60 



INSECTS OF SAMOA. 



26. Zizera labradus (Godt.). 

 Polyommatus labradus Godt., Enc. Meth., 1819, IX, p. 680. 

 Zizera labradus ; Druce, p. 435, PL XXVII, fig. 1. 



Waterhouse, 1904, p. 494. 



Eebel, 1910, p. 421. 



Pagenstecher, p. 302. 



Fruhstorfer, 1923, p. 926, PI. CLIII. 

 Lycaena communis (Koch. M. S.) ; Schmeltz, p. 188. 



Fraser, p. 148. 

 Lycaena phoebe ; Butler, 1874, p. 285. 



In a long series of this insect from various localities in Samoa and Tonga, 

 there is considerable variation ; in the male this chiefly affects the width of the 

 dark border on the upperside, and in the female the extent of the blue on the 

 upperside. This latter is present and usually well-developed in twenty-six 

 Samoan females, and absent or obsolescent in five Tongan ones, but the numbers 

 from Tonga are insufficient in such a variable species to show whether the 

 difference is a constant one. The spots on the underside vary considerably in 

 development. There is also much variation in size, my largest and smallest 

 males (both from Upolu, Samoa) measuring 30 and 20 mm. respectively. My 

 series from Samoa includes fifty-two males and twenty-six females. 



Very common in the coastal belt of all the islands of Western Samoa, and 

 also of Tutuila, Vavau, Haapai and Nukualofa. Buxton captured a single 

 male on Nanumea, Ellice Islands, in September 1924, but did not see it on any 

 other islands of the group. The butterfly, unlike Z. alsulus, may be found some 

 way inland where there are clearings ; this is probably due to the fact that it 

 has several food-plants. In Samoa I usually found the larvae on Indigofera 

 anil, but also on Desmodium umbellatum, while in Fiji it is recorded as eating 

 Phaseolus adenanthus Mey., and Vigna catiang Walp. 



The larva is olive-green in colour, with a dark green mid-dorsal line and 

 an interrupted narrow yellow lateral line, connected by short yellowish oblique 

 stripes in each segment ; head brown ; legs and prolegs green. Whatever the 

 food-plant, only the flowers are eaten. 



Pupa pale buff, with dark brown freckling, mid-dorsal line, and dorsolateral 

 line ; length about 7 mm. ; attached to either side of a leaf of the food-plant. 



