Flight of the October insects
Each year we look forward to the marvels that the natural world shows us in early October. With a dazzling display of bright colors in the tree leaves, we are seldom disappointed. As usual, this year my woods walks were surrounded by yellows and ...
Each year we look forward to the marvels that the natural world shows us in early October. With a dazzling display of bright colors in the tree leaves, we are seldom disappointed. As usual, this year my woods walks were surrounded by yellows and reds, and on some days, it was hard to find a tree that did not hold a blend of this fall foliage. Looking at the display, I noticed some of the other happenings at this time as well. Early October is a time of migration in our yards, parks and woods. Though quite varied, the ones that I noted most were the yellow-rumped warblers (usually the last of the warblers' fall flight) along with white-throated sparrows, juncos, robins, blue jays and rusty blackbirds all in flocks. They are on their way south, but remain with us for a while before resuming the wintering trek. But a clear October day, as this month is so frequently known for, also offers many other nature sightings.
As the chilly mornings warm into mild afternoons, myriads of insects that survived the frost will bask in the autumn sunlight. Out on the trails and roads, we can often see grasshoppers, crickets, dragonflies, woolly bear caterpillars and butterflies. Insects on these October days are facing the coming winter and deal with it in different ways. Some, like the grasshoppers, crickets and most dragonflies and butterflies, will lay eggs and die. We are seeing them now in their latter days. Migrants exist in the world of insects, best known being the monarch butterfly. Their flight is now beyond us, but the large green darner dragonflies seen now are also on the way to the southern states for winter. And quite a few insects will hibernate to cope with the coming cold. This group is diverse, but best observed in October with some butterflies.
Lately, I have been seeing plenty of black-orange butterflies called Milbert's tortoiseshells. With this color pattern in this month, it is easy to see why they have also been called "Halloween butterflies." Members of a group called anglewings, they, along with others called Compton tortoiseshell, comma and mourning cloak, sleep through the winter as adults and now use these mild October days to bask, feed and locate a site for winter: behind bark, cracks on branches or within a stack of firewood all suffice. These Milbert's tortoiseshells are present every fall, but I've see more this year than usual. And there's another strange insect that waits until night for its flight.
Last week, I was out for an evening walk. The sunset was pleasant, the hour was calm and a mild autumn day was ending. I paused to look over a swamp. I often stop here and watch the local bats performing their dusk flight. These flying mammals were here to gather insect meals over this shallow body of water. But as I watched their aerial antics, I noticed that there was another flight going on here, too. Every few minutes, I saw that something else was in the air. Large insects were rising from the swamp water and quickly making use of their powerful wings. And I realized that I was witnessing the autumn dispersal flight of the giant water bugs.
Up to three inches long and about half as wide, it may be the largest insect in the Northland. Not only big, it also possesses powerful front legs that act as claws and a strong piercing mouth. They prove to be one of the top predators in ponds and swamps all summer. But now with the shorter cooler days moving in, they need to find a larger body of water, usually a lake, to winter in. And they take this flight at dusk. Avoiding the bats, they moved fast. We don't usually see these water bugs despite their size, but during the night flight they sometimes get confused by parking lot and porch lights, and flutter here until exhausted. The next day, we might find them on the ground nearby. And so, I was not too surprised when, two days later, I was given one that was found nearby. It may be warm, but these clear mild October days show plenty of preparation for winter.
Retired teacher Larry Weber is the author of several books that are available now, including "Butterflies of the North Woods," "Spiders of the North Woods" and "Webwood." Contact him c/o firstname.lastname@example.org .