- 34 — 



sis, like all other locusts possessing; like habits, is able to choose 

 at all times the most favorable breeding grounds, the richest 

 pastures and the most pleasant weather, each and all of which 

 features are ver3' favorable to its increase and afterwards to 

 its existence in unusually large numbers, in addition to the 

 above favoring conditions, there may be still others that add 

 to its multiplication, and that favor it beyond its congeners. 

 Only further studies can decide these points for us. 



By bunching at all times the insect escapes many natural 

 enemies that it would surely come into contact with were it to 

 scatter over the whole landscape. When young, as shown on a 

 preceding page, this bunching prevents the insects from d^'ing 

 for lack of moisture at the time of molting. There is also less 

 in-breeding under these conditions than there would be in a 

 normal non-migratory life, which also means the better pre- 

 servation of strength. 



Climatic Influences. — This is a subject concerning Avhich 

 we know comparatively little in connection with the life of our 

 locust. Of course there are a few facts that have come to light, 

 and wliich may be recorded here. 



In the first place it is safe to assume that it is probably due 

 to certain climatic conditions in connection with the peculiar 

 life-habits of the locust that it has been permitted to increase 

 beyond the norma. But just what these climatic influences are 

 and have been seem, as j^et, unsettled ideas. 



The eggs of all insects require more or less moisture and 

 heat for their preservation and final hatching. Some kinds 

 require more and others less of both these elements. That the 

 locust's eggs are also affected one way or the other b}' the 

 presence or absence of heat and moisture in varying degree 

 cannot be gainsaid. Just what each variation in these elements 

 means in the final development of the insect under different 

 circumstances, our individual researches and the study of re- 

 sults as reported by others have not revealed. 



It is known that where the eggs are deposited in very dry 

 soil and rains fail to fall they either dry up and are lost alto- 

 gether, or they are retarded in hatching. Sometimes when 

 there is just sufficient moisture present to prevent their drying 

 up, but not sufficient to cause theni to swell as they should, 

 they may be retarded a month or more. On the contrar^^•if 

 there be too much moisture the eggs are likewise kept from 

 hatching for a greater or less period. Both very wet and very 



