INSECTS. 



95 



entirely on other insects; when touched squirt an 

 acrid stinking fluid out of the abdomen. Larvae 

 longish, six-legged, with short antennae and sharp 

 jaws, with a few exceptions live exclusively on other 

 insects and lower animals. 



Several species are of service, both in the adult and 

 larval conditions, since they destroy injurious insects, 

 e.g. surface caterpillars, wireworms, cockchafers. 



Fig. 68 —A GrouDd Beetle 

 ({7ara&ws auronitemi). 



Fig. 69.— Corn Ground Beetle 

 (Zabrus gibius) and larva. 



grubs, crane-fly larvae. The following do good in 

 cultivated fields: Golden Ground Beetle {Carabus 

 auratus). Garden Ground Beetle (G. hortensis), Granu- 

 lated Ground Beetle (0. granulatus), Cross-barred Ground 

 Beetle {G. cancellatus), Field Ground Beetle (G. 

 nemoralis), Large-headed Ground Beetle {Gephalotes 

 vulgaris), species of Harpalus, Pterostichus, etc. 



The only destructive form is the Com Ground Beetle 

 {Zabrus gibhus, Fig. 69) ; short, thick-set ; back 

 black ; belly, legs, and antennae dark brown. Larva 

 cylindrical, slightly hairy, brown, with yellowish 

 white belly; head broad and flattened, black. The 

 beetles (June, July) usually remain hidden in the 

 soil during the day, climbing up the stalks of barley, 

 wheat, and rye during the evening and in dull 

 weather, and eating the grain in the ear. The larvae 

 remain during the day in vertical holes which they 

 dig out ; but at night and during dull weather they 

 devour the overground parts of the grain-plants 



