THECLA BETUL^E. 165 



except in the case of rubi which passes the winter at 

 the pupal stage. 



T. betulae, Linn. (Brown Hairstreak, or Thecla of the 

 Birch) (Figs. 180 to 184), is the largest of the genus, 

 sometimes expanding more than i^in. from tip to tip of 

 the fore-wings. Although the specific name is derived 



THECLA 



from the Birch (Hetula alba), the Sloe (Prunus spinosa) 

 is as often as not selected as the food-plant, and on 

 that the caterpillar may be fed in captivity. While 

 the Brown Hairstreak has a liking for oak-woods, it also 

 frequently leaves them, giving the collector a sight of its 

 charms as it flits along some country hedgerow, enticing 

 him forward in pursuit. Though there are many localities 



