460 



COLEOPTERA. 



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

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

 suddenly relaxing 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 by their elasticity the whole body is propelled 

 upward." 



The larvfB, known liy the name of AVire-worms, are vegetable 

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

 turnips and other garden vegetables. Fig. 419 (enlarged 

 (I four times) represents a larva of this famih^ found by 

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

 are laid probably in pastures and fallen ground where 

 the surface is undisturbed, or in the vicinity- of rotten 

 wood. The larvae moult three times, and some species 

 are known to live in this state five years. "When fully 

 '\\ grown they transform in an earthen cocoon, and may 

 r be seen rising out of the ground during the summer, 

 Fig. 419. ggpggj^^jjy in June. The larvae are ver}' 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. The^^ 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- 

 tennae being inserted in approximate grooves at the margin of 

 the thorax beneath, which makes the cljpeus narrow. The 

 species do not leap so vigorously' as those of 

 other leaping genera. Fornax differs from 

 Eucnemis in the antenna being filiform. 

 In Aclelocera (Fig. 420, A. obtecta Say) the 

 third joint of the antennte is equal to, or 

 larger than the fourth. In Elater and its 

 allies, the antennte are widel}' separated, 

 being inserted in small cavities (fovese) 

 under the margin of the front, and before 

 the e3'es. Alans oculatus Esch. is the largest 

 Elater we have, the scutellum is oval, and the elytra ha^e a 

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

 convex and margined quite broadly, and the thorax is always 



