154 TRUE TALES OF THE INSECTS. 



colour, veining, shape, and appearance generally, 

 being very leaf-like. Katydids have beautiful green 

 and opaque fore-wings, like the leaves of trees, and 

 display characteristic leaf-like veinings, which afford 

 them protection from observation, and thus safety. 

 There can be no doubt that the plant-like appearance 

 of some of the Locustidae renders it most difficult to 

 detect them in their native haunts. It is well known 

 how these insects may attest their presence in con- 

 siderable numbers in the immediate neighbourhood by 

 their song, and yet it may be almost impossible to 

 succeed in tracino^ the sound to its source, even in a 

 single instance. 



This resemblance of the tegmina to leaves is carried 

 to the highest possible pitch of perfection in Locustidae. 

 It is in the exotic genus Pterochroza, of South America, 

 that the phenomenon is most marked (see Fig. 24). 

 The tegmina in the species of this genus, in form and 

 in tint, look exactly like withered leaves. In some of 

 the species the wing-covers not only display the different 

 shades of colour of dry leaves, but markings due to 

 cryptogamic growths on leaves are reproduced. Not 

 only this, transparent spots and tracks are present, like 

 those on leaves due to the mining of insects. When 

 settled, their tegmina closed, such insects are provided 

 with perfect disguise. 



Nor is this family entirely destitute of active means 



