THAIS MEDESICASTE.
PLATE V. Fig. 2.
Godart’s Pap. de France, ii. Pl. 3, fig. 3, 4.—Pap. Medesicaste, Hubn. Pap. 124, fig. 632.—Pap. Rumina, Hubn. Pl. 394, 395.—Thais Honnoratii, Boisd. Icon. Pl. 3, fig. 3-5, var.
The genus Thais is confined to the southern countries of Europe, the north of Africa, and Asia Minor. All the species are of moderate size, and may at once be known by the peculiar design of the colouring of the wings, which are always yellow spotted with red and black, and bordered externally with a dark festooned line. The palpi are composed of three nearly equal articulations, and rise conspicuously above the head; the antennæ rather short and terminating in a club slightly curved upwards. The body is slender, and the abdominal margin of the hinder pair of wings is curved downwards as if to leave room for the movements of the abdomen. The caterpillars are short and cylindrical, covered with fleshy spines and short hairs, the first segment provided with a fleshy bifurcated tentaculum. They live solitarily or in small groups on the Aristolochia, and obviously bear a considerable analogy, as well as the perfect insect, to Parnassius. The chrysalis is cylindrico-conic, somewhat angular in front.
The species represented on the annexed plate may possibly be a variety of T. Rumina. Surface pale ochreous yellow, with a black marginal band divided on the upper wings by a series of eight or nine yellow spots; along the costal margin are several black irregular transverse bands, some of them inclosing rounded red spots; inferior wings with a black festooned line along the exterior border; towards the base are always three red spots, one near the abdominal margin, another in the upper part of the discoidal cell, and a third near the anterior edge, usually united in the form of a transverse band with that in the cell. Body blackish, marked with rows of fulvous spots.
The caterpillar lives on the Aristolochia pistolochia. Sometimes the colour is reddish-yellow, at other times brown or dull yellowish-green, with numerous rows of black lines often interrupted; the body bearing six rows of fleshy spines, of an orange yellow hue, and ciliated with black at the extremity.
The insect is found in Languedoc, in the neighbourhood of Digne, &c.
Genus PIERIS.
According to the definition which it has been found necessary to give to this genus in general works on the lepidoptera, it includes a very extensive range of species, and may be said to be represented in this country by the white butterflies, which British authors generally place in the genus Pontia. In this extended acceptation, however, it comprehends individuals somewhat diversified in appearance, and which may be assumed as the types of particular groups or sub-divisions, perhaps of sufficient importance ultimately to become genera, if a corresponding dissimilarity be found to characterise their different states and metamorphoses. The antennæ are of moderate length or slightly elongated, the articulations pretty distinct, the club obconic and compressed; palpi thickly covered with fascicles of long hairs, the terminal joint at least as long as the penultimate: wings of ordinary size, the discoidal cell closed; the under pair partially embracing the abdomen: eyes naked, head rather small.
The caterpillar is elongated, and nearly cylindrical, pubescent, and marked with longitudinal rays; the head small and rounded. Chrysalis terminating in a single conical point anteriorly, attached by the tail and a medial band.