ODOUR OF INSECTS. 



31 



All these insects are carnivorous, and possess the power of 

 emitting a very strong odour when handled or alarmed. This 

 odour is not sweet and flower-like, as is the case with most of 

 the Tiger Beetles, but is very foetid, repulsive, and persistent, so 

 that it clings tightly to the fingers of anyone who incautiously 

 seizes a Carabus with the hand. If, however, the insect be 

 smartly grasped across the body, just as one picks up a live 

 lobster or crayfish, the fingers are quite safe, and the Beetle 

 may discharge its red-brown evil-smelling liquid as much as 

 it pleases without injuring its captor. 



All British entomologists are familiar with the splendid but 

 rare Beetle, the Calosoma sycophanta, with its glittering green 

 and gold elytra, and deep purple head and thorax. The larvae 

 of this genus of Beetles feed upon the larvae of other insects, 

 mostly those of social moths, and are wonderfully voracious, so 

 that if two of them happen to meet, one is sure to devour the 

 other. It is rather a remarkable fact, that of all the Calosomas 

 our British species is by far the most splendid. There is one 

 Australian species, Calosoma McLcayii, which has similar colours, 

 though not nearly so brilliant. As to the others, they are no- 

 where in the race for splendour of colour, and look quite dull 

 and dingy beside the British species. 



Fig. 9. —Calosoma Indicnm. 

 (Brown, with burnished goH punctures.) 



There is, however, one exception, namely, Calosoma Indicnm, 

 which requires a quick eye to see that it is an exception, for the 

 Beetle appears at first sight to be plain chocolate brown. If we 

 look at the British insect, we shall see that among the distin- 



