Nettle-Leaf Tent-builders
VERY few of our readers will need an introduction to the nettle. It is, perhaps, the one plant which may claim the largest number of intimate acquaintances. It was Dr. Culpepper, the old-time herbalist, I believe, who claimed, moreover, that it was one of the easiest of plants to distinguish, in proof of which he affirmed that "it could be found even on the darkest night by simply feeling for it." Even those most ignorant of botany, after having once "scraped acquaintance," as it were, with the nettle, find it to their interest to keep its memory green.
It is partly because it is so well known, and partly because so few people use their eyes analytically, that a certain little mystery of the plant is so well guarded. For almost any bed of nettles may well tempt the young entomologist to tarry, while he forgets the tingling fingers as he fills his collecting-box with welcome specimens.
We are sure to have company if we linger long about our nettles. There is a small brood of butterflies which we can always count upon. Here is one of them coming over the meadow. It has a sharp eye for nettles, and is even now on the lookout for them. In a moment more its beautiful black, scarlet-bordered and white-spotted wings are seen fluttering among the leaves, alighting now here, now there, each brief visit leaving a visible witness if we care to look for it. It has now settled upon a leaf within easy reach. Creeping along its edge, it is soon hanging beneath, but only for a second, and is off again on the wing. Let us pluck the leaf. Upon looking beneath it we may see the pretty token of the Red Admiral, a tiny egg which we may well preserve for our microscope.
We shall not wait long before another butterfly visitor arrives, smaller than the last, and with its deep orange, black-spotted wings conspicuously jagged at the edges—one of the "angle-wings," which immediately announces his name as he alights with wings folded close above his back, disclosing the silver "comma" in the midst of the dull brown of the nether surface. Many are the tiny tokens which she also leaves behind her as she flutters away in search of a new nettle-clump.
We have been closely observing these two butterflies perhaps for half an hour, and during that time our eyes have rested a dozen times upon a condition of things here among the leaves which certainly should have immediately arrested our attention. Almost within touch of our hand, upon one stalk, are three leaves which certainly do not hang like their fellows. One of them has been drawn up at the edges, and fully one-half of its lower portion is gone, while its angle of drooping indicates more than the mere weight of the leaf. "A spider's nest, of course," you remark. As such it has been passed a thousand times even by young and enthusiastic entomological students who would have risked their lives for a "cecropia" or a "bull's-eye" caterpillar, or stung their hands mercilessly as they swept their butterfly net among those very stinging leaves. It is interesting to gather a few of these "spider's nests," and examine the cause of their heavy droop, which proves to be a healthy-looking gray caterpillar an inch or more in length, covered with formidable spines, perpetuating as it were the tendency of its fosterplant. Only yesterday he built himself this tent, having abandoned the remnant tent just below, for he eats himself out of house and home every couple of days. About five weeks ago he began his career, his first meal consisting, perhaps, of the iridescent shell of a tiny egg—precisely such a one as our first butterfly visitor has just left, for this is the caterpillar of the Atalanta or Red Admiral.
We may find a number of these tents if we look sharp, and even while gathering them may overlook a still more remarkable roof-tree of another caterpillar, which constructs its pavilion on quite a different plan. This, too, might even deceive a "spider," the edges of the leaves being drawn together beneath, and the veins partly severed near the stem, giving it quite a steep pitch. Upon looking beneath, we disclose another prickly tenant somewhat similar to the first, only that he is yellow and black instead of gray, while he is clothed with the same complementary growth of branching spines.
A single nettle-clump of any size will disclose dozens, perhaps hundreds, of these tent-dwellers. Though armed with formidable chevaux-de-frise, these species are stingless, and the caterpillars may be safely gathered. The object of my directing attention to them is not simply to disclose them in their haunts, but to recommend their transfer to our collecting-box, looking to the further beautiful surprise—always a surprise—which they have in store for us. Although they quickly desert their tents in captivity, they continue to feed on the fresh leaves provided from day to day, and suffer little in confinement.
The full-grown caterpillars are about an inch and a half in length, and if our specimens average such dimensions we shall not have many days to wait for our surprise. Perhaps to-morrow, as we open the lid of our box, the caterpillars will be seen to have left the leaves, and to be scattered here and there on the lid or walls of their prison in apparent listlessness. Let us observe this individual here beneath the box cover. Its body is bent in a curve, and a careful inspection reveals a carpet of glistening silk, to which it clings. Now the insect regains confidence, and takes up the thread which it dropped a moment ago when the box was opened, its head moving from side to side in a motion suggesting a figure 8, with variations. Gradually, through the lapse of several minutes, this sweep is concentrated to a more central point, which is at length raised into a minute tuft of silk; and if we wait and watch for a few moments longer, we shall see our spinner turn about and clasp this tuft with its hinder pair of feet. And this same process has been going on in different parts of our box. Lifting the lid an hour or two later, we find the interior full of the caterpillars dangling by their tails, each with its body forming a loop.
Twenty-four hours after this suspension a singular feat and a beautiful transformation take place, a revelation which, as I have said, even to those already familiar with it, is always new and surprising. Here, indeed, may we observe "the miraculous in the common."
It is as though our box had met with some enchantment beneath the wand of Midas or Iris; for is it not, indeed, a box of jewels that is now disclosed, a treasury of quaint golden ear-drops of a fashioning unlike any to be seen in a show-case, but which might well serve as a rare model for the mimetic art of the jeweller? When we consider the length to which these exquisite artisans will go for their natural originals—the orchids in gems, beetles in jewelled enamel, butterflies in brilliants and emeralds and rubies—need we wonder that this one most significant model of nature's own jewelry, apparently designed as a tempting pendant, should have been ignored by a class of designers to whom its claims would seem irresistible? But we forget. The jeweller is not necessarily an entomologist or naturalist. The butterfly, the beetle, the flower, every one sees; how few even dream of these glowing chrysalids (aurelias) which hang beneath the nettle leaves or in unseen coverts among the hop or thistle?
I have looked in vain among all the designs in the shops for any hint of the existence of such a thing as the aurelia of Archippus, comma, semicolon, Red Admiral, Hunters, White J.; and, indeed, even if wrought to imitative perfection, how few would recognize any resemblance to aught on the earth or in the waters under the earth!
I will not attempt to describe this living gem of our "comma." There are degrees in its brilliancy, an occasional specimen being almost a mass of gold. Indeed, we need scarce wonder that the aurelia should have proved so tempting a lure to the ancient alchemists.
Almost any group of nettles will show us our "comma" caterpillar, but one of its favorite haunts is the wood-nettle, a large-leaved, low variety, which is to be found in moist woods and shady river-banks, and will be recognized by the illustration on the preceding page. I have gathered many of these animated tented leaves in a few moments' search among the plants.
I have said nothing of the wonderful transformation of the caterpillar to its chrysalis, and the astonishing trick by which the latter gets out of its skin, and again catches the silken loop with its tail. This feat is well worth a close study; the authorities in the past have all been at sixes and sevens as to what really takes place. Which of our boys or girls can discover the facts as they are, and tell us why the chrysalis does not fall out at the last moment?