92 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



affecting, when properly carried out, the o-ermination of grains or 

 miscellaneous seeds. The very large stock of seeds and grains of all 

 sorts carried by this office is submitted to fumigation with carbon 

 bisulphid as often as necessary to keep it free from insect pests, and 

 usually several times a year. 



]\Ir. Morrill said that he had made a small test on cotton seed, 

 which was actually immersed in the liquid carbon bisulphid for a 

 few minutes without injury to its germinating power. 



Mr. Marlatt considered the use of 8 pounds of carbon bisulphid to 

 30 bushels of grain, as reconmiended by Mr. Conradi, as excessive 

 and unnecessarily expensive. The fumigation in the manner sug- 

 gested in the loose wagons seemed to offer the worst possible condi- 

 tions for effectiveness, owing to the fact of the quick dissipation of 

 the carbon bisulphid. 



Mr. Conradi said that the corn used had not been husked when 

 treated, and that because of this, as well as the rapid loss of the 

 insecticide through the cracks of the wagon boxes, it was necessary 

 to use the large amount recommended. 



Mr. Marlatt said that some doubt had been expressed regarding 

 the efficiency of tobacco dust for the woolly aphis of the api)le. lie 

 quoted from memory the substance of a letter reporting the very 

 successful use of this substance received from Mr. M. B. AVaite, a 

 pathologist of the Bureau of Plant Industry, who is also the owner of 

 a large commercial orchard in Maryland near Washington. The 

 test was made in a ()-year-old apple orchard containing about 1,800 

 trees, a good many of which (about one-fourth) showed more or less 

 injury by the woolly aphis. Mr. Waite's description of the condition 

 of his trees and of the treatment is here quoted : 



The trees had a wiry, slender, and soniewlnit more feeble growth than then- 

 uninfected neighbors, and the aphis could be found i:i varying quantities by 

 digging up the roots. I l»ought a ton of tobacco dust in Baltimore, costing .$25, 

 and ai)plied about a peck in a circle of '2 to :'. feet around each of the trees, 

 which were on the average about 2i to 8 inches in diameter, while the uninfected 

 trees usually were 4 to .^) inches in diameter. Some s-nialler vci)lanted tr(>es. 

 from 1 to P> years old, in the orchard we gave about a gallon, and i)laced 

 the tobacco dust in a smaller circle innnediately around the little tree. The 

 result was (luite s;itisfactory. The growth this season has been more vigorous 

 and the twigs strong and stubby. I think I can safely say that the remedy was 

 a success. Perhaps it will pay me to repeat it another year, and I am siu'e I 

 am going to go over all my young orchards, whetlKn' they are affected or not, 

 and give them, say, a gallon per tree to trees (inder '2 inches in diameter and a 

 greater amount to the larger ones. 



Mr. Burgess said that it had given with him very satisfactory 

 results in a small orchard of H-year-old a})i)le trees. 



Mr. Washburn asked why Mr. Siuith i)referred the tobacco water 

 to kerosene emulsion. 



Mr. Smith replied that the kerosene enuilsion was usually poorly 



