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. 3 > 
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: 
seeder widths of seed treated with strychnine. 
seeder widths without treatment, as a check. 
seeder widths of seed treated with coal tar. 
seeder widths check. 
seeder widths of seed treated with lead arsenate. 
seeder widths check. 
seeder widths of seed treated with coal tar. 
seeder widths check. 
seeder widths of seed treated with arsenate of lead. 
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