52 



THE LIFE-STORY OF INSECTS [CH. 



destructive to tadpoles and young fish, have com- 

 pletely armoured bodies as well as long jointed legs. 

 More commonly, as with most of the well-known 

 Ground-beetles (Carabidae), the cuticle is less con- 

 sistently hard, firm sclerites seg- 

 mentally arranged alternating with 

 considerable tracts of cuticle which 

 remain feebly chitinised and flexible. 

 Most of the adephagous larvae (fig. 

 13) have a pair of stiff processes on 

 the ninth abdominal segment, and 

 the insect, from its general likeness 

 to a bristle-tail of the genus Cam- 

 podea,is often called a,campodeiform 

 larva (Brauer, 1869). From such as 

 these, a series of forms can be traced 

 among larvae of beetles, showing 

 an increasing divergence from the 

 imago. The well-known wireworms 



Fig. 13. Larva of , _ , , . . T . 



a Ground-beetle grubs or the Click- beetles (Mate- 

 (Aepus). Magni- r idae) that eat the roots of farm 



fied6tim.es. After TIT 



Westwood. MO- crops, have well-armoured bodies, 



o 



but tlieir sna P e is e l n g ate > cylin- 

 drical, worm-like ; and their legs are 



relatively short, the build of the insect being adapted 

 for rapid motion through the soil. The grubs of the 

 Chafers (Scarabaeidae) are also root-eaters, but they 

 are less active in their habits than the wireworms, 



