86 MOTHS 



PLATE XLV 

 THE RED UNDERWING (2) 



As you will see by the illustration, this is a 

 very fine and handsome moth indeed ; but when 

 it is at rest it is very difficult indeed to see it, 

 for the bright red hind-wings are quite covered 

 up by the grey front ones, so that it looks 

 exactly like the bark of the trees on which it is 

 so fond of sitting. If you want to catch it, the 

 best place to look for it is on the trunks of 

 willow trees, in August and September. But 

 sometimes you may find it on fences, and just 

 now and then it will fly through an open window 

 into a well-lighted room by night. 



The caterpillar of this beautiful moth feeds on 

 the leaves of willows, sallows, and poplars. It is 

 rather oddly shaped, for its back is very much 

 arched, while its lower surface is almost flat. 

 And, if you touch it, it only clings more tightly 

 to its foothold, instead of curling up into a ring 

 and dropping to the ground, as most caterpillars 

 do. In colour it is ashy-grey, and generally has 

 two dark, wavy stripes running along the back. 

 When it is fully fed it spins a silken cocoon, 

 either between two leaves or in a crack in the 

 bark, and changes to a reddish-brown chrysalis 

 covered with purple bloom, just like that on a 

 ripe plum. 



