212 



REPORT OF STATE GEOLOGIST. 



which stridulate in this manner mostly belong to the sub-families 

 TryxalincB and Acridince. 



The members of the sub-family (Edipodince usually sound their 

 call during flight by rubbing together the upper surface of the front 

 edge of the wings and the under surface of the tegmina, thus pro- 



-iS^i^2&2ii:^:ia 



Fig. 35. Inside of hind femora of a locust. «, ridge with teeth. Ridfcc and teeth preatly 

 enlarged. (After Landois.'l 



ducing a sharp, crackling sound which has been likened to that of 

 burning stubble. By paying close attention the observer can soon 

 learn to know each species by its peculiar call. Like the other fami- 

 lies of Orthoptera, the males alone of the AcYididce have musical 

 organs, which is quite the reverse among some animals higher in the 

 scale of life, where the females make most of the music and often- 

 times much of the noise. 



The great majority of Indiana Acridid* pass the winter in the 

 egg stage, the eggs being deposited by the mother insect in early 



''fe**^;^^ 



Fig. 36. Locust in the act of laying eg.irs. (After Riley.) 



autumn. AVlu'U ready to oviposit, she forms a hole in the ground or 

 other nidus to a depth corresponding to the length of her abdomen. 

 The eggs are then deposited one at a time to the number of 30 to 60, 

 being placed in regular order in this hole. During the process a 



