30 BULLETIN 156, U. S. DEPARTMENT OF AGRICULTURE. 



Remedial measures may be classified under three headings: (1) 

 Seed treatment to prevent insects eating the seed; (2) introduction 

 of poisonous or noxious substances into the soil; and (3) cultural 

 methods. 



TREATMENT OF SEED. 



Under the first head many substances have been used and reported 

 as more or less efficient, among which might be mentioned Paris 

 green and coal tar, gas tar, coal oil, tar, Paris green, and arsenate of 

 lead. In 1884 Webster used kerosene as a treatment of seed corn to 

 protect seed from wireworms. Although his experiment did not 

 apparently impair the vitality of the seed, a farmer who attempted 

 to apply the recommendation claimed that the vitality of the seed 

 was destroyed thereby. In 1888 Forbes treated corn seed with Paris 

 green, and though wireworms fed on corn so thoroughly coated as to 

 be quite green they seemed to experience no ill effects; He also ex- 

 perimented with alcoholic solutions of arsenic and water solutions 

 of strychnine and potassium cyanid. 



In the spring of 1911 wireworms were very numerous on the wheat 

 land at Wilbur, Wash., and the writer carried on a series of very 

 extensive experiments to determine the value of some of these sub- 

 stances and also added a few which, to his knowledge, had not been 

 tried before. 



Three sacks of wheat (6 bushels) were treated on March 24 with 

 arsenate of lead. Six pounds of insecticide were used for the batch. 

 The arsenate was thinned to the consistency of thick whitewash, 

 with water, and thoroughly mixed into the seed in a large box. 

 The seed, when dry, was very white and well coated. On the same 

 date two sacks (4 bushels) were treated with coal tar. The tar was 

 applied with a paddle, the paddle being first dipped into the tar and 

 then stirred around in the wheat until the seed was well coated. 

 The seed was then mixed with sand and allowed to dry. One sack 

 of wheat was treated with strychnine, 2 ounces of this poison being 

 used to 2 bushels of wheat. The strychnine was dissolved in 2 quarts 

 of hot water and 1 pound of sugar was added as an adhesive. The 

 seed was then soaked in this liquid and allowed to dry. On March 



31 all of these treated batches of seed were sown. The sowings 

 were made in plats which were about half a mile long. They were 

 made in an 11-foot wheat seeder, and were arranged as follows: 



2 seeder widths of seed treated with strychnine. 

 2 seeder widths without treatment, as a check. 



2 seeder widths of seed treated with coal tar. 



4 seeder widths check. 



5 seeder widths of seed treated with lead arsenate. 

 5 seeder widths check. 



3 seeder widths of seed treated with coal tar. 

 9 seeder widths check. 



4 seeder widths of seed treated with nrsenate of lead. 



