FAMILY PAPILIONIDAE
Latreille, [1802]

[The system adopted for the higher classification within the Papilionidae by Ackery et al., 1995 closely followed Miller, 1987 (Bulletin of the American Museum of Natural History 186: 365-512). ).]

The swallowtails, swordtails, festoons, birdwings and apollos are a small family of large to very large butterflies that are generally showy, conspicuous insects. Included in the family are the largest butterflies in the world, the birdwings of the Malay Archipelego, some of which have wingspans of nearly 300mm.

There are about ?85 Afrotropical species but only 17 of these occur in southern Africa, one of which is endemic. The paucity of species in the Subcontinent is due to the fact that Swallowtails are primarily forest butterflies, with a lesser number in frost-free savanna. The southern African species are divided into two groups: the true Swallowtails (genus Papilio) and the Swordtails (genus Graphium), both of which are dealt with below.

Female Swallowtails lay their eggs singly on the leaves or on young leaf shoots of the larval foodplants. For true Swallowtails these are usually trees belonging to the Citrus family (Rutaceae) and for Swordtails, shrubs or trees of the Custard-apple family (Annonaceae).

The eggs are spherical, smooth, pale yellow and are about one millimetre in diameter. The larva hatches within a week and consumes the empty egg shell as its first meal. It feeds on the edges of young leaves and rests in the middle of the leaf. There are five larval stages (instars), which take three to four weeks to complete. In true Swallowtails the first four larval instars resemble bird droppings and in certain species this resemblance is enhanced by the larva kinking its body in the middle (?); in the final (fifth) instar the larvae are green, with some brown or white markings, are rather slug-like, and are well camouflaged (?).

In Swordtails the larvae tend to be marked with variously-coloured transverse bands (?). All Swallowtail larvae have a remarkable, eversible, forked organ just behind the head, known as an osmeterium. When the larva is alarmed, this brightly coloured organ is everted and releases a pungent citrus-like odour. Swallowtail pupae are long and cylindrical (resembling a twig), or are leaf-shaped, and are suspended by a silken girdle (?).

In some species the pupa may be either green or brown, depending on the surroundings in which the larva pupates. Such dimorphic pupae are seen in the Citrus and Green-banded Swallowtails. Pupae may hatch into adult butterflies after a few weeks, or the pupae may undergo diapause ("hibernate") in autumn and winter, hatching only the following spring, some four to six months later. Because of this pupal diapause, adult Swallowtails are mostly seen on the wing from about September, reach a peak in numbers in February and March and become scarce by May. Few are seen during the winter months (June to August), except in the warmer coastal areas of KwaZulu-Natal and Mozambique.

Some species of Swordtail that occur in more arid savanna habitats can diapause as pupae for several years, should drought conditions persist.