408 



REPORT OF STATE GEOLOGIST. 



love calls of tlie (lifTcront species of crickets make up the greater 

 part of that ceaseless thrill which fills the air, usually at night, from 

 mid-August until after frost. These sounds are made only by the 

 males, and are not vocal, as most persons suppose; but arc produced 

 by the tympanum, the insect rubbing the veins in the middle of one 

 wing cover over those of the other. It is often difficult to locate one 

 of these chirpers by its song. The distance and even the direction 

 are often most deceiving; the crickets being exceedingly shy, much 

 more so than katydids and grasshoppers. Those which live in the 

 ground generally chirp near the entrance to their burrows, and re- 

 treat thereto at every approaching footstep. Those which live upon 

 trees or shrubs resemble closely the hues of bark 

 or foliage, and are therefore difficult to find even 

 when close at hand; while the majority, dwelling as 

 they do, among grasses and beneath logs and chips, 

 liiid also a safe protection in their color, which is 

 usually closely like that of the objects beneath 

 wliicli they rest while sounding their cymbals. 



'J'lie inner wings of the crickets are, for the most 

 part, short, weak, and comparatively useless as fly- 

 ing organs, though sometimes they are nearly 

 twice as long as the outer pair. Like their nearest 

 relatives, the grasshoppers and katydids, these in- 

 sects, therefore, travel mostly by leaps and, in the 

 course of time, their hind femora have thus be- 

 come greatly enlarged. 

 The ovipositor of the female, when exposed, is usually a long, 

 cylindrical spear-shaped organ, consisting apparently of two pieces. 

 Each of these halves, however, when closely examined, is seen to be 

 made up of two pieces so united as to form a groove on the inner 

 side, so that wlicn the two halves arc fitted together, a tube is pro- 

 duced, down which the eggs pass to the repository in the earth or 

 twig, fitted to receive them. 



The eggs of most crickets are laid singly in the ground. A few of 

 the burrowing species deposit them in irregular masses in under- 

 ground cavities. The tree crickets place them uniformily in a single 

 row in the pith of twigs. Most species are represented in winter by 

 the eggs alone. A few, however, pass the cold season as nymphs, or 

 as adults. The mole crickets are said to exist for several years. 



Among the families of Orthoptera the Grylli'dce and Locustidw-take 

 a rank superior to all others. The high specialization of the oviposi- 

 tor of the female and the perfection of structure of the stridulating 



^6 



Fig. 103. Stridulat- 

 ing ridges in a 

 house-cricket; «, 

 stridulating 

 ridge; at, stridu- 

 lating teeth. 

 (After Landois.) 



