Studies in the Theory of Descent, Volume I

73

[Mr. A. G. Butler (Trans. Zoo. Soc., vol. ix., part. x., 1876) gives a list of about eighty-four species of Chærocampa, and sixteen of Pergesa, besides numerous other species belonging to several genera placed between Chærocampa and Pergesa. Of Darapsa, he states “that this genus was founded upon most heterogeneous material, the first three species being referable to Hübner’s genus Otus, the fifth to Walker’s genus Diodosida, the sixth and eighth to the genus Daphnis of Hübner, the seventh, ninth, and tenth to Chærocampa of Duponchel; there therefore remains only the fourth species, allied to Chærocampa, but apparently sufficiently distinct.” The species still retained in the genus Darapsa is D. rhodocera, Wlk., from Haiti. R.M.]

74

[Otus Syriacus of Butler’s revision. R.M.]

75

Abbot and Smith. “The Natural History of the rarer Lepidopterous Insects of Georgia, collected from the observations of John Abbot, with the plants on which they feed.” London, 1797, 2 vols. fol.

76

[Otus Chœrilus and O. Myron of Butler’s revision. R.M.]

77

[To this group may also be added Ampelophaga Rubiginosa, Ménétriés, from China and Japan, the caterpillar of which, having the distinct subdorsal line without any trace of eye-spots, is figured by Butler (loc. cit., Pl. XCI., Fig. 4). This author also gives a figure of another species belonging to the subfamily Chærocampinæ (Pl. XC., Fig. 11), viz. Acosmeryx Anceus, Cram., from Amboina, Java, Silhet, and S. India; the caterpillar is green, with seven oblique yellow stripes along the sides, and a very conspicuous white subdorsal line with a red border above. As there are no eye-spots, this species may be referred to the present group provisionally, although its general marking is very distinct from that of the Chærocampa group. R.M.]

78

[Eng. ed. Dr. Staudinger has since obtained the caterpillar of C. Alecto from Beyrout; it possesses “a very distinct subdorsal line, and on the fourth segment a beautiful eye-spot, which is repeated with gradual diminution to segments 7–8”.]

79

Figured in “A Catalogue of Lepidopterous Insects in the Museum of the East India Company,” by Thomas Horsfield and Frederick Moore. London, 1857. Vol. i., Pl. XI.

80

Figured in Trans. Ent. Soc., New Series, vol. iv., Pl. XIII.

81

Ibid.

82

[The following species figured by Butler (loc. cit. Pls. XC. and XCI.) appear to belong to the second group —Chærocampa Japonica, Boisd., which is figured in two forms, one brown, and the other green. The former has two distinct ocelli on the fourth and fifth segments, and a distinct rudiment on the sixth, whilst the subdorsal line extends from the second eye-spot to the caudal horn, and beneath this line the oblique lateral stripes stand out conspicuously in dark brown on a lighter ground. The ocelli are equally well developed on the fourth and fifth segments in the green variety, the subdorsal line commencing on the sixth segment, and extending to the caudal horn; there is no trace of a third eye-spot, nor are there any oblique lateral stripes; the insect is almost the exact counterpart of C. Elpenor in its fourth stage. (See Fig. 21, Pl. IV.) Pergesa Mongoliana, Butl., is brown, without a trace of the subdorsal line except on the three front segments, and with only one large eye-spot on the fourth segment. Chærocampa Lewisii, Butl., from Japan, is likewise figured in two forms. The brown variety has the subdorsal line on the three front segments only, distinct ocelli on the fourth and fifth segments, and gradually diminishing rudiments on the remaining segments. The green form appears to be transitional between the present and the third group, as it possesses a distinct, but rudimentary eye-spot on the third segment, besides the fully developed ones on the fourth and fifth, and very conspicuous, but gradually decreasing repetitions of rudimentary ocelli on segments 6–10. To this group may be added Chærocampa Aristor, Boisd., the caterpillar of which is figured by Burmeister (Lép. Rép. Arg., Pl. XV., Fig. 4) in the characteristic attitude of alarm, with the front segments retracted, and the ocelli on the fourth segment prominently exposed. The subdorsal line is present in this species. Burmeister also figures two of the early stages (Pl. XV., Fig. 7, A and B), and describes the complete development of Philampelus Labruscæ, another species belonging to the subfamily Chærocampinæ. The earliest stage (3–4 days old) is simple green, with no trace of any marking except a black spot on each side of the fourth segment, the position of the future ocelli. A curved horn is present both in this stage and the following one, during which the caterpillar is still green, but now has seven oblique red lateral stripes. The caudal horn is shed at the second moult, after which the colour becomes darker, the adult larva (figured by Madame Mérian, in her work on Surinam, pl. 34 and Sepp., pl. 32) being mottled brown. In addition to the ocellus on the fourth segment, there is another slightly larger on the eleventh segment, so that this species may perhaps be another transition to the third group; but our knowledge is still too imperfect to attempt to generalize with safety. R.M.]

83

Cat. Lep. Ins. East Ind. Comp., Pl. XIII. [Figured also by Butler (=Chæerocampa Silhetensis, Walker), loc. cit. Pl. XCII., Fig. 8. R.M.]

84

Cat. Lep. Ins. East Ind. Comp., Pl. XIII. [Figured also by Butler, loc. cit. Pl. XCI., Fig. 1. R.M.]

85

Horsfield and Moore, loc. cit. Pl. X.

86

Ibid. [=Pergesa Acteus, Walker. R.M.]

87

[Figured also by Burmeister, loc. cit. Pl. XV., Fig. 3. R.M.]

88

Horsfield and Moore, loc. cit., Pl. XI.

89

To be accurate this should be designated the infra-spiracular line; but this term cannot be well applied except in cases where there is also a supra-spiracular line, as, for instance, in Anceryx (Hyloicus) Pinastri.

90

Upon this fact obviously depends the statement of that extremely accurate observer Rösel, that the caterpillar of Euphorbiæ is but very slightly variable (“Insektenbelustigungen,” Bd. iii. p. 36). I formerly held the same opinion, till I convinced myself that this species is very constant in some localities, but very variable in others. It appears that local influences make the caterpillar variable.

91

The green is considerably too light in Fig. 45.

92

“Die Pflanzen und Raupen Deutschlands.” Berlin, 1860, p. 83.

93

Fig. 62, Pl. VII., is copied from Boisduval.

94

The fading of the red anteriorly has not been represented in the figure.

95

[The caterpillar of Deilephila Euphorbiarum, figured by Burmeister (Lép. Rép. Arg., Pl. XVI, Fig. 1) belongs to this stage. R.M.]

96

[In concluding this account of the Chærocampinæ I may call attention to the following species, which have since been figured by Burmeister: —Pachylia Ficus, Linn. (loc. cit. Pl. XIV., Figs. 1 and 2); during the three first stages the larva is uniformly green, with a yellow subdorsal line, and below this ten oblique yellow stripes slanting away from the head; after the third moult the colour completely changes, the whole area of the body being divided into two distinct portions by the subdorsal line, above which the colour is red, and underneath of a pale green; the oblique stripes have almost disappeared; no occelli nor annuli are present. Pachylia Syces, Hübn. (loc. cit. Fig. 3); very similar to the last species in its young stages (figured also by Mérian, Surin. pl. 33). Philampelus Vitis, Linn. (loc. cit. Figs. 4 and 5); two stages represented; between first and second moults green, with oblique paler stripes slanting in same direction as in Pachylia, and each one containing a red streak surrounding the spiracle. When adult, the ground-colour is yellow above and green beneath, the whole surface being mottled with deep black and red transverse markings; the oblique stripes whitish, bordered with black at their lower extremities (figured also by Mérian, pls. 9 and 39). Philampelus Anchemolus, Cram. (loc. cit. Pl. XV., Fig. 1; Mérian, pl. 47); green when young, with seven oblique red stripes; when adult, uniformly brown, with seven pale yellow lateral markings, the first four of which are spots, and the remainder broad oblique stripes slanting forwards. Philampelus Labruscæ, (see note 82 (#cn_85), p. 195 (#Page_195)). R.M.]

97

[Mimas Tiliæ of Butler’s revision. The author states that this genus is “easily distinguished from Laothoë by the form of the wings, the outer margin of secondaries deeply excavated below the apex, and the secondaries narrow and not denticulated.” Here again we have a clashing of the results arrived at by a study of the ontogeny of the larvæ, on the one hand, and the founding of genera on the characters of the imagines only, on the other. Of the three species discussed by Dr. Weismann, Mr. Butler, following other authors, refers Tiliæ to the genus Mimas, Populi to Laothoë, and Ocellatus to Smerinthus. It is to be hoped that when our knowledge of the developmental history of larvæ is more complete in all groups, a reconciliation between the results of the biological investigator and the pure systematist will be brought about, so that a genus may not, as at present, have such very different values when regarded from these two points of view. R.M.]