38 INJURIOUS AND USEFUL INSECTS 



their life-history within the year, and several broods may be 

 produced in the course of a single summer. Wire-worrns are 

 long, narrow larvae, with three pairs of 

 thoracic legs. The end of the abdomen 

 is bent downwards, and forms a support 

 for the body, so that it has the appear- 

 ance of a prop or foot. The segments 

 are protected above and beneath by 

 of wfr'e.wirrn,\howfngThc chitinous shiclds. When 



under surface and the anal f^g J^rva is fuU-grOWH it 

 foot. .° , 



descends deep into the 

 ground, and pupates within a small oval 

 cocoon. This usually happens in July or 

 August. The beetle emerges in two or three 

 weeks, but often does not appear above ground 

 until the following spring. The body of the 

 beetle is elongate, rounded in front, and some- 

 what pointed behind; the feelers are serrate 

 (saw-toothed) along the 

 inner margin ; the legs 

 are rather short, and the 

 tarsus five-jointed. The 

 beetles climb upon plants, 

 and escape notice by their 

 dingy colours and sluggish 

 habits. When threatened, 

 they let themselves drop to the ground. 

 If they alight on the ground back down- 

 wards, and if no convenient objects can 

 be grasped by the short legs, they are 

 enabled to right themselves by a pecu- 

 liar mechanism, to which they owe the 

 name of click-beetles. The under side 

 of the prothorax is drawn out into a 

 strong spine, which locks into a cavity 

 on the mesothorax. The sides of the 

 groove offer' considerable resistance to 

 the entrance of the spine, a resistance 

 which can perhaps be increased by 

 the muscular effort of the beetle. When the beetle puts 

 forth its whole strength to force the spine into its socket, 



Fig, 27. — Head 

 and thorax of 

 wire-worm, show- 

 ing the under sur- 

 face, with the jaws 

 and legs. 



Fig. 28. 

 (Agriotes lineatus). 



Click - beetle 



X7. 



