58 



THE SUGAR-BEET WIREWORM. 



results, which arc summarized in tlic following tabic, do not promise 

 much for the use of this substance in protecting seeds. 



Table XI. — Experiments with cresol as a deterrent against the sugar-beet mreworm. 



OTHER SUBSTANCES TESTED AS DETERRENTS. 



The other deterrents will be considered very briefly, since, with 

 the possible exception of two, none gave much promise of ultimate 

 success. 



Copperas solution. — Seeds soaked overnight in a copperas solution, 

 dried, and planted in the pots were ahnost as readily eaten as those 

 in the check cages. 



Copper sulphate. — -Copper sulphate did not give much promise as a 

 deterrent, as the seeds soaked in a solution of it overnight were eaten 

 readily by the wu-eworms, and with apparently no ill effects. 



Potassium sulphid. — -Seeds treated with a concentrated solution of 

 potassium sulpliid appeared neither distasteful nor injurious to the 

 wire worms. 



Salt. — -The seeds treated by soaking in a salt solution seemed for a 

 time to be partially immune to the attack of wu-eworms. By the 

 time several tests were completed, however, it was seen that while 

 they were more immune from attack just before germination, enough 

 were killed just after germination to make this procedure useless 

 from a practical standpoint. 



Sulphur. — %Some seeds were coated with a paste made of equal parts 

 of sulphur and flour, and after being allowed to dry were planted. 

 When examined later many had rotted and the rest had been riddled 

 by the wireworms. Some of the larva? were })artially covered with 

 sulphur, but did not seem in the least inconvenienced. It was con- 

 sidered that this experiment would give negative results, since the 

 sulphur, kept under the damp cool soil, would not give off fumes to 

 any extent, and lience its best effect would be lost. 



Lead chromate. — Seeds treated as in the foregoing experiment, but 

 using lead chromate in place of sulphur, were not protected in the 

 least, nearly every seed being drilled through in several places. 



