Black Flies

I've been traveling to the UP for twenty five years now, and have somehow always managed to avoid black fly season (even though I once visited in June, albeit an unusually cold one). I had heard the horror stories, but this year I made their intimate acquaintance.

Black flies are endemic to the UP, and spend a good bit of their life cycle as larvae and pupae in running water (even very slowly running water), unlike mosquitoes, who prefer stagnant pools. Black fly larvae of various species may be found in every type of flowing water, from minute seepages in which the flow is scarcely detectable, to the largest rivers and waterfalls.

Black flies are very, very small, and seem, to all outward appearances, to be swarms (for they always seem to swarm) of irritating but innocuous gnats. But, appearances are sometime truly deceiving. Make no mistake about it, these creatures are EVIL.

...[black flies] can be so numerous and can attack so persistently that outdoor activity during the day without some protection becomes almost impossible. Black flies often land and take off repeatedly without biting. Their numbers, and their tendency to bite, increase as sunset approaches. Even when they are not biting, however, their buzzing presence and constant crawling is as irritating as the bloodsucking itself.


Mercifully, relief comes after dark, for unlike mosquitoes and biting midges, black flies do not attack at night. Also unlike mosquitoes, black flies seldom attack indoors or even in a vehicle; once they sense being trapped their attention seems permanently diverted to escape and they spend the rest of their lives crawling up the screen or window pane.

Like the mosquito, the female requires a blood meal before she can breed. Most black flies seem to prefer birds, but seem to be attracted to humans, probably by the carbon dioxide they breathe out.

Mosquitoes are big and noisy; you get fair warning that they are around. Not so with the black flies. They are quiet and stealthy.

Although they cannot bite through clothing, black flies have a predilection for crawling into hair or under clothing, biting in inaccessible places, such as the ankles and belt line.

They also like landing on your watch band, and nipping the skin right next to it. Not only does it itch like crazy later, but the watch band irritates the inflamed skin even more.

Being unused to the creatures, I wasn't aware of the need for light colored clothing, or the avoidance of scent. They attacked me over and over again, beginning with the lovely morning I went birding with Laurie (warblers were coming through), and continuing on the weekend I spent with Jan and Mark at their log house in Eagle Harbor. I had bites and bumps on my ankles (the weekend was hot), at my sock line, and on my arms, behind my ears, and throughout my scalp.

Since I'm somewhat used to mosquito bites, I tolerate them fairly well. They bite, it itches a bit, and then it gets better. Not so with the black fly bites. The bites itched, and itched and itched. I had huge swollen lumps where I'd been bitten. I may have even had a few enlarged lymph nodes.

The itching became unbearable. Antihistamines (first generation) help the itch, but make me very, very sleepy............Um, what was I saying? Right, sleepy. So I avoided them (driving while sleepy with deer in the area is a dangerous), and scratched and scratched and scratched. I drew blood. The scabs are only now non-pruritic and beginning to heal.

And I'm still finding lumps on my head.

(All quotes are from a Canadian government bulletin about black flies. Apparently, THEIR black flies make ours look like wussies!)