TiiK cMCK i:i;i;ti,ks. 



600 



Fiimilv XXXV 11. KLA'PF/KIDJO. 

 ('lick Beetles. Spking Beetles. Snapping Bugs. Skip.jackh. 



Every eonntry boy in lii(li;m;i li;is IuiiikI hcticath llic bark of 

 logs or stumps eitlu-r a big' oTayisli-black beetle an ineh or more in 

 I.Mii^tli, or smaller, slender bi-owh ones, which feiG;n death wlieii first 

 picked n|). inil. when placed on Iheii- l)aeks. aftei- a I'ew seconds give 

 a, click, and spring several inches into the air, turn over in their 

 descent, alight on their i'eet and erawl rapidly away. These beetles 

 are typical I'cpresentatives ol* the great family Klaterida-. This 

 power of springing into the air when i)laced on the back is effected 

 liy bending back the head and thorax, thus bringing the prosternal 

 spine to and slightly above the front edge of a cavity in the meso- 

 sternuiu (Fig. 272, c), and at the same time raising the base of 

 elytra slightly above the surface upon which the beetle is resting; 

 then by suddenly relaxing the muscles the spine descends with 

 force into the cavity, causing the base of elytra to strike violently 

 against the supporting surface, and by their elasticity the whole 

 body is propelled ui)war(ls. To bring about the motion in the 

 manner indicated there nnist be a loose articulation, so as to give 

 fi-ee movement between the pro- and mesosternum, and this char- 

 acter is a prominent one in the majority of the genera of Elateridfe. 

 The hind angles of tlie thorax are prohmged backward into a point 

 so as to embrace the base of the elytra, and as tlu^ bases of the tho- 

 rax and elytra slope downwards toward each 

 other, a slight separation between them is suffi- 

 cient to permit the freedom of motion necessary 

 to the upw'ard movement. 



The great nuijority of Elateridffi are small or 

 medium in size; elongate in form, tapering more 

 or less toward i>ach end; dull broAvn or blackish 

 in color and have the surface clothed with a 

 fine pubescence. They occur beneath bark, logs 

 and stones, or on the foliage of various plants, 

 most commonly in dry upland localities. The 

 word "Elater" means literally a "driver or 

 hurler," and refers to the elastic power of 

 moticMi possessed by these beetles. 



The jirincipal distinguishing chai-acters of 

 the family ai'e the ll-jointed, more or less ser- 

 rate (rai'cly flabellate or |)ectinate) antenna;, 



Fig. 272. 

 'I, antenna in reposp; 

 /), antennal groove; 

 r, tarsiil groove; 

 it, pro.«ternal spine; 

 c, nieso.sternal eavity; 

 f, metastcrnuMi; 

 7, liind coxal plate?. 



(Original.) 



