Coleoptera 



217 



sternum. The body is elongate and pointed behind. The short legs 

 have the front trochanters large and free, and the feet five-segmented. 

 The larvs are remarkable on account of the small head, the very 

 broad prothorax into which the head can be withdrawn, and 

 vestigial legs; they feed under bark or in wood (fig. 120). The 

 beetles are hard and firm in texture, and often of brilliant metallic 

 colours ; their elytra are used for ornamenting dresses in tropical 

 countries, where the family is abundantly represented. In cooler 

 regions the species are comparatively scarce. 



Throscidae. — The Tkroscid^ are a family of small beetles agreeing 

 with the Buprestidz in their elongate form and prosternal processes. 

 The feelers are saw-like entirely or at the tip only. The pro- 

 sternum is produced forwards as well as backwards ; the hinder 

 angles of the pronotum are also elongate, and the prothorax is 

 closely jointed with the mesothorax. The front haunches are 

 enclosed behind by the mesosternum. The family contains but few 

 genera, and the species are, as a 

 rule, dull and inconspicuous as 

 well as small. 



Elateridae. — The ElaUrlda or 

 Click-Beetles are a large family, 

 whose members agree with the 

 BuprestidjE in their elongate 

 form, prosternal processes, and 

 short legs. The feelers, thread- 

 like, saw-like or comb-like (fig. 

 6 a, y), arise in front of the eyes ; 

 the upper lip -is free and visible. 

 The hinder corners of the pro- 

 notum are drawn out and the 

 prothorax is loosely jointed with the mesothorax, so that the sudden 

 forcing of the prosternal process into the mesosternal cavity enables 

 the beetles to leap high into the air when placed on their backs ; the 

 front coxal cavities are open behind and entirely prosternal, while 

 the front trochanters are small. The larvse of the Elateridae are 

 narrow elongate grubs with hard skins and short legs ; they 

 feed on roots, and those of various common species are well- 

 known as "wire-worms" (fig. 121). The family is distributed 

 in all parts of the world. The "fire-flies" of the tropics are 

 large Elaterids which give out light from paired spots on the 

 pronotum. 



Eucnemidae. — The Eucnem'tiLe are a family of beetles closely allied 

 to the ElateridsE ; some genera share with the members of that 

 family the power of jumping when laid on the back. They are 

 distinguished by having the upper lip hidden and the feelers in- 

 serted at the inner edge of the eyes. The larvsE resemble those of 

 the Buprestidae in having the prothorax very broad ; the maxilla 

 as well as the legs are vestigial. The species are fairly numerous 



Fig. 120. — Beetle iChalcophora tnari- 

 ana, Lap.), Europe, and its grub. 

 Natural size. 



