418 BRITISH LEPIDOPTERA. 



is the last instar, in it the larva assumes its well-known colour and 

 markings (Gauckler, in lift.). 



Variation of larva. — A century ago Goeze described and 

 figured (Naturf., xviii., pp. 195 et sea., pi. iv., fig. 25) a variety of the 

 larva of this species of a dirty light grey colour tinged with yellow 

 dorsally, darker red-brown ventrally and on the head, whilst Schroter 

 describes (Joe. cit., xxi., pp. 173 et seq.) several distinct varieties of it. 

 Capieux attempted (JVaturf., xxiv., p. 97) to establish a connection 

 between the varieties of this species and the different foodplants, based 

 on the fact that he found 3 black-brown larvae on Lycium which he 

 states refused to eat potato. Borkhausen dissents (Rhein. Mag., p. 324) 

 from this, points out that Schroter's black-brown larvae were found on 

 the ordinary food, and adds that Goeze's striking variety of the larva 

 (supra) also shows how variable the species is in this stage. Stainton 

 notes two forms of the larva of M. atropos: (1) Lemon-yellow, 

 towards the head and lower part of the sides green, with 7 

 oblique, lateral violet stripes ; horn yellowish. (2) Brownish-olive, 

 with the lateral stripes darker; the anterior segments whitish. 

 Authors frequently speak of the larva as dimorphic, and Bartel (Pal. 

 Gross-Schmett., ii., p. 18), after describing the yellowish-green form, 

 writes : " More rarely there is a darker form of the larva which 

 corresponds with the dark larval forms of Deilephila elpenor and D. 

 ■porcellus. It is brown-grey or olive-brown and covered with innumerable 

 white granulated dots arranged in rows. .... This dark form 

 does not occur in young larvae, but only in the later stages. After the 

 last moult it becomes light green, to return some hours later to the original 

 olive-brown colour." Newman also refers (Ent., v., p. 102) to two 

 forms, and describes the dark form (Ent., ii., pp. 281-282), although 

 Edmunds (and others) had already described it very well (Ent. Wk. 

 Int., v., p. 17). Bellier de la Chavignerie notes {Ann. Soc. Ent. France, 

 (2), iv., pp. cx-cxi) that the larvae are usually yellow or green, ornamented 

 with blue or violet chevrons, which are clearly marked on the ground 

 colour, but Marchand had found at Chartres, an aberration, which 

 was of a very dark grey-brown colour, spotted with white, the chevrons 

 of the same colour, the thoracic segments white marbled with black. 

 Boisduval, he says, described a somewhat similar form, and Engramelle 

 figured one, whilst others were found in September, 1846, in a potato- 

 field near Paris by Lorquin, and others again were taken by Abicot at 

 Gien. Guenee also observed that this form had been often described and 

 that Hiibner had figured it. Powell notes (in lift.) that it occurs at 

 Hyeres in the proportion of about 33 per cent., and that the largest 

 specimen yet captured measured 150mm. Buckler gives (Larvae, 

 &c., ii., pi. xxi., figs, i-ia) two excellent figures of this larva : 



1. Of a lovely apple-green, the thorax unicolorous, the abdomen with the 8 

 characteristic oblique yellow stripes, edged above with purple and violet, and with 

 the dorsum of the abdominal segments 1-8 with 8 rows of tiny black shagreen-spots 

 in no case extending venlrad of the coloured borders of the oblique stripes. The 

 caudal horn of the ground colour ; the aual flap with a yellow border. 



2. The ground colour brownish-drab; the thorax whitish-drab, with a 

 double blackish median line and broken black subdorsal ; the oblique stripes black 

 and united with the subdorsal lines into a rough reticulated pattern over the dorsum 

 of the abdomen ; the dorsal area above the oblique stripes of abdominal segments 

 1-8 red-brown ; the abdominal segments 1-9 each with 8 rows of white shagreen- 

 spots extending down to (and on) the prolegs ; the caudal horn of the inound colour ; 

 the brown anal flap edged with drab. 



