SOUNDS MADE BY INSECTS. 



tions, more by their odor tliau by their visible characters. But no organ 

 of smelling has been discovered, and this sense is supposed, from anal- 

 ogy, to be located in the lining membranes of the spiracles. 



Taste and Touch. — It is impossible to determine, but there is no reason 

 to doubt, that insects, like other animals, taste and enjoy the food of 

 which they partake ; and the manner in which they frequently touch 

 their food, and the surfaces over which they walk, with the tips of their 

 palpi, which, indeed, have received the common name of /eeZers, renders 

 it probable that these organs are endowed with a special sense of touch. 



SOUNDS PRODUCED BY INSECTS. 



The songs of birds, and the noises made by other animals, are pro- 

 duced by the forcible passage of air through the glottis, which is the 

 narrow opening at the top of the wind pipe, aided by the vibration of 

 certain muscular folds near the outlet, called the vocal chords. But we 

 have seen that insects never brear,he through their mouths, and there- 

 fore they never make any oral sounds. But the hummiug of bees and 

 flies is produced in an analogous manner, by the expulsion of air through 

 the thoracic spiracles, and the vibration of a delicate valve-like fold, 

 just within the opening. 



But besides this, insects make a variety of noises, which are produced 

 in different ways. The singing of the Cicada, which is the loudest noise 

 made by anj' insect, is produced by the expulsion of air from the first 

 abdominal spiracle, striking upon a large transparent drum-like appa- 

 ratus, situated at the base of the abdomen. The chirping of crickets is 

 produced by rubbing together their parchment-like wing covers. The 

 well-known noise of the katy-did is produced in the same way, but here 

 the sound is intensified by a thin talc-like plate set into the base of each 

 wing-cover. The stridulation of grasshoppers is caused by the friction 

 of their spined shanks across the edge of their wing-covers. The 

 fainter, squeaking sounds, made by many insects when captured, are 

 produced simply by the rapid friction of one part of their bodies upon 

 another ; in certain Hemiptera, by the friction of the head upon the pro- 

 thorax ; in the Capricorn beetles, by the friction of the pro-thorax upon 

 the meso-thorax; and in some of the Lamellicorn beetles, by the friction 

 of the abdomen against the wing covers. 



The more complex and special apparatuses of insects for the produc- 

 tion of sounds, are possessed exclusively by the males, and are supposed 

 to be exercised by them as calls to the opposite sex; but the simpler 

 squeaking sounds are emitted by both sexes, and appear to be mere 

 notes of alarm. 



