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



From the last experiment we conclude that the use of coal tar and 

 Paris green is not a remedial measure to be recommended. However, 

 Dr. H. T. Fernald has published 1 an account of a series of experi- 

 ments that seem to reach quite the opposite conclusion, and it is 

 very probable that gas tar will not prevent germination as did the 

 coal tar of our experiments. 



The copper-sulphate plat was more severely infested than the 

 check plats, so this treatment is quite useless as an insecticide for 

 wireworms. The potato bait poisoned with strychnine was a fail- 

 ure because the potatoes were allowed to dry up before being placed 

 in the ground. 



Mr. G. I. Beeves carried on an experiment at Pullman. "Wash., 

 using a commercial tobacco extract applied to the seed corn as a re- 

 pellent. This experiment was carried on in a root cage. On May 27, 

 1909, he treated 15 kernels of seed com by soaking for 21 hours in a 

 solution of commercial tobacco extract, 1 part to 16 parts of water. 

 The seed was dried before planting and was sown with alternate 

 untreated seeds as a check. "Wireworms were introduced at the time 

 of seeding and also on June 2. The experiment was discontinued 

 on June 10, and all the seed carefully examined. Of the treated 

 seeds, eight were eaten into by wireworms, while nine of the un- 

 treated seeds were destroyed. It is very evident from this experi- 

 ment that tobacco solution as a repellent is quite useless, at least for 

 wireworms. 



Soaking the seed in formalin has been suggested as a means of 

 repelling wireworms. This measure is quite useless. In the re- 

 gions of the Pacific Xorthwest where the author was studying 

 severe wireworm outbreaks nearly all the seed wheat had been 

 treated with formalin as a means of preventing the development 

 of smut fungus. 



Mr. O. A. Johannsen and Miss Edith M. Patch have published 2 

 the results of a series of experiments carried on in Maine. They 

 treated seed corn with tar and Paris green, and with arsenate of lead, 

 and found both of these treatments inefficient. 



SOIL TREATMENT. 



The second group of remedial measures— -soil treatment — has re- 

 ceived considerable attention. Experiments with soil fumigants are 

 now being carried on by the writer, but as the methods have not as yet 

 been placed on a practical basis this matter will not be treated herein. 



1 Fernald, H. T. A new treatment for wireworms. In Jour. Econ. Ent.. v. 2, No. 4. 

 p. 279-280, August, 1909. 



- Johannsen, O. A., and Patch, Edith M. Insect Notes for 1911. Maine Agr. Exp. Sta., 

 Bui. 195, p. 229-248, December, 1911. 



