138 FORFICULID^E, OR EARWIG TRIBE. 



the tropics. All the known Orthoptera are terrestrial, both in 

 their perfect and two previous states. Some are purely carni- 

 vorous, and others are adapted to a mixed diet, the Cock- 

 roaches, for example, being capable of feeding on almost any 

 kind of organised matter; but the greater number feed upon 

 plants. Hence from their large size, and the enormous quantity 

 which each individual can devour, they are among the most 

 destructive of all the Insect tribes, when they appear in large 

 numbers. This is particularly the case with the Locusts in 

 warm countries ; the ravages of which not unfrequently cause 

 famine and pestilence, both among men and beasts. Some 

 details upon this subject will be given in the latter part of 

 this volume. 



663. Before treating of the true Orthoptera, we shall first 

 notice the family FORFICULID^E ; which has been raised by some 

 into a distinct order, under the name DERMAPTERA, or leathery- 

 winged (^ 637). The Earwigs and their allies, of which this 

 group is composed, have the anterior wings formed into elytra, 

 possessing a consistence intermediate between that of the horny 

 elytra of Beetles, and the parchment-like anterior wings of the 

 Orthoptera ; they are of small size ; and they meet, when folded 

 together, upon the central line, as in Beetles. The posterior 

 wings are folded across when at rest, as in the preceding Order, 

 but the part thus doubled down is itself folded in a fan-like 

 mode, as in the Orthoptera. These insects are further distin- 

 guished by the two large appendages at the posterior part of 

 the body, which form a pair of forceps (Fig. 306). They are 

 very common in damp situations, where they assemble in troops 

 under stones and the bark of trees ; they do much injury to 

 the flowers and fruits of our gardens, and they will devour the 

 bodies of their dead companions. Their forceps appears to serve 

 as an instrument of defence ; whether it answers any other 

 purpose is not known. Their common name is derived from the 

 incorrect notion, that they have a peculiar tendency to creep into 



,the ears of sleeping persons. 



664. The proper Orthoptera may be divided into two prin- 

 cipal sections ; in the first of which the legs are nearly of the 



