Northland Nature: A couple of late-season moths in early NovemberAs October was making its exit, it did with many features that are part of these days.
As October was making its exit, it did with many features that are part of these days.
After the first half of the month being far above normal in temperature, we dropped down beyond the usual lows several times. Readings that had avoided the 20s so far this season reached into this subfreezing range and we saw the responses.
During my morning walks last week, I noticed how the ice had begun to creep onto the surface of ponds. Its rate surprised even me, and in a few ponds the entire wetland held this thin covering.
October 20 also marked the beginning of measurable snowfall with some areas recording several inches of this blanket. I watched as flakes accumulated on the leaves of apples and lilacs, both still green, and coat a nearby fern.
As if these conditions were not enough for the end of October, they were frequently accompanied by strong winds. North and west winds at this time can aid in bird migration, but also hit the trees hard.
These tall woody plants that still held foliage — maples, oaks, aspens, birches and basswoods — all shed copious amounts of leaves. The woods that resisted the drop for so long is now mostly without leaves, while nearby tamaracks of the swamps continue to abound with golden glows.
The time of AutWin is upon us.
AutWin is the unique time slot that we experience each year at the end of October and early November. It is the weeks after the leaves have dropped from the trees until the ground is covered with snow.
Some years AutWin is six weeks long;
others, only two. But it happens each year and provides us with a chance to look at another view of the Northland landscape. Among the bare trees and drab scene, evergreen conifers stand out. But along with them, plenty of other plants remain green as well: ferns, princess pine, mosses and even a few deciduous trees.
It is a great time to walk through the woods, or on adjacent roads, with still plenty to see here, but what is not expected are insects. However, nature holds lots of surprises, and recently I noticed two kinds of moths still active on this late date. One was in the warm sunlight, the other in the chill of darkness.
Wooly bear caterpillars have been with us throughout the autumn. During earlier bike rides and walks on roads, I expected to see these fuzzy caterpillars and I was rarely disappointed. These hairy critters are the young (larva) of a type of moth. And their bands of black and red-brown are a familiar sight in fall.
Unlike most caterpillars that we see at this time, it is not going to spin a cocoon for the winter and emerge next spring. Instead, the woolybear will winter as a caterpillar.
And what we are seeing now is the caterpillars looking for a wintering site, usually curled up under leaves and grasses. Surviving the cold season here, it will form a cocoon next spring and by summer develop into the adult form, an Isabella moth. Though the adult is a colorful yellow-white pattern, we don’t see the adults much, but we know the moth by its immature stage.
(This happens with other moths too. There are others better known as caterpillars — armyworms, tomato hornworms, inchworms, etc. — but with butterflies, we tend to know the adults more than the
The other late-season moth is even weirder.
The other night as I sat inside during a 38-degree evening, I noticed movement against the windows. Taking a closer look, I saw that these brown-gray moths had arrived. We collectively call these “late-season” moths because of the time of their flight (I have even seen them on snow), but they are actually a couple of different species, linden or basswood looper and fall cankerworm. (With their flight time of late October coinciding with the baseball autumn classic, I have frequently referred to them as “World Series moths.”)
Adults wait until this time of chilly temperatures and little food to emerge. Such conditions make their survival look difficult, but they adapt to the cold.
As I watched these moths at the window, I could see one adaptation: they shivered their bodies to raise their body temperature before taking flight.
Also, food is no problem since the adult does not feed; it doesn’t even have a mouth. It suffices on stored food until mating and egg-laying is over.
And fewer bird predators here at this time makes easier movement for the moths.
The AutWin days of early November will be cool; but taking a walk now, we’ll see how nature remains active, including a couple of moths.
Retired teacher Larry Weber is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods” and “Webwood.” Contact him c/o firstname.lastname@example.org.