380 NOISES OF INSECTS. 
many of them, their hum is a sound of terror and dis- 
may to those who hear it. ‘To man, the trumpet of the 
gnat or mosquito; and to beasts, that of the gad-fly ; 
the various kinds of horse flies (Zabanus, Stomoaxys, 
Hippobosca); and of the Ethiopian zimb, as I have 
before related at large*, is the signal of intolerable 
annoyance. Homer, in his Batrachomyomachia, long 
ago celebrated the first of these as a trumpeter— 
“ For their sonorous trumpets far renown’d, 
Of battle the dire charge mosquitos sound.” 
Mr. Pope, in his translation, with his usual inaccuracy, 
thinking no doubt to improve upon his author, has 
turned the old bard’s gnats into hornets. In Guiana 
these animals are distinguished by a name still more 
tremendous, being called the devil’s trumpeters®. I 
have observed that early in the spring, before their thirst 
for blood seizes them, gnats when flying emit no sound. 
At this moment (Feb. 18th) two females are flying about 
my windows in perfect silence. 
After this short account of insects that give notice 
when they are upon the wing by the sounds that precede 
them, I must inquire by what means these sounds are 
produced. Ordinarily, except perhaps in the case of 
the gnat, they seem perfectly independent of the will of 
the animal; and in almost every instance, the sole in- 
struments that cause the-noise of flying insects are their 
wings, or some parts near to them, which, by their 
friction against the trunk, occasion a vibration—as the 
fingers upon the strings of a guitar—yielding a sound 
more or less acute in proportion to the rapidity of their 
@ Vou. I. 4th Ed, 113. 146—. ' © Stedman’s Surinam, i. 24. 
