NECTARIA JASONIA (Plate 1, Fig. 1).
Hestia Jasonia, Westwood, Cabinet of Oriental Entomology, p. 87, pi. 42, fig. 1 (1848).
Male and female. Semihyaline, fuliginous-white, veins black: upper-side, fore-wing with a black basal costal border, an oblique irregular broad band across middle of the cell, a short streak on middle of the costa, a streak through the disco cellular veins, a large spot between the base of the two lower median veins, a crutch-shaped mark extending to the base above the sub median vein, a discal series of seven angulated-oval spots, a submarginal series of duplex spots terminating in a thickened streak at end of each vein, and a marginal row of spots: hindwing with a black round spot in middle of the cell, two small spots below it, a discal series of eight angulated-oval spots two of which are between the costal and subcostal veins, a sub- marginal series of duplex spots terminating in a thickened streak at end of each vein, and a marginal row of spots.
Head and thorax spotted with white, thorax above, palpi and femora beneath streaked with white, abdomen black above, white beneath. Underside of both fore and hind wings marked as above. Some specimens are darker coloured than that above described, being blackish-fuliginous; others, again, have a slight ferruginous tint pervading the wings.
Expanse 4¾ to 5¾ inches.
This beautiful butterfly is called by Europeans in Ceylon, according to a statement in Tennent’s “Natural History of Ceylon,” p. 426,” 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, usually 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.”
“In the forests and especially about waterfalls in the western, central, and southern provinces this butterfly may be found all the year. It has a very slow floating flight, often poising nearly motionless, and is very easily caught” (Hutchison).
Source: The Lepidoptera of Ceylon by Frederic Moore. London, L. Reeve & co.,1880-1887.