NOISES OF INSECTS. 521 



of insects of sounding wing, and proceed to an order, the Hymenoptera, 

 in wiiicli the insects that compose it are, many of them, of more fame for 

 this property. 



The indefatigahle hive-bee, as she flies from flower to flower, amuses the 

 observer with her hum, which, though monotonous, pleases by exciting the 

 idea of happy industry, that wiles the toils of labor with a song. When 

 she alights upon a flower, and is engaged in collecting its sweets, her hum 

 ceases ; but it is resumed again the moment that she leaves it. The wasp 

 and hornet also are strenuous hummers; and when they enter our apart- 

 ments, their hum often brings terror with it. But the most sonorous flies 

 of this order are the larger humble-bees, whose homhination, hooming, or 

 bombing, may be heard from a considerable disttince, gradually increasing 

 as the animal approaches you, and when, in its wheeling flight, it rudely 

 passes close to your ear, almost stunning you by its sharp, shrill, and 

 deafening sound. Many genera, however, of this order fly silently. 



But the noisiest wings belong to insects of the dipterous order, a 

 majority of which, probably, give notice of their approach by the sound 

 of their trumpets. Most of those, however, that have a slender body, — 

 the gnat genus (^Culex) excepted, — explore the air in silence. Of this 

 description are the Tipularia, the Asilida, the genus Empis, and their 

 affinities. The rest are more or less insects of a humming flight ; and 

 with respect to many of them, their hum is a sound of terror and dismay 

 to those who hear it. To man, the trumpet of the gnat or mosquito, and 

 to beasts, that of the gad-fly, of various kinds of horse-flies, and of the 

 Ethiopian zimb, as I have before related at large, is the signal of intolera- 

 ble annoyance. Homer, in his JBatracliomyomachia, long ago celebrated 

 the first of these as a trumpeter : — 



" For their sonorous trumpets far renown'd, 

 Of battle the dire charge mosquito's 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. 18.) two females are flying about my win- 

 dows 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 instruments that cause the noise of flying 

 insects are their wings, or soine 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 flight, the action of the air perhaps upon these organs giving it 

 some modifications. Whether, in the beetles that fly with noise, the elytra 

 contribute more or less to produce it, seems not to have been clearly ascer- 

 tained : yet, since they fly with force as well as velocity, the action of the 

 air may cause some motion in them, enough to occasion friction. With 



• Sledman's Surinam, i. 24. 



44* 



