Think Chicago’s Recent Midge Swarms Are Wild? You Ain’t Seen Nothing Yet

A midge swarm on Lake Erie. (National Oceanic and Atmospheric Administration)A midge swarm on Lake Erie. (National Oceanic and Atmospheric Administration)

Swarms of gnat-sized midges have been reported along Chicago’s lakefront in recent days.

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It’s mating time for the tiny bugs, which hatch in the water every spring and live for less than two weeks. A WTTW producer captured hordes of the insects swirling into formations above Wilmette and Evanston over the weekend, the plumes resembling smoke.

Video: A swarm of midges is captured in Evanston on March 30, 2022. (Jen Cotto / WTTW News)

The swarms consist almost entirely of males, which makes it easier for them to attract the ladies’ attention. 

While midges have been uncommonly numerous in Chicago this year, other cities along the Great Lakes, including Toronto, are accustomed to the annual crowds.  

“Hold my beer,” interjects Iceland, where Lake Myvatn translates as Midge Lake. Midges are found in such huge numbers there, researchers report that in high emergence years the insects’ dead carcasses can contribute 55 metric tons of dry biomass to the soil.

Watch this modern-day Viking sail straight into the eye of a Lake Myvatn midge hurricane.

Despite their mosquito-ish appearance, midges, also known by the nicknames mucklehead or mufflehead, don’t bite. And while humans might get grossed out inhaling a mouthful of them during a lakefront jog or bike ride, midges are the perfect meal for all the birds migrating through the city.

But midges are just one of the water-loving insects that hatch in the Great Lakes region every spring. They’re often confused with mayflies, which are significantly larger.

If you want to talk swarms, mayflies show up on radar. Indeed, a study of mayflies rising up over Lake Erie counted nearly 90 billion of them. In a single night. Fish and other freshwater wildlife will gorge on the buffet.

Here’s what it looks, and sounds like, to be in the middle of a mayfly swarm.

These adult mayflies live to mate — lacking mouths and digestive systems, they don’t even eat — and die within days.   

Though it’s been decades since Chicago’s witnessed an explosion of mayflies, up until the late 1930s, dead mayflies were known to pile up several inches deep on DuSable Lake Shore Drive, according to the University of Illinois Extension.

But plenty of towns, including along the upper Mississippi and lakeside communities in Ohio, still deal with annual mayfly swarms and subsequent die-offs, occasionally bringing in bulldozers to shovel up the remains. Pro tip from entomologists: Dab a little Vicks VapoRub under the nose to mask the scent of decomposition.

Speaking of stench, let’s not forget the June beetle grub infestation of 2021 that destroyed the grounds of Welles Park in Lincoln Square (and to a lesser extent nearby Winnemac Park).

The grubs, the product of adult June beetles mating in early summer, surfaced in the tens of thousands. Countless numbers of them baked to death on the pavement, to putrefying effect.   

Piles of decaying beetle grubs at Lincoln Square's Welles Park. (Patty Wetli / WTTW News)Piles of decaying beetle grubs at Lincoln Square's Welles Park. (Patty Wetli / WTTW News)

From one year to the next, it’s impossible to predict whether conditions will lend themselves to a boom or bust in terms of insect swarms or random infestations. But broods of periodic cicadas can be relied on to emerge like clockwork.

Chicago dodged 2021’s brood, but the countdown is on for 2024, when a brood of 17-year cicadas is set to surface across all of northern Illinois. 

Contact Patty Wetli: @pattywetli | (773) 509-5623 |  [email protected]

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