HASTINGS, Minn. -- Mayflies have long been a sloppy seasonal presence
in Hastings, where the Mississippi River proves to be an excellent
But residents awoke Monday morning to what some are calling the
biggest hatch in a decade or more, resulting in a slippery, smelly mess.
Hastings Police Chief Paul Schnell says so many mayflies descended on the Highway 61 Hastings bridge that they triggered a crash.
"Minnesotans are accustomed to a variety of road conditions," Chief
Schnell told KARE. "But the last thing we'd expect would be a thick
layer of insects on the roadway."
One driver spun out on the bridge, due to the slick coating of dead
mayflies, and careened across the centerline of the two-lane, undivided
roadway into an oncoming car.
Fortunately the injuries were minor, and state and local authorities
could focus on the huge clean-up job at hand. MnDOT sent out a plow to
scrape all the mayflies off the roadway, and laid down some sand to give
motorists better traction.
"The City shut off all the lights downtown," Hastings insurance agent
Steve Johnson told KARE. "But I had a snow drift of mayflies in front
of my office this morning. I used a shop vac to clear them all off."
When KARE encountered Johnson he was taking his mother's car to a
service station automatic car wash, in hopes he could remove scores of
mayflies that had been sun-baked onto the hood and roof.
"It was parked under a light last night, and was covered in
mayflies," he explained. "These are just the ones that were blown off
by driving the car around town."
Across the street high school student Matt Boogren was sweeping
up dead mayflies in the parking lot of the Holiday convenience store
where he works.
"I've been out here at least four hours," Boogren told KARE. "The
sidewalk was covered with bodies of flies. We'll have to clean the
windows too, because they were coated this morning."
The good news is that the siege won't last long.
The insects, which spend most of their one-year life span in the
water, live only one to two days after sprouting their wings and taking
flight. And they have one thing on their minds during that short burst
"They really have one task, and that is to find a date and mate,"
Jeff Hahn, a long-time University of Minnesota entomologist, told KARE.
"Both the male and females die shortly after that. It's like speed dating. They don't have any time to lose."
The adult females lay eggs before they die, which begins the mayfly life cycle all over again.
Hahn said the "mating swarm" experienced by people in the Hastings
area Sunday night was more concentrated than usual. That created a
virtual "insect cloud" around the bridge, where the lights were left on
And, while the bugs be a temporary nuisance in river towns such as
Hastings, huge swarms signal something positive in the environment.
"They are really good indicators for water quality," Hahn said. "That
means the river is doing pretty good if we have such an abundant number