176 INJURIOUS INSECTS OF 1904. 



not made of iron. Slake four lbs. of fresh lime gradually. When 

 slaked add 25 gals, of water, and the water containing the dis- 

 solved bluestone. Stir thoroughly and add 25. gals, more water, 50 

 gals, in all. This mixture should be strained through burlap, or, 

 better, a wire strainer, before being used, to remove particles which 

 might clog the sprayer. To kill potato beetles or "bugs" at the 

 same time, add one lb. Paris green to the amount of the mixture 

 necessary to cover one acre. Each plant must be thoroughly cov- 

 ered. To be successful the spray should be used before the blight 

 starts. This process (four sprayings) costs about $4.00 per acre, 

 and each farmer must decide for himself whether the expense is 

 justified. 



It may well be said here that when one is treating potato vines 

 for the beetle alone, arsenate of lead is safer and better than Paris 

 green. 



' Farmers should read in this connection the article on potato 

 diseases, page 66 of Farmers' Institute Annual No. 16. These 

 Annuals are obtained by mailing a request to O. C. Gregg, New 

 York Life Building, St. Paul, Minn., enclosing postage. 



Potatoes this year are much troubled by rot, which subject, as 

 well as that of potato blight, naturally belongs to another depart- 

 ment, and does not call for detailed discussion here. We are led 

 to say, however, that the old theory that potatoes should be dug 

 early to avoid rot appears to have been disproved in the light of cer- 

 tain recent experiments, in which only 7 per cent rotted when they 

 were allowed to remain in the ground ten days after the tops were 

 all dead, while some which were dug much earlier lost 55 per cent 

 by decay. It is claimed that the common dry rot of the tuber is 

 caused by the same fungus that produces the late blight of the foli- 

 age, and potatoes in blighted fields are likely to be infested with 

 rot ; if not during the same season in Avhich the blighted tops ap- 

 par, then the following. It is believed by some that the spores 

 are washed down by rain into the soil. Said spores would remain 

 dormant for a while, until favorable conditions for germination 

 occurred. Much remains to be learned on this question. 



