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?

Eye Spy: Afield with Nature Among Flowers and Animate Things · 第 26 / 40 题