FROSTED YELLOW. 323 



when they appeared on all sides and were fairly active on 

 the wing. 



The distribution abroad is northern and Alpine, and the 

 range extends to North-east Siberia. 



Frosted Yellow {Fidonia Uvtharia). 



This black-bordered orange-yellow species (Plate 141, Fig. 3) 

 is not likely to be confused with any other occurring in Britain. 

 The wings are more or less sprinkled with black, but this is 

 usually most noticeable on the hind wings which are some- 

 times thickly sprinkled, or, more rarely, the yellow ground 

 colour is entirely obscured. The form with a black discal spot 

 on all the wings has been named ab. qtiadripunctaria^ Fuchs. 

 In ab. fiimata^ Mathew, the orange yellow is replaced by 

 smoky umber brown, tinged with orange, and dusted with 

 black atoms (bred July, 1899). 



The caterpillar is greenish with grey-edged yellowish lines 

 along the back, and a black-edged yellow one along the sides. 

 The ground colour is sometimes purplish brown. It feeds on 

 broom chiefly, but will eat other Genisteas. There appears to 

 be two broods, one in June, and the other in September, or 

 earlier sometimes. The moth is out in May and early June, 

 and again in July and August, but it has been known to remain 

 in the chrysalis for four years. It flies in the sunshine, and 

 when resting, it sits like a butterfly, with its wings brought 

 together over its back. 



Stephens (183 1) states that the species was "not uncommon 

 among high broom in the vicinity of Birch-wood in Kent." 

 Later authors give Stowmarket (common), Needham, Barham, 

 and Ipswich, in Suffolk. There are no recent records from the 

 county of Kent ; and not much has been heard of the species 

 from Suffolk, although it may still exist, in greatly reduced 

 numbers, in some of its old haunts therein. 



