The Butterfly Book Part 35

SHAKESPEARE.

_b.u.t.terfly._--The antennae are short; the eyes of moderate size; the front full, protuberant; the palpi slender; the fore wings somewhat produced at the tip, with the outer margins rounded and the hind margins very slightly, if at all, sinuated. The nervules of the fore wings are slightly dilated toward the base; the hind wings are elongated, oval, with the outer margins evenly rounded. The color of these b.u.t.terflies is some shade of brown; the outer margin is generally lighter than the base of the wing, and is marked with black spots, sometimes pupiled with white. The wings are generally marbled and mottled on the underside, and sometimes crossed on the middle of the hind wings by a broad band of darker color. The fringes are brown, checkered with white.

[Ill.u.s.tration FIG. 122.--Neuration of the genus _OEneis_, enlarged.]

_Egg._--The egg is ovate-spherical, higher than broad, marked on the side from the apex to the base with raised sculptured ridges. These eggs are deposited, so far as we have been able to learn, on dried gra.s.s and the stems of plants in proximity to the growing plants upon which the young caterpillars are destined to feed.

_Caterpillar._--The head of the caterpillar when it emerges from the egg is somewhat larger than the rest of the body, but as it pa.s.ses successive moults and attains maturity the relative thickness of the body increases, and the adult larva tapers a little from about the middle in either direction. The larvae are pale green or brown, marked by darker stripes upon the back and on the sides, the markings on the sides being in most species more conspicuous than those on the back. The species all feed on gra.s.ses.

_Chrysalis._--The chrysalids are stout, very slightly angulated, and are formed, so far as we know, unattached, under stones and at the roots of gra.s.ses. When pupating, the caterpillar often makes for itself a slight depression or cell in the soil, in which a few threads of silk have been deposited, though not enough to justify us in calling the structure a coc.o.o.n.

This genus is composed of b.u.t.terflies which are mainly arctic in their habitat, or dwell upon the summits of lofty mountains, where the summer is but brief. Only a few species are found at comparatively low elevations, and these in British America, or the parts of the United States immediately contiguous to the Canadian line. The most widely known of all the species up to this time is the White Mountain b.u.t.terfly, _OEneis semidea_, Say, a colony of which has existed probably ever since the glacial period upon the loftiest summit of Mount Washington, in New Hampshire. A number of species are found in the region of the Rocky Mountains. One species, _OEneis jutta_, Hubner, occurs in Maine, Nova Scotia, and parts adjacent. There are in all about a score of species of this genus recognized by authors as occurring in our fauna. In spite of the fact that these insects are boreal or arctic in their habits, Mr. W.H. Edwards has with marvelous skill and patience succeeded in obtaining the eggs and rearing at his home in Coalburg, West Virginia, a number of species. We are indebted to him for more of our knowledge of the generic characteristics of these insects, in their early stages, than had been ascertained hitherto during a century of investigation. His work is one of the beautiful triumphs of that enduring zeal which is a supreme quality in the naturalist. In their early stages all of the species show a close likeness to one another.

(1) =OEneis gigas=, Butler, Plate XXVII, Fig. 1, ?; Fig. 2, ? (The Greater Arctic).

_b.u.t.terfly._--This, one of the largest species in the genus, occurs on Vancouver's Island. The b.u.t.terfly hides among the dark mosses and upon the trunks of prostrate trees. The males are vigilant and inquisitive, and dart out suddenly when alarmed, or attracted by pa.s.sing insects. The females have a slower and more leisurely flight and are more readily taken. Expanse, 2.00-2.25 inches.

_Early Stages._--Edwards has figured the egg and the caterpillar in its first three stages, but the remaining life-history of the species awaits investigation.

(2) =OEneis iduna=, Edwards, Plate XXVII, Fig. 4, ? (The Iduna b.u.t.terfly).

_b.u.t.terfly._--This insect, which even exceeds _OE. gigas_ in size, is found on the Coast Range in northern California. It is decidedly lighter on the outer third of the wings than the preceding species, the male being prevalently a pale yellowish-brown, with the basal and median areas of the fore wing dark brown. On the under side the wings are somewhat lighter than in the preceding species, and the transverse lines are more distinctly marked. Expanse, 2.00-2.30 inches.

+--------------------------------------------------------------+ | | | EXPLANATION OF PLATE XXVII | | | | 1. _OEneis gigas_, Butler, ?. | | 2. _OEneis gigas_, Butler, ?. | | 3. _OEneis macouni_, Edwards, ?. | | 4. _OEneis iduna_, Edwards, ?. | | 5. _OEneis jutta_, Hubner, ?. | | 6. _OEneis taygete_, Hubner, ?. | | 7. _OEneis brucei_, Edwards, ?. | | 8. _OEneis varuna_, Edwards, ?. | | 9. _OEneis ivallda_, Mead, ?. | | 10. _OEneis chryxus_, Dbl.-Hew., ?. | | 11. _OEneis semidea_, Say, ?. | | 12. _OEneis uhleri_, Reakirt, ?. | | | | [Ill.u.s.tration PLATE XXVII.] | +--------------------------------------------------------------+

_Early Stages._--These have been most beautifully delineated by Edwards in the third volume of "The b.u.t.terflies of North America."

(3) =OEneis macouni=, Edwards, Plate XXVII, Fig. 3, ? (Macoun's Arctic).

[Ill.u.s.tration FIG. 123.--Caterpillars of _OEneis macouni_ (Riley).]

_b.u.t.terfly._--This species is closely allied to the two foregoing, but may be distinguished by the broad median band of dark brown traversing the under side of the hind wings, as well as by other peculiarities of marking. It lacks the bar of raised scales which is found in the male s.e.x about the lower part of the cell of the fore wing in most of the species of the genus. It has been found thus far only on the north sh.o.r.e of Lake Superior and at the eastern base of the Rocky Mountains in the territory of Alberta. Expanse, 2.00-2.25 inches.

_Early Stages._--For a knowledge of these in all their minute details the reader is again referred to the pages of the indefatigable Edwards.

(4) =OEneis chryxus=, Westwood, Plate XXVII, Fig. 10, ? (The Chryxus b.u.t.terfly).

_b.u.t.terfly._--This species is widely distributed, being found in Colorado, British Columbia, and the vicinity of Hudson Bay. It is distinguished from other species by the darker brown color, which covers the basal and median areas of both the fore and hind wings, leaving a broad band of lighter brown on the outer margin. On the under side the wings are beautifully mottled with white and dark brown. _OEneis calais_, Scudder, is probably only a form of _chryxus_, which is somewhat lighter in color on the base of the wings. Expanse, 1.60-1.75 inch.

_Early Stages._--The life-history is fully recorded in the pages of Edwards.

(5) =OEneis ivallda=, Mead, Plate XXVII, Fig. 9, ? (Mead's Arctic).

_b.u.t.terfly._--This species is easily distinguished from all others by the peculiar pale ashen-brown of the upper side of the wings. It is not a common species, and is apparently restricted to the mountains of Nevada, princ.i.p.ally about Lake Tahoe, though it probably occurs elsewhere. Expanse, 1.90-2.10 inches.

_Early Stages._--Unknown.

(6) =OEneis varuna=, Edwards, Plate XXVII, Fig. 8, ? (The Varuna b.u.t.terfly).

_b.u.t.terfly._--This species is much smaller than any of those which have thus far been mentioned. It is found in the prairie lands of Montana, North Dakota, and the parts of Canada adjacent. It is not uncommon about Calgary. It is light in color on the upper side of the wings, and on the under side it is mottled with brown, strongly marked with blackish blotches or shades. Expanse, 1.50-1.60 inch.

_Early Stages._--These await description.

(7) =OEneis uhleri=, Reakirt, Plate XXVII, Fig. 12, ? (Uhler's Arctic).

_b.u.t.terfly._--This species is found in Colorado. It is redder on the upper side than _varuna_, and the females are generally very richly ornamented with eye-spots on the outer borders of both the fore and hind wings. Expanse, 1.45-1.55 inch.

_Early Stages._--These have been most thoroughly described and beautifully delineated by Edwards.

(8) =OEneis jutta=, Hubner, Plate XXVII, Fig. 5, ? (The Nova Scotian).

_b.u.t.terfly._--This beautiful species, which is also found in Europe, is not uncommon in the State of Maine as far south as Bangor, and occurs also in Nova Scotia, and ranges thence westward to Ottawa and the Hudson Bay country. It is one of the more conspicuous species of the genus, the eye-like spots upon the wings having a very striking appearance.

Expanse, 1.80-2.10 inches.

_Early Stages._--For a thorough knowledge of these the reader may consult the pages of Scudder and Edwards.

(9) =OEneis semidea=, Say, Plate XXVII, Fig. 11, ?; Plate III, Figs. 1, 2, 4, 7, 15, _larva_; Plate IV, Figs. 4, 5, _chrysalis_ (The White Mountain b.u.t.terfly).

_b.u.t.terfly._--This species has thin wings, and is much darker in color than any of the species which have thus far been mentioned. It is restricted in its habitat to the summit of Mount Washington, in New Hampshire, and only reappears on the high mountains of Colorado and in Labrador. Its life-history has been very carefully worked out. It is to be hoped that entomologists and tourists resorting to Mount Washington will not suffer it to disappear by reason of too wholesale a capture of the specimens, which hover about the barren rocks on which the race has existed since the great continental ice-sheet melted away and vanished from the face of New England. Expanse, 1.75 inch.

_Early Stages._--The curious reader is again referred for a knowledge of these to the pages of Scudder and Edwards. They are similar to those of other species, and the generic description which has been given must suffice for all in this work.

(10) =OEneis brucei=, Edwards, Plate XXVII, Fig. 7, ? (Bruce's Arctic).

_b.u.t.terfly._--Though somewhat closely related to the last species, Bruce's Arctic may at once be distinguished from it by the broad dark band on the under side of the secondaries and the great translucency of the wings, which permits a label to be read through them. It is found in Colorado and in British Columbia at an elevation of from twelve to thirteen thousand feet above sea-level. Expanse, 1.75 inch.

_Early Stages._--All we know of these is contained in the pages of Edwards' great work.

(11) =OEneis taygete=, Hubner, Plate XXVII, Fig. 6, ? (The Labrador Arctic).

_b.u.t.terfly._--Much like _OE. brucei_, but the wings are not so translucent as in that species, and the broad mesial band on the under side of the hind wings is differently shaped, being more strongly directed outward just below the costa. The figure in the plate is from a specimen taken at Nain, in Labrador. Expanse, 1.75 inch.

_Early Stages._--Unknown.

There are eight or nine other species of _OEneis_ in our fauna, but they are all arctic, and most of them very rare. Those we have described and figured will give a good idea of the genus.

IN THE FACE OF THE COLD

When the full moon hangs high overhead, the snow creaks underfoot, the north wind roars with furious blast, and the trees of the forests crack in the frost with a report like that of cannon, then, hanging in its little nest on the bare branches of the wind-tossed trees, the tiny caterpillar of the Viceroy keeps the spark of life where men freeze and die. Nothing in the realm of nature is more wonderful than the manner in which some of the most minute animal forms resist cold. The genera _Erebia_ and _OEneis_, and many species of the genus _Brenthis_, are, as we have already learned, inhabitants of the arctic regions or of lofty Alpine summits, the climate of which is arctic. Their caterpillars often hibernate in a temperature of from forty to fifty, and even seventy, degrees below zero, Fahrenheit.

It has been alleged that caterpillars freeze in the winter and thaw out in the spring, at that time regaining their vitality. Thus far the writer is unable to ascertain that any experiments or observations have positively decided for or against this view. A number of recorded cases in which caterpillars are positively stated to have been frozen and to have afterward been found to be full of vitality when thawed are open to question.

The most circ.u.mstantial account is that by Commander James Ross, R.N., F.R.S., quoted by Curtis in the Entomological Appendix to the "Narrative" of Sir John Ross's second voyage to the arctic regions. The specimens upon which the observations were made were the caterpillars of _Laria rossi_, a moth which is found abundantly in the arctic regions of North America. I quote from the account: "About thirty of the caterpillars were put into a box in the middle of September, and after being exposed to the severe winter temperature of the next three months, they were brought into a warm cabin, where, in less than two hours, every one of them returned to life, and continued for a whole day walking about; they were again exposed to the air at a temperature of about forty degrees below zero, and became immediately hard-frozen; in this state they remained a week, and on being brought again into the cabin, only twenty-three came to life; these were, at the end of four hours, put out once more into the air and again hard-frozen; after another week they were again brought in, when only eleven were restored to life; a fourth time they were exposed to the winter temperature, and only two returned to life on being again brought into the cabin; these two survived the winter, and in May an imperfect _Laria_ was produced from one, and six flies from the other."

The foregoing account seems to verify more thoroughly the stories that have been told than anything else I have been able to discover within the limits of entomological literature, but does not conclude argument.

It would be interesting in these days, when methods of artificial freezing have been so highly perfected, to undertake a series of experiments to prove or disprove, as the case may be, the view which has been held since the time of the ancients. There is here a field for nice investigation on the part of some reader of this book. In making the experiment it probably would be well to select the larvae of species which are known to hibernate during the winter and to be capable of withstanding a great degree of cold.

The effect of cold suddenly applied to the chrysalids of b.u.t.terflies at the moment of pupation is often to produce remarkable changes in the markings. The spots upon the wings of b.u.t.terflies emerging from chrysalids thus treated are frequently rendered more or less indistinct and blurred. The dark markings are intensified in color and enlarged; the pale markings are also in some cases ascertained to experience enlargement. Many of the strange and really beautiful aberrations known to collectors have no doubt been produced by the action of frost which has occurred at the season when the larva was pupating. The species believed by the writer to be most prolific in aberrations are species which pupate early in the spring from caterpillars which have hibernated or which pupate late in the autumn. Some are species found at considerable alt.i.tudes above sea-level, where late frosts and early frosts are apt to occur. A number of very beautiful experiments upon the effect of cold upon the color of b.u.t.terflies have been made in recent years, and some very curious phenomena have been observed. The writer has in his collection a considerable number of strikingly aberrant specimens which emerged from chrysalids treated to a sudden artificial lowering of the temperature at the critical period of pupation.