OM INSECT SOUNDS. ^4^ 



4, Fitch of the insect note. 



Many insects possess only one tone which is produced by the 

 motion of their wings ; other insects have a voice but their flight 

 is silent. A third group possesses both flight-tone and voice, as 

 e.g. the flies and bees. 



The voice of most insects is different from the flight tone. 

 The difference being mostly that of a few intervals, but often very 

 much more. The flight tone of the honey bee is a! its voice is an 

 octave higher, and often rising to h'' flat and c'". Again which 

 the common fly hums with its wings in f its voice sounds h 

 and c". The difference of tone is very great in the Anthidium 

 manicatum, its flight tone being g' and its voice tone f" nearly 

 two octaves higher. 



The flight tone is for the most part tolerably constant as it varies 

 only by sinking, when exhaustion compels the insect to lessen the 

 rapidity of its wing movement. The insect voice is, however, 

 capable of a real modulation both in pitch and intensity. In fact 

 a distinct melody may be recognised in the sounds of some insects. 

 The common blue bottle buzzes the tones d" sharp, d' natural, c", 

 sliding down or up with the finest intertones, and after a short 

 pause repeating the same sequence. A hovering fly {Syrphus 

 rihesii) utters the notes e" and d" sharp, running them into each 

 other at short intervals. The anthidium before mentioned 

 exhibits the greatest compass of any insect examined by Dr. 

 Landois, and it hums the notes c'" c'" sharp, d'" e'" f " with 

 numerous changes. 



Friction tones as before remarked, rise or sink in pitch 

 according to the fineness of the toothed or notched organ, and the 

 rapidity of the bow stroke, e.g. the ceramhyx moschatus, whose 

 normal note is d"" can produce a higher or lower note by quicker 

 or slower friction movement. 



The modulation of the insect voice may be attributed, firstly, to 

 the varying number of vocal tongues set in motion, secondly, to 

 their different length and state of tension into which they can be 



