Brown and White- Letter Hairstreaks 



THE BROWN HAIRSTREAK (Theda betul<e\ 

 Plate XII., Fig. 6. There are five British species 

 included in the very distinct group of interesting little 

 butterflies, to which this species belongs. All of them 

 are nearly black on the upper surface, but the under- 

 sides are exceedingly chaste in pattern, if not showy 

 in colour. The Brown Hairstreak is the largest of the 

 five. The male is a dark brown relieved by a lighter 

 spot edged with black on the fore- wing, and the 

 bottom angle of the hind-wing and the little tails are 

 orange. The female has an orange bar across the fore- 

 wing. The under side (Plate XIV., Fig. 7) is a tawny 

 orange inclining to deep orange at the margins ; a 

 double white irregular line edged with black runs 

 across the hind-wings, and between these lines the 

 tawny shade is darker ; the fringe is white. 



The caterpillar is green, marked with diagonal 

 yellow lines and tapers considerably towards each 

 extremity. It feeds on Birch and Blackthorn. Though 

 by no means a common insect, it is found in a great 

 many localities from North to South of England, but 

 not in Scotland. The butterfly is out in August. 



THE WHITE-LETTER HAIRSTREAK (Theda w- 

 album\ Plate XII., Fig. 4. A smaller and, on the 

 upper surface, a blacker insect than the last. Except- 

 ing for a small indistinct spot in the centre, and near 

 the outer margin of the fore-wing, the upper surface is 

 devoid of markings of any kind. The under side, 

 however, provides all the distinctive features necessary 

 for identification. The colour is a cool brown-grey, the 

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