We recently began the new season of fall; the equinox was the night of Sept. 22 and 23 this year (the same as the full moon). Now the hours of darkness outnumber those of light; as it will be for the next six months.
Preparation for the impending chilly temperatures abounds in the Northland, and we see this happening each day. Trees have put on their autumn attire as they await the massive leaf drop of October. Ripening apples join other fruits and berries maturing now. Lingering summer wild flowers are fading as new batches of late mushrooms adorn the woods.
Overhead, we see plenty of migrants. The hawks and other raptors continue their southbound trek. Every morning and evening Canada geese tell of their journey as well. And in our yard, we observe groups of blue jays, sparrows, thrushes and a few warblers.
This is the time that I like to visit the bay of a nearby lake and watch the changing season here. Water is still relatively warm and, though freeze-up is nearly two months away, things are happening here in this aquatic world too. I have been watching a pair of young loons that grew up on the lake this summer. Now, with the adults gone, the youth rest, feed and grow for the flight which they'll be taking soon, as the water cools. A few ducks come by to rest. The local kingfishers, sandpipers and herons are finishing their rounds before going.
And then there are insects. Through much of September, the surface of this bay is alive with the movement of small insects called whirligig beetles. Their strange name is appropriate. When threatened or scared, they go through gyrating motions, making them hard to see or capture. They can dive under water and take flight, but they usually do neither, being more willing to stay on the surface.
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Only about one-half inch long, dark in color and shaped like an oval, they are well adapted to this wet world. A plethora of insects swim in this scene but nearly all are subsurface. While aquatic insects usually have developed back legs for swimming, whirligig beetles use powerful front appendages to make their circling motion. Here in the protection of the bay, they spend the summer days feeding as predators on any available small invertebrates. Staying in one location for much of the day, they go out at night on long travels around the lake. I have noticed many days when the bay is full of their kind, but they are absent the next day. With such small bodies, their treks are, no doubt, quite a challenge, but with the calming of winds, as usually happens in evening, they move as far as they can. With the coming of daylight, they find safe harbor in bays, coves or even behind downed logs, to wait out the winds.
Much of the summer is spent with the addition of the new crop for this year. The young hatch in spring, and after the immature stages, they emerge in summer. Molting frequently, they reach the size of the adults by late summer. By September, the population of these gyrating insects in the bay is at its peak.
Now they prepare for the autumn changes in their own way. Moving about the waters, they get into the shallows and near shore where these water-borne insects, never on land, spend winter in a dormant stage in mud and aquatic plants. Like the woods, the bay shows more seasonal preparations as we get cooler.
Retired teacher Larry Weber is the author of several books that are available now. Contact him c/o budgeteer@duluthbudgeteer.com .
