THE ORTHOPTERA OF MINNESOTA. 25 



their stock such fields can not be plowed. The same is true 

 with pastures. In this case it is best to poison the plants 

 growing on the edges of adjoining grain-fields; a strip ten 

 feet wide is usually sufficient. The locusts, driven away by 

 the animals in the enclosed pastures, gradually reach the 

 poisoned plants outside and are soon killed. The best mate- 

 rial for this purpose, and the one that has been used in a 

 number of cases with marked success, is London purple. It 

 is best simply because it is light, and sticks better to such 

 smooth plants as wheat, etc., than the heavier Paris green. 

 Poisoning locusts in gardens and fields from which chick- 

 ens and cattle can be kept away, may also be resorted to 

 with good results, using bran-mash as poisoned bait. This 

 is made b\' thoroughly mixing Paris green or London purple 

 with drj^ rye or wheat bran, about one and one-half to two 

 pounds of the poison to twenty-five pounds of bran is a 

 good proportion ; to this is added enough water to form a 

 mash thick enough to be formed into balls without falling 

 apart when laid upon the ground. Frequently cheap 

 molasses is added to keep the mash from becoming too dry. 

 Such balls are laid among the plants that we wish to pro- 

 tect. If an army of young locusts is moving towards a field 

 it can be stopped and almost annihilated by oifering them 

 this food, which seems to have a wonderful attraction, as the 

 balls are soon covered by struggling insects all eager to 

 devour it. The consequence to them can be imagined. 



Catching by Means of "Hopper-dozers" and Other 

 Machinery.— The "hopper-dozers" mostly used are mjide as 

 follows: A sheet of ordinary sheet iron, such as is used for mak- 

 ing stove-pipes, is turned up one and one-halt inches around 

 the edges and riveted at the corners. This makes a shallow 

 pan about eight feet long, two feet broad and one and one- 

 half inches deep. To the bottom of this are riveted six 

 small strips which can be fastened to the three runners on 

 which the pan rests. To the rear side of the pan is screwed 

 a light wooden frame, as long as the pan and one and one- 



