Northland Nature: Insect mimicry seen on goldenrods
Retired teacher Larry Weber, a Barnum resident, is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him via Katie Rohman at email@example.com.
The wildflowers of September were fading. Roadsides and fields glowed with asters of several species and colors of whites and purples. Nearby, mixed with these late-flowering plants, were sunflowers of varying heights and kinds.
And there were the goldenrods. With ample sunlight and moisture, these delightful yellows of late summer lingered through the weeks. Some began blooming earlier in summer and for them, these September days were the time of waning blossoms and formation of seeds.
This continued to happen through this month of the autumnal equinox, and as the days exited, most goldenrods have now gone to seed. Producing the fluffy growths where flowers were, they allow seeds to drift in the breeze. But not all have made seeds.
Recently, as the second half of the month unfolded, I went for a walk in the roadsides and fields. Many of the goldenrods were past flowering, but others were still well in bloom. I went into these flowering patches and I quickly discovered that I was not the only one to find these fascinating flowers still in bloom. The plants were buzzing with activity of myriad insects. I paused to observe these six-legged critters.
Large and numerous, easy to see (and hear), were the bumblebees. A couple different species were here wearing various colors. They appeared to be totally oblivious to my presence and went about their business gathering pollen and nectar from the abundant tiny yellow florets of the goldenrods. But they were not the only bees.
I also saw honeybees and sweat bees along with some distant cousins: hornets, yellowjackets, paper and spider wasps (black wasps that specialize on catching spiders). We often associate these insects with stinging and so, it would be beneficial for other insects to look like bees and wasps and get left alone.
As I walked, I found these mimics. Among the bees were the look-alike flower flies. Again, there were several species and they ranged in shape and sizes. Some of the smaller flower flies (syrphid flies) are also known as hover flies since they can hold still at one spot in their flights.
This bee mimicry is superficial and when we look more carefully, we can discern the bees from the flies. Bees have four wings while flies have only two wings, held out away from the body. The mimicry comes from the stripes of brown and black mixed with yellow to somewhat resemble bees. Mimics or the real thing, they were all active here and no doubt doing much pollinating.
But this site gathered more and I saw the predaceous ambush bugs, stink bugs, ladybugs, damselflies and two kinds of dragonflies: large darners and small meadowhawks.
Some crab spiders were also taking advantage of the possible prey.
Black and yellow goldenrod soldier beetles climbed over the stalks while crickets, grasshoppers and locusts hopped and moved along the ground. A day-flying moth came by for a rest.
A couple south-bound monarchs paused for a snack and two other butterflies, a white cabbage and a yellow sulphur, were here, too.
As we proceed further into autumn, the insects (and goldenrods) will be fading. While the monarchs migrate, most of the remaining insects will succumb to chilly temperatures and frosts, but not before laying eggs. A few, like the ladybugs, will hibernate.
But for a time during these clear and pleasant days of late September and early October, the lingering blooming yellow flowers continue their hosting of predators, herbivores and mimicry, all in a single patch of goldenrods.