Although the Euploeinae are not represented on the African continent, it is the headquarters of another distasteful family of butterflies—the Acraeinae—which is but sparingly represented in the Oriental region[[17]].
Of smaller size than the Danaines they are characterised, like this group, by their tenacity of life and by the presumably distasteful character of their body juices. They are said also to possess an offensive odour apparently exuded through the thorax. The majority of the members of the group fall into the two genera Acraea and Planema. Species of Acraea are on the whole characterised by their general bright red-brown colour and by the conspicuous black spots on both fore and hind wings. A typical Acraeine pattern is that of Acraea egina ([Pl. VI], fig. 7) which is mimicked remarkably closely by the Nymphaline Pseudacraea boisduvali and by the Swallow-tail Papilio ridleyanus ([Pl. VI], figs. 5 and 6).
In the genus Planema the spots are as a rule fewer and clustered near the body, while on both fore and hind wings there is a tendency to develop clear wide band-like areas of orange or white (cf. [Pl. VII]).
Like the Acraeas the Planemas are principally mimicked by species of Pseudacraea and of Papilio. Some of the cases of resemblance between Planema and Pseudacraea are among the most striking known. Planema macarista is one of those comparatively rare instances in which a model shews a marked difference in the pattern of the two sexes. The clear area on the fore wing of the male is deep orange, whereas in the female it is somewhat different in shape, and, like the area on the hind wing, is white (cf. [Pl. VII], figs. 1 and 2).
Pseudacraea eurytus hobleyi ([Pl. VII], figs. 6 and 7) shews a similar difference in the sexes, the male and female of this species mimicking respectively the male and female of Planema macarista. The case is made even more remarkable by the fact that both of the sexual forms of Planema macarista are mimicked by the Satyrine Elymnias phegea ([Pl. VII], fig. 9), though in this species either the black and white, or the black, white, and orange form may occur in either sex. Among the best Papilionine mimics of the Planemas is Papilio cynorta whose female is extraordinarily like the common Planema epaea ([Pl. VII], figs. 5 and 10). The resemblance of the planemoides female of P. dardanus to P. poggei has already been noticed.
A striking feature of the African continent is the frequency with which mimetic forms are found among the Lycaenidae. As a rule the "blues" rarely exhibit mimetic analogies, but in Africa there are several species, especially those of the genus Mimacraea, which closely resemble Acraeines. Others again bear a marked resemblance to certain small Pierines, Citronophila similis from S. Nigeria for example being extraordinarily like the common Terias brigitta, a small bright yellow Pierine with black-edged wings.
A remarkable feature of the African continent is the absence of the Pharmacophagus Swallow-tails. Of such Papilios as exhibit mimicry, and as compared with the total number of the group present the proportion is large, the majority resemble one or other
of the characteristic Danaines, while a few such as P. ridleyanus and P. cynorta resemble either an Acraeoid or a Planemoid model.
As in the Oriental region the African Pierines do not offer many instances of mimetic analogies. The genus Mylothris, in which certain species are characterised by orange patches at the bases of the undersurfaces of the fore wings, is regarded by some authors as providing models for allied genera such as Belenois and Phrissura. But as neither models nor mimics offer a marked divergence in appearance from the ordinary Pierine facies it is doubtful whether much stress can be laid on these cases.
Africa also offers a few striking instances of mimicry in which day-flying moths play a part. The conspicuous Geometer Aletis helcita is an abundant form, and with its strong red colour and black wing margins broken by white it is a striking object in the preserved state. Among the forms which bear a close resemblance to it are the Nymphaline Euphaedra ruspina, and the Lycaenid Telipna sanguinea[[18]].