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NINTH ANNUAL R?:PORT 



the trouble to carefully examine a few females when laying. But 

 just how often, or how many eggs each one lays, is more difficult to 

 determine. With spretus I have been able to make comparatively 

 few experiments, but on three different occasions I obtained two pods 

 from single females, laid at intervals of 18, 21 and 2(5 days respectively. 

 I have, however, made extended experimenis with its close conge- 

 ners, femur-ruhrum and Atlanis^ and in two cases, with the former, 

 have obtained four different pods from one lemaie, the laying cover- 

 ing periods of 58 and 62 days, and the total number of eggs laid being 

 06 in the one case and 110 in the other. A number of both species 

 laid three times, but most of them — owing, perhaps, to their being 

 confined — laid but twice. They couple with the male between each 

 period, and I have no doubt but that, as in most other species of 

 animals, there is great difference in the degree of individual prolifi- 

 cacy. 



We may, therefore, feel tolerably confident that the Rocky Moun- 

 tain Locust will sometimes form as many as four egg-pods. 



The time required for drilling the hole and completing the pod 

 will vary according to the season and the temperature. During the 

 latter part of October or early in November last year, when there 

 was frost at night and the insects did not rouse from their chilled 

 inactivity until 9 o'clock a. m., the females scarce had time to com- 

 plete the process during the four or five warmer hours of the day; but 

 with higher temperature not mo/e than from two to three hours would 

 be required. 



HOW THE EGGS ARE LAID. 



The question as to how best to treat the soil, or to manage the 

 eggs so as to most easily destroy their vitality, is a most important 



and practical one, and as 

 assisting to a decisive an- 

 swer, I have carried on a 

 series of experiments, 

 which will be presently 

 detailed. To make the ex- 

 periments the more intelli- 

 gible, I will first give the 

 reader a deeper insight into 

 the philosophy of the pro- 

 cesses of egg-laying and of 

 „ „ -, .,.,„.. hatching than I have hith- 



RocKY Mountain Locust:— o, a, a, female in difTerent 



positions, oviiiositing; b, e-g-pod extracted from ground, q-j^^q doue, and this the 

 vUh the end broken oiien; c, a lew eggs lying loose on the ' 



ground; d, e, shows the earth pnrtiallv removed, to illustrate vnnro roaHilv that \i hac 



Snegg-massalreudyini.lace. and one being placed; /.shows "^"^® reaOliy lUai 11 nas 



where such a mass has been covered up. never been ffiven bv anV 



other author. 



[Fig. 18.] 





