3l8 THE MOTHS OF THE BRITISH ISLES. 



Horse Chestnut {Pachycnema hippocastanaria). 



The rather loDg and somewhat oval fore wings of this species 

 (Plate 137, Figb. 8, 9) are brownish grey, inclining to purplish 

 grey ; the two cross lines are blackish, edged with whitish, but 

 generally indistinct ; when the lines are well defined, the enclosed 

 central area is sometimes darker than the other parts of the 

 wings ; there is a black central dot, and occasionally there is a 

 well-marked dusky central shade. Hind wings, whitish, more 

 or less tinged with smoky grey ; frequently there is a dusky, 

 curved line beyond the middle, and this is sometimes outwardly 

 edged with whitish. 



The caterpillar is greyish brown, dotted with black, and 

 marked on the back and sides with reddish brown. When 

 at rest on the twigs of its food plant, heather or ling (Calluna 

 vulgaris), this caterpillar agrees so well with its surroundings 

 that it is not at all easy to see ; at least, we may see it. but 

 fail to distinguish it from the twigs of the plant. It may be 

 obtained in June and July, and again in the autumn. (Figured 

 on Plate 140, after Hofmann.) 



The first flight of the moth occurs in April and Mav ; the 

 second in August, but specimens of the later generation are 

 usually small in size and in number, as compared with those of 

 the early brood. 



In Britain, this species has so far only been found on the 

 heaths of Kent, Surrey, Sussex, Hampshire, Dorsetshire. 

 Somersetshire, Berkshire, and Suffolk ; in all these counties 

 it is more or less local, but it abounds in some of its haunts. 

 It has been recorded from Hereford, and Edwards states that 

 it occurs rarelv in the Malvern district of Worcestershire. 



