Latest Information on Invasive Species in Michigan
Giant Hogweed
How Do You Know If It's Really Giant Hogweed? A number of common plant species resemble Giant Hogweed, but there are ways to tell them from the real thing. Here are a few guides you may find useful:
If you have seen a plant that appears to be Giant Hogweed, and need help identifying it email to MDA-Info@Michigan.gov, along with any pictures, so that it can be examined by professional staff of the Michigan Department of Agriculture & Rural Development. You can also call 1-800-292-3939.
Giant Hogweed is a public health hazard that ranks up there higher that poison ivy, poison oak and poison sumac in respect to its potential to harm humans. The reason for concern is that the sap from this plant can cause a severe skin reaction known as photo-dermatitis or photo-sensitivity. The reaction can happen up to 48 hours after contact. After coming in contact with the sap, the skin blisters when exposed to sunlight. Contact with the eyes can lead to temporary or possibly permanent blindness. The weed can be especially troublesome for children that may find the long stems attractive to play with. There are accounts from Great Britain about instances where children suffered from severe skin reactions after playing with the hollow stems as pea-shooters, telescopes and even play swords. If you do come into contact with the plant, and especially the sap, you are advised to wash the affected areas immediately, keep the exposed area out of direct sunlight and seek medical advice.
Besides these public health concerns, Giant Hogweed is also reported to be invasive under certain conditions. It does especially well in disturbed soils and also along waterways where seeds can be spread long distances. Large colonies have been known to form from a single plant, where an abundance of seeds coupled with shoots arising from the roots gives rises to dozens of offspring. Weed specialists have reported that once it becomes established it takes up to five years to completely get rid of a colony due to regrowth from seeds and roots.
This unwanted plant is found on the Federal Noxious weed list. This means that it is illegal to sell or transport it across state lines, a violation punishable by fines. Florida, North Carolina, Oregon and Washington also regulate giant hogweed as a noxious weed.
Giant Hogweed was introduced into North America in the early 1900s. Its native range is Central Asia, although now it now occurs throughout the United Kingdom, Australia, Europe, parts of Canada and the United States. It is suspected to have made its way into this country as an ornamental. Its size made it somewhat of an oddity and gardeners that wanted something unique imported it.
Giant Hogweed has been confirmed in 11 counties in Michigan: Branch, Calhoun, Gogebic, Ingham, Jackson, Kalamazoo, Kent, Manistee, Oakland, Ottawa and Saginaw. The rest of Michigan should be watchful for this species. It's reported distribution in North America includes Maine, Michigan, New York, Pennsylvania and Washington in the U.S. and in the Canadian provinces of British Colombia and Ontario. Small colonies of giant hogweed have recently been found in Indiana, Maryland, Ohio and Vermont where eradication is underway.
If you have seen a plant that appears to be Giant Hogweed, report it via email to MDA-Info@Michigan.gov, along with any pictures, so that it can be examined by professional staff of the Michigan Department of Agriculture & Rural Development. You can also call 1-800-292-3939.
A few informative web sites are:
Hemlock Wooly AdelgidExotic Hemlock-Killing Insect Found in Berrien County: Infestations confirmed in New Buffalo
April 4, 2012 - Today, the Michigan Department of Agriculture and Rural Development (MDARD) confirmed an infestation of the hemlock woolly adelgid (HWA) in Berrien County. This is the first confirmation of HWA in Berrien County.
HWA is a small, aphid-like insect that uses its long, siphoning mouthparts to extract sap from hemlock trees. Native to eastern Asia, HWA was discovered in Virginia in 1951, and has since spread over an area from Georgia to Maine, decimating hemlock stands across much of the eastern U.S. Heavy infestations of HWA have killed trees in as little as four years.
The initial positive site in New Buffalo was discovered by an alert landscaper who reported his suspicion to the Michigan Department of Natural Resources (DNR). DNR informed MDARD which initiated a survey of all hemlocks trees within a half mile of the positive site and second positive site was discovered. Surveys will continue in the area to determine the full extent of the infestations. Minimally, infested trees will be removed and destroyed; and hemlock trees in the area surrounding the infested trees will be treated with an approved insecticide.
Michigan law restricts the movement of hemlock into the state, and includes a complete ban on the movement of hemlock from infested areas. Read MDARD's "Hemlock Woolly Adelgid Quarantine" here.
Read the full press release here. (Photos courtesy of the USDA Forest Service. Additional photographs can be found here.)
People who live, work and play in the area of concern should be aware that the movement of hemlock materials (trees, branches and twigs) could spread HWA. At this time, hemlock materials should not be removed from the property from which they originate. Also, it is recommended that no hemlock trees be brought into the area of concern as they run the risk of becoming infested. The area of concern is roughly described as the area bounded by S. Red Arrow Hwy. to the east, Townline Avenue to the north, Lake Michigan to the west and a line between the intersection of Arbor and Marquette Dr. and the intersection of Hwy. 12 and S. Red Arrow Hwy to the south.
Map of area of concern can be found here.
Watch MDARD's video about the Hemlock Wooly Adelgid here.
ADDITIONAL INFORMATION FROM THE USDA FOREST SERVICE
Native to Asia, the hemlock woolly adelgid (Adelges tsugae) is a small, aphidlike insect that threatens the health and sustainability of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana) in the Eastern United States. Hemlock woolly adelgid was first reported in the Eastern United States in 1951 near Richmond, Virginia. By 2005, it was established in portions of 16 States from Maine to Georgia, where infestations covered about half of the range of hemlock. Areas of extensive tree mortality and decline are found throughout the infested region, but the impact has been most severe in some areas of Virginia, New Jersey, Pennsylvania, and Connecticut.
Hemlock decline and mortality typically occur within 4 to 10 years of infestation in the insect's northern range, but can occur in as little as 3 to 6 years in its southern range. Other hemlock stressors, including drought, poor site conditions, and insect and disease pests such as elongate hemlock scale (Fiorinia externa), hemlock looper (Lambdina fiscellaria fiscellaria), spruce spider mite (Oligonychus ununguis), hemlock borer (Melanophila fulvogutta), root rot disease (Armillaria mellea), and needlerust (Melampsora parlowii), accelerate the rate and extent of hemlock mortality.
Read the full Pest Alert for the Hemlock Woolly Adelgid here.
