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LETTEK XXIV. 



ON THE NOISES PRODUCED BY INSECTS. 



THAT insects, though they fill the air with a variety of sounds, have no 

 voice, may seem to you a paradox, and you may be tempted to exclaim with 

 the Roman naturalist, What, amidst ihis incessant diurnal hum of bees ; 

 this evening boom of beetles ; this nocturnal buzz of gnats ; this merry 

 chirp of crickets and grasshoppers ; this deafening drum of Cicadse, have 

 insects no voice ! If by voice we understand sounds produced by the air 

 expelled from the lungs, which, passing through the larynx, is modified by 

 the tongue, and emitted from the mouth, it is even so. For no insect, 

 like the larger animals, uses its mouth for utterance of any kind : in this 

 respect they are all perfectly mute ; and though incessantly noisy, are ever- 

 lastingly silent. Of this fact the Stagyrite was not ignorant, since, deny- 

 ing them a voice, he attributes the sounds emitted by insects to another 

 cause. But if we feel disposed to give a larger extent to this word ; if we 

 are of opinion that all sounds, however produced, by means of which ani- 

 mals determine those of their own species to certain actions, merit the 

 name of voice ; then I will grant that insects have a voice. But, decide 

 this question as we will, we all know that by some means or other, at 

 certain seasons and on various occasions, these little creatures make a 

 great din in the world. I must therefore now bespeak your attention to 

 this department of their history. 



In discussing this subject, I shall consider the noises insects emit 

 during their motions when they are feeding, or otherwise employed 

 when they are calling or commanding or when they are under the in- 

 fluence of the passions ; of fear, of anger, of sorrow, joy, or love. 



The only kind of locomotion during which these animals produce sounds 

 is flying : for though the hill-ants (Formica rufa), as I formerly observed, 

 make a rustling noise with their feet when walking over dry leaves, I know 

 of no other insect the tread of which is accompanied by sound except 

 indeed the flea, whose steps, a lady assures me, she always hears when it 

 paces over her night-cap, and that it clicks as if walking on pattens ! That 

 the flight of numbers of insects is attended by a humming or booming is 

 known to almost everyone; but that the great majority move through 

 the air in silence, has not perhaps been so often observed. Generally 

 speaking, those that fly with the greatest force and rapidity, and with wings 

 seemingly motionless, make the most noise ; while those that fly gently and 

 leisurely, and visibly fan the air with their wings, yield little or no sound. 



Amongst the beetle tribes (Co/eoptera) none is more noticed, or more 

 celebrated for "wheeling its droning flight," than the common dung- 

 chafer (Geotrupes sterccrarius') and its affinities. Linne affirms but the 



