1868.] 



187 



LTC^NA MEDON (AGESTIS) AND ARTAXERXES, ARE THEY DISTINCT? 

 BY PKOF. P. C. ZELLEB. 

 (Translated and extracted from the " Stettiner Ent. Zeitung" 1868, pp. 401 — 405. 



Englishmen consider it as now proved,* and Staudinger in his 

 Catalogue follows their precedent, that Artaxerxes is only a variety of 

 Medon, the transition to which is formed by Salmacis, Steph. That 

 the latter belongs to Medon cannot be doubted ; but the former does 

 not yet seem to me so sure as not to necessitate confirmatory experi- 

 ments. What probably constitutes the rule with Salmacis, namely, 

 that white scales border the black median spot of the fore-wings on 

 both sides, I notice only in some specimens of Medon from the South 

 of Europe and Asia Minor, where it is more or less finished on the inner 

 side by a few white scales. But that, as in Artaxerxes, the whole 

 black spot should be missing, and the white scales so much increased 

 instead, as to form a white oval spot, has probably nowhere been 

 observed on the continent. The natural history of Artaxerxes is, 

 at all events, well known to Englishmen. Stainton writes (Manual, 

 p. 62) — "Larva pale bluish-green, with a green dorsal line and a 

 pinkish lateral one ; head glossy black. On Selianthemum vulgare in 

 May ; time of appearance of imago June and July." I doubt not but 

 that in some one of the many English publications, which I am sorry 

 to say are mostly unknown and unused on the continent, the natural 

 history is given at length. The same is no doubt the case with Medon; 

 for, if the description of its larva taken from Westwood, and in the 

 Manual, — " green, with a pale angular dorsal row of patches, and a 

 yellow-brownish dorsal line," — should still be considered as correct, it 

 is not to be understood how people in England could have their doubts 

 about the most complete specific difference between Medon and Arta- 

 xerxes. The natural history of our common Medon I have carefully 

 observed from the egg, and described in the Ent. Mo. Mag., vol. iv., 

 pp. 73 — 77. I therefore mention here only the following. Stainton 

 has indicated the correct food-plant, but the full-grown larva must be 

 thus described : — " Lively pale green, finely white-haired ; the head 

 black ; the dorsal line purplish-brown ; with two very pale green 

 oblique lateral lines, and broad purplish-red lateral swellings." 



It is owing to the kindness of my friend, Mr. Henry Doubleday, of 

 Epping, that I have become acquainted with the caterpillar of Arta- 

 xerxes in nature ; I got from him four larvae, which, after having probably 



* In Stainton's Manual I. (1857) L. Agestis (Medon) and Irtaxerxet were still kept separate. 



