BEETLES 351 



Allied Species. 



The Black Carrion Beetle (Silpha atrata) may often be met with 

 upon roads. It is about £ inch long, black, and emits an abominable 

 smell. Its larva, in the absence of carrion, will also eat vegetable 

 substances, and often does much damage in beetroot-fields. 



More distantly related to the useful burying beetle is the Bacon 

 Beetle (Dermestes lardarius), a highly injurious insect, frequently met 

 with in houses, where both the beetle and its larvas make themselves 

 unpleasantly familiar by attacking meat, skins, furs, etc. The beetle 

 is about J inch long, and black, with the exception of a broad, 

 grayish-yellow band at the base of the wing-cases, by which it may be 

 easily recognised. When touched, even quite gently, the beetle at once 

 simulates death (see click beetles). 



Family 5 : Skipjacks, or Click Beetles (Elateridae). 



Like many other insects, the click beetles on the approach of danger 

 instantly allow themselves to drop to the ground, where they disappear, 

 often completely — especially in the grass — from the sight of their 

 enemies. The skipjacks use an additional means of protection ; they 

 draw up their legs, lay the coxse in furrows of their body armour 

 (some do the same also with their antenna), and remain motionless 

 in this position until the danger seems past ; in short, they pretend to 

 be dead. Hence they are nearly certain to remain untouched by such 

 predatory animals as are in the habit of feeding only on prey which 

 they themselves have slain, whilst reptiles and amphibians, which only 

 observe movirfg animals, are most likely to overlook them. If these 

 beetles in falling happen to alight on their back, they are unable to 

 touch the ground with their legs, which are remarkably short ; they are 

 then, however, capable of skipping upwards (name), which is effected as 

 follows : Before jumping, the beetle arches its back, so that only the 

 prothoracic shield and the tips of the elytra remain in contact with the 

 surface of support, and then wedges a spiny process developed upon the 

 middle of the under surface of the prothorax firmly against the edge 

 of a groove in the second thoracic segment. The muscles of the body 

 are next contracted with such force that the spine slips from its abut- 

 ment (the edge of the groove), and snaps into the groove with a sharp, 

 clicking sound ; the back of the insect is thereupon arched with such 

 force that it impinges violently against the supporting surface, and the 

 beetle is hurled violently upwards by the force of the recoil. The whole 



