8 



The RICE GRASSHOPPIiR 



by which the egg-mass is formed." It is, however, quite 

 conceivable that, by this method of study, he was not able 

 to obtain an exact picture of what took place beneath 

 the surface of the ground. In any case, there is no doubt 

 that, in the case of the Eice Grasshopper, oviposition does 

 not take place exactly as described by Riley for the Rocky 

 Mountain Locust. 



In order to get as accurate information on the mode 

 of oviposition as possible, the following method was 

 adopted. Females, ready to lay eggs, were placed in a glass 

 dish, in which a thin layer of earth (one-quarter to one- 

 half inch), close to the wall 

 of the dish, was separated 

 of! by means of stiff card- 

 board. Only this thin layer 

 was exposed above, all the 

 rest of the soil being cove red 

 by cardboard. The result 

 was that the grasshoppers 

 were forced to dig their 

 holes and lay their eggs in 

 the thin layer of soil close 

 to the glass. In many 

 cases, the whole course of 

 the digging, the preparation 

 of the hole for the reception 

 of the eggs and the laying 

 of the eggs themselves 

 could be observed through 

 the glass side of the dish 

 and even photographs of 

 the process could be taken 

 (see Plate II, Fig. 4). Round breeding jars were used for 

 some of these observations, but the best results were ob- 

 tained by using a rectangular glass trough such as that 

 employed by analytical chemists. 



The time required for the actual excavation will, of 

 course, vary with the hardness of the soil. In our obser- 

 vations, the excavation took about thirty minutes. It was 

 accomplished, as already described by Riley, by means of 

 the four horny valve-like ovipositors situated at the 

 posterior end of the body. The accompanying Text-lig. 2 

 indicates how these valves work. They are shoved into 



Text-fig. 2. 



Posterior end of female of Rice Grass- 

 hopper to show action in digging hole pre- 

 vious to egg-laying. The dotted outline 

 shows the ovipositors closed, the rest of the 

 figure shows them separated to shove the 

 soil outward. A. Anal cercus. 13. Dorsal 

 ovipositors. C. Ventral ovipositors. D. 

 Furcula vulvalis. E. Ovipositors closed. 



