198 [September, 



NOTES ON THE LIFE-HISTORY OF OLETRREUTES {SERICORTS) 



BIFASCIANA, Hw., 



WITH DESCRIPTIONS OF THE LARVA AND PUPA. 



BY EUSTACE R. BANKES, M.A., F.E.S. 



Learning from Meyrick's HB. Brit. Lep , 468 (1895), that the 

 larva of OlefJireittes* hifasciana, IIw., was, so far as he knew, un- 

 described, and having, in 1900, found, in the Isle of Purbeek, Dorset, 

 a locality for this species, I determined, if possible, to rectify the 

 omission, so gathered some clusters of male catkins of Pinus pinaster 

 on June 12th, 1901. On the following day the laborious task of 

 picking these to pieces in seach of larvae was undertaken, with the 

 result that a single cluster yielded two empty pupa shells, two live 

 pupse, an ichneumon cocoon, and about half a dozen larvae of different 

 sizes. Subsequent experience showed that the pupa shells, pupae, and 

 larger larvae were referable to hifasciana, while the smaller larvae be- 

 longed to Evetria sylvestrana, of which a few imagines were afterwards 

 bred from the same collection of pinaster catkins. 



The following description of the k^rva of hifasciana, when about 

 full-fed, was made on June 13th : — 



Length, when moderately extended, = 11*5 mm. Greatest breadth, ^= TS mm. 



Mead black, polislicd, rather flattened, and conspicuously narrower than the 

 prothorax, into which, however, it is only slightly retractile ; ocelli black, polished ; 

 antennae short, watery- white, but brown towards apex ; mouth-parts blackish-brown. 

 Prothorax mai'kedly narrower than the mesothorax and following segments, and 

 bearing a brownish-black plate of fair size, narrowly bisected by a pale central line. 

 The thorax and ahdomen together form a fairly cylindrical mass, which, however, 

 tapers abruptly at the prothorax, and also near the anal extremity : this mass is 

 smooth, shining, seraitransparent, watery dirty whitish-yellow, sometimes tinged 

 with dirty reddish, and has the segmental divisions well defined. In the male larva 

 the embryo testes are seen through the back of the fifth abdominal segment as two 

 oval brown spots, and the pulsating dorsal vessel often shows through the skin as an 

 indistinct dark dorsal line. Anal plate pale brown, of medium size. The tubercles 

 and spiracles appear as minute darker spots, and emit pale hairs, mostly of moderate 

 length, those on the anal segment being the longest. Ventral surface, with prolegs, 

 concolorous with dorsal. Legs highly polished, externally brownish-black with paler 

 bars, internally paler. 



On June 28th, 1902, I had before me larvae of very various sizes 

 collected in the same locality, and was able to learn from them that 

 the larva gradually becomes paler in colour as it increases in size. 

 The smallest ones examined, which were only 3*5 mm. in length, had 

 the ground-coloqr ochreous-tawny, but were otherwise similar to the 



* The generic name used by Meyrick is Eucosma.—^. R. B. 



