WAX MOTHS AND AMERTCAN FOUL BROOD. 21 



larval feces and scales in about equal proportion by volume. On ac- 

 count of the reduction of the photograph the scales do not appear 

 plainly; nevertheless, this demonstrates what becomes of the scales 

 of American foul brood in a set of combs destroyed by Galleria mel- 

 lonella. A few scales are seen placed on a card resting on the mass of 

 feces and scales. 



Mr. Burton N. Gates, of this Bureau, took some of these scales and 

 put them in a small box with small larva? of Galleria mellonella. 

 The scales remained untouched and the larva? died, evidently of 

 starvation. 



WORK OF THE LESSER WAX MOTH. 

 (Achroia grisella Fab.) 



Plate III is a photograph of a comb taken from a colony which had 

 died of American foul brood. It was obtained by the author in June, 

 1906, near Fillmore, Ventura County, Cal., and is of interest as com- 

 ing from an apiary which in less than two years had been reduced 

 from about 200 colonies to 15 by the ravages of this disease. When 

 the apiary was visited there were 151 hives in place, and of these 136 

 contained no bees. This comb was wrapped up and put away for 

 future study, but became infested with Achroia grisella. Whether 

 it contained eggs when taken in the apiary or whether the moths 

 entered after the comb reached Washington is not known. 



It is obvious from this illustration that the larva? have not eaten 

 the scales formed by dried-down larva^ which died of American foul 

 brood. This comb was not cleaned of webs and illustrates very nicely 

 the characteristic work of this moth. 



After the photograph was taken the scales were picked out of the 

 frame and this material was used in some of the inoculation experi- 

 ments recorded in Circular No. 94; obviously, therefore, the material 

 was still infectious. 



CONCLUSION. 



In the control of brood diseases of bees the constant reinfection of 

 apiaries from diseased combs of colonies in a wild state is one of the 

 things which must be combated constantly. It is not difficult for a 

 bee keeper to rid his own apiary of disease, but ho must constantly 

 watch for an introduction of the disease from wild bees or an adjoin- 

 ing apiary. If then the wax moths actually destroyed the infected 

 combs of wild colonies or of colonies in tin 1 apiaries of careless bee 

 keepers, they would be a benefit to the industry to that extent. Nat- 

 urally if the moth larva? eat out everything excepl the scales and these 

 drop to the bottom as shown in Plate II, they are less available to 



