The Butterfly Book Part 30

Of fossil b.u.t.terflies there have thus far been discovered sixteen species. Of these, six belong to the subfamily of the _Nymphalidae_, and five of the six were found in the fossiliferous strata of Florissant, Colorado. Two species belong to the subfamily _Satyrinae_, both occurring in deposits found in southern France, and representing genera more nearly allied to those now found in India and America than to the _Satyrinae_ existing at the present time in Europe. One of the fossils to which reference has already been made belongs to the subfamily of the _Libytheinae_. The remainder represent the subfamilies of the _Pierinae_, the _Papilioninae_, and the family _Hesperiidae_.

It is remarkable that the b.u.t.terflies which have been found in a fossil state show a very close affinity to genera existing at the present time, for the most part, in the warmer regions of the earth. Though ages have elapsed since their remains were embedded in the mud which became transformed into stone, the processes of life have not wrought any marked structural changes in the centuries which have fled. This fixity of type is certainly remarkable in creatures so lowly in their organization.

+--------------------------------------------------------------+ | | | EXPLANATION OF PLATE XXIV | | | | 1. _Pyrrhanaea andria_, Scudder, ?. | | 2. _Pyrrhanaea morrisoni_, Edwards, ?. | | 3. _Pyrrhanaea portia_, Fabricius, ?. | | 4. _Ageronia feronia_, Linnaeus, ?. | | 5. _Ageronia fornax_, Hubner, ?, | | _under side_. | | 6. _Victorina steneles_, Linnaeus, ?. | | 7. _Cystineura amymone_, Menetries, ?. | | 8. _Synchloe crocale_, Edwards, ?, | | _under side_. | | 9. _Synchloe crocale_, Edwards, ?. | | 10. _Eurema lethe_, Fabricius, ?. | | | | [Ill.u.s.tration PLATE XXIV.] | +--------------------------------------------------------------+

SUBFAMILY SATYRINae (THE SATYRS)

"Aught unsavory or unclean Hath my insect never seen; But violets and bilberry bells, Maple-sap and daffodils, Gra.s.s with green flag half-mast high, Succory to match the sky, Columbine with horn of honey, Scented fern and agrimony, Clover, catch-fly, adder's-tongue And brier-roses dwelt among."

EMERSON.

The b.u.t.terflies belonging to this subfamily are, for the most part, of medium size, and are generally obscure in color, being of some shade of brown or gray, though a few species within our territory are brightly colored. Gaily colored species belonging to this subfamily are more numerous in the tropics of both hemispheres. The wings are very generally ornamented, especially upon the under side, by eye-like spots, dark, pupiled in the center with a point of lighter color, and ringed around with one or more light circles. They are possessed of a weak flight, flitting and dancing about among herbage, and often hiding among the weeds and gra.s.ses. Most of them are forest-loving insects, though a few inhabit the cold and bleak summits of mountains and gra.s.sy patches near the margins of streams in the far North, while some are found on the treeless prairies of the West. In the warmer regions of the Gulf States a few species are found which have the habit of flitting about the gra.s.s of the roadsides and in open s.p.a.ces about houses. The veins of the fore wings are generally greatly swollen at the base, enabling them thus to be quickly distinguished from all other b.u.t.terflies of this family.

The eggs, so far as we have knowledge of them, are subspherical, somewhat higher than broad, generally ribbed along the sides, particularly near the apex, and rounded at the base, which is generally broader than the apex.

The caterpillars at the time of emergence from the egg have the head considerably larger than the remainder of the body; but when they have reached maturity they are cylindrical, tapering a little from the middle to either end. They are bifurcated at the a.n.a.l extremity, a character which enables them to be distinguished at a glance from the larvae of all other American b.u.t.terflies except those of the genus _Chlorippe_. They are mostly pale green or light brown in color, ornamented with stripes along the sides. They feed upon gra.s.ses and sedges, lying in concealment during the daytime, and emerging at dusk to take their nourishment.

The chrysalids are rather stout in form, but little angulated, and without any marked prominences or projections. They are green or brown in color. Most of them are pendant, but a few forms pupate at the roots of gra.s.ses or under stones lying upon the ground.

The b.u.t.terflies of this subfamily have been arranged, so far as they are represented in the faunal region of which this book treats, in nine genera, which include about sixty species. It is quite possible that a number of species still remain to be discovered and described, though it is also true that some of the so-called species are likely to prove in the end little more than local races or varieties.

Genus DEBIS, Westwood

(The Eyed Nymphs)

"The wild bee and the b.u.t.terfly Are bright and happy things to see, Living beneath a summer sky."

ELIZA COOK.

_b.u.t.terfly._--Characterized by the stout but not greatly swollen costal vein of the fore wing, by the rather short costal vein of the hind wing, which terminates before quite reaching the outer angle, by the great length of the lower discocellular vein of the fore wing, and by the prolongation of the outer margin of the hind wing at the end of the third median nervule. The outer margin of the fore wing is either rounded or slightly excavated. The palpi are long and narrow, thickly clothed with hairs below; the antennae are moderately long, gradually thickening toward the tip, without a well-marked club; the fore legs in both s.e.xes greatly atrophied.

[Ill.u.s.tration FIG. 114.--Neuration of the genus _Debis_. (After Scudder.)]

_Egg._--Flattened spheroidal, broadly truncated at the base, the surface smooth.

_Caterpillar._--Body long, slender, tapering from the middle; the head cleft, each half being produced upward as a conical horn; the a.n.a.l segment provided with a pair of horns similar to those of the head, produced longitudinally backward.

_Chrysalis._--Strongly convex dorsally, concave ventrally, with a stout tubercular eminence on the thorax, without any other projecting tubercles or eminences; light green in color.

This genus is large, and is well represented in Asia and the Indo-Malayan region. I cannot see any good ground for generically separating the two species found in North America from their congeners of Asiatic countries, as has been done by some writers.

(1) =Debis portlandia=, Plate XVIII, Fig. 20, ?; Plate III, Fig. 16, _larva_; Plate IV, Fig. 6, _chrysalis_ (The Pearly Eye).

_b.u.t.terfly._--The b.u.t.terfly, the male of which is well depicted as to its upper side on the plate, does not differ greatly in the s.e.xes. The hind wings on the under side are marked with a series of beautiful ocelli. In the North the insect is single-brooded; in the region of West Virginia and southward it is double-brooded. Expanse, 1.75-2.00 inches.

_Early Stages._--The ill.u.s.trations give a good idea of the mature larva and the chrysalis. The caterpillar, like most of the _Satyrinae_, feeds upon gra.s.ses.

The range of this pretty insect is extensive, it being found from Maine to the Gulf of Mexico, and westward to the Rocky Mountains.

(2) =Debis creola=, Skinner, Plate XVIII, Fig. 18, ?; Fig. 19, ? (The Creole).

_b.u.t.terfly._--Easily distinguished from the preceding species by the elongated patches of dark raised scales upon the fore wings, situated on the inters.p.a.ces between the median nervules. The female has more yellow upon the upper side of the fore wings than _D. portlandia_.

Expanse, 2.25 inches.

_Early Stages._--Unknown.

_Creola_ ranges from Florida to Mexico along the Gulf.

Genus SATYRODES, Scudder

(The Gra.s.s-nymphs)

_b.u.t.terfly._--The head is moderately large; the eyes are not prominent, hairy; the antennae are about half as long as the costa of the fore wing, not distinctly clubbed, gradually thickening toward the extremity. The palpi are slender, compressed, hairy below, with the last joint rather short and pointed. The fore and hind wings are evenly rounded on the outer margin. The costal vein of the fore wing is thickened, but not greatly swollen. The first and second subcostals are emitted well before the end of the cell, the third beyond it, and the fourth and fifth from a common stem, both terminating below the apex. The upper discocellular vein is wanting, and the upper radial, therefore, springs from the upper angle of the cell of the fore wing.

[Ill.u.s.tration FIG. 115.--Neuration of the genus _Satyrodes_. (After Scudder.)]

_Egg._--Flattened spheroidal, broader than high, flat at the base and rounded above.

_Caterpillar._--The head is full, the summit of either half produced upward and forward into a slender, conical horn. The body is nearly cylindrical, tapering backward, the last segment furnished with two pointed, backward projections, resembling the horns of the head.

_Chrysalis._--Relatively longer and more slender than in the preceding genus, with the thoracic prominence more acute and the head more sharply pointed.

This genus was erected to receive the single species which, until the present time, is its sole representative.

(1) =Satyrodes canthus=, Boisduval and Leconte, Plate XXV, Fig. 1, ?; Plate III, Fig. 9, _larva_; Plate IV, Fig. 9, _chrysalis_ (The Common Gra.s.s-nymph).

_b.u.t.terfly._--It always haunts meadows and hides among the tufts of tall gra.s.ses growing in moist places. It is rather common in New England and the Northern States generally. It is found in Canada and is reported from the cool upper mountain valleys in the Carolinas. It has a weak, jerking flight, and is easily taken when found. Expanse, 1.65-1.90 inch.

_Early Stages._--These have been well described by various writers. The caterpillar feeds upon gra.s.ses.

Genus NEONYMPHA, Westwood

(The Spangled Nymphs)

"Oh! the bonny, bonny dell, whaur the primroses won, Luikin' oot o' their leaves like wee sons o' the sun; Whaur the wild roses hing like flickers o' flame, And fa' at the touch wi' a dainty shame; Whaur the bee swings ower the white-clovery sod, And the b.u.t.terfly flits like a stray thoucht o' G.o.d."

MACDONALD.

_b.u.t.terfly._--Eyes hairy. The costal and median veins of the fore wings are much swollen at the base. The palpi are thin, compressed, thickly clothed below with long hairs. The antennae are comparatively short, gradually thickening toward the outer extremity, and without a well-defined club. Both the fore wing and the hind wing have the outer margin evenly rounded.

[Ill.u.s.tration FIG. 116.--Neuration of the genus _Neonympha_. (After Scudder.)]