Terias mexicana, the Mexican Yellow, is larger than Terias lisa, and somewhat paler in color. The black borders or the fore wings are very wide and indented, and the hind wings are pointed. Very little is known of its early stages. It is common in Texas, Arizona, and Southern California, and often strays much farther north. I have myself taken a number of specimens in Kansas.
THE PAPILIONINAE
This is the subfamily of the true swallowtails, the largest and most distinctive of American butterflies. The hind wings are prolonged into two tail-like projections, and are characterized, by the absence of the internal vein. The caterpillars are all provided with peculiar V-shaped scent-organs called osmateria; these organs are thrust out just back of the head when the insect is disturbed, and give off an offensive odor, supposed to discomfit birds and other enemies.
Papilio troilus, the Green-clouded Swallowtail, is velvety black with a row of yellow spots along the margin of the fore wings. The marginal spots on the hind wing are pale green, and the whole outer half of the hind wing is clouded with the same greenish tinge. The female deposits her eggs on sassafras and spicebush leaves; the caterpillar is lead-colored or greenish, with a swollen thorax bearing two large eye-spots, and lives in a nest made of a folded leaf. Papilio troilus is common throughout the Atlantic States and in the Mississippi Valley.
Papilio turnus, the Tiger Swallowtail, is the magnificent yellow-and-black species found in practically every part of the United States. In the northern portion of its range the male and female appear very much alike, but in the South there are two distinct types of females. One female is black-and-yellow like its northern sisters; the other is black-and-blue, with no yellow at all except a few small crescents in the outer border of the hind wing. The black female, was for a long while considered a distinct species and called Papilio glaucus. Later, however, it was discovered that some of the eggs laid by the yellow turnus produced the black glaucus females, and that, conversely, the eggs of glaucus often produced the ordinary yellow-and-black Tiger Swallowtail. The smooth bluish-green eggs are usually found on the wild cherry leaves; the caterpillar is green, with enlarged thoracic segments bearing two large eye-spots like those of Papilio troilus.
Papilio ajax, the Zebra Swallowtail, is another striking member of this magnificent subfamily. The combination of green and black stripes, the blue and red crescents and the long tails on the hind wings, distinguish ajax immediately from any of its splendid fellows. There are at least three slightly different seasonal varieties of this butterfly, due probably to differences in the temperature to which the chrysalids are exposed. The butterfly may often be seen hovering about pawpaw bushes, upon which the eggs are deposited. The mature caterpillar is pea-green with bands of yellow and black; the chrysalis is green or brownish, and the last crop of chrysalids does not produce butterflies until the following Spring. This butterfly ranges from New England south to the Florida Keys, and west to the foot-hills of the Rockies.
Papilio cresphontes, the Giant Swallowtail, is the largest butterfly in this country, measuring nearly six inches from tip to tip. The color is dark brown with bands and blotches of bright yellow, and there is a red-and-blue spot on the inner margin of the hind wings. The under side of both wings is yellow, with narrow dark brown bands. This butterfly is very common in Florida, where the caterpillars—the natives call them orange-dogs—do a great deal of damage to the orange and lemon trees. Each female butterfly is known to lay a great number of eggs, and it has been suggested that the ravages of the orange-dog may be checked by shooting the butterflies on the wing with miniature shotguns. In recent years the species has extended its range northward, and has become quite common in the Middle West; a number of specimens have been taken in New England, and even in Canada. In the northern part of its territory there are no citrus trees, but the caterpillar feeds well enough upon prickly ash and several kinds of poplars.
THE SKIPPERS
The Hesperiidae or Skipper family includes all the large bodied, small-winged, moth-like butterflies, called Skippers because of their jerky, erratic manner of flight. They are mostly small, dull colored butterflies with short, hooked antennae. The caterpillars are recognized by their large heads and small necks, and usually live in nests made of leaves fastened together with silk. The chrysalids are rounded and moth-like, and (unlike all the other families) are usually enclosed in a loose cocoon of silk. The classification of Skippers is a complicated business; the Hesperiidae is the only family in which the beginner will find it difficult to identify his specimens.
Epargyreus tityrus, the Silver-spotted Skipper, is the largest member of the family, with an expanse of about one and three-fourths inches. The general color is dark brown, with yellowish spots; the common name is derived from the silver area on the lower surface of the hind wing, which shows when the insect is at rest. The caterpillar is yellowish green, with a dark brown head; it feeds upon the leaves of the locust and other leguminous trees. When the caterpillar is mature it leaves its hammock in the locust tree and builds a light silken cocoon upon or near the ground. The Silver-spotted Skipper is found in nearly every part of the United States.