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1876.] The Chirp of the Mole-Cricket. 97 
THE CHIRP OF THE MOLE-CRICKET. 
BY SAMUEL H. SCUDDER. 
TEF common mole-cricket of the United States ( Gryllotalpa 
borealis Burm.) usually commences its daily chirp at about 
four o’clock in the afternoon, but stridulates most actively at 
about dusk. On a cloudy day, however, it may be heard as 
early as two or three o’clock ; this recognition of the weather is 
rather remarkable in a burrowing insect, and the more so since 
it does not appear to come to the surface to stridulate, but re- 
mains in its burrow usually an inch below the surface of the 
ground. The European mole-cricket is said to chirp both within 
its burrow and at its mouth (plerumque sub terrd, Fischer says), 
and it may be that our species sometimes seeks the air in chant- 
ing; but the chirp, as far as I have heard it, always has a uni- 
formly subdued tone, as if produced in some hidden recess. 
Fischer says that the European species, which is twice as large as 
ours, cannot be heard more than from one hundred to one hun- 
dred and fifty feet (ultra spatium 20-30 passuum). Ours, when 
certainly beneath the surface, is easily distinguished at a distance 
of five rods; and one would presume that it could be heard, if 
above ground, nearly twice as far away. 
Its chirp is a guttural sort of sound, like grü or grééu, re- 
peated in a trill indefinitely, but seldom for more than two or 
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TOSTOEDIT ET Ceriperperciercertesits 
three minutes, and often for a less time. -It is pitched at two oc- 
taves above middle C, and the notes are usually repeated at the 
tate of about one hundred and thirty or one hundred and thirty- 
five per minute ; sometimes, when many are singing, even as 
rapidly as one hundred and fifty per minute. Often, when it 
rst commences to chirp, it gives a single prolonged trill of 
more slowly repeated notes, when the composite character of. the 
chirp is much more readily detected ; and afterward is quiet for a 
long while. When most actively chirping, however, the com- 
mencement of a strain is less vigorous than its full swell, and the 
notes are then repeated at the rate of about one hundred and 
twenty per minute; it speedily gains its normal velocity. The 
hote sounds exceedingly like the distant croak of toads (Bufo) 
at spawning season, but is somewhat feebler. Zetterstedt com- 
VOL. x. — No, 2. 7 
