Invasive Species Strike Team
The Invasive Species Strike Team is a five-person crew that operates out of the Ottawa Conservation District office from May through October. This team serves the West Michigan community by providing information, identification, and eradication efforts for high-threat invasive species. The goal of this work is to prioritize early detection and rapid response of invaders to prevent widespread establishment.
The Invasive Species Strike Team is primarily funded by grants from the Michigan Department of Natural Resources and United States Forest Service. These grants allow the crew to provide survey, treatment, and monitoring services for several Watch-List, Prohibited, and Restricted plant species designated by the State of Michigan. Some of these species include:
- Japanese knotweed (Fallopia japonica)
- Chinese yam (Dioscorea oppositifolia)
- Swallow-wort (Cynanchum louiseae)
- European frog-bit (Hydrocharis morsus-ranae)
- Yellow floating heart (Nymphoides peltata)
- Flowering rush (Butomus umbellatus)
However, with recent budget cuts to our grants, our Strike Team also relies on landowner investment to sustain management efforts.
The crew also offers service to remove invasive species that are not covered by these grants. This service is expected to be paid for in full by the landowner.
To learn more about our West Michigan Cooperative Invasive Species Area group, upcoming events and trainings, and local partners, click here.
Invasive species are a serious threat to ecosystem biodiversity. They are known to out-compete natives for resources and have potential to monopolize an area if not controlled. The Ottawa Conservation District encourages landowners to contact us or their local natural resources professionals to assist in identifying and/or managing unwanted exotic species. For more information on invasive species, visit michigan.gov/invasives .
Please contact our West Michigan Cooperative Invasive Species Management Area Coordinator, Joe Vander Yacht, for more information on available funding for invasive species treatments.
Hemlock Wooly Adelgid (HWA) Project
The Hemlock Woolly Adelgid Crew is working to control and eradicate hemlock woolly adelgid (HWA): an invasive insect that feeds on and kills Eastern hemlock (Tsuga canadensis) trees.
In 2017, the Ottawa Conservation District was a sub-recipient of Environmental Protection Agency funds awarded to the West Michigan Shoreline Regional Development Commission. This money was used to conduct extent surveys and record presence of HWA infestations throughout Lake Michigan’s coastal zone. Some of these funds were also used to hire a contractor to begin treatments of HWA. Now, we are building off that work with Michigan Invasive Species Grant Program funds to continue to survey as well as take on treatments of HWA internally. Our team has been working primarily in Oceana County to target the northernmost known HWA infestations. The goal of this work is to cap the northernmost populations to prevent this insect from invading our valuable hemlock resource in the Upper Peninsula. We will continue to move our efforts south as funding allows. Local landowner investment helps us build capacity to take on additional HWA management.
The effort to slow the spread of HWA and protect stands of hemlock trees will strengthen Michigan’s natural forest ecosystem. The loss of the hemlock tree would increase the effects of climate change by allowing the forest temperatures to rise, which would be detrimental to wildlife, as well as the beauty of our natural forests. It would also adversely affect the outdoor recreation economy, especially in northern Michigan.
Hemlock Woolly Adelgid: What is it?
Hemlock woolly adelgids (HWA) are tiny insects native to Japan. Found in the eastern United States in 1951, HWA has since spread to 16 states, from Georgia to Maine, including Michigan. Specifically targeting hemlock trees as their food and reproductive source, HWA sucks moisture and nutrients from a hemlock’s needles and shoots. HWA can be found feeding at the base of needles where they attach to woody shoots and are best seen on the underside of a branch.
Measuring 1.5mm in length, HWA is difficult to see but can be identified by finding the white, woolly masses, called “ovisacs.” These protective masses, which cover the insects and their eggs, are most detectable in late fall through spring. HWA asexually reproduces and complete two life cycles per year.
How HWA Spreads
HWA can move from tree to tree by coming into contact with:
- Birds and wildlife
- Recreational vehicles
- Equipment and field gear
- Infested nursery stock
Michigan has over 170 million hemlock trees growing in forests, along streams and riverbanks, and in landscapes throughout the northern lower peninsula and the upper peninsula. Hemlocks are some of the oldest living trees in Michigan, providing important habitat and winter cover for many species.
Signs of Infestation
First, identify any hemlock trees on your property. Hemlocks have:
- Needles that are flat and are attached individually to the branch, not in bunches like pines
- Flat needles are roughly a 1/2″ long
- Two white “racing stripes” on the underside of each needle
- Tolerance to shade
Once you have identified hemlocks on your property, check for these signs of infestation:
- White, cottony masses about 1/4 the size of cotton swab attached to the twigs, at the base of needles on underside of branches
- Needle loss and branch die back, no new growth
- Gray-tinted foliage