Exploring The Last Green Valley: Black fly a springtime winged tormentor


Exploring The Last Green Valley: Black fly a springtime winged tormentor

“The sun always crosses the line on time, but the seasons which he makes are by no means so punctual; they loiter, or they hasten, and the spring tokens are 3 or 4 weeks earlier or later some season than others.” — John Burroughs from “Spring Jottings”

Here we are, two-thirds through spring, and finally we’re getting a bit of warmth from the sun. Yes, our rainy April has delayed things a bit, but with the warmth comes fresh blooms, bird hatchlings, newly unfolded leaves and nature’s little wonder bug – the black fly.

A lifetime of outdoor experience confirms for me black flies are small in size but mighty in bite. They seem to suddenly be everywhere, usually on a beautiful warm day when I am finally getting started on some serious work in the vegetable garden.

They swarm my sweating face and seem to enjoy exploring my ears and the back of my neck. They munch on my forehead finding the hidden scalp hairline under my hat, and even venture up my nose. Their bites are painful and itchy, and, for me, usually cause a nasty welt that lasts for a week or so.

The only way to avoid them is either arm yourself with protective gear or do outdoor work earlier in the day or late afternoon, avoiding the hotter more humid times of the day. Dry and breezy days are best for outdoor work if you want to avoid black flies.

Protective gear means covering up pretty much any exposed skin. A light colored long sleeve shirt and pants with socks turned up over the cuffs are recommended. Apparently, black flies are more attracted to dark colors.

A handkerchief around your neck and a large brim hat with insect netting over the top and tied at the neck (like a beekeeper would use) is really the only way to keep them from your face. Yes, a summer T-shirt and shorts would be so nice on a sunny day but believe me the little buggers will find the smallest unexposed area for biting, so it is best to cover up.

I highly recommend the face netting. You’ll look silly, but not as silly as a face covered with painful red welts. You can find them at most garden supply stores. You may only have to use it a few times a year, but you’ll be glad you have it.

I use insect spray with DEET to repel ticks and mosquitos, and it can help with black flies. Some recommend natural repellants, such as vanilla extract and lavender, but I prefer the manly smell of DEET.

Being the curious sort, I scanned some of my resource books about the natural world for more information on this springtime tiny tormentor and found some fascinating information by two well-known author naturalists.

Edwin Way Teale is one of The Last Green Valley’s most beloved authors, and I have referenced his books several times in this column. He was fascinated by the insect world and one of his early books, published in 1937, “Grassroots Jungle,” included some 200 of his insect photographs.

In his book “North With The Spring,” Teale describes in poetic detail the interesting aquatic life of black fly larvae in the chapter “Timberline.” He and his wife Nellie were hiking up to the timberline of Mount Washington when they stopped by Cutler River.

“It roared or murmured as the windings of our trail carried us nearer or farther from its rocky bed. In the midst of the crash and smother of its cascading water tiny larvae were clinging by suckers at the ends of the tails to the downstream side boulders. Their massed bodies clustered so thickly on some stones that they resembled moss. These immature insects were the larvae of that scourge of the north woods, the black fly.”

“All were busy sweeping microscopic bits of food from the water into their mouths with fan-shaped brushes. Some tossed at the end of silken threads to feed in the swifter current or let themselves down from rock to rock. Others were wrapped in golden-brown pupal cases fringed along the top with tracheal gills that provided oxygen for the transforming insects within. Still others were ready for the greater adventure of riding a bubble of air upward through tumbling water to the surface.”

Unlike mosquitoes that begin life in brackish still water, the black fly requires oxygen-rich water of moving streams. Just a guess, but perhaps their painful bite (when compared to that of the diminutive mosquito), is the result of their difficult upbringing in cold rushing streams.

My search for more information on the interesting life of the black fly also led me to William Amos, a biologist and nature writer from Vermont who contributed to several natural resource publications including the Northern Woodlands Magazine book, “The Outside Story, Volume 1.” His essay “In Praise of Blackflies” caught my attention.

“The life stages of a blackfly resemble those of many insects. A female enters the water to lay 500 or so eggs… Each tiny larva soon hatches and creeps to find a place to attach in the swift water. It feeds, molts up to nine times, and then, before transforming into a flying insect, enters a non-feeding stage, a blackish, hump-shaped little pupa inside a streamlined silken cocoon.”

“An efficient bloodsucker, the awful adult female blackfly uses chemically sophisticated saliva to keep blood from clotting while she drinks her fill. It is this saliva that arouses our body chemistry to inflammation. Her sense of survival causes her to bite precisely where we are least likely to notice her presence. Then with inflated body, she flies off to rest and digest the meal, an elusive little Dracula. The males? Inoffensively mild little creatures who sip nectar from flowers.”

Our natural world is full of wonder and beauty here in The Last Green Valley. We share it with countless amazing creatures, even the horrid little black fly. I hope you’ll join me, and together we can enjoy it, care for it and pass it on.

Bill Reid is chief ranger of The Last Green Valley National Heritage Corridor and has lived in the region for more than 35 years. He can be reached at bill@tlgv.org.


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