Page:EB1911 - Volume 16.djvu/496

Rh the five-branched radial nervure of the forewing, the cylindrical hairy larva, and the pupa attached only by the cremaster.

The Papilionidae are large butterflies with ample wings, and all six legs fully developed in both sexes. The forewing has five radial and two anal nervures, the second of the latter being free from the first and running to the dorsum of the wing, while the hindwing has but a single anal, and is frequently prolonged into a “tail” at the third median nervure (fig. 58). The larva is cylindrical, never hairy but often tuberculate and provided with a dorsal retractile tentacle (osmaterium) on the prothorax. The pupa, which has a double “nose-horn,” is attached by the cremaster and a waist-girdle to the food-plant in the Papilioninae (fig. 58), but lies in a web on the ground among the Parnasiinae (figs. 59, 60). The latter sub-family includes the well-known Apollo butterflies of the Alps. The former is represented in the British fauna by the East Anglian swallow-tail (Papilio machaon), and is very abundant in the warmer regions of the world, including some of the most magnificent and brilliant of insects.

Agreeing with the Papilionidae in the six perfect legs of both sexes and the cincture-support of the pupa we find the Pieridae—the family of the white and yellow butterflies (figs. 61, 62)—represented by ten species in the British fauna and very widely spread over the earth’s surface. In the Pieridae there are two anal nervures in the hindwing, while the second anal nervure in the forewing runs into the first; the larva is cylindrical and hairy without an osmaterium. The pupa has a single “nose-horn,” and in the more highly organized genera there is no mobility whatever between its abdominal segments. The wintering pupae of the common cabbage butterflies (Pieris brassicae and P. rapae) are common objects attached to walls and fences and their colour harmonizes, to a great extent, with that of their surroundings.

The Nymphalidae are by far the largest and most dominant family of butterflies. In both sexes the forelegs are useless for walking (fig. 63), the tarsal segments being absent and the short shins clothed with long hairs, whence the name of brush-footed butterflies is often applied to the family. The neuration of the wings resembles that found among the Pieridae, but in the Nymphalidae the pupa, which has a double nose-horn (fig. 65)—as in Papilio—is suspended from the cremaster only, no girdling thread being present, or it lies simply on the ground. The egg is elongate and sub-conical in form and ornamented with numerous ribs, while the larva is usually protected by numerous spines (fig. 64) arising from the segmental tubercles. To this family belong our common gaily-coloured butterflies—the tortoiseshells, peacock (fig. 65), admirals, fritillaries 