viil THE COLOURS OF INSECTS IN GENERAL 165 



apparent reason why insects should not themselves 

 produce lipochromes, and why such lipochromes 

 should not occur in the cuticle as in the Crustacea. 

 We have seen that lipochromes occur in the elytra 

 oi Lina populi ; according to Krukenberg they perhaps 

 also colour the red lady-birds (Coccionellae) and some 

 other red beetles, but whether these are intrinsic or 

 derived pigments remains undecided. 



Colours of the Different Orders of 

 Insects 



It is interesting to observe the types of colouring 

 prevalent in the more important orders of insects. 

 Thus in the Orthoptera optical colours seem to be 

 practically absent, and deep black is also rare ; shades 

 of brown, green, and red are perhaps the commonest 

 colours, as notice the brown " stick " insects, the 

 brown and green (or sometimes red) grasshoppers 

 and locusts, and so on. Associated with these 

 peculiarities of colouring we notice the fact that the 

 cuticle is in most cases but slightly developed. The 

 relatively sober tints do not, however, prevent the 

 Orthoptera often displaying great beauty of colour- 

 ing. Thus Dr. D. Sharp describes the female of 

 Pneumora scutellaris as being " one of the most 

 remarkably coloured of insects." " She is of a gay 

 green, with pearly - white marks, each of which is 

 surrounded by an edging of magenta ; . . . the face 

 has magenta patches and a large number of tiny 

 pearly-white tubercles, each of which when placed 

 on a green part is surrounded by a little ring of 

 mauve colour." The male is much plainer, being 



