Charaxes

The rajah and pasha butterflies, also known as emperors in Africa and Australia, (genus Charaxes) make up the huge type genus of the brush-footed butterfly subfamily Charaxinae, or leafwing butterflies. They belong to the tribe Charaxini, which also includes the nawab butterflies (Polyura). Charaxes are tropical Old World butterflies, with by far the highest diversity in sub-Saharan Africa, a smaller number from South Asia to Melanesia and Australia, and a single species (C. jasius) in Europe. They are generally strong flyers and very popular among butterfly collectors. Charaxes means 'to sharpen' or 'to make pointed', referring to the pointed 'tails' on the hind wing. Charaxes may also be related to charax, meaning 'a sharp stake', or charaxis, a 'notch' or 'incision', which are also features of the hind wing. Charaxes frequent sunny forest openings and glades where they rest with open or partly open wings sunning themselves. When alerted, they close the wings exposing the cryptic underside. Certain favoured perches are selected and intruders are chased and driven off, Charaxes feed in part at oozes from tree wounds infested with beetle or other larvae and on rotting fruit (they come to hanging traps baited with fermenting banana). They lay their eggs on small understorey or marginal trees. Tender shoots are usually selected for egg laying but as the larvae grow they move to older leaves. Larvae rest on the upper surface of a leaf on which they have spun a protecting silk pad. The most striking features in the habits of Charaxes are the rapid flight, the partiality to putrid matter and the constancy with which a specimen returns to the same spot. Few species are found in the open country (C. pelias pelias, C. jasius and C. fabius), where there are only bushes and rarely trees; most species inhabit the more wooded country and some are found only in and near larger forests. The males come often in some numbers to water pools on roads; both sexes are fond of the juice of trees, decaying fruits, dung of animals and putrid meat and can successfully be entrapped by the use of such baits; one is known to come to flowers (C. zoolina). The larvae feed variously on Rhamnaceae, Leguminosae, Sapindaceae, Melianthaceae, Euphorbiaceae, Gramineae, Ochnaceae, Lauraceae, Tiliaceae, Meliaceae, etc. Charaxes acraeoides is part of a mimetic ring with Pseudacraea and Acraea. 'We have examined the eggs of a number of species, taken from the bodies of dry specimens. Apart from size, there is no apparent difference in the eggs of the various species. The micropyle end is flattened, slightly concave, with the centre raised; from the centre radiate slight ribs, which gradually disappear at the sides and do not reach the base or underside; the longitudinal ribs are connected by extremely feeble transverse ridges, and bear, as Doherty correctly points out, small projecting points, which are easily visible under a good lens.