_b.u.t.terfly._-This very common and beautiful insect may easily be recognized from the figure in the plate. The broad, irregular silvery spot on the under side of the hind wings distinguishes it at a glance from all other related species in our fauna. Expanse, 1.75-2.00 inches.
_Early Stages._-These have been accurately described by several authors, and a very full account of them is contained in "The b.u.t.terflies of New England." The caterpillar feeds upon leguminous plants, and is especially common upon the _Wistaria_, which is grown about verandas, and on the common locust (_Robinia pseudacacia_). The caterpillar makes a nest for itself in the same manner as _Eudamus proteus_. Pupation generally takes place among fallen leaves or rubbish at the foot of the trees upon which the caterpillar has fed.
This b.u.t.terfly has a wide range, extending to the Gulf, south of a line pa.s.sing from Quebec to Vancouver, and ranging still farther south as far as the Isthmus of Panama. It is single-brooded in the North, and double- or triple-brooded in the South.
Genus THORYBES, Scudder
(The Dusky-wings)
_b.u.t.terfly._--The club of the antennae is not very heavy, hooked, the hooked portion about as long as the rest of the club. The palpi are directed forward, with the second joint heavily scaled, and the third joint very small. The fore wing may be with or without the costal fold in the male s.e.x. The cut gives a correct idea of the neuration. The hind wing is evenly rounded on the outer margin, sometimes slightly angled at the extremity of the submedian vein.
[Ill.u.s.tration FIG. 155.--Neuration of the genus _Thorybes_.]
_Egg._--The egg is subglobular, somewhat flattened at the base and on top, marked with numerous fine and not much elevated longitudinal ridges. The micropyle covers the upper surface of the egg and is not depressed.
_Caterpillar._--The caterpillar somewhat resembles that of the genus _Epargvreus_, but is relatively shorter, the head proportionately larger and more globular. The neck is greatly strangulated.
_Chrysalis._--The chrysalis is somewhat curved in outline, with a strongly hooked cremaster and a prominent projection on the back of the thoracic region.
(1) =Thorybes pylades=, Scudder, Plate XLVIII, Fig. 6, ?; Plate II, Figs.
25, 29, _larva_; Plate VI, Fig. 28, _chrysalis_ (The Northern Dusky-wing).
_b.u.t.terfly._--The upper side is represented correctly in Plate XLVIII.
On the under side the wings are dark brown, shading into h.o.a.ry-gray on the outer margins. The hind wings are crossed by irregular basal, median, and postmedian brown bands of darker spots, shaded with deeper brown internally. The translucent spots of the upper side reappear on the lower side of the fore wings. Expanse, 1.60 inch.
_Early Stages._--These are elaborately described in the pages of Dr.
Scudder"s great work. The caterpillar feeds on clover, _Lespedeza_, and _Desmodium_.
This insect is found throughout the United States and Canada, but is not as yet reported from the central ma.s.ses of the Rocky Mountain region.
It probably, however, occurs there also in suitable locations. It is very common in New England.
(2) =Thorybes bathyllus=, Smith and Abbot, Plate XLVIII, Fig. 5, ?; Plate II, Fig. 32, _larva_; Plate VI, Fig. 24, _chrysalis_ (The Southern Dusky-wing).
_b.u.t.terfly._--Easily distinguished from the preceding species by the much larger size of the translucent spots on the fore wings. Expanse, 1.40-1.50 inch.
_Early Stages._--The habits of the larva are very similar to those of the preceding species, and the caterpillar feeds on herbaceous leguminosae.
It ranges from the Connecticut Valley, where it is rare, southward along the coast and through the Mississippi Valley as far south and west as Texas.
(3) =Thorybes aemilia=, Skinner, Plate XLVI, Fig. 39, ? (Mrs. Owen"s Dusky-wing).
_b.u.t.terfly._--This little species, which may readily be identified by the figure of the type given in the plate, is as yet quite rare in collections. We know nothing of the early stages. The types were taken at Fort Klamath, in Oregon. Dr. Skinner named it in honor of the estimable wife of Professor Owen of the University of Wisconsin, the discoverer of the species. Expanse, 1.20 inch.
(4) =Thorybes epigena=, Butler, Plate XLVIII, Fig. 13, ? (Butler"s Dusky-wing).
_b.u.t.terfly._--Readily distinguished by its large size, the conspicuous white fringes of the hind wings on the upper side, and the broad white marginal band of these wings on the under side. Expanse, 2.00 inches.
_Early Stages._--Unknown.
This insect is common in Arizona and Mexico.
Genus ACHALARUS, Scudder
_b.u.t.terfly._--The antennae and palpi are as in the preceding genus. The neuration is represented in the cut. The hind wing is slightly lobed at the a.n.a.l angle; the fore wing may or may not be provided with a costal fold.
(1) =Achalarus lycidas=, Smith and Abbot, Plate XLV, Fig. 10, ?, _under side_; Plate II, Fig. 23, _larva_; Plate VI, Fig. 21, chrysalis (The h.o.a.ry-edge).
_b.u.t.terfly._--The general appearance of the upper side of the wings strongly recalls _E. t.i.tyrus_, but the h.o.a.ry edge of the secondaries and the absence of the broad median silvery spot found in _t.i.tyrus_ at once serve to discriminate the two forms. Expanse, 1.65-1.95 inch.
_Early Stages._--What is known of them may be ascertained by consulting the pages of "The b.u.t.terflies of New England." The caterpillar is found on the leaves of _Desmodium_ (Beggar"s-lice).
The insect is rare in southern New England, and ranges thence southward and westward to Texas, being scarce in the Mississippi Valley north of Kentucky, and apparently not ranging west of Missouri.
[Ill.u.s.tration FIG. 156.--Neuration of the genus _Achalarus_.]
(2) =Achalarus cellus=, Boisduval and Leconte, Plate XLV, Fig. 12, ? (The Golden-banded Skipper).
_b.u.t.terfly._--The figure in the plate will enable the instant identification of this beautiful species, which, on the under side, has the hind wings banded much as in _E. proteus_. Expanse, 2.00 inches.
_Early Stages._--What little we know of these is based mainly upon the observations of Abbot, and there is an opportunity here for some young naturalist to render a good service to science by rearing the insect through all stages from the egg. The habits of the larva are not greatly different from those of allied species.
_A. cellus_ is found in the Virginias, and thence southward and westward to Arizona and Mexico. It is common in the Carolinas.
Genus HESPERIA, Fabricius
_b.u.t.terfly._--The antennae are relatively short; the club is stout and blunt at the tip. The palpi are bent upward, with the third joint buried in the scales covering the second joint. The hind wing is usually evenly rounded. In all the American species the male is provided with a costal fold. The neuration is represented in the cut.
_Egg._--Hemispherical, ribbed.
_Caterpillar._--The caterpillar is much like those which have been previously described, but is relatively much smaller.
_Chrysalis._--The chrysalis has a somewhat blunt and not very distinctly developed cremaster.
(1) =Hesperia domicella=, Erichson, Plate XLVII, Fig. 19, ? (Erichson"s Skipper).
_b.u.t.terfly._--Allied to the following species, from which it is easily discriminated by the broad, solid white bands on both the fore and the hind wings. Expanse, 1.25 inch.
_Early Stages._--Unknown.
_H. domicella_ is found in Arizona, Mexico, and southward.
[Ill.u.s.tration FIG. 157.--Genus _Hesperia_. Neuration. Antenna, magnified 3 diameters.]
(2) =Hesperia montivaga=, Reakirt, Plate XLVII, Fig. 18, ?; Plate VI, Fig. 35, _chrysalis_ (The Checkered Skipper).
_b.u.t.terfly._--The upper side is correctly delineated in the plate. The under side of the fore wings is much paler than the upper side, but with all the spots and markings of that side reproduced. The hind wings are creamy-white, crossed by median, postmedian, and marginal irregular bands of ochreous, somewhat annular spots. There is a triangular black spot at the a.n.a.l angle of the secondaries. Expanse, 1.15 inch.