10 TEEATMEXT OP BEE DISEASES. 



A very characteristic and usually penetrating odor is often iiotice- 

 able in the decaying larvae. This can perhaps best be likened to the 

 odor of heated glue. 



The majority of the larva? which die of this disease are attacked 

 after being sealed in the cells. The cappings are often entirely re- 

 moved by the bees, but when they are left they usually become 

 sunken (fig. 2. g, c, j) and frequently perforated (fig. 2, e, j). As the 

 healthy brood emerges the comb shows the scattered sunken cappings 

 covering dead larvae (fig. 4) , giving it a characteristic appearance. 



Pupse also may die of this disease, in which case they, too, dry down 

 (fig. 2, 0, d). become ropy, and have the characteristic odor and color. 

 The tongue frequently adheres to the upper side wall and often 

 remains there even after the pupa has dried down to a scale. Younger 

 unsealed larvae are sometimes affected. Usually the disease attacks 

 onh" worker brood, but occasional cases are found in which queen 

 and drone brood are diseased. It is not certain that race of bees, 

 season, or climate have any effect on the virulence of this disease, 

 except that in warmer climates, where the breeding season is pro- 

 longed, the rapidity of devastation is more marked. 



European Foul Brood. 



European foul brood was formerly called " black brood " or " New 

 York bee disease." The name " black brood " was a poor one, for the 

 color of the dead brood is rarely black or even very dark brown. 

 European foul brood usually attacks the larva at an earlier stage of 

 its development than American foul brood and while it is still curled 

 up at the base of the cell (fig. 5, ;•). A small percentage of larv'se 

 dies after capping, but sometimes quite young larvae are attacked (fig. 

 5, e. m). Sunken and perforated cappings are sometimes observed 

 just as in American foul brood (fig. 2, c, g, j). The earliest indication 

 of the disease is a slight yellow or gray discoloration and uneasy 

 movement of the larva in the cell. The larva loses its well-rounded, 

 opaque appearance and becomes slightly translucent, so that the 

 tracheae may become prominent (fig. 5, &), giving the larvae a clearly 

 segmented appearance. The larva is usually flattened against the 

 base of the cell, but may turn so that the ends of the larva are to the 

 rear of the cell (fig. 5, p), or may fall away from the base (fig. 5, 

 e, g, 1) . Later the color changes to a decided yellow or gray and the 

 translucency is lost (fig. 5, q, h). The yellow color may be taken as 

 the chief characteristic of this disease. The dead larva appears as a 

 moist, somewhat collapsed mass, giving the appearance of being 

 melted. "Wlien the remains have become almost dry (fig. 5, c) the 

 tracheae sometimes become conspicuous again, this time by retaining 

 their shape, while the rest of the body content dries around them. 

 Finally all that is left of the larva is a grayish-brown scale against 



442 



