Genus Lycæna Fabricius (the Blues)
The butterflies in this group are generally small, with the upper side of some shade of pale blue. On the under side the wings are paler in color, variously marked with spots and lines. The genus in recent years has been subdivided into smaller subgenera but as an ability to discriminate these involves a knowledge of minuter anatomical details, which is only possessed by specialists, the writer has not deemed it worth the while in a little manual like this to go deeply into these matters. The old name Lycæna, which has been in vogue for a century, and which is still applied to part of the group, is sufficiently characteristic. If we were reviewing all the species of the world, of which there are many hundreds in this assemblage of forms, we would be forced to use the minuter methods of classification. The eggs are turban-shaped; the caterpillars are slug-shaped, feeding on the petals and bracts of flowers or tender terminal leaves; the chrysalids are short, rounded at either end, supported by a silken girdle and closely appressed to the supporting surface.
(1) Lycæna couperi Grote, Plate XC, Fig. 2, ♂, under side (Couper’s Blue).
On the upper side the wings of the male are pale shining blue with a narrow black border; of the female darker blue broadly margined with dusky. On the under side in both sexes the wings are brownish gray relieved with white spots, having dark pupils. Expanse 1.25 inch. It is a boreal form.
(2) Lycæna aster Edwards, Plate XC, Fig. 3, ♂, under side (The Aster Blue).
On the upper side the male is pale lilac-blue, the female darker blue, with a submarginal row of paler blue spots on the margin of the hind wing. On the under side the fore wings have a dark bar at the end of the cell followed on the limbal area with a curved band of small dark spots. This style of decoration is repeated on the hind wings, and in addition there is a marginal band of pale yellow oval spots, each surrounded by a fine black encircling line. Expanse 0.95-1.00 inch. The insect is known thus far only from Newfoundland.
(3) Lycæna melissa Edwards, Plate XC, Fig. 4, ♀ (The Orange-margined Blue).
The male on the upper side is pale blue, with a narrow black marginal line and white fringes. The female is brown or lilac-gray with a series of orange-red crescents on the outer margin of both wings. The wings below are stone-gray with the usual spots, but on the hind wings the orange crescents are oblong tipped inwardly with black and outwardly with metallic green. Expanse 0.90-1.15 inch.
Ranges from Arizona to Montana.
(4) Lycæna scudderi Edwards, Plate XCI, Fig. 1, ♂ (Scudder’s Blue).
Our figure gives a good idea of the upper side of the male, which is hard to discriminate from the same sex of L. melissa. The female is darker, and has only a few orange crescents on the outer margin of the hind wing on the upper side. On the under side the wings are shining white, the spots much reduced in size, the large orange spots found in L. melissa being replaced by little ochreous spots very obscurely tipped externally by a few greenish scales.
The caterpillar feeds on lupine and allied plants. The insect is very common in the basin of the St. Lawrence River and the Great Lakes. It abounds in central New York.
(5) Lycæna pseudargiolus (Boisduval & Leconte), Plate XCI, Fig. 2, ♂; Fig. 3, ♀. Form neglecta Edwards, Plate XCI, Fig. 4, ♂; Fig. 5, ♀. Form lucia Kirby, Plate XCII, Fig. 1, ♂, under side. Form marginata Edwards, Plate XCII, Fig. 2, ♂, under side; Fig. 3, ♂, upper side. Form nigra Edwards, Plate XCII, Fig. 4, ♀ (The Common Blue).
This insect which is very common and may be found upon the wing from early spring until late in the autumn illustrates in a remarkable manner the phenomenon of polymorphism; that is to say, it has a number of forms, some of which are seasonal, some of which are sexual, some of which are climatic. It is in fact only through the labors of the late William Henry Edwards that some of the mysteries were cleared up, he having by breeding established the fact that some of the so-called species could be raised from eggs derived from one common stock. The great series of specimens upon which his conclusions were founded are in the possession of the writer, and have from time to time been supplemented by a vast amount of other material all of which confirms his teachings.
The forms lucia and marginata are winter forms, coming from chrysalids which have endured the long cold of the winter months and are the first to appear in spring. They are the only forms which occur in the far north near the Arctic Circle.
The forms pseudargiolus and neglecta are summer forms of the second and third generations, produced from eggs laid by lucia and marginata. Nigra is a dimorphic female form belonging to the summer broods and is melanic; that is to say, it is a form in which dark color prevails. Students of biology recognize a tendency in some animals to become black, while there is also a tendency to become white, or to produce albinoes. These tendencies in opposite directions in color are often observed in butterflies, and the melanic female of the species under consideration illustrates it. There is still another form, piasus, which occurs in Arizona and Mexico, and is climatic, or due to the influence of environment.
The winter forms are dwarfed and darkly marked on the under side as our figures show; the summer forms are larger, pale on the under side and dark on the outer borders above.
The species has a range in the expanse of wing of from 0.85-1.25 inch.
It occurs from Alaska to Florida, and from Anticosti to northern Mexico.
(6) Lycæna amyntula Boisduval, Plate XCIII, Fig. 1, ♂; Fig. 2, ♀ (The Western Tailed Blue).
Male pale blue on upper side; female darker, the hind wings with a submarginal row of orange crescents pupilled with black. Expanse 1.00-1.25 inch.
Ranges from the Rocky Mountains to the Pacific in British America and southward as far as Colorado.
(7) Lycæna comyntas (Godart), Plate XCIII, Fig. 3, ♂; Fig. 4, ♀ (The Eastern Tailed Blue).
Somewhat closely resembling the preceding, but appreciably smaller. Expanse 1.00-1.10 inch.
Ranges from the Saskatchewan to Costa Rica, and from the Atlantic to the Rocky Mountains.
(8) Lycæna isophthalma Herrich-Schäffer, Plate XCIII, Fig. 5, ♀ (The Dwarf Blue).
Light brown above in both sexes, with a row of dark spots on outer margin of hind wings; below pale brown profusely marked by light spots and bands, the dark marginal spots of the upper side reappearing, and defined by circlets of metallic scales. Expanse 0.75 inch.
Found in the Gulf States and the Antilles.
(9) Lycæna exilis Boisduval, Plate XCIII, Fig. 6, ♂ (The Pygmy Blue).
The smallest of North American butterflies, closely resembling the foregoing, but distinguished by the white spot on fringe near inner angle of fore wing, and the white fringes of the same wing near apex. Expanse 0.65 inch.
The Pygmy occurs in the Gulf States and in tropical America.
(10) Lycæna theona Lucas, Plate XCIII, Fig. 7, ♀ (The West Indian Blue).
Male shining lavender-blue; this color also glosses the dark outer borders of the wings; female white, with outer borders heavily blackish; fore wings shot with shining sky-blue at base. Hind wings near anal angle have conspicuous eye-spots both above and below. Expanse 0.80 inch.
Occurs in the Gulf States and throughout the tropics of the New World.
(11) Lycæna acmon Doubleday & Hewitson, Plate XCIV, Fig. 1, ♂ (Red-margined Blue).
In many respects resembling L. melissa, but somewhat smaller. Male on upper side brighter blue, and female not as brown as L. melissa, though darker than the male, her wings broadly shot with violet-blue. In both sexes a broad deep red submarginal band on hind wings, marked with black spots. Expanse 0.85-1.10 inch.
Ranges from Arizona to Washington and Montana. The larva feeds on Hosackia.
(12) Lycæna ammon Lucas, Plate XCIV, Fig. 2, ♀, under side (The Indian River Blue).
Male brilliant lilac-blue on upper side; female violet-blue with wide black borders on fore wings, and one or two conspicuous eye-spots near anal angle of hind wings, each surmounted by a carmine crescent. Expanse 0.95-1.10 inch.
Not uncommon in southern Florida; abundant in the Antilles and tropical America.
(13) Lycæna marina Reakirt, Plate XCIV, Fig. 4, ♀ (The Marine Blue).
Male on upper side pale dusky lilac, the dark bands of the under side showing through on upper side. Female dark brown above, with wings at base shot with lilac-blue; the dark bands on the disk are prominent in this sex, especially on fore wings. Expanse 1.10 inch.
Occurs in Texas, Arizona, southern California, and southward. The larva feeds on alfalfa and allied plants.
(14) Lycæna lygdamus (Doubleday), Plate XCIV, Fig. 3, ♂ (The Silvery Blue).
The upper side is well shown in our illustration. The under side is pale chocolate-brown, having on both wings a submarginal band of black spots encircled with white, similar spots at the end of the cells, and one or two also on the costa of the hind wing. Expanse 0.85-1.00 inch.
Ranges from Michigan to Georgia.
(15) Lycæna heteronea Boisduval, Plate XCIV, Fig. 5, ♂; Fig. 6, ♀ (The Varied Blue).
The largest species of the genus. Male blue, female brown; the markings on upper side of latter recalling the female of the genus Chrysophanus. Expanse 1.25-1.40 inch. Below the wings are white marked with faint brown spots on the hind wings and more distinct spots on the fore wings.
Ranges from Colorado to California at suitable elevations among the mountains.