Part 7 (1/2)

NORTH AMERICA NORTH OF MEXICO

”Lo, the bright train their radiant wings unfold!

With silver fringed, and freckled o'er with gold: On the gay bosom of some fragrant flower They, idly fluttering, live their little hour; Their life all pleasure, and their task all play, All spring their age, and suns.h.i.+ne all their day.”

MRS. BARBAULD

ORDER LEPIDOPTERA SUBORDER RHOPALOCERA (b.u.t.tERFLIES)

FAMILY I

NYMPHALIDae (THE BRUSH-FOOTED b.u.t.tERFLIES)

The family of the Nymphalidae is composed of b.u.t.terflies which are of medium and large size, though a few of the genera are made up of species which are quite small. They may be distinguished from all other b.u.t.terflies by the fact that the first pair of legs in both s.e.xes is atrophied or greatly reduced in size, so that they cannot be used in walking, but are carried folded up upon the breast. The fore feet, except in the case of the female of the snout-b.u.t.terflies (Libytheinae), are without tarsal claws, and hence the name ”Brush-footed b.u.t.terflies”

has been applied to them. As the anterior pair of legs is apparently useless, they have been called ”The Four-footed b.u.t.terflies,” which is scientifically a misnomer.

_Egg._--The eggs of the Nymphalidae, for the most part, are dome-shaped or globular, and are marked with raised longitudinal lines extending from the summit toward the base over the entire surface or over the upper portion of the egg. Between these elevations are often found finer and less elevated cross-lines. In a few genera the surface of the eggs is covered with reticulation arranged in geometrical patterns (see Fig.

1).

_Caterpillar._--The caterpillars of the Nymphalidae, as they emerge from the egg, have heads the diameter of which is larger than that of the body, and covered with a number of wart-like elevations from which hairs arise. The body of the immature larva generally tapers from before backward (see Plate III, Figs. 7 and 11). The mature larva is cylindrical in form, sometimes, as in the Satyrinae, thicker in the middle. Often one or more of the segments are greatly swollen in whole or in part. The larvae are generally ornamented with fleshy projections or branching spines.

_Chrysalids._--The chrysalids are for the most part angular, and often have strongly marked projections. As a rule, they hang with the head downward, having the cremaster, or a.n.a.l hook, attached to a b.u.t.ton of silk woven to the under surface of a limb of a tree, a stone, or some other projecting surface. A few boreal species construct loose coverings of threads of silk at the roots of gra.s.ses, and here undergo their transformations. The chrysalids are frequently ornamented with golden or silvery spots.

This is the largest of all the families of b.u.t.terflies, and it is also the most widely distributed. It is represented by species which have their abode in the cold regions of the far North and upon the lofty summits of mountains, where summer reigns for but a few weeks during the year; and it is enormously developed in equatorial lands, including here some of the most gloriously colored species in the b.u.t.terfly world. But although these insects appear to have attained their most superb development in the tropics, they are more numerous in the temperate regions than other b.u.t.terflies, and a certain fearlessness, and fondness for the haunts of men, which seems to characterize some of them, has brought them more under the eyes of observers. The literature of poetry and prose which takes account of the life of the b.u.t.terfly has mainly dealt with forms belonging to this great a.s.semblage of species.

In the cla.s.sification of the brush-footed b.u.t.terflies various subdivisions have been suggested by learned authors, but the species found in the United States and the countries lying northward upon the continent may be all included in the following six groups, or subfamilies:

1. The _Euploeinoe_, the Euploeids.

2. The _Ithomiinoe_, the Ithomiids.

3. The _Heliconiinoe_, the Heliconians.

4. The _Nymphalinoe_, the Nymphs.

5. The _Satyrinoe_, the Satyrs.

6. The _Libytheinoe_, the Snout-b.u.t.terflies.

The insects belonging to these different subfamilies may be distinguished by the help of the following a.n.a.lytical table, which is based upon that of Professor Comstock, given in his ”Manual for the Study of Insects” (p. 396), which in turn is based upon that of Dr.

Scudder, in ”The b.u.t.terflies of New England” (vol. i, p. 115).

KEY TO THE SUBFAMILIES OF THE NYMPHALIDae OF THE UNITED STATES AND CANADA

I. With the veins of the fore wings not greatly swollen at the base.

_A._ Antennae naked.