early 1800’s and now occurs throughout the United States. It aggressively develops dense mono-cultural stands, degrades native vegetation, reduces overall vegetative biodiversity, and directly impacts wildlife by the loss of habitat and food.