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Back Roads Bill shares the buzz on annoying critters we'll soon be seeing

This week Back Roads Bill reminds us how little springtime annoyances are just around the corner and shares a Northern Ontario invention that could offer relief from them

Is it a camp or a cottage or what is more annoying: black flies, or mosquitoes?

And why should we now be reading about bugs in the middle of the winter Back Roads Bill?

One reason is the story of a bug repellent that has its fourth generation roots in Northern Ontario at the turn of the last century, with an original slogan: Guaranteed to Scatter Black Flies and Mosquitoes and Relieve the Irritation caused by Fly Bites, with a reputation of: “Any self-respecting person who has lived in the north knows, that only McKirdy's Repalfy really works!”

Mosquitoes first

But first some background on our seasonal airborne annoyances. Proponents behind The Tick and Mosquito Project. They have been helping people learn how to control mosquitoes, black flies and ticks since 2000.

“I started the site because I spend lots of time in the outdoors in tick and mosquito country, and most of the resources for keeping them at bay was too academic," said Paul Miller a proponent of the project. "I wanted us to write something more geared toward the typical outdoorsy person. We are independent."

“Our content is developed through studying the latest findings and news associated with ticks and mosquitoes, and learning about and testing techniques for controlling them. We work with entomologists and arachnologists to periodically review our work and be sure we are representing the latest knowledge of mosquitoes, ticks, and how to control them.

“Mosquitoes are fascinating insects It might be a surprise to you that these little anthropods can survive for a month or more, and that is the case for female mosquitoes in preferable conditions.

"Males, on the other hand, only live for a week. But the brief period they do spend on earth is indulging in mating and giving birth more to more mosquitoes! Once it has sucked enough blood, the female would wait for the blood to digest and the eggs to develop before laying them anywhere it could find a sufficient amount of water (that is why we advised targeting water when it comes to yard mosquito control)."

And, another opinion from Miller, “On a hike, or a canoe, black flies are more annoying than mosquitoes. They have a way of really picking a human, and then persistently focusing on them. They seem to have a sixth sense for how to get you in places that you can't easily swat at -- like the back of your head or your ankles. But with that said, black flies usually are only a problem for a small portion of the summer.”

Blackflies – most annoying

A real black fly expert was found. Doug Currie’s Ph.D. dissertation, ‘Morphology and Systematics of Primitive Simuliidae,’ examined the early evolutionary relationships of black flies — a notorious pest of birds and mammals. He joined the Royal Ontario Museum in 1993 after post-doctoral fellowships at the University of British Columbia and the Canadian National Collection of Insects and Arachnids in Ottawa. He is actively engaged in teaching at the graduate- and undergraduate levels through his cross-appointment to the University of Toronto.

The query was what he thought was more annoying between the two.

“It’s difficult to say whether black flies or mosquitoes are more annoying as it really depends on place and time of year," Currie said. "Overall, mosquitoes are the most serious pests based on their ubiquitous distribution, length of time they’re out and about, the fact they bite day and night (and indoors as well as outdoors) and the fact they’re vectors of disease (including those affecting humans).

"Although black flies are essentially as widespread as mosquitoes in Canada, the ones that include humans as hosts are more restricted in distribution, occurring predominantly in northern forested areas — particularly on the Canadian Shield. Those species reach their peak abundance as adults in June and can become so numerous that one doesn’t even notice the mosquitoes (which are also abundant that time of year)!

"Black flies are far more annoying in their attacks as they swarm about one’s head and bombard one’s mouth, nose, eyes and ears. And their bites — although initially painless — weep for hours afterwards and remain itchy for days (or even weeks). On that basis, I suppose one could argue that black flies are more annoying than mosquitoes in June in Northern Ontario."

Currie provided some black fly background.

They are small, dark-coloured insects belonging to the family Simuliidae. Of the world’s more than 2,300 species, at least 164 are found in Canada.

Black flies reproduce in streams and are found all across Canada. They are particularly common in northern temperate and subarctic regions. Because female black flies need to feed on blood to lay eggs, their biting can be a nuisance to humans and other animals.

They can be found virtually anywhere there is flowing water to serve as a habitat for larvae. In Canada, they are especially abundant in northern wooded areas and near large rivers and lake outlets. Unlike mosquitoes, adult black flies are mainly active during the day.

Black fly larvae are an important part of aquatic food webs.

Larger rivers can host over 600,000 larvae per square metre and can produce close to a billion adults per kilometre per day. Larvae are eaten by fish and aquatic invertebrates, while adults are prey for birds. In the act of feeding, black fly larvae transform fine organic particles into nutrient-rich fecal matter.

As we know black flies can be quite annoying to humans.

“Species that bite humans are drawn to subtle odours in sweat," said Currie. "They tend to swarm around the head and skin before biting and will bite any exposed skin, especially on the wrists, ankles, waistline, neck and hairline. Their bites normally leave a small welt and a droplet of blood and may itch for several days. Doug said black fly bites can be avoided by wearing light-coloured clothing that covers the wrists, ankles, and beltline, and by applying commercial insect repellents to the skin and clothing.”

North American Indigenous peoples have also deterred biting flies using naturally occurring insect repellents found in bracket fungi and in plants such as fireweed and sweetgrass.


The organic product was created at the end of the nineteenth century in Nipigon when William McKirdy experimented with mixtures that made black flies and mosquitoes “bearable.” The product was later developed in 1906 and patented in 1911 as an “alleged new and useful improvement in fly repellents.” The final product was called Repalfly, which the main component was citronella imported from Ceylon (Sri Lanka).

Oil of citronella is derived from two grass varieties, repels target pests rather than killing them. It works by masking scents that are attractive to insects. Thus, insects find it difficult to locate their target to feed.

Its organic compounds, if they get into the environment, are expected to turn into vapours. In water, they vaporize from the surface at a moderate rate. Once vapours are airborne, they break down in a matter of hours, with half-lives ranging from 38 minutes to 3.2 hours. These compounds are readily broken down by microbes. For humans, it may also cause skin allergies with prolonged or frequent exposure.

Great-grandson, James McKirdy told me, ”It's likely that someone told my great grandfather about the 'repellent' capabilities of citronella. At the time I think they smothered themselves with bear fat, which did not smell so good. Original mixture was 25 per cent citronella. This was reduced to 15 per cent at some stage. When I was making it in the garage as a kid it was 15 per cent. We would get 45-gallon drums of it. We went through a lot. The muscle memory of pouring from our old metal teapots into a jar was immediate and quite surprising. But we had spent many, many hours doing this in our garage with my Mom, Dad and sister. Also, the smell of the shed with concentrated citronella (aka Repalfly in the liquid state) immediately took me back to the garage.”

John McKirdy took over Repalfly, “…from Dad in 73, then passed it on about 25 years ago (to Ian). I had some great distributors across the north I would drop in on small tackle shops to introduce them to Repalfly. . William, my grandfather tried adding citronella to various cream-like products and settled on cocoa butter and applied for a patent in 1911. My recollection is that repellents weren’t regulated 100 years ago, then eventually the Dept. of Agriculture became involved and Dad (Jack) was encouraged to add dimethyl phthalate, used during the Second World War and found to work in insect repellents. DEET came along later. Both are used in plastics and in high concentrations affect fabrics, plastic, leather etc…” An early jar of McKirdy’s went for $0.35, pre-WWII.

Another great-grandson, Ian explained that McKirdy’s is now “citronella creme/creme citronelle.” The Canadian federal government banned citronella in 2010.

“Interestingly, DEET seems to have escaped any such scrutiny. I wonder why - lots of horror stories about the corrosive effects of DEET-based repellents. Feds backed down a couple of years later. But it did mess things up a bit. In the meantime we let Repalfly lapse as a trademarked repellent; we could not say it was a repellent due to presence of citronella.” Citronella-based bug sprays did get eventually get a second chance. After a long battle with Health Canada, (2015) massive media coverage, and public outcry, the government agency decided to review its plan to ban the product and reversed the decision.

What is now available from McKirdy’s is the same formula as the original insect repellent patented in 1906; the active ingredient is 15 per cent Oil of Citronella with base ingredients of natural non-animal products, available here.

And finally, a few words about DEET (chemical name, N,N-diethyl-meta-toluamide), developed by the U.S. Army in 1946, is the ingredient within insect repellents thought to be the "best for black fly and does a good job at keeping all insects away." As recommended by Paul Miller.

“When looking for the most benefits of a repellent spray look for higher concentrations of DEET. You’ll find a plethora of products with DEET concentrations. If the number is very high, then the spray will work much better as a repellent," he says. "The majority of sprays tend to be around 25 per cent DEET, but do check the number and try to get a repellent that is higher as it will work better at keeping those pesky flies off." 

For more information see this review and this Farmer’s Almanac, what to do article.

The Blackfly Song

Twas early in the spring when I decide to go
For to work up in the woods in north on-tar-i-o
The unemployment office said they'd send me through
To the little abi-tibi with the survey crew
And the black flies, the little black flies
Always the black fly, no matter where you go
I'll die with the black fly a-picking my bones
In north on-tar-i-o-i-o, in north on-tar-i-o...”

It is the national anthem of Northern Ontario. "The Blackfly Song" is a song by Wade Hemsworth, written in 1949, about being tormented by black flies while working in the wilds of Northern Ontario. It is an enduring classic of Canadian folk music, covered by a variety of other artists. It won’t be long so have a listen to the lyrics.

Don’t be annoyed with me please, the swatting and waving will be here before you know it; looking forward to it, on the back roads.