KATYDIDS AND THEIE KIN, 211 



LOCUSTID.E. 



The family of Orthoptera known as the Locustidaz 

 comprises those insects commonly called katydids, 

 green grasshoppers, and stone or camel crickets. The 

 distinguishing characters of the members of this fam- 

 ily are the long, slender, tapering, many-jointed 

 antennae ; the almost universal absence of simple 

 eyes; the four-jointed tarsi or feet; and the sword- 

 shaped ovipositor of the females. The outer wings, 

 when present, slope obliquely downwards, instead of 

 being bent abruptly, as in the cricket family ; and in 

 most cases the wings are longer than the wing covers. 



The stridulating or musical organ of the males is 

 quite similar in structure to that of the male cricket, 

 being found at the base of the overlapping dorsal 

 surface of the wing covers and usually consisting of 

 a transparent membrane, of a more or less rounded 

 form, which is crossed by a prominent curved vein 

 bearing on the under side a single row of minute file- 

 like teeth. In stridulating, the wing covers are moved 

 apart and then shuffled together again, when these 

 teeth are rubbed over a vein on the upper surface 

 of the other wing cover, producing the familiar, so- 

 called "katydid" sound. Each of the different spe- 

 cies makes a distinct call or note of its own, and 

 many of them have two calls, one which they use by 

 night and the other by day. Any one who will pay 

 close attention to these different calls can soon learn 

 to distinguish each species by its note as readily as 

 the ornithologist can recognize different species of 

 birds in the same manner. The ear of these insects. 



