(African) Citrus Swallowtail Butterfly Papilio demodocus

Citrus Swallowtail Butterfly topside
African Lime Swallowtail Butterfly emerged from pupa
The African Citrus Swallowtail Butterfly, also called just the Citrus or African Lime Swallowtail, is native to sub-Saharan Africa. Its caterpillars feed on citrus trees. It doesn't have a swallow tail and from the topside (above left) looks very similar to the related Asian Lime Swallowtail. From the underside (above right), however, it looks totally different.
African Citrus Swallowtail Butterfly
African Citrus Swallowtail Butterfly
African Lime Swallowtail Butterfly
Male and female look similar; females are usually larger. Individual patterns vary. The dark underside is the key difference between the African and Asian species (see link below).
African Citrus Swallowtail Butterfly
African Citrus Swallowtail Butterfly
African Citrus Swallowtail Butterfly
Like the Asian Lime, which has spread to Australasia and Central America, the African Citrus is a strong flier. The tattered individual shown above centre/right was in my garden in North London -- probably an escapee but it was many miles from any tropical butterfly house. It was interested in the lobelia (liking small blue/purple flowers) but flew up to the roses when camera-shy.
Asian Lime Swallowtail tornal spot
Citrus Swallowtail Tournal Spot
Asian Lime Swallowtail tornal spot
Although the topsides of the Asian and the African Lime/Citrus swallowtails look very similar, there are subtle differences in addition to the obvious pale vs dark underside (see link below). The red "eye-spot" or "tornal spot" differs: the round "pupil" in the Asian (demoleus) is black with a blue "eyebrow"; the "pupil" is blue in the African (demodocus) with a black under curve.