INJURING THE LEAVES. 253 



The third head given above, that of trapping, in- 

 cludes ditching, trenching, and the use of pans cov- 

 ered with coal oil, or coal tar. In the first two pro- 

 cesses, ditches or trenches are dug in favorable situa- 

 tions, into which the young insects are driven. Prob- 

 ably the use of pans covered with coal oil will be as 

 simple and advisable a method, unless we except that 

 of rolling, as can be employed in most infested 

 districts. A small pan which is well adapted for the 

 purpose is described as follows : "A good and cheap 

 pan is made of ordinary sheet iron eight feet long, 

 eleven inches wide at the bottom, and turned up a 

 foot high at the back and an inch high at the front. 

 A runner at each end, extending some distance be- 

 hind, and a cord extending to each front corner, 

 completes the pan, at a cost of about $1.50." The 

 upper surface of the bottom is wet with kerosene, 

 and the pans are pulled rapidly through the field by 

 boys who take hold of the ropes. 



The use of destructive agents, such as London 

 purple, Paris green, and the like, has not been 

 attended with any very great success when applied 

 on a large scale. But for limited areas, doubtless a 

 great many of the locusts may thus be easily de- 

 stroyed. A mixture which has been successfully 

 employed, consists of "arsenic, sugar, bran, and 

 water, the proportions being one part, by weight, of 

 arsenic, one of sugar, and five of bran, to which is 

 added a certain quantity of water. The arsenic and 

 bran are first mixed together, then the sugar is 



