Bug bites don’t normally have much long-term affect on me. Oh, I’ll swat at a biting mosquito, deer fl, or the tiny little pirate bugs of late summer (no-see-ums). I’m fortunate because I don’t generally swell up or have itchy bumps afterward. Black flies are the exception. Their bites swell up and stay itchy for several days. I’ve had plenty of black fly bites up north in the canoe country where late spring and early summer is often known as “black fly season.” These little flies often form pesky swarms around your head even if they’re not biting. Their bite is stealthy, too. You don’t feel them land and you don’t feel the initial bite. I don’t know I’ve been bitten until several hours later when the itch and swelling starts. Some people react more intensely to black fly bites with severe swelling around the bites, swollen glands in the neck and headaches. I have seen eyes swollen clear shut. The condition isn’t caused by an infectious agent like a virus or bacteria, but it’s still called black fly fever. Black flies are known to transmit several diseases to birds and animals. They’re being blamed for the deaths of the famous little Decorah baby eagles this year. They aren’t known to transmit disease to people here in North America.


We don’t normally have large hatches of black flies around here, but this year we’re seeing more of them than usual. There have even been alerts posted for people with poultry and other livestock. Another name for the little pests is buffalo gnats, and they will pester cattle and horses. I don’t recall ever having been bitten by them around here, but there are several itchy bumps on the back of my neck near the hair line (a favorite spot to bite). I actually swatted one on my ear and was able to recognize it as the same little demon that has plagued me so often up north. Like mosquitoes, it’s the female that bites us. She needs a blood meal from some kind of warm-blooded critter in order for her eggs to develop. Mosquitoes are pretty much homebodies that may live their entire life cycle on a few acres, but a female black fly can fly up to 10 miles to find a blood meal. She fuels such long flights by drinking nectar from flowers. Black flies are a primary pollinator of wild blueberries. Mosquitoes pierce and suck up our blood. Black flies make tiny slashes with blade-like mouth parts and then drink the blood that flows. They keep it flowing by spitting anticoagulant into the wound. That’s what our bodies react to and is the cause of the later discomfort.


Repellents containing DEET may give some relief from black flies, but unfortunately, my experience with them indicates that repellents aren’t very effective. Even the 100% DEET (kind of nasty stuff in its own right) hasn’t stopped them completely. The only real defense is avoiding them by not being out when they’re most active around sunrise and sunset (unfortunately my favorite times of the day), and keeping them off of exposed skin by wearing long sleeves, a hat and pants. Those who must be or may just want to be active outdoors during black fly prime times may want to invest in a fine mesh head net like beekeepers wear. The little pests can find the smallest opening to get in and bite, too. I recall being out in a canoe fishing one evening years ago on a lovely wilderness lake. I had on proper clothing to avoid them and even had the pants legs tucked into the sock tops, like I would around here trying to avoid ticks. The only problem was a small hole no larger than a pea in the sock on my left ankle. I glanced down and noted blood running down the sock, but I didn’t recall injuring myself. Then I noticed several black flies standing on their heads in that hole in my sock! I don’t know how many of the little beasts I fed that night, but I do recall that the spot they all worked on didn’t heal for days and itched for several weeks! I’m willing to put up with a few bites to enjoy the outdoors at those nicest times of the day. Anti-itch creams like hydrocortizone or benedryl can give some relief from the itching. I still hope they all go away – SOON.


Steve Lekwa is a former director of Story County Conservation.