Michigan seeks help tracking these two invasive species

Michigan seeks help tracking these two invasive species

Gregg Krupa | The Detroit News | 12/02/2020

The state is urging awareness of two invasive species: A fast-growing weed that could eventually threaten Christmas tree farms and nurseries, and a colorful little fly that could threaten crops like grapes, apples and hops.

The state Department of Natural Resources, and Department of Agriculture and Rural Development recently confirmed the presence of the mile-a-minute weed — also known as Asiatic tearthumb — at the Whitehouse Nature Center of Albion College.

The barbed vine, native to Asia — including India and the Philippine Islands — had been unknown in the state.

It can enshroud juvenile trees and shrubs.

Also, after confirming that three dead spotted lantern flies were found on shipments of products to the state in recent weeks, the Michigan Department of Agriculture and Rural Development is asking freight carriers, warehouse workers and delivery drivers to be on the lookout for the insects.

Spotted lantern flies suck sap from plants and secrete large amounts of a sticky, sugary liquid, honeydew.

The result can be black, sooty mold that kills plants, fouls surfaces, and attracts hornets, wasps and ants.

Patterns on spotted lanternfly’s wings
No live lantern flies have been found in the state.

“The mile-a-minute weed, we are really concerned about; it can spread rapidly and one of the things threatened would be Christmas tree farms,” said Joanne Foreman, coordinator of the Invasive Species Program for the state.

“It produces a lot of fleshy fruit that is attractive to birds and mammals, so that suggests a very easy spread even from long distances away from original plants,” Foreman said.

Doug White, a professor of ecology at Albion College, discovered a patch of the mile-a-minute weed Oct. 3 in a forest opening while surveying house wrens.

“I’m not normally out there in October. But we color-banded nestlings this year, and I was following the fledglings,” said White, whose said his dissertation was on bird-dispersed fruits.

“I saw these purple and blue fruits on a plant, and I was curious.”

After taking photographs and doing some research, White realized what it might be and contacted the state.

The mile-a-minute weed is an annual vine that can grow up to six inches in a day, 25 feet in six to eight weeks.

Its light green leaves are shaped like equilateral triangles, state officials said, and both the stems and leaf blades are lined with small, recurved barbs that help it climb over other vegetation

It buds small white flowers in spring and eventually pea-sized blue fruit in midsummer.

Often, circular leaves, ocrea, grow from the stems below the fruit, they said.

The mile-a-minute weed grows in open areas, like roadsides, banks of rivers and streams, the edge of forests and along fence lines.

Susannah Iott, a specialist on invasive species at the Department of Agriculture and Rural Development, said the weed first got to the United States in the 1930s in a shipment of contaminated nursery stock.

“It is present in a lot of states in the northeast, and they’re working on getting rid of it,” Iott said. “It was on our watch list, and we’re particularly concerned because it grows in these dense, heavy thickets that can easily overtake native vegetation.”

No further evidence of the mile-a-minute weed has been discovered, the officials said, and the state has employees looking for it and will continue to do so in the spring.

Local groups are spreading word of the discovery and information about detecting the plant in Calhoun and nearby counties.

The weed can be removed by hand. But seeds may then persist in the soil for up to six years, state officials said. Infested sites must be monitored after removal.

If residents discover what they believe is mile-a-minute weed, they should take a photograph, note the date, time and location, and use the online reporting tool of the Midwest Invasive Species Information Network, officials said.

They may also download an app to report it from a phone at MSU.edu/Tools/Apps/#home, or contact Iott at IottS@Michigan.gov or 517-420-0473.

The spotted lantern fly has been on officials’ watch list for some time, and finding the remains of them on two recent shipments to the state is worrying, officials said.

“The largest infestation is in Pennsylvania, but just this summer it was confirmed in Ohio,” Foreman said. “So we’ve been watching for this and doing what we can to prepare.”

The dead flies were discovered by the U.S. Department of Agriculture during a routine inspection of a shipment to a nursery in Kent County, and at a warehouse in Wayne County, by workers concerned enough about something they had not seen before to contact the state, she said.

No live spotted lantern flies were found. No egg sacks were found. But the remains of three dead adult flies, one at the nursery and two at the warehouse, have officials concerned.

“This tells us exactly what we were anticipating but hoping wouldn’t happen,” Foreman said. “We’re starting to see these bugs show up in shipments from areas that are infested, and it could be from areas where the infestation is not even known.”

They do not fly far, so the way they will enter the state is by sacks of eggs they attach to objects, including the underside of vehicles, or by attaching to shipments, she said.

The state and federal departments of agriculture have investigated after both discoveries, including along the paths of the shipments through Michigan.

“Let me be clear that to date we have no evidence that we have populations of spotted lantern flies in the state of Michigan,” said Robert Miller, an invasive species specialist for the state Department of Agriculture and Rural Development.

“But spotted lantern flies are an invasive species that pose a threat to our agricultural products, including our grape growers on the west side of the state. Spotted lantern fly is a significant pest of grapes,” Miller said. “It can also be a problem just in the general landscape, and for homeowners.”

Other crops that would be threatened include apples, hops and hardwood trees.

As they feed on plants, the flies both deprive the plants of nutrients and fluids and, in large enough numbers, weaken plants, making them susceptible to other pests or diseases.

They also eject the waste, the honeydew, which provides for the growth of black sooty mold, which can cover leaf surfaces, sidewalks, garages, vehicle and outdoor furniture with “a sticky, foul-smelling material,” Miller said.

About an inch long, spotted lantern flies’ wings are gray to brown with black spots when folded, state officials said. When open, the wings reveal a yellow and black stomach and bright red hind wings with black spots transitioning to black and white bands at the end.

The egg masses look like chewing gum, with a gray, waxy, putty-like coating, they said.

State officials ask that residents photograph any suspected spotted lantern flies, note the date, time and location, and report it to MDA-Info@Michigan.gov or call the agriculture department at 800-292-3939.

Additional information on identifying or reporting the spotted lantern fly is available at Michigan.gov/SpottedLanternfly.

Actions like those of the warehouse workers in Wayne County are something the states seeks to encourage.

“We’re excited about the vigilance so far,” Foreman said. “But this is the kind of thing we want people across the state to do, whether it is spotted lantern fly, or something else.

“If you see something that just doesn’t look right, get in contact with us.”

gkrupa@detroitnews.com

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