NOTES ON THE EARLIER STAGES OF PAPILIO MACHAON. 277 



Some notes on the earlier stages of Papilio machaon, particularly 

 witli regard to the colour dimorphism of its pupa. 



By CECIL FLOERSHEIM, B.A., F.E.S., F.Z.S. 



At the suggestion of Mr. Merrifield, I have been breeding this 

 species during the past summer with a view to ascertaining whether 

 the colour dimorphism ol' its pupa is due to a mechanical adaptation to 

 surroundings or to any pre-existent condition — other than the variation 

 which urged the particular larva to choose such surroundings. The 

 experiment was carried out principally in my butterHy-house, out-of- 

 doors, and in all respects other than that of semi-captivity, in a state 

 of nature. As, in the course of my observations, I came upon other 

 facts relating to the life-history of Papilio machaon. which appear to 

 me to be new or of interest, I have incorporated them with this 

 description of the result. 



The ova (from wild English pupse), with the exception of a few 

 deposited on leaves of Ptelea tripoliata, were laid upon Skiinmia 

 fra<ira)is, a hardy evergreen shrub of .Japanese origin, chiefly upon 

 the young shoots, between June 4th and 15th. They began to hatch 

 about .June 21st, and the larva? fed up rapidly, the first commencing 

 to pupate on -July 22nd. It may not be amiss to attempt to give 

 here some account of the natural contents of my butterfly-house, a 

 light wooden structure of considerable dimensions, covered with gauze. 

 Besides the .S7i7'»/,y/( /a -bushes (four large and sixteen small) it holds 

 some six young willow-trees, two Ptelea, many plum, birch and cherry, 

 five small lavender- bushes, several large plants of Aristolochia siplio, 

 besides Krifsinutin, pansy, phlox, sweet-william, zinnia, valerian, and 

 other flowers, as food for the butterflies which inhabit it. Between 

 August 1st and the time when I am writing (October 1st), I have been 

 collecting pupa? of the P. marliaon which fed up in it, and have, up to 

 the present, found about 300, including those which had rotted or were 

 devoured by predaceous beetles and other enemies before I came upon 

 them. From Skiwuiia firu/ran^i itself, the principal foodplant, I took 

 183 living puptp, 121 being of the green variety. Of these latter I 

 found 115 upon the young gi'een and green-brown stems amongst the 

 green leaves at the top of the shrubs in question ; 4 upon the older 

 wood just below the leaves, and 2 upon the black-brown stems at or 

 towards the bottom of the bushes. The remaining 68 were of the 

 brown variety. Of these I found 9 amongst the lower green leaves 

 (though none upon the topmost green shoots), 10 on the older wood 

 just beneath the leaves, and 49 upon the black-brown stems at or 

 towards the bottom of the bushes. In addition to these, on the white- 

 painted wood of the butterfly-house itself, I found fifteen, most of 

 which had pupated at a distance of some two or three feet from the 

 ground. All these were of the brown variety. From the lavender 

 bushes I got 40 in all, 30 of which were of the green, and 10 of the 

 brown, variety. Of these 25 of the green were either amongst the 

 lavender leaves or on the young wood near them, whilst all the brown 

 were upon the older wood. 



With a view to obtaining confirmatory evidence of my results with 



/'. marhanti, I bred this summer some 40 specimens each of Pa/iilio 



aKterias and /'. iiJdlenor, two North American species with dimorphic 



pupse. /'. asterias, as I daresay most readers of this article know, is a 



No\^MBER 15th, 1905. 



