Gyrinidae: The Ultimate Sports Bug
by Dr. Tom Kazo, Ph.D.
Liking and looking at our wildlife is one thing. Living amongst it and just trying to understand it is a much different circumstance.
I have spent countless wonderful years in a canoe navigating the many salt and freshwater creeks, rivers, and bays of not only Florida, but many other countries as well. Most of us know or have seen the "big" animals that are featured on television and are seen in zoos. We have read about them and have even studied them. But, how many times have YOU paddled around a bend and had to stop and let a hippopotamus cross the stream, leaving your straw hat vulnerable to a passing giraffe? Not that many.
Now, how many of you, while out in your boat or just walking along the bank or shore, gazed under an overhanging tree or patch of grass and saw "a bunch of bugs," scooting around like bumper cars in a little circle on the water? It is not difficult to guess what your next question will be— "Why do they do that?" They have never been featured on television so you would probably never find out. Nonetheless, they too are an important participant in the web that Nature has so splendidly spun. They are not a spotlight item of acknowledgement, but their life is no less spectacular.
They are commonly called a whirligig, water bug, crazy beetle and a host of other colloquial names. Scientifically, they are Gyrinidae, in the order of Coleoptera. For normal folks, that's the beetle family.
While engaged in other research, I many times have watched these maniacally-acting little water critters spin, dive, and whirl, and try to investigate their activities. Where they do what they do is important, but why and when they do it are the answers I seek. Some of the answers that I found are fascinating.
Closer inspection of their behavior finds that they can spin and whirl at speeds up to five miles an hour. This makes them the fastest of the aquatic insects. Most persons would think that this activity would be efforts of evasion and escape, or maneuvers to confuse and catch their prey. Only a minute part of this is true.
As curiosity took over my mind, I found that trying to collect one of these little critters for study is more difficult than it looks. As your net hits the water they scatter, only moments later to return to their "round-the-wagons" behavior.
It is during this time, even to the human nose, that a distinct acrid odor can be detected. This noxious odor, when chemically produced by the beetle, makes it a poor table fare for most predators.
Looking at the anatomy and physiology of our little friend can give roller coasters and carnival enthusiasts a new spectrum of thought on excitement. With a body reminiscent of a 1949 Hudson Hornet with mud flaps, the whirligig beetle is a delight of maneuvering achievements. Oar-like back legs are lubricated by body oils that repel water. The oil enables him to "row" up to 60 strokes per second, an accomplishment that surpasses most hummingbirds. The front surface of his body is a hardened fore-wing that stores an air bubble. Used as a scuba diver would use an aqualung, he can dive into the depths and maintain there.
Once under the water, he will swim rapidly in search of plant material or any other anchor that he can adhere to. He then feeds off the micro-organisms that find these areas their home. To ascend, the beetle just lets go and bobs to the surface like a balloon.
Being equipped with two pairs of eyes —one for underwater viewing, the other for surface scanning— gives this beetle visionary perfection. At the end of his abdomen there is a segmented section that when flexed, acts like a rudder. The term, "turn on a dime" must have come from observing this fellow with his uncanny versatility.
When a predator (which includes a few fish, fewer frogs, and very little else) does attempt to dispatch this little morsel into an unsavory snack, "Ol' Slip-and-Slide" will jump off the surface of the water, beat his little wings and fly away. Far, far away. His flight patterns have been observed to the distance of two miles.
He is not a lion, a tiger, or a bear, but he is just as perplexing. I now sit back in my canoe and ponder how perfectly Nature has built and planned all of its creatures. I also smile when I think of the next time someone will ask me, "Why, or how, do they do that?"
Photo Credits— Marko Kivela, Tony Bates, Jacob Enos.