278 INJURIOUS INSECTS 



is chiefly beneficial around cultivated fields or along the 

 road sides, from which the locusts may be driven, or 

 from which they will of themselves pass for the shelter 

 the prairie aifords. 



As locusts disperse more and more from their hatch- 

 ing-grounds into the prairie as they develop, burning the 

 grass in spring is beneficial in proportion as it is delayed. 



2nd. CRUSHING. The wholesale destruction of locusts 

 by this means, can only be advantageously accomplished 

 where the ground is smooth and hard. Where the sur- 

 face of the ground presents this character, heavy rolling 

 can be successfully employed, especially in the mornings 

 and evenings of the first eight or ten days after the newly 

 hatched young have made their appearance, as they are 

 generally sluggish during these times, and huddle to- 

 gether until after sunrise. It is also advantageously em- 

 ployed during cold weather at any time of day, since the 

 young when the temperature is low seek shelter under 

 clods, etc. Various machines have been devised for 

 crushing the young. 



3rd. TRAPPING. This can easily be accomplished, es- 

 pecially when the locusts are making their way from roads 

 and hedges. The use of nets at sunrise, or long strips 

 of muslin, calico, or similar materials, converging after 

 the manner of quail-nets have proved very satisfactory. 

 By digging pits or holes three or four feet deep, and then 

 staking the two wings so that they converge toward 

 them, large numbers may be secured in this way after the 

 dew is on 6 the ground, or they may be headed off when 

 marching in a given direction. Much good may be ac- 

 complished by changing the position of the trap while 

 the locusts are yet small and congregate in isolated or 

 particular patches. 



DITCHING and TRENCHING properly come under this 

 head; and both plans are very effectual in protecting 



