What’s Eating You? Michigan’s Biting Black Fly Swarms

The Michigan black fly is small, but its bite is mighty and long-lasting. To make matters worse, these tiny terrors swim, crawl, hatch, fly, and dine together. What's on the menu? You are if you don't take the necessary steps to avoid becoming a black fly swarm's walking buffet.

Clean, Flowing Water Attracts Black Flies

Black flies lay their eggs in running water, so the shorelines and rivers of the Upper Penisula provide the perfect breeding ground. Some black flies lay their eggs in the water around Fall, allowing them to incubate until the water warms to around 40 or 50 degrees before hatching. This puts the FIRST hatch of the year sometime around mid-May to early June.

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The problem is that the black fly lives to mate and eat. Once a new generation of eggs is laid, they attach themselves to underwater rocks and hatch within 4 to 30 days. The final larval stage only lasts 4 to 7 days before the pupal stage ends, and the flying and biting begin.

The Bite That Lasts...And Itches...And Bleeds

The mighty bite of a single Michigan blackfly is horrible! The swelling, the uncontrollable need to scratch, and the blood. Black flies dine on your blood. The good news is, like mosquitos, only the females crave blood; the males prefer nectar. Bad news? The black fly population is 90% female.

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Treatment of a black fly bite, or bites, is very similar to that of a mosquito bite according to Mountain-Hiking.com:

1. Wash the area affected with soapy water
2. Use hydrocortisone cream or calamine to reduce itching and swelling
3. Avoid scratching as it may lead to an infection

Michigan Black Fly Bite Prevention and Deterrent?

Michigan State University recommends that if you're going to use bug spray, be sure it contains DEET. It is not guaranteed that it will work, and many black flies will bite you whether you're wearing it or not.

Related: Does Killing a Stink Bug Really Attract More?

Even Yoopers, as tough as they are, find black flies to be maddening. Here are some tips from AwsomeMitten.com to avoid being eaten by a swarm of hungry little blood suckers:

Wearing Protective Clothing & Gear

One of the best things that you can do to keep black flies from biting you is to wear the right clothing and extra protective gear.

Long Pants & Long-Sleeved Shirts

Since black flies can’t bite through clothing, you should wear long pants and long-sleeved shirts, tucking your clothes into each other to minimize openings. Avoid shirts with button holes, too, because they could crawl inside — zippered clothing will protect you better.

And according to scientific studies, black flies are attracted to dark colors — including black, blue, brown, and purple — so wearing light colors is the better option.

Bug Hats

Also, you’ll want to cover your head, and a bug hat — like what beekeepers wear — will do the trick. The netting will protect your ears, eyes, and mouth while still allowing you to see through. Additionally, it will prevent the flies from getting tangled in your hair.

Don't Let a Little Thing Like the Black Fly Keep You Out of Michigan's Upper Peninsula

The Upper Peninsula of Michigan is well worth the extra precautions. If you've been there, you know. If you haven't, plan a weekend trip to the UP soon. Bring a long-sleeve shirt, long socks, a bug hat, and a fanny pack (to carry your bug spray).