LOCUSTS AND GRASSHOPPERS {ACRIDIID.-E). 137 



He finds red-winged species most common in humid 

 regions, yellow-winged in more or less arid districts, 

 while the blue-winged forms are found chiefly in 

 mountainous regions just between the dry and the wet 

 conditions ; and this same variation is observed among 

 the representatives of the tribe in Mexico. So 

 characteristic does this variation in colour of the wings 

 appear, that he almost comes to the conclusion that an 

 examination of a fair representative collection of these 

 insects would be a sufficient index of the climate of the 

 region from which they came. 



Modifications for a Desert Life. 



The Eremobiens, a subdivision of Oedipodides, include 

 some of the most interesting forms of Acridiidce. The 

 most peculiar members of the group are some very 

 large insects, specially modified for a sedentary and 

 desert life. Metkone anderssoni, found in the Karoo 

 Desert of South Africa, and one of the largest of the 

 Acridiidce, is most noteworthy (see Fig. 23). This 

 species is remarkable for its complex instruments for 

 producing sound, and for the modification of its great 

 hind legs, which have no saltatorial function, and but 

 little, if any, power of locomotion, but act as parts of 

 the sound-producing apparatus, and as agents for 



