NOISES OF INSECTS. 379 



tion of the base of the wings against the thorax seems to 

 be the sole cause of the alarming buz of the gnat as well 

 as that of other Diptera. The warmer the weather, the 

 greater is their thirst for blood, the more forcible their 

 flight, the motion of their wings more rapid, and the 

 sound produced by that motion more intense. In the 

 night but perhaps this may arise from the universal 

 stillness that then reigns their hum appears louder than 

 in the day : whence its tones may seem to be modified 

 by the will of the animal. 



Sounds also are sometimes emitted by insects when 

 they are feeding or otherwise employed. The action of 

 the jaws of a large number of cockchafers produces a 

 noise resembling the sawing of timber ; that of the 

 locusts has been compared to the crackling of a flame 

 of fire driven by the wind ; indeed the collision at the 

 same instant of myriads of millions of their powerful 

 jaws must be attended by a considerable sound. The 

 timber- borers also the Buprestes; the stag-horn beetles; 

 and particularly the capricorn-beetles the mandibles of 

 whose larvae resemble a pair of mill-stones a most pro- 

 bably do not feed in silence. A little wood-louse (Atropos 

 pulsatorio) which on that account has been confounded 

 with the death-watch is said also, when so engaged, to 

 emit a ticking noise. Certain two-winged flies seen in 

 spring, distinguished by a very long proboscis (Bomby- 

 lius\ hum all the time that they suck the honey from 

 the flowers ; as do also many hawk-moths, particularly 

 that called from this circumstance the humming-bird 

 (Macroglossa Stellatarum), which, while it hovers over 

 them, unfolding its long tongue, pilfers their sweets vvith- 



a Linn. Trans, v. 255. /. xii./. 7- b. 



