Towering swarms of nonbiting flies called midges are blanketing Chicago: ‘A little disturbing but cool’

No, you’re not imagining those 10-foot-high insect clouds hovering near Lake Michigan, each teeming with thousands of mosquito look-alikes.

Chicago, we’ve got midges.

They don’t bite, they don’t harm humans, and they emerge from lakes, streams and puddles every year like clockwork, but the cold gray spring of 2022 has spawned — Wouldn’t you know it? — a noticeable population surge.

Chicagoans report swallowing midges on lakeside runs, picking them off their window screens and driving with open car windows to air out the interlopers.

“I felt like I was in a plague,” said Peggy Stenger, of the Printers Row neighborhood, who didn’t realize she had parked in a midge swarm until her windshield was covered in insects.

It’s unclear exactly why this is such a good year for midges, according to Allen Lawrance, an associate curator of entomology at the Peggy Notebaert Nature Museum, who noted he was speaking from an office with a window screen covered in — you guessed it — midges. Midge populations can be affected by weather, climate, disease and predators.

“This year we’re seeing a pretty big outbreak,” Lawrance said.

Midges serve an important role in local ecosystems: Their arrival coincides with the peak of spring songbird migration, and they provide food for a wide range of birds, including flycatchers, warblers, sparrows, blackbirds and vireos.

In one of the more spectacular midge-related phenomena of 2022, birders from the South Side to Evanston have seen swallows swarming by the hundreds to catch midges in midair.

“It looked like a tornado of swallows,” said Kat Jercich, a writer and editor who saw swallows feeding on midges at Montrose Point Bird Sanctuary.

In a phone interview conducted from his deck in Evanston, Josh Engel, a professional birding tour leader, said he could see a cloud of thousands of midges hovering, even as he spoke. He estimated that he’s seen millions over the last few days.

“It’s a really neat natural history phenomenon that we get to witness around here,” he said.

As for the seemingly infinite number of midges that covered railings at a Northwestern University parking lot during Engel’s recent visit: “It was pretty cool to see — a little disturbing, but cool.”

There’s a reason midges are found near the lake. Females lay eggs near water, and the larvae actually live on the bottoms of lakes, rivers — even puddles. Like butterflies, midges go through a complete metamorphosis, Lawrance said, emerging from a pupal phase before the adult flies away.

Midges can grow in saltwater and in areas with pollution and poor water quality. While they are seen mostly in summer in this region, there are some species that can fly in winter.

“There’s even a species that lives in Antarctica — so they’re pretty hardy creatures,” said Lawrance.

For midges, swarming in big clouds is actually a mating behavior; the males emerge a little earlier than the females and start to gather. Females fly into the swarms and mate with the males.

Midges only live about three to 11 days, and Lawrence expects that the current population surge will die down in about 10 days, with more midges arriving over the course of spring and summer.

“I can’t necessarily say we’re going to see another emergence this big — I think the conditions are kind of right (at the moment),” he said.

Jercich, a Rogers Park resident who birds and runs along the lake, has seen remarks about the midges on social media, many of them along the lines of “Oh man, I’m really eating bugs today.”

“People are definitely chatting about them — it’s the talk of the town,” she said.

It’s not ideal to run headlong into a cloud of insects with your mouth open, she said, but she is happy the birds have an abundant food source and grateful for a sign that winter is on the wane.

If the midges are here, can warmer temperatures be far behind?

nschoenberg@chicagotribune.com

nschoenberg@chicagotribune.com