FIELD CROP INSECTS 245 



done by a number of children armed with branches. Where 

 ditches containing water are available the young hoppers 

 may be destroyed by oiling the surface of the water with 

 kerosene emulsion and then driving them into the ditches, 

 for even if they succeed in crawling out they will succumb 

 to the oil. 



Where the young hoppers have congregated in large 

 numbers on the edges of fields, in patches of weeds, etc., they 

 may be destroyed by spraying them with kerosene or crude 

 petroleum either pure or, preferably, in an emulsion, and the 

 weeds and grass along fences and in neglected fields should 

 be thoroughly treated with a strong arsenical spray or dust. 



On pastures, small grains or any crops permitting their 

 use, immense numbers of nymphs may be caught by the 

 use of hopperdozers, which may be utilized where the use 

 of poisoned bran would not be possible. The hopperdozer 

 consists of a shallow pan, mounted on runners or wheels, con- 

 taining water with a surface of kerosene or crude petroleum, 

 and, if larger than about three feet square, is usually provided 

 with partitions to prevent slopping. The back and sides are 

 high and sometimes are made of canvas. "A good cheap 

 pan is made of ordinary sheet iron, eight feet long, eleven 

 inches wide at bottom, and turned up a foot high at the back 

 and an inch high in front. A runner at each end, extending 

 some distance behind, and a cord attached to each front 

 corner, complete the pan (Fig. 171). It is easily pulled by 

 two boys, and by running several together in a row, one boy 

 to each rope, and one to each contiguous pair, the best work 

 is performed with the least labor." Larger hopperdozers 

 are drawn or pushed by horses. 



Poisoned bran mash has been used against both nymphs 

 and adults, using from one to two pounds of Paris green to 

 25 pounds of bran. Poisoned horse-droppings have been 



