Grant Truskowski and Kara Ermatinger, dressed for the cold, met at the Ludington School Forest disc golf trailhead off Jebavy Drive, not looking to work on their golf game Wednesday.
The two Mason-Lake Conservation District seasonal employees were surveying the roughly 150-acres of land for the hemlock woolly adelgid (HWA), an insect the size of a pepper flake on the underside of a hemlock tree.
Hemlock woolly adelgids are tiny insects from Asia that feed on the sap of hemlock trees, spinning white, waxy ovisacs to protect their eggs. Over time, their feeding kills needles, branches and whole trees. These insects are considered invasive because they are not native and can cause significant harm to Michigan’s hemlock resource, estimated at 170 million trees.
The survey for the HWA began in early December and runs into April, according to Truskowski, who, along with Ermatinger, has surveyed nearly 2,000 acres of both private land and city and township parks to date.
“We have roughly 1,800 acres left to survey,” Ermatinger said.
Truskowski who received a natural resources management degree from Grand Valley State University has field work experience is aquatics, streams and rivers, but said this seasonal position was a natural transition toward forestry and the pest-related field.
Ermatinger has a biology degree from Northern Michigan University and has always been interested in anything to do with plants and animals. She learned about and became interested in HWA while working with the Ottawa Conservation District last summer and was able to assist on HWA treatments while in that position.
With this position in Mason County, she is learning the surveying side of HWA.
Truskowski said the survey crew tries to stay within five miles of the lakeshore because that is where the bulk of it has been found.
“When we originally scout out an area to survey,” he said, “we start there, send out permissions to land owners. When those permissions begin to filter in, that is when will we head out to do a survey.”
During Wednesday’s survey, both Truskowski and Ermatinger already knew the property had hemlock trees based on a survey and data from last year.
The crew headed to the south west corner of the property to where a cluster of hemlock trees were located.
When the two are out surveying and they believe they covered an acre of land, they take a data point on Survey 123, a field data gathering program that makes sharing and analyzing surveys possible. The program provides a GPS point and data about the area such as the number of trees, according to Ermatinger.
“We do not really check more than 30 trees in an acre,” she said.
Ermatinger said when they walk up to a tree, the first thing they do is look on the underside to a branch.
“We look specifically at four branches, one in each cardinal direction,” she said. “We try to pick branches that are about 5 feet off the ground and then look up to see if we can see anything.”
Where the pine needles meet the branch that is where you will find the ovisacs. They appear as white and cottony and are about the size of the tip of a pen. It is about a quarter of the size of a spider sac with tiny spots on it.
The survey is done in the winter because that is when it is the easiest to see the invasive species, according to Truskowski.
The invasive species was found last year in Mason County and the winter surveys will continue during the winter months as a way to combat the disease.
“The first instances of this insect in Mason County was found last winter at a property owned in Summit Township,” said Dani McGarry, executive director Mason-Lake Conservation District. “We are working in conjunction with the (Department of Natural Resources), and it was DNR staff that found that last year.”
The DNR also reported that the invasive species was found within Ludington State Park in October 2020.
“Even when a tree is super-infested, that does not mean it will be on all four sides. It could be super-infested on one quarter of the tree all the way up,” said Ermatinger. “There can be one ovisac on one branch on one tree in the whole entire 200 acres we are surveying.”
It is that tiny. Like finding a paper flake in a hay stack.
Invasive hemlock woolly adelgid found in northern Benzie County
The Michigan Department of Agriculture and Rural Development recently verified a new detection of invasive hemlock woolly adelgid at the Sleeping Bear Dunes National Lakeshore in northern Benzie County.
To date, a survey of the surrounding area has found just one infested tree in the Platte River Campground, a popular destination within the national lakeshore.
With support from the Great Lakes Restoration Initiative, national lakeshore staff began surveying high-use areas throughout the park in January, looking for the invasive insect.
The survey crew worked alongside a team from the Northwest Michigan Invasive Species Network (ISN), which has been surveying hemlock trees within 5 miles of Lake Michigan since 2018 as a part of a Michigan Invasive Species Grant Program early detection project.
On Feb. 4, surveyors found round, white ovisacs characteristic of the hemlock woolly adelgid on one tree in the Platte River Campground. A sample sent to the U.S. Department of Agriculture was verified the following day.
Michigan has been combating hemlock woolly adelgid since 2006 and has current infestations in Allegan, Ottawa, Muskegon, Oceana and Mason counties.