. Bulletin of the Department of Agriculture. Agriculture; Agriculture. SACBEOOD. 37 RESISTANCE OF SACBROOD VIRUS TO DRYING AT ROOM TEMPERATURE. In the experiments made for the purpose of determining the amount of drying which the virus of sacbrood will withstand, larv« recently dead of the disease were used. These are crushed, strained through cheesecloth, and the crushed mass poured into Petri dishes (fig. 32) to the extent of a thin layer for each dish, the material in each being the crushed remains of about 30 larvae. These are placed in a drawer, shielding the larval material from the
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. SACBEOOD. 37 RESISTANCE OF SACBROOD VIRUS TO DRYING AT ROOM TEMPERATURE. In the experiments made for the purpose of determining the amount of drying which the virus of sacbrood will withstand, larv« recently dead of the disease were used. These are crushed, strained through cheesecloth, and the crushed mass poured into Petri dishes (fig. 32) to the extent of a thin layer for each dish, the material in each being the crushed remains of about 30 larvae. These are placed in a drawer, shielding the larval material from the light. The drying then pro- ceeds at the temperature of the room. This temperature varied greatly from day to day, sometimes being as high as 93° F. (34° C). At intervals, reckoned in days, after the preparation of the virus, colonies are inoculated. An aqueous suspension is made of the drying larva] content con- tained in a Petri dish. This is added to sirup, and the sirup suspension is fed to a healthy colony gave the following results:. Fig. 32.—Open Petri dish. One-half of Petri dish, either top or bottom. (Original.) The experiments Table I^'.—Resistance of sacbrood virus to drying at room temperature. Date of inoculation. Time of drying. Results of inoculation. Aug. 8. 1914., Aug. 14, 1914. Sept. 6, 1915. July 1, Sept. 28, 1915 July 6, Sept. 3, 1915. Sept. 27, 1915 Oct. 9, July 29, 1915. Sept. 3, 1915. Do May 22,1915. Do 3 days , 7 days , 13 days , 16 days 18 days , 20 days 22 days 26 days 28 days 28 days 35 days 45 days , 7 months 12 days 7 months 21 days Sacbrood produced. Do. Do. Do. Do. Do. No sacbrood produced. Do. No. Do. Do. Do. Do. Do. From the results recorded in Table IV it will be noted that the virus of sacbrood in the experiment referred to withstood drying at room temperature for approximately three weeks. The inoculations made during the third week indicated, by the re- duced amount of sacbrood produced, that much of the virus had
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