boingboing links to this story in the Milwaukee Journal-Sentinel about a cloud of mayflies in La Crosse, Wisconsin, so thick that it showed up on National Weather Service radar.
I drove through just such a cloud in La Crosse a few years ago around this time of the season. It was one of the freakiest things I’ve experienced.
The mayflies hatch along the banks of the Mississippi River, and Highway 14 runs right alongside it. The Journal reports that the flies “leave the water, and mate in a sudden burst of aerial theatrics before dying.”
At first, it was just a few amorous insects smacking the windshield. Pretty soon, the windshield was covered with mayfly goo. Then we hit the full swarm. Visibility was near zero and the crackling sound of the flies smacking the car was deafening. The windshield wipers were useless against the piling fly carcasses.
Just as I was about to give up and pull over, the swarm subsided. I directed the car into a service station and, along with a dozen other motorists, began the disgusting process of scraping the fly bodies off the windows and headlights. There was about a half-inch of build-up all over the car.
When we finally got to where we were going, I was advised to hose the car off as much as possible right then — at 11:00 pm — so that the fly paste wouldn’t bake onto the car in the sun the next day. The fly corpses were in every crevasse and cranny of the car, including under the hood. It took about an hour of spraying and scraping to get most of the rest off.
