OUTLINES OF ENTOMOLOGY. 59 



some years ago in imported carpets from Europe, and has already be- 

 come a widely disseminated pest. Among the beetles classified as 

 SERRICORNIA are found many very beautiful and interesting insects, as 

 well as some that are exceedingly pernicious. Most of the species 

 have rather short serrate antennae, are of oblong or elongate oval form, 

 with five-pointed, or in a few species, four-pointed tarsi. The most 

 important Families are Spring or snapping beetles ( ELATERID^E ), the 

 saw-horned borers (BuFRESTiD^j), and the fire-fly and soldier beetles 

 ( LAMPYRAD^E ). The spring beetles have the entirely peculiar habit, 

 if laid upon their backs, of throwing themselves into the air with a 

 jerk, in most cases coming down in proper position. If held loosely in 

 the hand, also, they will bend themselves backward and strike again and 

 again in the effort to obtain their freedom. The power to effect these 

 motions lies in an ingenious sort of spring in the shape of a strong 

 pointed projection on the prosternum ( the under side of the prothorax), 

 which by curving the body backward is caught suddenly in a socket 

 on the mezo sternum, causing an elastic rebound of the whole body. 

 These beetles are of long, oval, somewhat flattened form, and usually of 

 dull brown color, though a few species display brighter tints, and the 

 surface is covered with a fine pubescence. The outer angles of the 

 very wide prothorax are prolonged into points which curve around 

 the edge of the wing covers. 



The larvae are known as " Wire- worms,* 7 in reference to their long, 

 hard, slender bodies. Some species rank with injurious insects from 

 their habit of cutting off the roots of young corn and other vegetation. 

 On the other hand, several are beneficial, and are known to find their 

 way into the tunnels of wood-boring larvae and destroy them. The 

 majority, however, so far as known, breed in decaying wood or the pith, 

 of weeds. A few large species are luminous, and are, at night, objects 

 of great splendor. 



Our largest and most striking American species, the Eye-spotted 

 Elater or Snapping-beetle (Alaus oculatus, Linn.), varies in length from 

 one to one and one-half inches. It is of a black color, with the wing 

 covers longitudinally ridged, and marked with fine lines and flecks of 

 white, which, being of the nature of scale-like hairs, are liable to rub 

 off. On the top of the broad pro-thorax are two large velvety black 

 spots encircled with white, which from their resemblance to eyes are 

 often mistaken for them. 



The Saw-horned borers (BUPRESTID^:), compose a large group of 

 handsome hard-shelled, compactly formed beetles, all of which have the 

 antennae, which are rather short, serrate on the inner edge. They are 

 usually of a pale brown or gray color, with brassy or coppery reflections : 



