LEPIDOPTERA. Butterflies.—Butterflies in the interior of the island are comparatively rare, and, contrary to the ordinary belief, they are seldom to be seen in the sunshine, They frequent the neighbourhood of the jungle, and especially the vicinity of the rivers and waterfalls, living mainly in the shade of the moist foliage, and returning to it in haste after the shortest flights, as if their slender bodies were speedily dried up and exhausted by the exposure to the intense heat.
Among the largest and most gaudy of the Ceylon Lepidoptera is the great black and yellow butterfly (Ornithoptera darsius, Gray); the upper wings, of which measure six inches across, are of deep velvet black, the lower, ornamented by large particles of satiny yellow, through which the sunlight passes, and few insects can compare with it in beauty, as it hovers over the flowers of the heliotrope, which furnish the favourite food of the perfect fly, although the caterpillar feeds on the aristolochia and the betel leaf and suspends its chrysalis from its drooping tendrils.
Next in size as to expanse of wing, though often exceeding it in breadth, is the black and blue Papilio Polymnestor, which darts rapidly through the air, alighting on the ruddy flowers of the hibiscus, or the dark green foliage of the citrus, on which it deposits its eggs. The larvæ of this species are green with white bands, and have a hump on the fourth or fifth segment. From this hump the caterpillar, on being irritated, protrudes a singular horn of an orange colour, bifurcate at the extremity, and covered with a pungent mucilaginous secretion. This is evidently intended as a weapon of defence against the attack of the ichneumon flies, that deposit their eggs in its soft body, for when the grub is pricked, either by the ovipositor of the ichneumon, or by any other sharp instrument, the horn is at once protruded, and struck upon the offending object with unerring aim.
Amongst the more common of the larger butterflies is the P. Hector, with gorgeous crimson spots set in the black velvet of the inferior wings; these, when fresh, are shot with a purple blush, equalling in splendour the azure of the European "Emperor."
Another butterfly, but belonging to a widely different group, is the "sylph" (Hestia Jasonia), called by the Europeans by the various names of Floater, Spectre, and Silver-paper-fly, as indicative of its graceful flight. It is found only in the deep shade of the damp forest, frequenting the vicinity of pools of water and cascades, about which it sails heedless of the spray, the moisture of which may even be beneficial in preserving the elasticity of its thin and delicate wings, that bend and undulate in the act of flight.
The Lycoenidoe[1], a particularly attractive group, abound near the enclosures of cultivated grounds, and amongst the low shrubs edging the patenas, flitting from flower to flower, inspecting each in turn, and as if attracted by their beauty, in the full blaze of sun-light; and shunning exposure less sedulously than the other diurnals. Some of the more robust kinds[2] are magnificent in the bright light, from the splendour of their metallic blues and glowing purples, but they yield in elegance of form and variety to their tinier and more delicately-coloured congeners.
1: Lycana polyommatus, &c.
2: Amblypodia pseudocentaurus, &c.
Short as is the eastern twilight, it has its own peculiar forms, and the naturalist marks with interest the small, but strong, Hesperiidoe,[1] hurrying, by abrupt and jerking flights, to the scented blossoms of the champac or the sweet night-blowing moon-flower; and, when darkness gathers around, we can hear, though hardly distinguish amid the gloom, the humming of the powerful wings of innumerable hawk moths, which hover with their long proboscides inserted into the starry petals of the periwinkle.
1: Pamphila hesperia, &c.