BUTTERFLIES OF SAMOA AND SOME NEIGHBOURING ISLAND-GROUPS. 25 



9. Hypolimnas antilope lutescens (Butler). 

 Diadema lutescens ; Butler, 1874, p. 283, PI. XLIV, fig. 3. 



Swezey, 1921, p. 603. 

 Diadema antilope lutescens ; Schmeltz, 1875, p. 185. 

 Hypolimnas antilope lutescens ; Rebel, 1910, p. 418. 



All the Samoan and Tongan specimens of this species that I have seen 

 are referable to the forms lutescens Butler and sila Fruhst, the difference be- 

 tween which in these islands appears to be sexual, all the lighter specimens 

 being males and the darker ones (form sila) females. 



The species is not found in Western Samoa, but Swezey recorded it from 

 Tutuila, and I found eggs, larvae, and imagines there at Pago-Pago and other 

 localities on the south coast of the island, at sea-level, in August 1925 ; it pro- 

 bably occurs all round the coast. In Tonga it was not uncommon near Neiafu, 

 Vavau, in February and March 1925, especially at an elevation of about 200 feet 

 on Talau Hill, but I did not see it elsewhere in the group. 



In striking contrast to its relatives H. bolina and H. errabunda, this is a 

 very unwary insect ; its flight is lazy and floating, and it does not seem to 

 frequent flowers ; it is fond of settling on a leaf at some distance from the 

 ground, and is then easily captured. 



The eggs are laid in batches of several hundred on the underside of a leaf 

 of Pipturus incanus Wedd. (Urticaceae), and are very small in proportion to 

 the size of the butterfly (diameter - 77 mm., height 0*9 mm.). 



The larva is black, with spines arranged like those of H. errabunda, but pale 

 brown in colour ; the pair on the head are much larger than the rest, and are 

 black. The larvae feed in companies at least until the last moult, and remain 

 on the food-plant by day. I did not find early stages in Tonga. Unfortunately 

 I was not able to obtain the food-plant in Upolu, and in consequence all my 

 larvae died. Subsequently I found the tree not uncommon there at an elevation 

 of about 1,000 feet ; in Tutuila it occurs very commonly at sea-level, and also 

 up to an elevation of at least 1,500 feet. 



In our area the butterfly appears to be confined to Tonga and American 

 Samoa, but it has a wide range in the Pacific, occurring in Fiji, Papua, the 

 Cook Islands, the New Hebrides, and elsewhere. Butler's types are from 

 Ovalau, Fiji. 



