Mathematics Explains Mysterious Midge Behavior

Here’s a place that’s unlikely ever to be a vacation spot for Yankee pitcher Joba Chamberlain: Lake Myvatn, in Iceland.

Midges, baseball fans recall, are the gnat-like insects that rose from Lake Erie last October and descended upon Chamberlain in the bottom of the eighth inning of a playoff game against the Cleveland Indians, distracting him into throwing two wild pitches. Cleveland scored the tying run without a hit. The Yankees eventually lost the game and eventually the series.

During mating season, the air at Lake Myvatn can also be thick with male midges, each hovering, waiting for a female to join him. “It’s a like a fog, a brown dense fog that just rises around the lake,” said Anthony R. Ives, a professor of zoology at the University of Wisconsin.

Yet at the same time in other years, hardly a midge was to be seen at the lake. This boom-and-bust cycle — the density of midges can rise or fall by a factor of a million within a few years — drew the interest of ecologists like Dr. Ives.

In the current issue of the journal Nature, Dr. Ives and colleagues report that the population fluctuations depend largely on the abundance of hard-shelled algae known as diatoms, which the midges feed on, and that the complex dynamics can be captured within a simple equation.

The equation also suggests a fragility of nature — how a small, seemingly harmless action can ripple through the ecosystem and lead to unforeseen disruptions.

Read the full New York Times story here.