OCR Text |
Show 1902.] SOUTH-AFRICAN LEPIDOPTERA. point of a leaf; the lateral margins form a yellowish ridge from head to anal extremity, and are much expanded laterally at the point where the wing-covers are broadest; a thin raised median line dorsally and ventrally helps to complete the resemblance, by its likeness to the midrib of a leaf. Mr. G. F. Leigh, F.E.S., has given me the following information, and is, I believe, the only person who has bred P. dardanus from ova in Natal. A specimen of the common form of the female in Natal (P. cenea, PI. X X Y I. fig. 12) was captured and placed in confinement, and laid 42 eggs, 37 of which pupated and produced 17 male and 20 female insects. The eggs are white, and are generally laid on the underside of a leaf, not more than two eggs being deposited on one branch; the larval stages occupied one month, and the pupal stage fourteen days. The species is double-brooded, larvae having been found in February and in May, and probably they may be found in other months as well. It will be seen from this that the female (from which Mr. Leigh bred his specimens from the egg) was one of the form which was described by Stoll as P. cenea, this being the form of the female most commonly met with in the Durban district, and that which appears to mimic Amauris echeria Stoll. Among the female imagines that resulted, there were, besides this form, also specimens of a form of female near the form described by Fabricius as P. hippocoon, this being a rarer form of the female in Natal (Plate X X Y I. fig. 13); this form differs from the typical form of P. hippocoon from West Africa mainly in having a larger area of white on the hind wing than the latter, being modified in imitation of its model Amauris clominicanus Trimen (a local race of the West-African Amauris niavius Linnaeus), which is also distinguished from the West-African form by having a larger area of white on the hind wing. The males also differ from West-African specimens of P. dardanus in having the black discal spots and the marginal lunules on the upperside of the hind wing coalesced into continuous black discal fasciae, and in the discal band on the underside of the hind wing being tinged with rust-colour instead of fuscous; they were also, as a general rule, a good deal smaller. Mr. R. Trimen records the South-African form as a distinct species under the name of P. cenea Stoll (Soutli-African Butterflies, iii. p. 243. n. 313), while Professor Aurivillius (Rhopalocera yEfchiopica, p. 465. n. 8) considers P. cenea to be a " forma geographica " of P. dardanus. The species is subject to almost endless variation, the differences given above between the South- and West-African races being by no means constant, and it appears to the writer impossible to divide them except as subspecies or local races. Proc. Z g o l. Soc,- 1892, V o l . II. No. XX. 20 |