Genus THECLA, Fabricius , 1807 
THE BROWN HAIRSTREAK 
Thecla betulae (Linn., 1758). 
(Plate XXIV, facing page 289) 
The Brown Hairstreak, although not a rare species, is but 
seldom captured and is not often seen on the wing. Nearly 
all specimens in collections have been bred from larvae obtained 
by beating Blackthorn bushes, the food plant of this species. 
Usually when seen this butterfly is flying round or settling 
on Oak trees, or when on the Blackthorns is depositing its 
eggs. Occasionally it may be seen flying low over Bramble 
bushes in bloom, or feeding on the blossoms which appear 
to be its favourite flower. 
Haunts and Distribution. Although widely but locally 
distributed over England and Wales, the Brown Hairstreak is 
looked upon as rather an uncommon insect. It occurs in 
all the southern counties of England, from Kent to Cornwall, 
also in Essex, Suffolk, Norfolk, Cambridgeshire, Northampton¬ 
shire, Huntingdonshire, Staffordshire, Lancashire and West¬ 
morland, which is apparently the northern range of this 
species. It occurs also in Wiltshire, Somersetshire, Worcester¬ 
shire, and different parts of Wales. In Ireland it occurs in 
the south and west. In Cornwall I have found this butterfly 
frequenting the wooded valleys close to the seashore. 
Time of Appearance. The Brown Hairstreak is single- 
brooded, and appears on the wing in August, September, and 
sometimes early in October. 
Egg and Egg Laying. When intent on depositing its eggs, 
the female settles on a Blackthorn bush, generally rather low 
down, and then proceeds to creep up a twig, waving her 
abdomen from side to side feeling for a suitable spot on the 
twig with her ovipositor. As soon as she detects the right 
spot, she stops for a few seconds and lays an egg. The spot 
selected is usually close to, or at the base of a bud. During 
depositing she generally keeps her wings slightly open. The 
eggs are laid singly. 
The egg is 0*65 mm. wide and less in height, and of a com¬ 
pressed, conical form. The whole surface is composed of 
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