Genus Chlorippe Boisduval (the Emperor Butterflies)
Small butterflies generally of some shade of fulvous, with a submarginal row of eye-like spots on the hind wings, and in a few species with a similar spot on the fore wings. The apex of the fore wing is somewhat truncated and the lower two thirds is slightly excavated. Hind wings somewhat elongated posteriorly at the anal angle. Outer margins more or less crenulate. Eggs nearly globular, broad on top, ornamented with eighteen to twenty broad, but low, vertical ribs, between which are delicate crosslines; laid in clusters. Head of caterpillar squarish, crowned by two diverging spines on which are many little spinules. Back of the head there is a frill of spines. Body thickest at the middle, tapering fore and aft. Hind pair of pro-legs long and diverging. They feed upon hackberry trees (Celtis). The chrysalis has a very remarkable arrangement of the cremaster, which is disk-like, studded with hooks; the whole so arranged that the pupa, when suspended, hangs with the ventral or belly side parallel to the supporting surface.
There are numerous species in the genus, many of them tropical and very brilliant, only two commonly occur in the northern portions of our territory, the others found within our limits being inhabitants of the Southern States.
(1) Chlorippe celtis Boisduval & Leconte, Plate XLIX, Fig. 1, ♂ (The Hackberry Butterfly).
Under side grayish purple, with the spots and markings of the upper side reappearing. Female larger, and, as always is the case in the genus, with the fore wings not so pointed as in the male, and the ground-color paler. Expanse ♂, 1.80 inch; ♀, 2.10 inch.
Ranges from New Jersey west and south to the Gulf.
(2) Chlorippe clyton Boisduval & Leconte, Plate XLIX, Fig. 2, ♂ (The Tawny Emperor).
A larger species than the preceding; tawnier on the upper side of the wings and lacking the red-ringed eye-spot on the fore wing. Female much larger than the male, paler in color, with the eye-spots on the hind wings black and conspicuous. Expanse ♂, 2.00 inches; ♀, 2.50-2.65 inches.
Occurs rather rarely in New England, and extends westward to Michigan, thence southward to the Gulf of Mexico.
(3) Chlorippe flora Edwards, Plate L, Fig. 1, ♂, Type (The Red Emperor).
Like C. clyton this species has no red-ringed eye-spot on the fore wing. The ground-color on the upper side is bright reddish fulvous; the hind wings are not heavily obscured with brown, as is the case in C. clyton, and the black ocelli stand forth very prominently upon the lighter ground. The hind wings are more strongly angulated than in any other North American species, and are solidly bordered with black. Expanse ♂, 1.75; ♀, 2.35 inches. Ranges from Florida westward along the borders of the Gulf of Mexico to Texas.
(4) Chlorippe alicia Edwards, Plate L, Fig. 2, ♂, Type (The Buff Emperor).
Resembles C. celtis in having an ocellus in the fore wing, but it may at once be distinguished by its larger size in both sexes, the paler color of the wings on the upper side, which shade from pale fulvous at the base into light buff outwardly, upon which the eye-spots on the hind wings show up very prominently. Expanse ♂, 2.00; ♀, 2.50 inches.
The range of this species is the same as that of the preceding.