72 INSECTS INJURIOUS TO STAPLE CROPS. 



pose,* In this way many of the egg-pods may be broken 

 up or left exposed on the surface. Prof. Morgan has 

 shown that of eggs in land thus treated 80 per cent failed 

 to hatch. 



By plowing in the fall to a depth of about eight inches 

 the same result is more surely accomplished by turning 

 the eggs under to such a depth that the young hoppers 

 upon hatching are unable to reach the surface. This will 

 be made more eifectual by then harrowing and rollirg, so 

 as to compact the surface as much as possible. . Such 

 plowing might even be profitable if done in very early 

 spring were it then followed by the usual spring showers, 

 but in all probability it Avould be better to wait till the 

 young are hatching, when large numbers of them can be 

 buried by plowing infested fields in a square from the 

 outside inward. 



Destroying the Kymplis. — Burniug. — After hatching 

 every effort should be made to destroy the locusts while 

 still young. The burning of straw or hay stubble, dead 

 grass, or rubbish, where it is present in sufficient quanti- 

 ties, or even, if need be, by augmenting such with rows 

 of straw, is one of the best methods, esj)ecially on cold 

 days when the young hoppers are congregated under such 

 materials. Several machines have been devised both for 

 burning and crushing the nymphs, but all are of doubtful 

 utility. 



Crushing. — When, however, the surface of the ground 

 is smooth and hard, a heavy roller will crush large num- 

 bers of the nymphs while they are still young, especially 

 in the morning and evening. 



* Riley, Bull. 25, 1. c. 



