MIMETIC ASSOCIATIONS 



41 



chrysippus-like coloration. As will be seen from the figures, the contrast between the sexes 

 is very great, and reminds us of the marked difference between the male and female misippus. 

 D. iris appears to be a somewhat local insect, though not rare in its regular habitat. Other 

 members of this genus exhibiting a somewhat chrysippus-like pattern are D. veronica, 

 D. tadema, and D. karschi, some of the females of these species closely resembling that of 



D. iris. The latter species was taken by Mr. Neave at Lake Bangweolo in North-East Rhodesia, 

 whilst the other species named are West African forms. 



The females of some species of Euryphene, notably E. senegalensis, Schaeffer, and 



E. chriemhilda, Staudinger, occurring near Mombasa, have a somewhat chrysippus-like 

 pattern, though their flight and habits are such as to somewhat discount the value of their 

 appearance in this respect. They fly rapidly close to the ground in woodland or forest country, 

 As Rogers has, however, pointed out (Trans. Ent. Soc, p. 521, 1908), it is difficult to account 

 for the female pattern unless the insects do gain some advantage through their likeness 

 to the Danaine model. 



Other forms showing an approximation towards the chrysippus pattern are certain 

 forms of the female of Acraea esebria, which have a white sub-apical bar in the fore-wings, 

 also the female of Acraea petraea, which bears a close resemblance to A. encedon. The 

 opponents of mimicry have sometimes asked for proof that supposed mimetic forms are 

 found together in nature. Ample proof of this elementary fact is furnished by the large 

 collection of groups of mimetic butterflies taken on the same day and now preserved in the 

 Hope Museum at Oxford. It is, however, especially interesting to note that these groups 

 include associations taken by Mr. Marshall at Malvern, Natal, one of which contains D. chry- 

 sippus, H. misippus, A. esebria, and A. encedon, whilst another includes the above-named 

 species and also Acraea petraea, showing very clearly the incipient mimicry of the latter 

 species and the female A. esebria. 



THE ALETIS GROUP. 



ALETIS HELCITA. 



Clerck, Icon. Ins., ii, pi. 39, f. A (1759). 



Plate III, Fig. 11. 



This day-flying Geometrid moth forms the centre of an interesting mimetic 

 association.^ 



Forms of Aletis appear to be common throughout Tropical Africa, and the genus is 

 characterized by brilliancy of colour, relative abundance, and carelessness of pursuit, from 

 which it may be concluded that the species enjoy considerable freedom from attack. Many 

 of them are imitated also by other moths, notably Phaegorista similis ( = helcitoides) and 

 Xanthospilopteryx poggei ( = Eusemia falkensteinii) . 



1 Instances of mimicry between moths and 

 butterflies are by no means uncommon, and in the 

 Asiatic and Neotropical regions present some very 

 remarkable examples of the phenomenon. The sub- 

 famil}^ Pericopinae in South America includes many 

 species which in colour and markings resemble 

 certain Heliconid butterflies with the most perfect 

 accuracy. Perhaps the most wonderful instance of 

 mimicry between a butterfly and a moth is that 

 furnished by Alcidis aurora and Papilio laglaizei, 

 1200 F 



both of which insects occur at Milne Bay, New 

 Guinea. The resemblance on both surfaces is very 

 perfect ; but the most remarkable feature is the fact 

 that the underside of the body of the moth is bright 

 orange colour, whilst that of the butterfly is pale 

 green, but the latter has a bright orange patch on the 

 inner-margin of the hind-wings which exactly fits 

 against the abdomen when the insect is at rest, thus 

 causing it to appear to have an orange-coloured body 

 like the moth. 



