They're both dependable and irritating. What you need to know about mosquitoes
CBC News | Posted: May 20, 2024 4:01 PM | Last Updated: May 20
There are about 50 species of mosquitoes in Ontario, Brock University prof says
The little mosquito is easily the most dependable — and irritating — aspect of summer.
While they seem to all look the same when we're swatting them away — they aren't.
According to Fiona Hunter, there are about 50 species of the bloodsucking insects in Ontario.
Hunter, a medical and veterinary entomology professor at Brock University, studies all flies that bite.
Speaking with Windsor Morning's Amy Dodge, Hunter said even though mosquitoes are irritating, "we wouldn't want to eliminate all of them."
What attracted you to the mosquito?
I like all biting insects. Somebody's got to look at them, so I figure it might as well be me. We started looking at the mosquitoes way back at the beginning of 2001/2002 when West Nile Virus hits. So, it's been a long journey concentrating on mosquitoes. Although I must say, I love other biting flies too.
Why are mosquitoes so drawn to us?
The first cue that they use is carbon dioxide. So, if it is a living, breathing animal — it could be a bird or a little mammal running around or even ourselves — the carbon dioxide that we release when we're breathing out is the first thing that they cue into, and so they fly upstream into the plume of carbon dioxide until they see something. They then come even closer and investigate further and we may or may not be the correct host for them.
So, there are a lot of species for instance, that feed on birds and they're queuing in on odour cues that aren't ones that we would have. But for those mosquitoes that find our odour attractive, they land on us, they probe and if we're tasty, they'll feed.
What sort of landscapes are mosquitoes most drawn to?
So, because there are so many different species out there, it depends on the combination between the habitats and what species are going to be found in that habitat. As an example, last summer there were so many mosquitoes out in southwestern Ontario that they had to shut down festivals, I think near London, because of species that are called floodwater mosquitoes.
So, there'd been so much rain. The eggs for these mosquitoes had been laid possibly the year or two years before in farmers' fields when it's all wet. They can withstand drying out for a couple of years, then you have a big deluge of water and they all hatch and go about their business. So, it depends on the habitat and the environmental conditions and what species are found there.
Can you look at a mosquito bite and tell if you need to pay closer attention to it?
Unfortunately, looking at the bite isn't going to do you any good. What happens when they bite they spit into you a variety of small peptides and anticoagulants so that they can suck your blood without it clotting. And that reaction that you have is to what they're spitting into you in their saliva — it's not a reaction to any pathogens, it's a reaction to the things that are anticoagulants and so forth.
So, just the fact that you might have a welt doesn't tell you whether or not you've been infected.
How do we keep the mosquitoes away from us?
Avoid mosquitoes at their peak — dawn and dusk. There are a lot of species that are out at that time that would be biting you. There's also the tried and true 'use a mosquito repellent.'
If you can get into a place where there's a breeze, you're not going to have as many because of course they're trying to follow your carbon dioxide plume. And if the breeze is blowing that away, they don't know where they're supposed to be headed to try and find a blood meal host. And if you can stand it, you make a smudge fire and you sit by the campfire in a big plume of smoke, and that should protect you as well.
Could the world exist without mosquitoes?
It would be a very sad place without mosquitoes occupying the niche that they do. So, obviously we don't need to be bitten to pieces by them, but because there are so many mosquito species out there. Most of them don't bother us at all and they serve as food for fish and amphibians in the aquatic environment, they serve as food for birds. There are all sorts of insectivorous birds that will feed on mosquitoes. And a little known fact, there are some mosquitoes that pollinate orchids. So, especially up in the far north in the Arctic, the orchids up there are pollinated by mosquitoes, so they definitely have a role, and we wouldn't want to eliminate all of them.