Vol. XXIII, pp. 35-40 April 19, 1910 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



THE STRIDULATIONS OF SOME "KATYDIDS."* 



BY H. A. ALLARD. 



In tlie popular sense, the term "katydid" is applied to 

 members of several different genera of the Locustidse. These 

 insects are more strictly arboreal than the rest of the Locustidse, 

 and in many ways show marked adaptation to arboreal con- 

 ditions. Although of large size, the more or less oval outlines, 

 the green color, and the leaf-like venation of the large wing- 

 covers serve to harmonize them well with tlieir environment of 

 green foliage. 



The katydids are nearly all nocturnal singers, and stridulate 

 only rarely during sunshine. The species of katydids which I 

 have met and with whose stridulations I have become acquainted 

 are included in the four genera. — Scudderia, Ambb/corypha, 

 Microcentrum, and Ci/rtophyllus. Most species of these genera 

 stridulate in a manner markedly different from others, so that 

 far greater differences characterize their notes than is usual 

 among the species oi Xiphidium, Orchelimum, or Conocephalus. 



In the first genus, Scudderia texensis Saussure and Pictet is 

 one of the commonest and most widely distributed of all the 

 katydids. It is not an arboreal species, but dwells almost 

 entirely in the tall grass in neglected upland fields. At 

 Thompson's Mills, Ga., where it is exceedingly common, it is 

 almost entirely an upland insect. Here also it is a common 

 dweller among cotton plants. Its stridulations, produced by a 

 quick, shuffling wing-movement of brief duration, is soft, weak, 

 and delivered at rather long and irregular intervals. It is 

 usually heard during hazy afternoons and in the evening. It 



•The katydids listed in this paper were kindly identified for me by Mr. A. N. 

 Caudell, of the U. S. National Mnseum. 



7— Proc. Biol. Soc. Wash., Vol. XXIII, 1910. (35) 



