Other Invasive Pests & Plants

Besides the Spongy Moth and the Emerald Ash Borer (EAB), there are many insects and plants that can invade our yards and woodlands. The expansion of the Forest Sustainability Program Millage language allows Program staff to monitor for and provide educational programs about Spongy  Moth, EAB, and other invasive pests. There are both native and non-natives pests that can build up to population levels that can be harmful to area horticulture.

Non-Native Invasive Pests

Non-native invasive pests are those insects and plants that do not originate in our area and can build up to intolerable levels that affect the health of our trees and cause problems for people living in areas with high populations of the pest. Most of these pests have been accidentally introduced by expanded world trade and the movement of people.

•  Asian Longhorned Beetle (Anoplophora glabripennis)
   It is not currently known to be established in Michigan, but populations of this beetle are established in New York and Chicago.

• Beech Bark Disease (Nectria fungi)
  Beech bark disease is one of the latest exotic pest problems to plague Michigan forests. Beech bark disease refers to a complex that consists of a sap-feeding scale insect and at least two species of Nectria fungi.
   

• Boxwood Blight Disease (Cylindrocladium buxicola) 
  Boxwood blight is a fungal disease caused by the organism Cylindrocladium buxicola. Boxwood Blight produces dark brown leaf spots and causes rapid defoliation that sometimes kills young boxwood. 

•  Dutch Elm Disease (Ophiostoma ulmi )
  Dutch Elm Disease (DED) is a vascular wilt disease caused by a fungus. The American elm is extremely susceptible and disease has killed hundreds of thousands of elm trees across the United States.

• Hemlock Woolly Adelgid  (Adelges tsugae)
  This is a small, aphidlike insect that threatens the health and sustain-ability of the Eastern Hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) in the Eastern United States. Hemlock Woolly Adelgid has been found in the Traverse City area of Michigan.

•  Oak Wilt (Ceratocystis fagacearum) 
  Oak Wilt is a vascular disease of oak trees caused by a fungus. The fungus enters the tree and stops the flow of water and elements by plugging the vessels in the vascular systems. The disease is most serious on members of the red oak family, though it can affect many other members of the oak family. Once a red oak becomes infected with the oak wilt fungus, it usually dies within several months.
  
  

• Sirex Woodwasp (Sirex noctillo F)
  This is a medium sized wasp that attacks non-native species of pine trees. It does not attack people. It is especially harmful to trees in overgrown pine plantations.

• Spotted Lanternfly (Lycorma delicatula)                                                                                                                                                                              This is an insect native to the continent of Asia that appeared in the U.S. in 2014. It was confirmed in southeast Michigan in 2022. The Spotted Lanternfly is a planthopper that feeds through sap-sucking. Numerous insects on an individual plant may weaken it, and when these insects feed they secrete a sticky and sugary substance called honeydew. This honeydew attracts black sooty mold, which is detrimental to plant health. 

Native Invasive Pests

• Drain Flies - Winter Pests
  

  Drain flies (family Psychodidae), also known as moth flies (they are not moths) and sewer gnats, are small gnats with large fuzzy wings. They are very commonly mistaken for fruit flies. Both are small, hang out in groups, and, in general, anger people. The drain fly did not get it's name by accident. When they are in the house, most commonly lay their eggs (10–200 of them) in the organic matter (e.g., hair, grease, food, sludge, etc.) that builds up in your drain pipes. When the eggs hatch (after two days or less), the drain fly larvae live in and eat that organic matter for somewhere between 9 and 15 days before emerging as adults. Adult drain flies are most active in the evening. During the day they spend most of their time hanging out on walls and other flat surfaces, which makes it easy to kill drain flies. The adults usually live for around two weeks. But don't be fooled into thinking the problem is gone just because the adults have died off or you've killed them. If measures aren't taken to get rid of drain fly larvae and drain fly breeding grounds, you will never be rid of them.

  • Drain Fly Fact Sheet (OSU Extenstion)
  • How To Get Rid of Drain Flies (Psychodidae)

• Pavement Ants - Winter Pests
  Pavement ants typically nest in the soil, usually under objects, such as stones, bricks, sidewalks, and driveways. When they are found during winter, they are nesting in the soil under the concrete slab. When the nest is kept warm from the building's heat, the ants stay active, move through cracks in the concrete and actively forage for food and water. Ironically, many people that see pavement ants during winter do not see them in the summer. They are common in schools at this time of year.

  • How To Get Rid of House Ants in Winter

•  Cankerworms (Paleacrita vernata)
  There are two types of cankerworms common to Michigan, fall and spring cankerworms.

• Cottony Maple Scale (Pulvinaria innumerabilis)
  This Native Invasive insect is a pest of maple trees, especially silver maples and locust trees. This pest is very common in th tri-city area of Michigan.

• Tent Caterpillar, Eastern (Malacosoma americanum (Fabricius)
  Eastern Tent Caterpillar is responsible for forming unsightly silk-webbed nests at branch forks. Their population peaks every 8 to 10 years, when large infestations can completely defoliate trees in late spring/early summer. Eastern tent caterpillar's primary host plants are wild cherry (Prunus pensylvanica), apple (Malus) and crabapple (Malus). Occasionally, they feed on deciduous forest and ornamental trees such as ash (Fraxinus), birch (Betula), blackgum (Nyssa sylvatica), willow (Salix), witchhazel (Hamamelis), maple (Acer), oak (Quercus), poplar (Populus), cherry (Prunus), peach (Prunus), and plum (Prunus).

• Twig Pruner(Elaphidionoides villosus)
  The twig pruner cuts through the twig from the inside, but leaves the bark intact. For a short time, the injured branch remains on the tree, but eventually succumbs to the wind, breaks off and falls from the tree. A small, oval-shaped hole in the end of the branch is a tell-tale sign of the twig pruner. Look closely for this hole because the larva usually packs the opening with a frass plug to keep out predators and other unwanted guests. Twig diameters at the point of the cut usually range from about 3/8 to 3/4 of an inch. Common host trees are reported to include oak, hickory, pecan, walnut, basswood, redbud and hackberry. 

• Webworm, Fall (Hyphantria cunea)
  Fall Webworm feeds late in the season on nearly 100 different species of trees in North America. These caterpillars construct massive silk webs and prefer persimmon, sourwood, pecan, fruit trees and willows. The webs are unsightly in the landscape and generally more numerous when the weather has been warm and wet for extended periods. The insect thrives on sun and moisture. The fall webworm is usually of only minor economic importance as a forest pest.

 Invasive Plants

• Buckthorn - Common Buckthorn (Rhamnus catarticus) and Glossy Buckthorn (Rhamnus frangula)
  Small shrub or trees that invade wood lots. Is becoming common in Bay County. It crowds out native plants and inhibits natural regrowth of native trees in wooded areas. 

• Garlic Mustard (Alliaria petiolata)
  This is an exotic invasive plant from Europe that invades woodland habitats in North America and impacts forest biodiversity. This plant invades fields and open wood lots crowding out and shading native plants.

• Giant Hog Weed
  Giant hogweed (Heracleum mantegazzianum) actually look like a beautiful architectural addition to the landscape. The plant was introduced from Eurasia by plant collectors in the early 1900s for arboretums and gardens. Reaching a mature height of 6 to 12 feet, giant hogweed may be aptly named, but can be difficult for the outdoor enthusiast to identify. For more information about the Giant Hog Weed, please click HERE.

• Phragmites, Non-Native (Phragmites australis) - also known as Common Reed
  European strain of the common reed that invades wetland, roadside ditches and lake margins. It can crowds out native plants such as cat tails and our native stains of Phragmites.  Check out the Phragmites Location in Michigan Map.

• Purple Loosestrife - General (Lythrum salicaria)
  Since it was introduced, purple loosestrife has spread westward and can be found across much of Canada and the United States. Purple loosestrife grows an impressive four to seven tall. It grows prolifically in wetlands and other moist areas. Each mature plant produces 30 or more spikes and can produce over 2.5 million seeds per year.