io8 



THE MOTHS OF THE BRITISH ISLES. 



construct a silken tent-like web (Fig. 22). The exterior of the 

 tent afifords a suitable surface upon which they can lie when 

 they take a sun bath, which they seem fond of doing whenever 



the opportunity 

 offers. It is also 

 used, as well as 

 the interior, for 

 the process of 

 skin-changing. 



The full-grown 

 caterpillar is slaty 

 blue above ; along 

 the middle of the 

 back is a bluish 

 white line, bor- 

 dered on each side 

 by a reddish- 

 orange-lined black 

 stripe ; towards the 

 lower limit of the 

 slaty blue colour is 

 a black edged red- 

 dish-orange line, 

 and below this 

 again the ground 

 colour is flecked with orange, sometimes forming a line in the 

 region of the spiracles ; there are two velvety black spots on 

 the back of the ring nearest the head, and a smaller black 

 spot on each side of the next two rings ; the hairs are brownish, 

 rather more numerous on the sides than on the back. Head 

 slaty-blue with two black eye-like spots. It feeds from April 

 to June on hawthorn, sloe, and various fruit trees in orchards 

 and gardens ; also on birch, elm, oak, sallow, willow, etc. 



Chrysalis blackish, rather downy enclosed in a double 



Fig. 22. 

 Web of Lackey Caterpillars. 



(Photo by W. J. Lucas.) 



