THE DARK SPECTACLE. 73 



The Scarce Silver Y {Plusia interrogatio7iis). 



Portraits of two examples of this species will be found on 

 Plate 26, Figs. 4 and 5. The metallic central marks on the 

 fore wings vary a good deal in size and in form, and are some- 

 times almost absent ; these wings have the general greyish 

 colour more clouded or suffused with blackish in some 

 specimens than in others. Kane states that Irish specimens, 

 when freshly emerged, have a tinge of violet purple, and Tutt 

 notes some British specimens as beautifully tinted with rose 

 colour (ab. 7'osea). 



The caterpillar, which feeds on heather {Callufia) and 

 bilberry ( Vaccinium\ is green inclining to blackish on the sides 

 and underparts, with six white lines along the back; two of 

 which are irregular ; the raised dots are white and the bristles 

 therefrom dark ; head, green dashed with purple, shining. 

 (Fenn.) After hibernation it may be found without much 

 difficulty in May and June on its food plants, either in the day- 

 time, or by the aid of a lamp at night. Large numbers fall 

 victims to parasitical flies. (Plate 28, Fig. 2.) The white cocoons 

 enclosing the black chrysalids are spun upon or under the twigs 

 of bilberry and heather. The moth is out in July and August, 

 and may be found on moorlands, in the north of England from 

 Shropshire (with Radnor) and Staffordshire on the west, and 

 Lincolnshire on the east, through Scotland to Sutherland, and 

 in all suitable localities in Ireland. 



The Dark Spectacle {Abrostola triplasia). 



The fore wings of this moth are blackish grey inclining to 

 purplish and rather shining; the basal area is pale reddish 

 brown, edged by a curved dark chocolate brown cross line ; a 

 reddish grey band on the outer area clouded w^ith ground colour 



