Finally, it's summer, and you're looking forward to spending a day outside. You head off into the boreal forest, for a hike, or a camping trip. You notice a cloud of flies around you and think, “Uh oh. Here come the black flies!” Pretty soon you have them on your face, hands, ankles (really, anywhere with bare skin). And soon after, without intervention such as a bug jacket, gloves, long pants, etc, you feel the bites and see the welts. There are 254 Black Fly species in North America but thankfully, there are only about 20 species in Manitoba. There are also some positive things about the presence of these flies. They indicate that water quality is good in the area (flies need clean, flowing water to complete their cycle), they are only active during the day so you can avoid them by hiking, canoeing and looking for plants in the dark, and males help pollinate blueberry plants - ensuring we have those delicious fruits!
Other pesky insects we identify with here in Canada are Horse and Deer flies. There are approximately 145 species across Canada, mostly diurnal, or day-active. These flies need sugars to help give them energy for flight, as well as blood to aid in egg production. Though they have a painful bite, they are rather slow and easily brushed away. Having appropriate clothing is a huge help in keeping them off your skin. Eggs are normally deposited in masses on plant stems or under leaves overhanging water, and even wet soil. My most vivid memory of these resilient and persistent flies is seeing about 100 of them swarming our vehicle, which was parked along a trail. They were swirling round and round, and hitting the vehicle so hard, you could hear the impacts like rain drops.
And we have to mention those mosquitoes. Hearing one of these buzz around your head while you're trying to sleep, listening to a horde of them around you at dawn or dusk, and red, itchy bites are truly Canadian experiences. The females, which are the only ones who bite, may wander for kilometers from their natal pond in their search for blood. Like Horse and Deer flies, mosquitoes need blood to aid in egg production. Not even frogs and toads are exempt from their voracity. But there even mosquitoes have a beneficial side. The males feed solely on nectar and can be important pollinators for some plant species, such as Blunt-leaf Rein-orchids. Mosquitoes are also an important food source for a number of aquatic and aerial predators.
Predators of the afore-mentioned flies are favourites of mine, particularly when their hunts are successful. Canada Darner, one of our largest dragonflies, is one such predator. They are commonly seen over city lawns and parks and forests in early summer to fall. All dragonflies begin life as aquatic nymphs (in lakes, ponds, ditches, streams and/or rivers), and feed on fly larvae, in addition to other prey. Adult dragonflies are aerial hunters, grabbing prey with their feet, and holding on with the aid of spined legs. It is an awesome sight to watch the aerial acrobatics of these insects, and their flight prowess has even been the inspiration of engineers. They've had a long time to develop these flight skills. In fact, they've been around since before the age of the dinosaur, and even had wingspans of about two feet.
So when you’re outside swatting at mosquitoes and flies this summer, try to remember these “Canadian” insects all have a place in the ecosystem. And without them the Canadian experience would be incomplete!
Article and Photos by Deanna Dodgson