EFFECT OF CLIMATE ON DEVELOPMENT 29 



The}' all hatched out normally, although some of them 

 were very late in doing so. 



Much the same thing happens when egg-masses are 

 exposed to excessive moisture. If they are intact, they 

 are able to withstand this for long periods. If, however, 

 the masses are hroken they become I'apidly injured by 

 njoisture. In this connection, it should be noted that egg- 

 masses, as they approach the hatching time, swell out, due 

 to the growth of the embryos within the eggs. This may 

 lead to a loosening of the covering of the egg-mass so that 

 moisture may act more readily upon the eggs. 



The effect of climate on the growing and adult grass- 

 hoppers is more difficult to ascertain. It seems possible, 

 however, that very moist weather may have an injurious 

 effect on then}. There is no doubt that the pest was in 

 general less severe in 1910 than in 1909 in the neighbour- 

 hood of Anavatti, and the raiyats account for this by the 

 fact that the monsoon in 1910 was much more severe and 

 prolonged than that of 1909. On the other hand, 

 inspection revealed no dying off on the part of the 

 grasshoppers, nor was any trace of fungus disease 

 made out among them, something which commonly 

 attacks insects during abnormally moist seasons. It seems 

 very probable that the excessive moisture of the summer 

 of 1910 affected the hatching of the eggs, rather than the 

 development of the grasshoppers. On the whole, the Eice 

 Grrasshopper appears to be a particularly vigorous insect, 

 upon which adverse physical conditions seem to have 

 comparatively little effect. 



EXPERIMENTS IN THE CONTROL OF THE RICE 

 GRASSHOPPER. 



Experiments in the control of the Rice Grrasshopper 

 may be directed against either the eggs, the nymphs or 

 the adults. Of these, clearly measures for the destruction 

 of the eggs would be the most effective, could they be 

 satisfactorily carried out. Unfortunately, the fact that 

 the egg-masses are buried some two inches beneath the 

 surface of the ground, renders the task of collecting them 

 difficult, if not impracticable. It is true, we know where 



