298 ECONOMIC ENTOMOLOGY 



Control. — Professors Comstock, Slingerland and Forbes several 

 years ago carried on a long series of experiments in the hope of finding 

 out a satisfactory method of treating wireworms. These experiments 

 were carried out along three lines: 



1. By the protection of the seed. 



2. By the destruction of grubs by cultivation and clean fallow, 

 and immune crops, and by the use of insecticides and fertilizers. 



3. By trapping the adult click beetles. 



The following substances were used as a protection for the seed: 



1. A coating of Paris Green and flour. 



2. A coating of tar. 



3. Soaking the seed in a solution of salt. 



4. Soaking the seed in a solution of copperas. 



5. Soaking the seed in a solution of chloride of lime and copperas. 



6. Soaking the seed in a solution of kerosene oil. 



7. Soaking the seed in a solution of spirits of turpentine. 



8. Soaking the seed in a solution of strychnine. 



9. Soaking the seed in a mixture of Paris green and water. 



10. Soaking the seed in an alcoholic solution of arsenic. 



11. Soaking the seed in a solution of arsenic and boiling water. 



12. Soaking the seed in an alcoholic solution of corrosive sublimate. 



13. Soaking the seed in a saturated solution of potassium cyanide. 

 In almost every case the wireworms fed upon the grain or seed thus 



coated without injury to themselves, and the investigators were forced 

 to the conclusion that it was not practicable to protect the seed by 

 means of these substances even were it possible to use them without 

 preventing or retarding the germination of the seed. 



Buckwheat, mustard and rape, which are supposed by many to be 

 immune crops, were found to be not entirely so, for the wireworms 

 in some instances fed upon these plants almost as readily as upon cereal 

 plants. 



Insecticides were also used in the effort to destroy wireworms. 

 The following were applied directly to the soil: 



1. Kerosene emulsion, and pure kerosene. 



2. Crude petroleum emulsion, and pure crude petroleum. 



3. Poisoned dough. 



4. Bisulphide of carbon. 



5. Salt. 



