THOMAS ON ORTHOPTEKA OF DAKOTA AND MONTANA. 497 



to protect a single field of forty acres requires a mile of ditching, or the 

 removal of nearly 800 cubic yards of earth, which, in most cases, the 

 farmer and his son or single hand will have to do.* 



I have noticed the larger irrigating-ditches in Utah, with a water- 

 surface from three to four feet wide, covered with wingless crickets 

 {Anahrus simjilex), which were floating helplessly onward; but although 

 this was the case, the marching column passed on in its course with 

 •comparatively undiminished numbers. And in Utah and Colorado these 

 ditches form but little impediment to the movements of the pupae of the 

 C. spretus. In the cool of the morning, in those mountain regions, the 

 farmers frequently drive the semi-torpid young into the irrigating- 

 ditches, firing straw placed along one side to catch those that leap the 

 ditch. But among the chief agencies in this work of destruction I am 

 disposed to class birds and fowls, and to this end would recommend to 

 the legislatures of the States suffering from these visitations the passage 

 of stringent laws stopping entirely the destruction of all insect-eating 

 birds, not for a portion of the year only, but for the entire year, and 

 offering a premium for the destruction of rapacious birds. Let an offi- 

 cer be appointed in each district, if necessary, composed of four or five 

 counties, whose duty it shall be to see that the laws are enforced, and 

 who shall also experiment in introducing and multiplying the English 

 sparrow or some other insect-eating bird of similar habits. It would be 

 well, also, for the State and county agricultural societies to encourage 

 the increase of domestic fowls as far as possible. Hogs should be 

 raised, as they are not only fond of these insects, and also army- worms, 

 but would also soon learn to hunt for the egg-sacks as they do for acorns 

 ill oak-forests. 



Driving into traps and ditches are remedies which have long been 

 practiced. Scott in his "Excursions in llonda and Granada", as quoted 

 by Kirby says : — " During our ride from Cordova to Serville we observed 

 a number of men advancing in skirmishing order across the country and 

 thrashing the ground most savagely with long flails. Curious to know 

 what could be the motive for this Xerxes-like treatment of the earth, 

 we turned out of the road to inspect their operations, and found they 

 were driving a swarm of locusts into a wide piece of linen spread on the 

 ground some distance before them, wherein they were made prisoners." 

 Kirby adds in a note: — " The same plan is adopted for the destruction of 

 these insects in some parts of the United States ; deep trenches being dug 

 at the end of the fields, into which the grasshoppers are driven icith branches, 

 and then destroyed by throwing earth upon them." What has been 

 beneficial heretofore may be so again, and because it is old is no reason 

 for rejecting it for something new until thoroughly tried. 



But without discussing further the various methods of defense against 



* Subsequent observations have convinced me that the young locusts can be fought 

 with a good degree of success, and that ditching is practicable and one of the best 

 remedies that can be adopted. 



