1909.] 223 



The larva lives in a i^allery (in v^?hich I have failed to find definite 

 traces ot" a silken lining) among the male catkins of Pinus pinaster, 

 and from the nature and colour of the frass, which is buff -yellow, it 

 seems to me very probable that it feeds largely on the pollen, though 

 it evidently also eats portions of the scales of which the catkins are 

 composed. When removed from its natural surroundings, it is rest- 

 less, but is, nevertheless, slow and deliberate in its movements. In 

 my experience, the larva is singularly intolerant of any interference, 

 and, since it is impossible to avoid disturbing the individuals required 

 for description oi- close observation, I have never succeeded in rearing 

 any such into the imaginal state, so was obliged to prove the identity 

 of the larvjB and pupfe by rearing the former into the pupal state, 

 and breeding the moths from absolutely identical pupse found at 

 large. The larva, when described, had just finished spinning its 

 cocoon m confinement, but had not begun to shrink or to lose its 

 activity. The cocoon, which was firmly spun along the lower part of 

 the stem of a catkin of P. pinaster, with its base fixed to the base of 

 the latter, was situated in a gap where some scales were missing, and 

 was further attached to some adjoining scales. It measured (5 mm. in 

 length by To in breadth, and was composed of tough white silk, thin 

 but close in textui'e, and having the exact appearance of tissue paper. 

 Two other cocoons, both spun at large, the one containing a pupa, the 

 other an unchanged larva, occupied similar positions near the bases 

 of catkins of the above-mentioned pine. 



Since both JS. syloestrana and Olethreutes hifasciana may some- 

 times be found feeding together in the same clusters of male catkins 

 of P. pinaster, it is important to master the principal distinctions 

 between them. The larva of -E. sylvestrana differs from that of O. 

 hifasciana in the following points : (1) it is much smaller and shorter, 

 and is also far slower in its movements ; (2) it is much darker in 

 general colour, and this is especially noticeable when comparing well- 

 grown larvae, for O. bifasciana becomes considerably lighter as it 

 approaches maturity, whereas its associate does not do so to nearly 

 the same extent ; although the similarity is considerably stronger 

 when both are young, the latter has then a chocolate-brown, as 

 opposed to an ochreous-tawny, ground-colour ; (3) E. sylvestrana has 

 no distinctive dark anal plate, whereas 0. bifasciana has a conspicuous 

 brown or light brown one, much darker than the ground-colour, in all 

 but quite small individuals, and in these it is, as a rule, quite visible, 

 though occasionally pale and very inconspicuous ; (4) while O. bifas- 

 ciana spins silk freely wherever it is; and is thus easily able to get a 



