﻿253 



somp: notes on the papilionids. 



By Cecil Flokrsheim, F.E.S. 



(Continued from p. 229.) 



(5) P. jioli/xenes (asterias). — This butterfly, an inhabitant of 

 Southern Canada and the Central and Southern United States 

 of America, belongs to the Umbelliferse-feeding branch of the 

 Papilioninge, and is most likely sprung from the same original 

 stock as our own P. machaon. It is, however, sexually dimorphic, 

 the female differing greatly both in size and in colour from the 

 male, and being, like that of the dark southern variety of 

 Jasoniades glaucus, probably a mimic of Laert'ias philc7ior. In 

 its earlier stages it closely resembles Papilio machaon, except that 

 the larva when full-grown has the black bands on each segment 

 more broken, and the red spots replaced by yellow ones. The 

 pupa tapers rather more in the abdominal segments than that of 

 machaon. I have found this species easy to breed in my butter- 

 fly-house, where the female oviposits freely on fennel, unlike 

 that of machaon, which with me shows a decided preference for 

 laying its eggs on Skimmia (natural order Eutaceas). I think 

 that there would be no difficulty in getting polyxenes to establish 

 itself in Southern Europe, though in England its fixed habit of 

 being at least double-brooded would prevent it from ever 

 becoming naturalized. It is not a particularly rapid feeder-up, 

 and only in exceptionally hot summers, like that of 1911, would 

 it be able to complete its transformations here for the second 

 time. Some years ago I was fortunate enough to obtain a 

 pairing of this species, female with P. machaon male. The 

 resulting larvse fed up well and quickly on fennel, and resembled 

 typical polyxenes, but in trying to obtain a second brood I forced 

 the pupae in a vinery, and by subjecting them to too great heat 

 killed 'most of them. The pupae, like the larvae, were in- 

 distinguishable from normal jJoZz/^ew^s. The few imagines 

 that emerged were all males. They also seemed to be typical 

 polyxenes, though one of them paired readily with a feruale 

 machaon, which unfortunately was drowned the next night 

 during a heavy thunderstorm. It w^ould appear that polyxenes 

 is the Mendelian dominant in this case. 



(6) P. zolicaon. — I was only once able to obtain pupae of this 

 butterfly, an inhabitant of the Western United States of America 

 and Vancouver, in any quantity. It is an even nearer relative 

 of machaon than the preceding species, the differences between it 

 and its English relation being exceedingly small. I had intended 

 if possible to cross them, but my zolicaon began to emerge at the 

 end of April, three weeks before machaon, which I have always 

 found constant to May 20th or thereabouts, whatever the season 

 is like. In consequence of this most of my zolicaon were dead 



