HEARING IN INSECTS. 95 



mosquito (Culex ) is to us, but probably for 



a different reason *. 



The drone of the dung-beetle (Geotrupes stereo- 

 rariui), on the other hand, is, like the hum of the 

 industrious bee, rather pleasant than disagreeable, 

 from its being associated with the still twilight of a 

 summer's evening ; though Linnaeus was certainly 

 wrong in thinking it an indication of fine weather. 

 It is probably occasioned by the friction of the wing- 

 cases upon the base of the wings, throwing them 

 into vibratory motion. Though most commonly re- 

 marked in this beetle, it is not peculiar to it, for we 

 have observed it, though not quite so loud, in the 

 flight of the musk-beetle (Cerambyx odoratus, DE 

 GEER) and in the green rose-chafer (Cetonia aurata), 

 whose loud humming, as we once noticed in one 

 flying around a wild rose-tree in Epping Forest, made 

 us suppose it to be the violet carpenter-bee (Xylocopa 

 violacea), which has not hitherto been found in 

 Britain f- 



Most of the larger animals have particular cries ex- 

 pressive 6f fear, distress, or danger ; but we are not 

 well acquainted with these in the insect world. The 

 one most familiar, but not, that we are aware, men- 

 tioned by naturalists, is the peculiar buzzing of flies 

 when they fall into the fangs of the spider. We 

 say " peculiar," because it is altogether unlike any 

 sound emitted by flies at any other time. As a fly 

 does not emit this sound when it is accidentally 

 betrayed to venture too far into a honey-pot, nor 

 when it is caught by the hand, it must arise from 

 some instinctive knowledge of the nature of its arch 

 enemy, rather than from the mere circumstance of 

 its being entrapped : yet we have heard flies emit 

 this sound when caught in a spider's web that had 



* See Insect Architecture, p. 405. f J. R. 



