Flight of the Bumblebee

Bumblebee pollinating fireweed by Heather HinamIt’s been a long, long, long winter here in the north woods. Then, suddenly, it was summer. The browns and greys of last year’s decay vanished nearly overnight, replaced by the verdant greens of new growth. Flowers are coming up everywhere and the air is alive with insects. That last part doesn’t get most people up here all that excited. A large proportion of those insects at the moment are mosquitoes. However, trundling along through the clouds of bloodsuckers are the pollinators.

One of my favourite groups of the myriad species that call this region home are the bumblebees (Bombus sp.), the flying teddy bears of the insect world.  While most members of the Order Hymenoptera, like wasps and hornets, tend to send people running in the other direction, bumblebees hold a special place in the hearts of even the most nature deprived. Their brightly-coloured, fat, fuzzy bodies, topped with almost comically small wings, coupled with their almost roly-poly nature makes even the most hardened insect-hater melt a little bit on the inside.

Unlike honeybees, bumblebees are native to North American. There are a few dozen species that have fit into just about every niche across the continent, making up what may be the most important assemblage of pollinators we have.  What makes them so efficient at the job is their hairy bodies. Bumblebees feed on nectar and that is usually stored near the centre of the flower. As the bumblebee noses its way deeper into the blossom, the pollen-laden stamens brush against the insect’s body, transferring its important cargo to be transported to the next blossom.

While they do collect that nectar, bumblebees are not honey producers. Unlike the species we’re mostly familiar with, bumblebees are only semi-colonial, setting up small nests that only last for one year. It all starts once the frost is out of the ground. Queen bumblebees overwinter by themselves in the leaf litter or underground. Once she wakes up, her first order of business is finding food. With the late winter we had this year, she likely would’ve had a harder time than usual.

Once she’s managed to restore her energy levels, the queen will set up shop in a quiet, dry place like a woodpile, old rodent hole, tree cavity or even a nestbox. There, she will lay her first clutch of eggs, which she’s incubates in the most adorable fashion by sitting on top of them and ‘shivering’. To feed herself and her young larvae once they hatch, the queen gathers nectar that she stores in her nest in little wax pots.

That first generation of bees are all worker females, who quickly take over the foraging duties, bringing home more nectar and fashioning more wax pots, upon which the queen lays her subsequent eggs. Workers also take on guard and cleaning duties while the queen remains in the nest, taking a well-deserved rest and generally ruling the roost.

As the long days of summer begin to wane, the queen plans her insurance policy for the following year, laying eggs that hatch out both males and new queens. Both of these cohorts leave the nest and somehow find each other in the big, bright world outside of the colony.

Once mated, those new queens head off to find a place to hunker down for the winter while the home there were born from fades away.  It’s a system that’s worked for thousands of years, ensuring the proper functioning of pretty much every ecosystem in North America. Unfortunately, now, it’s in trouble. Like most pollinators, bumblebees are facing hits from all directions. Losing both nest and food sources to habitat loss from large-scale agriculture, timber harvest and urbanization, they are also having to contend with pesticide usage turning the plants they depend on into death traps.

However, if we, as a populace, make a conscious effort to change the way we do things, curtailing bee decline is not an insurmountable problem and every individual counts. By planting bee-friendly species in your yard that come from growers you know don’t use pesticides, you’re creating a haven for these beleaguered bugs. Talk to your greenhouse owners, talk to your representatives. There’s more and more data showing that certain types of chemicals are the problem and need to be taken off the shelves and out of our food production. We’ve done it before with DDT. We can do it again.If we don’t, the world as we know it will cease to function. It’s as simple as that.

For those of you who are a little less insect-inclined, it’s also good to remember that bumblebees are nothing to be afraid of. While they can sting, they’re pretty mellow individuals and if you take precautions like not wearing strong perfumes and running around barefoot, you’ll have no trouble co-existing peacefully with these fuzzy, buzzing, beautiful and essential bugs.

 

 

 

Flight of Dragons

Dragonfly portrait by Heather HinamAlthough growing up, I was very much a tomboy, climbing trees and mucking around in the bush and ditches near my house, my relationship with insects was more typical of most city girls. I didn’t like them.  I thought nothing of swatting a house fly and I’m sad to say that I’ve run, screaming, away from a pursuing horsefly or the longhorn beetles that show up around August at the cottage.

However, as I’ve aged, my impression of insects has evolved quite a bit.  As I’ve grown to appreciate the amazing beauty and complexity of our natural world, I find myself drawn more often to those things that used to frighten or disgust me to re-examine them with my new perspective on life. I’m pleased to report that I’ve developed a new appreciation for longhorn beetles.

However, the one group of insects has always fascinated me, even as a child, is the dragonflies. I have a vivid memory of canoeing with my father down the La Salle River, south of Winnipeg, when a dragonfly landed on my knee.  I was rapt as I carefully held my lower half as still as I could while paddling to ensure my visitor a smooth ride, wanting to keep it with me as long as possible.

I’m not the only one with this fascination. There’s just something about these bejewelled predators that captures the imagination. I see representations of dragonflies everywhere, on t-shirts, in wind chimes and other household decorations, on jewellery and even fridge magnets. I think most people simply find them attractive, with their iridescent colours and delicate wings. They’re also ‘benevolent bugs’ from the human standpoint, voraciously devouring our ‘undesirables’ like mosquitoes and black flies.

Even with all of this goodwill, I don’t think the average person really knows all that much about them.  Dragonflies, and damselflies belong to the order Odonata (toothed ones), which contains some of the most ancient and largest insects ever known. There are over 5,900 living species, with nearly 100 of them found in Manitoba.

They’ve been around a long time, with the earliest fossil Protodonata (pre-dragonflies) dating to around 325 million years ago.  They were also a lot larger then, with wingspans reaching nearly a metre. I’m not sure we would’ve been so fond of them if they were still that size. When these insects first took to the air, they were the monarchs of the skies, feeding on whatever flew into their path. Vertebrates were only just crawling out of the water and so dragonflies had little competition and few predators. The benefits of being big, however, only lasted until dinosaurs started coming into their own.

Although they’ve become much smaller over time, the overall structure of a dragonfly hasn’t really changed all that much in 250 million years. These bugs are built to hunt on the wing. Their compound eyes are enormous relative to the size of their body and over 80% of their brain function is devoted to analyzing the visual input from the up to 30,000 ommatidia (facets) that make up each eye.  Having eyes made up of independent facets results in an incredible ability to detect movement because they can see in just about all directions at once.

This hyped-up visual centre can also detect parts of the colour spectrum that we can’t. Human eyes have three types of opsins, light-sensitive proteins that detect red, green and blue light. Diurnal dragonflies have four or five types of opsins arranged very specifically throughout each compound eye, with blue and UV receptors pointed up and longer wavelength receptors pointed down, likely to maximize their efficiency.

With amazing visual acuity, the ability to focus on one prey item at the expense of all else, almost all of their limbs facing towards the head and prehensile labia (mouthparts), they can snatch their prey out of the air with about a 95% success rate.

The last part of this deadly equation is their stunning aerial ability. We’ve all seen them dive and weave, hover and back-up, all while reaching speeds of nearly 50 km/h.  Dragonfly flight is actually very complicated, probably the most complex process of all flying organisms.  With four wings that can move independently of each other and dynamic airfoils that can flex around several angles, things can get complicated and scientists are still trying to sort it all out with the help of high-speed film.

They can make use of the classical lift that keeps planes in the air and a back and forth figure-eight stroke much like hummingbirds as well as take advantage of the vortices they create.  Some can turn 360 degrees around the axis of their bodies with the wings on one side stroking forward and the other side stroking back in one coordinated movement.  All of it is driven by a circuit of 16 neurons hard-wiring the brain to the highly developed motor muscles in the thorax.

So, the next time you catch the flash of a dragonfly as it zips along, take a moment to marvel at these truly ancient wonders of the natural world.

Moonlight Becomes You

Luna Moth by Heather HinamSome childhood memories just seem to stick with you, lodging in your grey matter and coming back to haunt you at random intervals.

One that has been showing up quite frequently on the mental playlist lately harkens all the way back to a stint at Girl Guide Camp at Bird’s Hill Park, just northeast of Winnipeg over 20 years ago. It was a dark and muggy mid-June night as we trucked off as a group of giggling girls to the public washrooms. In the orange haze of the sodium lights, we heard a shriek of fright and immediately thought a bear had found its way into the campsite. Nervous, we crept around the corner toward the source of the sound and found girls from another troupe cowering under the lights over the door, pointing to the wall.

The source of their terror? Luna moths.

Looking back, I can see how these fluttering, green giants could scare the bejeepers out of a bunch of city girls. However, I was more fascinated than frightened by these enormous moths; still am.

I went a couple decades without seeing them again until one June day a few years ago. A friend came into work at the resort on Hecla Island and announced that they had a giant green moth on their door screen. Needless to say, I was over there with the camera in short order. The image above was the result.

There’s just something compelling about these ghostly green insects that float, like the moonbeams their named for, through the early summer nights.  With a wingspan of about 4 inches, they’re one of the largest moths in Canada and arguably one of the most beautiful; but few people get the chance to see them. They’re nocturnal and only exist in their adult form for about a week, so to catch a glimpse of these beauties, timing is truly everything.

They actually have a lot in common with a much more abundant and much less revered insect that emerges a few weeks later here in the north woods, namely the fishfly. Like its very distant cousin, adult luna moths have one purpose: to mate and deposit eggs to ensure the next generation. Like fishflies, these Saturnid moths have no mouths and do not feed. Their large, fuzzy bodies and consequently larger energy reserves from their larval stage allow them to live longer than the fragile fishfly.

In the dark labyrinth of the nighttime forest, finding a suitable mate is hard work, so male lunas can travel kilometres, tasting the air with their antennae for the pheromones drifting from a ‘wick’ extending from the abdomen of a waiting female.  Because they’re needed for this function, the antennae of male luna moths are much larger and fluffier than those of females, making the sexes fairly easy to tell apart. The moth pictured above is a female. Once the sexes find each other, they lock together in copulation for up to 20 hours before she sets off to lay her eggs. A female can produce up to 300 eggs, scattering them around the forest, a half dozen or so at a time, on the underside of birch leaves to incubate for almost two weeks.

The larvae are just as impressive as the adults, a bright, almost fluorescent green caterpillar that you can find trundling along the trunks and branches of its host plant, munching away on the leaves and growing up to 4 inches long by the time it sheds its exoskeleton for the fifth time (a process known as ecdysis).

Up here in Manitoba, where the summers are not long enough to allow for two generations, lunas overwinter as pupae in their cocoons. It isn’t until the following June that they will emerge from this stasis, all crumpled and fragile. Slowly, over at least half an hour, the new moth will pump hemolymph (insect blood) into their wings, ‘blowing them up’ until they harden into their characteristic green sails. It’s an event you can witness first-hand if you’re lucky enough to find a caterpillar before it pupates and keep it at home over winter. I’m actually planning to try and do just that later this summer so that I won’t miss the emergence of one of my favourite denizens of the dark.

We’re here for a good time, not a long time…

If you’d told me 20 years ago that I would be writing a piece extolling the virtues of the fishfly, I would’ve told you that you were crazy. As a child, I tried to get out of going to the cottage during the first few weeks of July, simply to avoid having to deal with these large, awkward insects that appeared in the thousands and stuck to everything. I would go to great lengths to avoid coming in contact with them and I couldn’t stand the smell that hung over the beach during those weeks that their bodies washed ashore, creating a putrid line in the sand.

However, here I am, much older and hopefully wiser, and an unapologetic fishfly fan. It was when I returned a few years ago to live alongside our great lake, that I discovered just how remarkable these insects truly are.

Whether you call them fishflies, mayflies or shadflies, these large-winged, long-tailed insects belong to the order Ephemeroptera, which literally means: ‘things with wings that don’t live very long’. It’s a fairly apt description if you only consider the adult form. With vestigial mouth parts and a digestive tract full of air, they’re lucky to last for more than a day. However, if you take into account the insect’s entire life cycle, they are actually relatively long-lived.

Here on Lake Winnipeg, our fishflies (mostly Hexagenia limbata) spend about two years as nyads (larvae), living in the sandy bottom of this immense, but shallow body of water. They’re detritivores, feeding on algae, diatoms and other bits and pieces that find their way to the bottom. They, in turn, form a large part of the food base for the numerous fish species that fill the lake.

Then, somewhere around the first week of July, an instinctual switch is flipped, sending the two-year-old nyads to the surface. Floating in the meniscus of the lake, their backs split open like a seam, letting the newly-formed winged morph  emerge. This stage is call the subimago and unlike any other order of insects, they’ll moult one more time into fully-fledged adults, all in the space of about a day.

It’s not so much the process that makes them remarkable, but the numbers. Lake Winnipeg, like many other shallow, fertile lakes and river systems, is home to millions of fishflies and they tend to show up all at once, carpeting everything: walls, roads, mailboxes, trees, lampposts, anything that’s standing still long enough for them to stick to. This mass emergence is their way of shuffling the genetic deck. It’s a nocturnal orgy of mating and egg-laying before everyone literally drops dead, their tiny bodies piling up under lights and along the beaches to be cleaned up by hoards of hungry gulls if the towns along the lake don’t get to them first with the front-end loaders.

Most people anticipate this yearly irruption with fear and distaste. I, on the other hand, look forward to it, because as long as there’s fishflies, Lake Winnipeg has hope.

Our lake is in trouble. Like way too many watersheds around the world, it is suffering from too much of a good thing: nutrients. An overabundance of phosphate and nitrogen are finding their way into the water, fuelling giant blooms of algae that, among other things, reduce the oxygen content of the lake both by using it themselves and by keeping it from reaching the bottom, where the fishflies live.

I fear for a fishfly-free summer. Thankfully, we’re not there yet and I’m optimistic that we can still turn the tide. Algae levels have been increasing for years, but public awareness has also risen and steps are being made to improve waste water treatment and watershed management. We have a very long road ahead, but as long as I keep finding fishflies stuck to my windows every summer, I’ll believe we can make it.