58 P. E. S. WHALLEY 



Neobanisia antiopa (Viette) 



Striglina antiopa Viette, 1954 : 120. 



Neobanisia antiopa (Viette); Whalley, 1967 : 46, figs 19, 44, 68, 69. 



Distribution. Map 26. Madagascar. 



BANISIA Walker 



Banisia Walker, 1864 : 77. Type-species, Banisia fenistrifera Walker, by original designation. 

 Banisia Walker; Whalley, 1964a : 117. 

 Banisia Walker; Whalley, 1967 : 47. 



This genus contains three species which are restricted to Africa and the Seychelles 

 and a subspecies of an almost tropicopolitan species, B. myrsusalis Walker. The 

 genus is structurally very distinct from other Thyridid genera and, with Neobanisia 

 and possibly Mathoris, forms part of a morphologically specialized group of genera 

 whose species, as far as known, feed during the larval stage on species of Sapotaceae. 



B. myrsusalis is unusual in its almost pantropical distribution, with very little 

 variation over the whole range. In the Malay Archipelago and New Guinea region 

 several closely allied, but distinct, species occur. Some of the problems of dis- 

 tribution were discussed previously (Whalley, 1967 : 47) where the whole American- 

 African-Indian group of specimens were regarded as one species. Further examina- 

 tion indicates that there is some justification for separating off the African-Indian 

 specimens from the American ones. However, at present I can find no morpho- 

 logical differences between the African and Indian specimens and accordingly regard 

 them as one subspecies. The Seychelles Islands have produced two distinct species, 

 closely allied to B. myrsusalis on two small islands only fifty miles apart, whereas 

 over the whole of the continent of Africa and in Madagascar no subspeciation of 

 myrsusalis has occurred. 



A possible reason for the pantropical distribution of B. myrsusalis may be found 

 in the distribution of the larval food-plant. From the few records of bred specimens, 

 the larvae of B. myrsusalis feed on species of Sapotaceae, particularly Manilkara 

 zapota L. (Sapodillo, Nispero or Naseberry). M. zapota is the tree from which 

 chewing-gum is obtained and which has for many years been transported by man 

 around the tropics from its native America. Various other species of Sapotaceae 

 also occur in the tropics and these may act as host-species, although at present there 

 are no host-records other than M. zapota. 



The introduction of B. myrsusalis during the transporting of its host-plant is 

 dependent on the correlation of a number of factors. For example, the stage at 

 which the planting material is taken (seed, cutting, etc.), and whether there is a 

 possibility of the eggs, larvae or pupa (perhaps even the adult) surviving transport 

 and finding suitable hosts while the introduced plant is getting established. There 

 are many factors which argue against man-made introductions, but against these 

 factors two facts must be set. Firstly, man-made introductions of a number of 

 species are known to have occurred and, secondly, the incontrovertible fact that the 

 species, B. myrsusalis, is at present widely distributed with little differentiation 



