88 



AFRICAN MIMETIC BUTTERLFIES 



necessarily showing that the Belenois was particularly palatable, certainly shows that it was 

 less distasteful than the Mylothris, and thus whilst other Pierine butterflies may be more 

 or less distasteful, it may well be that it is an additional advantage to resemble a species 

 of the latter genus. It is interesting also to note that besides the aposematic patterns of 

 the uppersides and the basal red or yellow warning mark of the undersides, all of which 

 are displayed when the insect is more or less on the alert, it is evidently an advantage to 

 many of these insects to avoid being attacked when in complete repose, and the portion of 

 their pattern then displayed is in many cases purely cryptic. This is notably the case in 

 many species of Eronia, which in the attitude of complete rest and therefore the state of 

 minimum alertness, become practically invisible, although when the fore-wings are not 

 completely hidden within the secondaries the red flush at the base of the former will act 

 as an aposeme. I am inclined to think that such species as present an extremely cryptic 

 appearance in repose are in all probability more Batesian than Miillerian mimics, and in 

 this class I should be inclined to place the members of the genus Eronia. In Africa its species 

 have not developed mimetic patterns to anything like the extent that obtains in the Oriental 

 region. There many or most of the species, more particularly in the female sex, have 

 developed mimicry of Danaine butterflies to a degree which can only be compared with the 

 Pierine mimicry of the Heliconidae in the Neotropical region. With regard to the combination 

 of cryptic and aposematic coloration, instances are by no means wanting in other orders 

 of insects ; and it is well known that many grasshoppers [Acridiidae), extremely cryptic 

 under ordinary circumstances, exhibit, when alarmed, the often brilliant colours of their 

 wings, previously concealed beneath the tegmina. Such colours are not necessarily a sign 

 of actual distastefulness. The sudden appearance of brilliant colours may, and probably 

 often does, have the effect of starthng an enemy and so frightening it away, quite apart 

 from any suggestion of distastefulness.^ 



FURTHER INSTANCES OF MIMICRY IN THE LYCAENIDAE 



It has already been remarked that mimicry in the Lycaenidae is a common phenomenon 

 in the African region, and it now remains to describe some further mimetic Lycaenidae in 

 addition to the forms of Mimacraea and Pseudaletis already noted. Several species of 

 Mimacraea, of which lack of space has prevented my giving illustrations, are more or less 

 mimetic of Acraeas and Planemas. Thus M. charmian, Smith and Kirby, which somewhat 

 resembles the male of M. fulvaria, but has a larger expanse of reddish-orange on both wings, 

 presents a general Planemoid appearance. M. krausi. Dew., is not unlike M. poultoni, to 

 which it is probably allied, and mimics the western representative of A. sotikensis, viz, 

 A, praeponina, Staud. M. neokoton, Druce, resembles on the upperside M. marshalli, 

 though the orange areas are paler, the sub-apical band yellow, and the species has a 

 generally Acraeine appearance. The Mimacraea neurata of Holland I have not seen. The 

 following are instances of mimicry in other genera : — 



PENTILA AMENAIDA. 



Hewitson, Exot. Butt., Pentila and Liptena, pi. 2, ff. 4-7 (1873). 

 Aurivillius (var. nyassana), Rhop. Aeth., p. 261 (1898). 



Plate IX, Fig. 26. 



1 Mr. Trimen informs me that he has noticed molested would suddenly display, and keep displayed, 

 that several species of the larger Saiurniidae in the usually brightly coloured hind-wings, with their 

 South Africa, resting with the hind-wings for the most great conspicious central ocellus like a vertebrate 

 part covered by the fore-wings, when disturbed or eye. 



