TRIFID^. 221 



edging to the siibterminal line; while a specimen from 

 Wicken Fen in the same collection is pale drab with the 

 first and second line conspicuously blackened, and a similar 

 stripe on the hind wings. 



On the wing in April and May. 



Larva plump, cylindrical, scarcely thickened behind ; head 

 ronnded, yellowish-brown or horn-colour; body pea-greon, 

 yellowish-green, or bluish-green ; dorsal and subdorsal lines 

 slender, white or pale green or even pale yellow ; above the 

 spiracles is a broader dark green, brown, or black stripe 

 shaded off above, edged below with white, pale green, or 

 pale yellow ; below this is a shaded-off pale green or yellow- 

 green stripe in which are the spiracles, white ringed with 

 black ; usual raised dots white ; undersurface pellucid pale 

 green; legs and prolegs similar. The spiracles on the 

 second and twelfth segments whiter and more distinct than 



the rest. 



Or the whole dorsal surface is light brown or dull 

 umbreous, with the dorsal and subdorsal lines pale but 

 indistinct; the lateral stripe conspicuously black or dark 

 brown or even pinkish-brown ; and the undersurface, with 

 the legs and prolegs, either pale green or pale brown. 



May to the beginning of July on LysimacUa vulgaris, 

 Spio^cea ulmaria, Genista tinctoria, Lythrum salicaria, and 

 Inula dysenterica, joining together the top leaves of a grow- 

 ing shoot at their tips, and rapidly eating out the heart of 

 the shoot with all the young leaves, then moving to another 

 plant, but leaving behind it a dirty tabernacle which is very 

 conspicuous. It also feeds with us upon sallow, blackthorn, 

 bramble, poplar, and sweet-gale, and abroad upon species of 

 Artcmesia, Achillea and Sanguisorha, doubtless in a similar 

 manner. It certainly prefers herbaceous plants, and more 

 particularly such as grow in swampy fields or open marshy 

 woods. 



Pupa plump and rather short, very glossy, eye-covers 



