22 



INSECTS OF SAMOA. 



7. Doleschallia bisaltide tongana, nom. nov. 

 Papilio drusius Fabricius, 1781, Sp. Ins., p. 61, no. 272. 



This form was described by Fabricius from two males taken at Rotterdam 

 Island (=Namuka in the Tongan group), but this name is preoccupied by 

 Papilio drusius Cramer, described in 1779. 



It is closely related to the Fijian D. b. vomana Fruhst., from which it differs 

 as follows : Male (PI. II, fig. 4), upperside ground-colour brighter tawny, 

 the fifth of the small white spots forming the sub-apical series on forewing 

 always completely obscured by a large tawny spot, which is united to the short 

 sub-apical tawny band ; hindwings much paler than in D. b. vomana, with little 

 dark suffusion and with all the dark markings reduced. Underside as in 

 D. b. vomana, but in all the specimens I have seen the ground-colour is a reddish- 

 brown, without any trace of the green sometimes found in Fijian specimens. 

 Five males from Neiafu, Vavau group, Tonga, March 1925, agree well with the 

 types. 



The female is undescribed : it is similar to the male, but ground-colour 

 paler and all dark markings less extensive. Type female from Tonga (G. F. 

 Matheiv), Godman and Salvin collection, in B.M. ; one paratype from Neiafu, 

 March 1925. 



Both sexes are smaller than Fijian specimens (expanse of male 63-71 mm., 

 mean of seven specimens 68 mm., and of female 74 mm.). Variation is slight, 

 affecting chiefly the proportions of the tawny band on the forewings ; in four 

 of my males and both the females this extends from the costa to join the ground- 

 colour as in the types ; in only one is the fifth spot of the sub-apical series not 

 connected with the tawny band. 



This insect was rather common on Talau Hill, Neiafu, during February 

 and March 1925, and Armstrong saw a single specimen there in March 1926. 

 It patrols back and forth over a chosen stretch of open ground, such as a path, 

 with a strong and rapid flight, usually keeping at a height of ten to fifteen feet 

 from the ground, and occasionally settling on leaves, though usually fairly high. 

 It did not seem to be attracted to flowers. On one occasion I saw one give 

 chase to a large hornet (Polistes macaensis F.), and they constantly flew at other 

 specimens of their own species as if to drive them off the chosen territory. One 

 of the captured specimens had a large symmetrical injury to the hindwings, 

 which must have been caused by the bite of either a bird or a lizard. 



The early stages are unknown. 



