As we move into the fall season, many familiar autumn insects are likely to catch our eye. Out-of-work yellow jackets are on the prowl. The glistening webs of the showy black-and-yellow Argiope spiders appear in dew-drenched splendor in meadowlands, and the less-admired nests of the fall webworm in roadside trees are all too visible. The so-called Halloween lady beetles are looking for overwintering sites, perhaps in your home, and children everywhere are examining the black and rust stripes of the fuzzy woolly-bear caterpillars in hopes of determining the severity of the upcoming winter.
As an insect enthusiast, I can truthfully say that no insect fails to interest me in some way. But some bugs have habits that would be remarkable to even the most blasé observer. A good example is the turtle-shaped tortoise beetle, which overwinters as an adult, hiding under the shelter of leaf litter or in other dry protected areas. The color of these leaf beetles varies by species, but many seem to be made of liquid gold, particularly during mating. When the beetles are seen on morning glory and bindweed, the common name “gold bug” is a perfect fit.
While the adult beetles can be real showstoppers because of their color, the immature form goes all out, in a rather bizarre way, to mask its appearance. The tortoise beetle larva is oval, flattened, and covered with thorny, branched spines. The longer posterior pair of spines curls back over the body like a tail and is used to catch and hold excrement and cast skins in a parasol-like shield.
Another member of the leaf beetle family also exploits the ready availability of its own excrement, but in a very different way. Rather than simply masking itself in debris, the larva of
the warty leaf beetle fashions a protective case of dried feces to look like caterpillar droppings. The bumpy surface of the adult beetle itself resembles droppings to such an extent
that pinned specimens of caterpillar droppings even end up in insect collections from time to time.
Sometimes the best a mother insect can do before she dies is to provide food for her young by laying eggs in or near an appropriate food source. A small minority of insects actually sticks around to protect their eggs or their young ones. The earwig is one such insect. The female earwig is readily recognizable because the forceps-like pincer at the tip of her abdomen is smaller and less curved than that of the male. The pincers are used offensively and defensively, as well as during courtship.
Earwigs spend the winter paired in cells in the soil. Males are banished in early spring at about the time the female lays eggs. The mother guards and tends the eggs, regularly turning and cleaning them to prevent mold and dessication, and she also protects newly hatched young from predators. Eighty years ago, the entomologist B. B. Fulton wrote, “a nest of young earwigs is a most interesting sight; they seem to fill the cavity, a squirming, writhing mass. The old earwig standing in their midst with the nymphs crawling under, over and about her, reminds one of an old hen with a brood of chicks.”
Eventually, the young earwigs take up a free-foraging lifestyle. That’s when they end up in the odd places in which we find them. And, no, contrary to a widespread superstition, I don’t mean your ears! (By the way, have you heard that pulverizing dried earwigs and mixing them with the urine of a hare is a remedy for deafness? Trying to locate the urine of a hare must have kept our ancestors hopping.)
Speaking of which, the insects called treehoppers also exhibit some interesting tactics for self-preservation. As adults, these insects have long attracted attention because of their bizarre forms and unusual behaviors. The noted entomologist, John Comstock, suggested that “nature must have been in a joking mood when treehoppers were developed.” The front section of the thorax, called the pronotum, is enlarged and often very ornate. It may bear spines, knobs, or other odd shapes.
Some treehoppers look like thorns and are easily mistaken as part of the plant on which they feed. At this time of year, you might keep your eyes open for the aptly named two-marked treehopper. Females of this species are relatively long-lived and may be observed laying eggs on black locust and other hosts from early August until the first heavy frosts.
The sometimes balmy, sometimes crisp days of fall are a great time for observing the lives of insects. As the curtain goes up on our ever-resplendent fall foliage, remember that there is also a great deal going on backstage.