They're coming: Mayfly hatch expected along Mississippi River soon

Hastings is turning off the lights to "lessen the impact" of the mayfly hatch.
Publish date:

The city of Hastings is preparing for the first big mayfly hatch of the summer by turning off all the lights. 

Yes, that's right. The city starting Wednesday and continuing through the weekend will turn off lighting along streets and parking lots in the downtown area, on the bridge and along the riverfront to "help lessen the impact" of the insects, which can be attracted to bright lights during their short lives.

Mayflies can be found in almost all freshwater systems that have adequate oxygen levels (they're actually a sign that the body of water is healthy), and when its time to hatch the mayflies often do it all together, the Minnesota Department of Natural Resources website says

These large hatches are so big they have been spotted on weather radar.

Hatches happen a few times a year when mayflies emerge from the water, becoming adults only a few days later. Then they mate, the female drops her eggs back into the water, and then they die soon after, the DNR says. An adult mayfly rarely lives longer than a month.

Sometimes when they die, they all die in the same place. Their dead bodies can make roads slippery. And sometimes snowplows have to be called in to clear the dead bugs off the road. 

The city of Hastings, which is familiar with large mayfly hatches, says "Any mess on public streets and parking lot areas resulting from mayfly hatch activity will be cleaned up only during normal business hours."

Next Up