A CRITICAL STUDY OF AJIOEPHA POPULI, LINN. 31 



A- popidi on as])ensixx the "Hinterlande" near Biedenkopf (;'i<Wr///,4Ber., 

 1854, p. 28).* 



Although there is not much difference between " white-grey " and 

 " light-grey," this new form of Glaser does not belong anyhow to 

 Esper's and Borkhausen's ab. tremidae, because the aberration of the 

 two latter authors has no mixture of rusty-yellow colour either in 

 the description or in the figure. Glaser's aberration is far more in 

 agreement with ab. pallida, Tutt, Brit. Lep., vol. iii., p. 469, as I 

 have already mentioned in Imekten BiJrse, xx., p. 29 (relatively in 

 Societas E?it., xvii., 1903, p. 162). Dr. P. Speiser is of the same 

 opinion in ZeiUchr. f. loissenscJi. Insektenhiologie, i., 1905, p. 178. In 

 my scheme of variation {Arch. d. Ver. d. Fr. d. Xatitrjiesrh. MecM. 

 58, 1904, p. 70), I therefore referred it to the pallida group, the 

 ground colour of which is white-grey or pale, and which often appears 

 rusty-yellow in the median and outer area of the wings. The first 

 notification for my reason for not having restored the name ab. 

 borkhaaseoii, Bart., confiscated already by me in 1902, appears in 

 Insekten Borse, xx., 1903, p. 29 (relatively in Societas Ent., xvii., 1903, 

 p. 162), and of this I shall later give details. 



Glaser did not remain steadfast in the description of his variety, 

 (var. tremnlae, Borkh.) of the " Hinterland " (Oberhessen), for, in 1863, 

 he describes the same in Neuen Borkhausen, p. 83, as being of " greenish- 

 whitish ground colour with weaker markings, mostly also with a 

 nearly disappearing rust-coloured spot." But a " white-grey " form 

 mixed with a weaker rust-yellow colour and a " greenish-white " form 

 cannot absolutely be identical, and the latter belongs to my cinerea 

 group in which often light grey specimens with olive-coloured median 

 and outer areas appear. This olive colour gradually turns into bronze 

 colour and then into rust colour, whilst the ash-grey ground colour 

 gradually turns yellowish-white. 



In his Palaearkt. Gross-Schwett., ii., p. 194, Mr. Bartel has called 

 ab. borkhameni, the small and light form of Glaser with a "greenish- 

 grey ground colour, with weaker markings, and with a nearly 

 obsolete rust-red basal spot of the hindwings." My ab. cinerea- diluta 

 {Arch., 58, 1904, p. 69), newly described in my variation scheme of 



* Glaser is, however, very uncertain about ab. tremulae, BorJv. : in 1853, he 

 confuses it with the Kussian species tremulae, Fischer de Waldheim. which 

 Heydenreich quotes as tremidae, Zett., in his System. Verz. d. europ. Schmett., ed. 

 iii., 1851, ]}. 19. Although he alters this mistake in 1854, at the instigation of Herr 

 von Heyden, yet, he commits a new mistake, making the Russian tremulae, Fisch. 

 de Waldh., a Lapland species. This error he committed by falsely reading the 

 abbreviation " Zett." as " Zetterstedt,"and thinking that this species was described 

 in Insecta Lapponica descripta, Lepidoptera , which is not the case at all. Even 

 Koch, who otherwise has carefully looked over the literature on ab. tremulae, Borkh., 

 and who records the same in his Schmett. d. siidicestl. Deiitschlands, 1856, pp. 51, 

 52, has followed Glaser's example and committed the same error. In yeuen 

 Borkhause7i, 1863, p. 83, Glaser repeats Koch's litei'ature and also his own 

 (Glaser's) old error, so that between 1854 and 1863 the error had not been corrected. 

 The right synonymy of ab. tremulae, Borkh., given by Glaser (1854) and by Koch 

 (1856), has been set aside again by the first-named author in his Cataloaus 

 etymologicus Coleopterorum et Lcpidopterorum, 1887, p. 137. He says (no. 22) : 

 ^' Populi, L., Pappelschwarmer, with the var. tremulae, Treitschke, Espensch warmer, 

 small or pale Pappelschwarmer (the caterpillar upon Populn.i trepiula. L., 

 Zitterpappel or Espe)." There truly cannot be anybody to assert that Glaser is to 

 be taken seriously as to ab. trevudae, Borkh., after all the muddle concerning this 

 aberration made in 1853, 1854, 1863 and 1887 by him. 



