234 MONTANA EXPERIMENT STATION. 



the ground. The eggs are about one-fifth of an inch in length and 

 are deposited in compact masses or "pods" which are arranged ver- 

 tically, or slightly inclined, just below the surface of the ground. 



In making the hole in the ground to receive the eggs, the female 

 makes use of special organs at the extremety of the abdomen. Plac- 

 ing the point of the abdomen against the ground the pointed organs 

 work rapidly back and forth and as the hole is made the abdomen 

 settles into the earth. When the hole is completed it is filled with 

 the mass of eggs and a viscid frothy substance. 



Prof. C. V. Riley's classic illustration of the process of egg- 

 laying of the Rocky Mountain Locust, together with his description 

 of the process, show that in that species the eggs are laid in four re- 

 gularly parallel rows and that the number of eggs varies between 

 20 and 35. He also found that two or three such egg-masses were 

 deposited by each female insect. 



The two-striped locust lays a larger number of eggs than this 

 for we have counted as high as 62, in a mass, and two or three masses 

 are deposited. The Big-headed Locust (Aulocara elliotti) probably] 

 deposits only two masses. 



In general the places most chosen by the females for the pur- 

 poses of egg-laying are those at which the soil is fairly free from 

 grass-roots, or other roots that would interfere with boring the 

 holes. Such places are found on the sides of roads, in abandoned 

 roads, among tall weeds, etc. When the mating season comes the 

 adults of a species gather into colonies where they stay for the re- 

 mainder of their life. As a result, the young are often found in the 

 spring of the year in more or less restricted localities. 



In our investigations of the outbreak of grasshoppers in Mon- 

 tana in 1903 we fovnd that the Big-headed grasshopper paid little 

 attention to where the eggs were laid ; for miles and miles over the 

 denuded ranges the females could be found performing this act. 



In the spring ot the year, in some species earlier than in others, 

 the eggs hatch into very small nymphs which on close examination 

 are seen to resemble adult grasshoppers, but there are no indications 

 of wings. As they increase in size and molt from time to time, rudi- 

 mentary wings appear which increase in prominence with each molt 

 until the last when with fully developed wings the insect is mature 



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