460 



COLEOPTERA. 



effected by extending the prothorax so as to bring the proster- 

 nal spine to the anterior part of the nusosternal cavity, then 

 suddenl}' rekixing the muscles so that the spine descends 

 violently into the cavity, the force given b}' this sudden move- 

 ment causes the base of the elytra to strike the supporting- 

 surface, and b}^ their elasticit}' the whole body is propelled 

 upward." 



The larvtB, known by the name of Wire-worms, are vegetable 

 feeders, living on the roots of grass, wheat, corn, potatoes, 

 turnips and other garden vegetables. Fig. 419 (enlarged 

 j^ four times) represents a larva of this family found by 

 Mr. Sanborn in the roots of the squash vine. The eggs 

 are laid probably iu pastures and fallen ground where 

 the surfiice is undisturbed, or in the vicinity of rotten 

 wood. The larvae moult three times, and some species 

 are known to live in this state three years. When fully 

 grown they transform in an earthen cocoon, and may 

 be seen rising out of the ground duriug the summer. 

 *'"-^'^' especially in June. Tlie larva^ are xcvy long cylin- 

 drical (whence their name wire- worm), hard -bodied and diffi- 

 cult to kill, and are generally pale testaceous, or yellowish red 

 in color. They have only six thoracic legs, and a slight anal 

 prop-leg ; the body is flattened towards the head and tail. 



Eucnemis differs from the true Elaters in the serrate an- 

 tenna? being inserted in approximate grooves at the margin of 

 the thorax beneath, which makes the cl3'pcus narrow. The 

 species do not leap so vigorousl^^ as those of 

 I 0^ %^ other leaping genera. Fornax differs from 

 ViSv ; y Encaem.is in the antennae being filiform. 



In Adelocera (Fig. 420, A. obtecta Sa}-) the 

 third joint of the antennae is equal to, or 

 larger than the fourth. In Elater and its 

 allies, the antennae are wddely separated, 

 being inserted in small cavities (fovea?) 

 under the margin of the front, and before 

 the eyes. Alans oculatu.s Esch. is the largest 

 Elater we have, the scutellum is oval, and the elytra have a 

 broad margin. The genus Elater has the front of the head 

 convex and margined quite broadl}', and tlie thorax is always 



Fig. 420. 



