340 REPORT OF STATE GEOLOGIST. 



about low moist places in many of the counties of tlie northern third 

 of the State. 



Family LOCUSTID.E. 



As already noted the sub-order, SaUatoria or Jumpers, includes 

 three families of Orthoptera, one of them being the Locustidce. This 

 family comprises those insects commonly called katydids, green or 

 long-horned grasshoppers and stone or camel crickets. 



The distinguishing characters of the members of the family 

 Locustidce, as given in the key, p. 210, are the long, slender, tapering, 

 many-jointed antenna;; the almost universal absence of ocelli or sim- 

 ple eyes; the four-jointed* tarsi or feet; and the sword-shaped or 

 falcate ovipositor of the females, which is made of four flattened 

 plates. The head in many of the species is wedge-shaped, and the 

 mouth parts are well developed," the mandibles, especially, being long 

 and sharp pointed. This enables the insect to dig into plant tissue 

 or to eat the seeds of grasses, as many of them do. The males have, 

 in many instances, abdominal appendages corresponding to the parts 

 of the ovipositor, which are used as clasping organs. The tegmina or 

 wing covers, when present, slope obliquely downwards, instead of 

 being bent abruptly, as in the Gryllidce or true crickets; and in most 

 cases, the wings are longer than the tegmina. 



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 area of the tegmina and usually consisting of 

 a transparent membrane, of a more or less rounded form, which is 

 crossed by a prominent curved vein, which, on the under side, bears 

 a single row of minute file-like teeth. In stridulating, the wing 

 covers are moved apart and then shufHed 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 species 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, when present, is also similar 

 in structure and position to that of the cricket's, being an oblong or 

 oval cavity covered w'ith a transparent or whitish membrane and 

 situated on the front leg, near the basal end of the tibiae. 



'■■■ The members of the genus Daihinia, no one of which occurs in Indiana, have the fore 

 and hind tarsi three jointed. 



