Butterflies Worth Knowing Part 22

These b.u.t.terflies come from the South in spring or early summer. They find milkweed plants and lay their eggs upon the leaves. These eggs soon hatch into small white and black caterpillars that feed upon the milkweed leaves and grow rapidly. One is likely to find them throughout most of the summer, wherever a milkweed shows partially eaten leaves. Bring in the half-grown caterpillars, place them in an open vivarium, and furnish fresh leaves every day or two. The caterpillars will soon mature and change to beautiful green chrysalids with golden markings. This chrysalis has been called "the gla.s.s house with the gold nails." (_See plates, pages 32-33, 241._)

About two weeks later the gla.s.s house will burst open and the b.u.t.terfly emerge. It will rest an hour or two while its wings and body harden and then it will want to fly away. It is not so anxious to do this, however, as most b.u.t.terflies. If one is kept beneath a good-sized bell-gla.s.s, or in a gla.s.s-covered box, or even in a closed room, and fed with sweetened water it will soon become so tame that it will perch on one's finger and suck nectar from a flower held in one's hand. On this account it is a particularly desirable b.u.t.terfly for the amateur photographer to cultivate, because he can easily get many interesting and beautiful pictures by posing the b.u.t.terfly on different flowers.

_The Change from Caterpillar to b.u.t.terfly_

The change from the caterpillar to the b.u.t.terfly is easier to watch in this species than in most others. The full-grown caterpillar spins--sometimes on the under surface of the milkweed leaf, sometimes elsewhere--a little mat of silk in which it entangles the hooked claws of its hind feet. Then it lets go with its fore feet, and hangs downward with the front end of its body curled upward. In this position it remains for some hours--perhaps a day--the body juices gravitating downward and causing a swollen appearance on the lower segments. Then the skin splits apart and is wriggled off by the contortions of the body. When it finally drops away, there is left a strange-looking creature, broader below than above. This is a transition stage that lasts but a very short time: soon the form is entirely changed so that the broadest part is above instead of below.

The definite outline of the chrysalis is soon taken on, the outer tissues hardening into a distinct covering. The insect is now a beautiful green with wonderful golden spots upon its surface and a few black spots just below the black "cremaster" by which the chrysalis is connected with the web of silk upon the leaf.

In this quiet chrysalis the insect remains for nearly a fortnight.

Then the structure of the forthcoming b.u.t.terfly begins to show through the thin outer covering and you know that the period of the chrysalis is nearly ended. If you keep watch you will probably see the sudden bursting of the outer envelope and the quick grasping of its surface by the legs of the newly emerged b.u.t.terfly. Its wings at first are short and crumpled, bearing little resemblance to those of the fully developed b.u.t.terfly. But as it hangs there with one pair of legs holding to the empty chrysalis and the other to the leaf above, the wings rapidly lengthen, hanging limply downward, and the body juices penetrate the veins. A little later they expand in the other direction, the hind wings reaching full size before the front ones do.

Finally both pairs of wings are fully expanded, and the b.u.t.terfly is likely to walk to the top of the support, where it rests for an hour or two while its tissues harden, before it attempts to fly.

In early autumn out of doors these b.u.t.terflies start southward on their long journey. They often gather in great flocks and roost at night on wayside shrubs and trees. At this season it is easy to catch them in an insect net and bring them indoors for pets. They live for a long while and lend interest and beauty to living room or window garden. To the photographer they offer opportunities for attractive indoor pictures. (_See plates, pages 32-33, 160, 225._)

=The Queen= _Anosia berenice_

The general form and color patterns of this fine b.u.t.terfly show at once that it is related to the Monarch. Its general colors are chocolate-brown and black, dotted and spotted with white. The eggs are laid upon milkweed and the life-history is much like that of the Monarch. One of the most interesting facts in connection with this species is that it seems to be mimicked by the Vicereine b.u.t.terfly in the same way that the Monarch is mimicked by the Viceroy.

THE SNOUT b.u.t.tERFLIES OR LONG-BEAKS

FAMILY _Libytheidae_

One has a suggestion of Hobson's choice in the common names of this unique family. If Snout b.u.t.terflies does not seem sufficiently elegant as a descriptive phrase for such delicate creatures, he can call them the Long-beaks, until he sees that this also is inadequate. As a matter of fact both are misnomers, for the projection from the head that gives them these names is neither a snout nor a beak. It is simply a pair of palpi unusually developed, which perhaps in an early stage of b.u.t.terfly history served a useful purpose. At present, however, they serve chiefly to set the few owners apart from the other b.u.t.terflies in the system of cla.s.sification; although possibly they may also serve the b.u.t.terfly by helping to give the impression of a leaf attached to a twig. (_See plate, page 240._)

=The Snout b.u.t.terfly= _Hypatus bachmani_

There is a peculiar interest in any form of animal life which can be definitely traced far back through the geologic ages. In nearly every group of living creatures there are certain types which scientists have found were once abundant but which now are on the wane. As a rule these are better represented in the museums through fossil species than by those now living. To a considerable extent also such forms are likely to present various features which mark their primitive condition and the living allies have peculiarities which set them off as distinct from those of their own relations which have been modeled in a more modern fashion. Among the mammals the curious marsupials, of which our southern opossum is an example, furnish good ill.u.s.trations of this general truth. Among the birds the curious little Least Bittern is an example. Among the b.u.t.terflies the strange Snout b.u.t.terfly is by far the best example.

These Snout b.u.t.terflies, of which only two species are now living in North America, are the sole representatives with us of the family _Libytheidae_ or the Long-beaks. Only one of these species occurs to any extent at least north of Texas. It is the curious little creature called the Snout b.u.t.terfly. It has a strange appearance due to the angular outline of both front and hind wings and the long palpi which project forward from the head in a way to attract attention. The common name is due to these projecting palpi. Even the coloring is primitive, the general tone of the wings being blackish brown, distinctly marked with white and orange spots. The under surface is less primitive in its coloring, being toned in iridescent grayish brown in a way to suggest protective coloring, except in that part of each front wing which is not hidden when the insect is at rest. This shows the white and orange-brown markings.

Some years ago there were found in certain fossil deposits in the West about a dozen species of fossil b.u.t.terflies. It is strange indeed that these ethereal creatures should be fossilized at all. One would think it scarcely possible that they could be so preserved that a million years after they had died man should be able to study them, determine to what families they belonged, and even guess with a high probability of accuracy upon what leaves their caterpillars fed. This little collection of fossil b.u.t.terflies was studied by one of the great American authorities on living b.u.t.terflies, the late Samuel H.

Scudder, who said of them: "They are generally preserved in such fair condition that the course of the nervures and the color patterns of the wings can be determined, and even, in one case, the scales may be studied. As a rule, they are so well preserved that we may feel nearly as confident concerning their affinities with those now living as if we had pinned specimens to examine; and, generally speaking, the older they are the better they are preserved."

A curious fact is that out of the comparatively few species of these fossil b.u.t.terflies two were easily recognized as members of this Long-beak family. They were given special scientific names and undoubtedly were closely related to the Snout b.u.t.terfly which is still flying every year in various parts of the United States. Our modern species lays its eggs upon the leaves of hackberry and in these geologic deposits of that far-gone era there have been found well-preserved leaves of old hackberry trees, upon which it is extremely probable that the caterpillars of these ancient Long-beaks fed. What an opportunity for a modern collector of b.u.t.terflies to work his fancy, as he thinks of those old times when these fossil creatures were flying in the sunshine, depositing their eggs upon the leaves of trees that made up landscape pictures probably very different from those of to-day! And how he wonders what flowers these b.u.t.terflies visited for their nectar food, what birds chased them from tree to tree, and what mammals wandered through those ancient forests. What a suggestion also it gives of the continuity of life upon our old earth to realize that these b.u.t.terflies of to-day are carrying on their brief existence in practically the same way that these forbears of theirs did so many millions of years ago.

Another way in which these b.u.t.terflies are peculiar is the fact that the females have six well-developed legs while the males have only four. As already indicated the caterpillars feed upon hackberry. When full grown they are about an inch long, dark green, striped with yellow, with two blackish tubercules on the second ring behind the head. They apparently pa.s.s the winter in the chrysalis stage. The b.u.t.terflies are likely to be found along the borders of brooks or streams running through woods, or along the margins of the forest.

Occasionally they become abundant in certain localities, but on the whole they are rare and highly prized by collectors.

THE METAL-MARKS

FAMILY _Riodinidae_

This small family of very small b.u.t.terflies contains five genera and a dozen species found in the United States and Mexico. Only two, however, occur in the eastern region and only one extends much north of the Gulf states. Aside from certain peculiarities of the wing-venation (a costal and a humeral vein on the hind wings) these Metal-marks may be known by their minuteness and the bright metallic markings on the brown wings.

Both our eastern species belong to the genus _Calephelis_. The Small Metal-mark (_C. caenius_) has been collected in Florida and Georgia.

The wings are rusty red on both surfaces, brighter below than above, and marked with blackish spots that almost converge to form stripes; in addition to which there are, beyond the middle of each wing, two lines made by special scales that glisten with a steel glitter. The wings expand only about three quarters of an inch. So far as I can learn, the egg, larva, or pupa have never been described.

The Large Metal-mark is called by science _Calephelis borealis_, but it deserves the latter name only in the sense that it is more northern than its allies. It has been collected as far north as New York and Michigan, but it seems to be very seldom found, at least in eastern regions. It expands a little more than an inch. The general color of the wings is yellowish brown, marked with blackish dots and lines, together with rows of steely spots on the under surface. In this case also the life-history is unknown.

[Ill.u.s.tration: _See page 236_

THE SNOUT b.u.t.tERFLY IN FLIGHT AND AT REST]

[Ill.u.s.tration: _See page 62_

GIANT SWALLOWTAIL JUST OUT OF THE CHRYSALIS]

[Ill.u.s.tration: _From a drawing by W. I. Beecroft_ _See page 233_

THE MONARCH b.u.t.tERFLY

Caterpillar feeding; caterpillar hung up for pupation; chrysalis, and adult]

THE GOSSAMER-WINGS

FAMILY _Lycaenidae_

The daintiest and most delicate of all our b.u.t.terflies are included among the Gossamer-wings. Their bodies are small and slender, their antennae ringed with white and almost threadlike, their wings thin and of exquisite beauty. Many of them are marked with the slenderest of tailed projections from the hind wings. When the face is viewed from in front it is seen to be much narrower than its height. At the insertion of the antennae the eyes are notched, and they are also more or less surrounded with white scales. Most of the caterpillars have oval, slug-shaped, smooth bodies, with the under surface flattened, and very small heads, which in many species can be extended by means of an extensile neck. The chrysalids are held in place by silken threads both at the tail and over the middle. They are rounded, short, and stout.

Notwithstanding their small size, the Gossamer-wings are among the most spritely of all our b.u.t.terflies. They seem indeed winged sprites, playing everywhere, in fields and open woods, along roads, lanes, and brooks, in dooryards and gardens--wherever, in fact, a bit of open s.p.a.ce invites their presence. Not alone upon the wing but even when at rest does their liveliness appear. For most of these b.u.t.terflies have the curious habit of keeping the hind wings in motion after alighting, rubbing them against each other in a vertical plane or "moving them backward and forward when half expanded." These habits are so fixed that when one sees a b.u.t.terfly thus engaged one can pretty certainly conclude it is a member of this family.

The Gossamer-wings are commonly separated into three rather distinct tribes--the Hair-streaks, the Coppers, and the Blues. The characteristic features are these:

Three branches arising from the radius of each front wing. Under surface of hind wing commonly marked with threadlike streaks: the Hair-streaks.

Four branches arising from the radius of each front wing. Under surface of hind wing commonly marked with spots rather than lines.

Colors brownish red: The Coppers.

Colors blue: The Blues.