As we are now into the hot and hazy days of summer, the birds have quieted down, the wildflowers are just sitting there, and it seems that Nature has engaged the summer vacation mode. But don’t be fooled into thinking “there’s nothing going on out there” — the insect world is hopping busy.
A few days ago, a young woman reported her discovery of a 'mutant' caterpillar. "It was huge! It was gross, it was so big! And it had, like, horns all over it that were orange and red and black! And no hair, just bright lime green skin! Eww, it was gross… but really pretty, too. What was it?"
I asked her to show me how big was 'huge'; turns out it was as long as her longest finger, only longer! Okay, and where was it, on a tree, or on the ground? "And it was, like, as round as a big cigar! It was mutant!" Okay, again, how about that habitat clue?
Taking her info and subtracting the excitement factor, it sounded like it may be the mature caterpillar of one of our large silk moths. When shown the illustrations in the field guide, she gasped and pointed out the culprit from the illustrated line up. "That's it! That's the one! Is it really a mutant caterpillar? It's so pretty, really."
Turns out to be larval form of a Cecropia moth, one our largest (and prettiest) moths. The caterpillars started in June as little itty-bitty black things and have been quietly munching on cherry and birch leaves over the past few months. Now that they are 'mutantly' big, and bright green, they will start construction of a winterized cocoon. Next June will see the emergence of another awesome Cecropia moth.
The next insect that revealed itself this week wasn't quite as glamorous as the Cecropia moth to look at, but quite fascinating to watch. It began with a shrew that was seen wiggling across the hiking trail. Not too unusual, as shrews often scoot from one side of the trail to other, but this one was doing it quite differently – it was laying on its back! Wiggle, wiggle, stop. Wiggle, wiggle, stop. I guess the most unusual part of this scenario was that the shrew was dead. Wiggle, wiggle, stop.
Begging a closer examination, we stooped over the amazing dancing carcass and watched to see what might happen next. Suddenly an orange-and-black beetle emerged from under the beast, paused as it wiped its brow (not that beetles have brows, but that's what it looked like), and scurried around the body as if checking the route. A second beetle then appeared, and the two of them seemed to have a quarrel as to how long this break was supposed to be. They then wriggled back under the huge beast and with a wiggle-wiggle-stop moved it ahead another short distance.
These were carrion beetles, and their important role in nature is to be a gravedigger. Once they move the carcass over a suitably soft spot of earth, they will then push the dirt aside and settle the corpse slowly into the ground. After the proper depth has been reached, more dirt will be thrown onto the body, thus burying it from other scavengers, such as crows and gulls.
And just before wiping their little beetle hands of a job well done, they will (or at least she will) lay eggs on the buried carcass. When the eggs hatch, the baby beetle maggots will have a delicious meal waiting for them. Fabulously fascinating!
The third insectivorous event of the week occurred in the grocery store parking lot. Neatly squashed and therefore easily studied, were the remains of three large bugs, each about the size, shape and colour of a dead elm leaf.
Assuming the stoop and stare position, I was able to identify them as giant water bugs. These are truly nasty looking insects, as their forelegs are well developed and end in a pointed hook. The protective coating above their delicate wings looks very much like a Zulu war shield, and they are big… big enough to command your attention where ever you might see them.
Giant water bugs normally live in beaver ponds, hunting tadpoles and minnows amongst the submerged aquatic vegetation. But if the water level in the pond drops (and the lack of significant rainfall over the recent few weeks has indeed had a negative effect on many streams and ponds), these insects have the ability to get airborne and easily fly to another pond.
However, if an attractive security light is encountered during their midnight flight, they tend to go towards the light. After using up their energy trying to “become one with the light”, they fall to the ground exhausted and confused (assuming bugs have the ability to become confused). And then they get drivena over by early morning shift workers, thus rendering them into a state of easy observation.
While the blaze and glory of autumn leaf colour is thankfully still a few weeks away, and the first heavy frost even further away (I hope), there are many interesting events to discover as wildlife starts to put the wrap on another summer season.
Dave’s Notebook: Certainly the weather for fun in the sun! Can't resist mentioning the ironic situation of a bee being swallowed by our Premier as he announces the closures of emergency rooms. Nature strikes back! But wait for it... will pollinators be banned from Ontario??
© 2022 David J. Hawke