EUTRICHID/E. 115 



in D. pini, and the pale double oblique stripes present in C. Rotatoria 

 are only faintly visible in D. pini. In the second instar, the larva 

 of D. pint alters greatly in appearance, is long, thinner, lies closer 

 to the pine-needles on which it rests, and resembles, in general character, 

 rather Eutricha (que re (folia) than Cosmotriche (potatoria); in this stage, 

 in the position formerly occupied by tubercles i (from mesothorax to 

 8th abdominal), are remarkable, scale-like hairs*, dark in colour, broad, 

 flat, square- (or ragged-) ended; tapering to base, the scales being 

 more numerous and larger on the meso- and metathorax and 8th ab- 

 dominal segment than elsewhere ; there are also some white, grass- 

 leaf-shaped hairs on various parts of the body, a few on anterior 

 edge of scutellum, a very marked ridge of them on mesothorax (just 

 behind position of i) and a slight ridge in same position on metathorax ; 

 a few small ones on the lateral area of each segment from mesothorax 

 to 8th abdominal ; on the 8th abdominal, the scale-like hairs have 

 a lovely blue or purple gloss on them ; the dark colour of the area 

 (occupied in ist instar by tubercle i) agrees with that exhibited 

 by the larva of C. potatoria. There is not such a strong development 

 of secondary hairs in D. pini (2nd instar) as in C. potatoria in the same 

 instar, and there is not the same suggestion of shagreen on the skin 

 as in the larva of the latter. Comparing the larvae of C. potatoria 

 and D. pini at this stage, one sees at once that the colour-scheme 

 is theoretically the same — strongly developed, however, in C. potatoria, 

 only faintly traceable in D. pi?ii — in the latter apparently develop- 

 ing towards an unicolorous larva, with the exception of certain 

 local startling or warning markings. In the larva of C. potatoria the 

 dorsal area is practically bright yellow with a series of large, oval, 

 central, dull blue blotches, one on each segment from ist to 8th 

 abdominal, joined to each other by two black spots set only slightly 

 apart and showing a streak of the yellow ground-colour between 

 them ; the black dorsal spots (similar to those of Dimorpha versicolora 

 in 2nd instar) are situated on the outer or subdorsal edge of the 

 blue dorsal patches ; this arrangement nearly fills up the central 

 dorsal area, but there is a broad, yellow, subdorsal band, and again, 

 below this, the yellow and blue mottlings in about equal proportions, 

 the blue chiefly above and the yellow beneath, but much more 

 broken up by being arranged roughly into double oblique stripes ; 

 blue was probably the original ground-colour, but it has been much 

 encroached upon by the spreading of the yellow. In the 3rd instar the 

 scale-like hairs of the larva of D. pini already described are very 

 marked and steel-blue in colour, whilst the white grass-leaf-like hairs are 

 also more strongly developed. The remarkable larval scales*, already 

 mentioned as being found on Eutrieha quereifolia and E. americana, are 

 figured by Packard (Proc. Amer. Phil. Soc, xxxi., pi. x., figs. 15-17 

 and pi. xi., fig. 18), as well as those of Heteropacha rileyana (loc 

 cit., pi. xi., fig. 19). Dyar considers (Jouwi. N.Y. Ent. Soc, 

 1896, pp. 22 et seq.) that the short hairs of the adult larva of 

 Dendrolimus howardi are of a defensive nature, and states that 

 they become detached when the larva is handled, and, entering the 

 skin, produce some irritation and finally small blisters which last for 



* See also antea, vol. ii., p. 437, where similar larval hair-scales are described 

 as present in the larvae of Eutricha quereifolia and E. americana. 



