♪ [upbeat music]
(Bruce Doran) Hello, my name is Bruce Doran.
I'm one of the staff scientists that works at Science North,
specifically on the third floor in the Wetlands Lab.
And what I want to do today is talk to you about mosquitoes and black flies.
And what I want to do is show you the habitats
where mosquitoes and black flies actually reproduce.
So that you can get a better idea of the life cycle
of these incredible insects.
So we are now in the perfect habitat
where mosquitoes will actually breed.
And right here,
we actually have what is called a vernal or temporary pool.
These are founds pretty much in any wooded area.
You'll even sometimes find them in your back yard.
And these are pools of water that form
during the spring rains or spring runoff or snowmelt.
And then these pools will be created and then they dry out
during the summer time.
And these are perfect breeding sites for mosquitoes.
And generally what happens is that the females will either lay the eggs
during the spring,
or the eggs have already been laid the year before into the mud.
And what happen is the eggs will then hatch.
And then we have little larvae that will then live within this.
The larvae, which is the baby form of the mosquito, is actually aquatic.
So they will actually live in here.
They will grow, they will eat algae and bacteria that are found in here.
And they will then emerge out to become the adults
that come and pester us.
That we know very, very well.
So this is the perfect site for them to breed because there are no predators.
There's no fish that will actually eat them.
There are very few insects that will eat them.
And you can find thousands and thousands of them,
even with a single scoop either with your hand or with a net.
So this is a perfect site for them.
The females will then emerge, as well as the adults,
and we know that they bite.
Females will bite.
And the reason why female mosquitoes bite --
same thing with black flies --
is that they want to get mammalian blood in order to make eggs.
So she actually takes blood from a mammal like us,
or maybe even a bird,
and then she will use the blood proteins
in order to make more eggs,
in order to create more babies.
Now, keep in mind that the adults themselves,
including females, don't really feed on the blood.
They use the blood in order to reproduce.
The males and the females will actually pollinate flowers.
Different types of flowers.
So a lot of times people will ask me, "Well, why are mosquitoes important?"
Well, without the mosquitoes a lot of the flowers that we actually see,
a lot of the plants,
wouldn't be pollinated without them.
So they do have their ecological role
and they are food for many different animals,
including things like dragonflies that will eat mosquitoes.
Now, one thing between the female mosquitoes and the female black flies
is how the female mosquitoes actually take the blood.
Their mouthpart actually comes out like a needle.
It's called a stylet.
which it uses to actually pierce the skin in order to take blood.
So that's how she does it.
Whereas, the black fly has a slightly different mechanism
in order to take blood.
So, it's kind of hard to control mosquito population,
especially when you have things like this all over Ontario.
All over people's land and things like that.
So it's quite difficult to control mosquito population in this case.
What people can do around their house
is to empty any containers that might have water in them.
Or to flush the water out on a regular basis
so that the female mosquitoes don't lay eggs
and have larvae to grow in them.
So there are things you can do around the house
in order to control mosquito populations.
This habitat right here, the stream,
is actually a great habitat for black flies.
So unlike mosquitoes that live more in these vernal pools and stagnant pools,
black flies love creeks.
They love moving waters.
And they actually start their life in here,
in this type of water.
And what happens is that the larvae, the babies,
will attach themselves to the bottom,
usually rocks,
and they will filter any particles that actually go through.
And they actually have these mouthparts
that we call cephalic head fans,
that area actually like little filters,
little sieves,
that will collect little particles in the water and then eat them.
And usually what happens is the larvae were actually over winter
will stay in the water over the winter.
And then they will come out as adults in early spring.
And that's why we tend to get the black flies in early spring.
What the females will do is that they will lay eggs in the stream.
During the summer and the fall,
these will hatch.
And then the larvae will then grow during the remainder of the summer,
fall season, and the winter
in this type of stream habitat.
So streams are actually the place where black flies will be found.
And also, what's really neat,
is that if black flies are found in these types of streams,
which are usually well oxygenated and cool,
that's also a very good habitat for trout.
So a lot of times,
people that love to fish for trout
will look for streams that black flies will actually be found,
because trout will actually eat black flies.
Black flies are also very important, the adults,
because they will pollinate all types of plants,
including blueberries.
In fact, there were studies that actually demonstrated
that if you have a good black fly population,
it's sometimes correlated to blueberry production
up here in the north.
So, you know what,
we'll take our black flies a little bit
so that we have lots of blueberries.
Now, the female black flies just like mosquitoes,
will bite us.
Will bite humans and birds and other mammals,
in order to get blood in order to produce eggs.
Now, unlike the mosquitoes,
their mouthpart isn't a piercing method.
But it's actually a cutting mouthpart.
So what they actually do is they cut the skin.
And then the other mouthpart is like a sponge,
where they actually lap up the blood
in order to get blood
in order to produce eggs.
So, just like the female mosquitoes,
she needs the blood in order to produce more babies.
Now, there's not really much we can do to really control black fly populations
like mosquitoes around our homes.
Because whatever we do in this type of habitat
will affect many other organisms in here,
including the trout that people like to fish.
So, generally, what I tell people is it's not a good idea to affect streams.
Not a good idea to put anything in streams
because it could affect all types of populations,
different organisms.
So, if you see a nice stream like that,
yes, you will get black flies,
but keep in mind,
good habitat for certain fish, like trout.
And also would probably be a good area,
if you had blueberries,
to have a good blueberry population,
or production.
As you can see these two types of insects reproduce
and are found in habitats that are quite quite different.
Stagnant habitats or creek habitats.
Now, there are things you can do to protect yourself
against getting bitten by these two insects.
One thing you can do is to wear light coloured clothing,
like I'm wearing right now.
Another thing you can do is actually wear DEET.
That chemical compound.
Now, keep in mind, if you're an adult
you can wear DEET that's about 30%.
That's usually quite effective.
But for children it is recommended
that they use a much lower percentage of DEET,
five to ten percent,
and even young children under the age of five
it's usually recommended not to wear DEET.
Now, what you could do in that case is wear protective clothing.
Wearing clothing where you're covering your face and your arms.
You can actually where bug suits.
They actually sell bug suits and they are actually quite effective
against those insects.
So these insects are found here in Ontario,
pretty much throughout Ontario.
And we must live with them.
They are really important ecologically.
And there are things we can do to protect ourselves against this.
So next time you go out for a walk,
just think about where these insects come from
and how they are part of our ecological system.
♪ [gentle music]