114 BRITISH LEPIDOPTERA. 



New York Ent Society, 1896, pp. 22 — 26, Dyar gives a summary of 

 the American species of Dendrolimus, based on the characters of the 

 2 s, but we are not altogether certain that the American species 

 are truly congeneric with the Palaearctic D. pini. 



The Eutrichid egg is somewhat different from the Pachygastriid 

 (Lasiocampid) egg. It is, however, of the same general flat type, 

 somewhat similar in outline, with only traces of the black points 

 at the angles of the polygonal reticulation so characteristic of the 

 tgg of Lasiocampa. It has, generally, in addition, a series of 

 concentric ovals of a different tint — purplish, green, etc. — from that 

 of the paler ground colour of the egg. There is some varia- 

 tion in the mode of egg-laying ; many species lay only a few 

 eggs in the same place, and these somewhat irregularly — Eutrkha 

 quercifolia, etc. — others place them more or less in rings or irregular 

 masses, several in a batch — Macrothylacia rubi, Cosmotriche potatoria, 

 etc. — whilst Dyar notes that the eggs of Dendrolimus howardi are laid 

 in irregular clusters without any covering (the latter character, of 

 course, being characteristic of all Eutrichids known to us), whilst 

 Fletcher observes {Ent., xxxiv., p. 198) that, at Wei-hai-Wei, on October 

 4th, 1899, the small fir-bushes were covered with ova of D. pini, most 

 of which had already hatched out, the young larvae being about half-an- 

 inch long. The larger (micropylar) end of the egg appears usually 

 to be eaten away by the Eutrichid larva on emergence. 



Graber states {Morph. Jahrbuch., xiii., 1888, pp. 609, 610) that 

 he found the abdominal segments of the developing embryo of 

 Eutricha quercifolia at first devoid of appendages, and that, when 

 the latter appeared, they developed only on those segments on 

 which they persist in the adult, and, on this ground, he is inclined 

 to consider the prolegs secondary appendages {vide, anted, vol 

 i., p. 22). The newly-hatched Eutrichid larva is characterised 

 by having tubercles i and ii large many-haired warts, iii a large 

 many - haired wart, iv + v a large many - haired wart, whilst there 

 is a large supplementary prespiracular wart towards the front edge 

 of the abdominal segments 1 — 7 (anted, vol. ii., p. 439). The presence 

 of a dull larval head in newly-hatched larvae of Eutricha 

 {quercifolia) and Dendrolimus {pini), whilst those of Cosmotriche 

 (potatoria), Macrothylacia {rubi), etc., have shiny heads in 

 this stage, suggests the more specialised character of the 

 former. The full-grown Eutrichid larvae are particularly specialised, 

 and that of Cosmotriche {potatoria) is possibly almost as specialised in 

 its own peculiar way, as are those of Dendrolimus, Odonestis, 

 and Eutricha, which, in specialisation for protective purposes, are 

 perhaps unequalled {anted, vol. ii., pp. 441-442) among any 

 lepidopterous larvae. Bacot notes certain resemblances between 

 the larvae of D. pini and C. potatoria, and observes that a faint 

 dark mediodorsal line is present in the first instar of the larva of 

 Dendrolimus pini, the 2nd and 3rd thoracic, and the 8th and 9th 

 abdominal, segments being darkened on the dorsal area. This 

 darkening is especially well-marked on the meso- and metathorax 

 and is strongest on the low transverse ridge that bears tubercles i ; 

 the space between being pale yellow, suggesting the similar yellow 

 blotches observable in Cosmotriche potatoria. Practically, the coloration 

 is the same as in the latter species, but the colours are much faintei 



