1228 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



like mass without rupture; contents 

 watery with many suspended, fine, brown 

 particles. There are no characteristic 

 intracellular bodies in aiTected tissues. 

 Dead larvae eventually dry down to form 

 scales that are black and roughened, that 

 separate readily from the cell wall, and 

 that may be lifted out intact. Colonies 

 tend to lose virus spontaneously. 



Transmission : By contamination of 

 food. Not by hands, clothing, or tools. 

 Perhaps through water supply of insects. 



Thermal inactival ion : In water, at 58° 



C in 10 mimites. In honey, at 70 to 73° 

 C in 10 minutes. 



Filterability : Passes Berkefeld and 

 Pasteur-Chamberland filters. 



Other properties : Withstands drying 

 20, not 22, days, exposure to sunlight 7 

 hours or less, storage in honey a month 

 or more, ^ to 2 per cent aqueous solutions 

 of carbolic acid 3 weeks or more. 



Literature : McCray and White, U. S. 

 Dept. Agr., Dept. Bull. 671, 1918; White, 

 U. S. Dept. Agr., Bur. of Entomol., Circ. 

 169, 1913; U. S. Dept. Agr., Dept. Bull. 

 92, 1914; ihid., Dept. Bull. 431,1917. 



