Category: insects

Thank you dragonflies

by On the River, posted in insects

Especially for JAC

By Colin MacKenzie

Editorials are meant to pose an argument, expand through a discussion and wind up with a ringing conclusion.

So here goes. 

Let’s hear it for dragonflies! 

Just when it seems the blackflies will last forever, after the first mosquitoes form their early clouds, the summer air force arrives to rescue us. 

This spring has been no different out on Eagle Lake where I’ve been conducting my one-person observations of insect life for the past two months. 

About a month ago the first blackflies emerged, dozy, clumsy and unaggressive. 

They were joined several days later by the first mosquitoes, the small black guys who are in a hurry. 

David Beresford, the Trent University entomologist to whom I owe most of the information in this piece, explains that the young blackflies, who came out when water temperatures hit about five degrees, needed a day or two to get their act together. The early mosquitoes, on the other hand, overwintered as adults and need to get it on right away. 

“They don’t have much time and they’re in a hurry,” he said, to explain their active hunting of our blood. 

And so began the cycle up on Eagle Lake. 

Bug jackets mandatory, every outdoor foray carefully planned for minimum duration. But after about 10 days, the primordial predators arrived. 

Emerging from ponds, rivers and lakes, where they may have lived as long as five years as nymphs, roving through the mud in search of food, they will live for about six weeks as the dragonflies we know. Beautiful – ever seen a brooch depicting a blackfly or mosquito? – they date back hundreds of millions of years and there are dozens of species in our region. (Fossil evidence shows that some of the earliest species were as much as 30 inches across.) 

Darting around – they can fly in six directions – endlessly hungry, unafraid of whizzing past my ear if there was a target, they were a most welcome arrival. 

With only a small splash of eau-de Muskol, it was suddenly possible to sit out on the deck and edit stories. 

And the best part is that they will be around all summer. 

Not the same guys, but successive generations, all equally ravenous, will be here to devour any other insect that flies. 

After the oppressive fortnight, there is a vengeful pleasure to be found standing at the end of a dock, watching the dragonflies consume my enemies, untroubled by being bitten because they have my back. 

“Air cover,” agreed Dr. Beresford, is a comforting thing. In fairness, he says, the dragonflies, for all their appetite, don’t actually obliterate the population of the biters. But they certainly make us feel better. 

“I have a pond on my property,” he said, “it draws a lot of dragonflies, and it sure feels like the mosquitoes and blackflies get knocked down when they arrive, although it may just be my imagination.” 

But what will really do the trick, Beresford said, is hot dry weather. 

“You need less flow in the streams to get rid of blackflies, and generally dry conditions to knock down the mosquitoes,” he said. And the places that really need to dry out, he added are the crevices in tree trunks, woodpecker holes and the like, which is where the later season mosquitoes lay their eggs. 

“If those dry out, they’re done,” he said. Unfortunately, the extended forecast looks comfortably cool, with showers every few days. 

So all the more reason to cheer our prehistoric-looking chums, those dragonflies.

Thanks to MJS