6 



multiply rapidlj', the larva soon showing signs of being aifected. 

 This usually takes place soon after the larva is capped. 



The majority of the infected larvae die in the late larval stage, 

 though some do not die until after transforming into the pupae. 

 Usually the first indication that the larva is diseased is a sunken 

 and slightly darkened appearance of the capping. The bees soon 

 begin removing this capping. First a tiny pin-hole perforation 

 is made, which is enlarged until finally the entire capping may be 

 removed. The diseased larva first shows a slight brownish dis- 

 coloration and begins to lose its normal shape. As the disease 

 advances the color becomes darker and the deea,ying mass passes 

 through all stages of brown, variously described as chocolate, 

 mahogany and coffee color. The larva sinks down to the lower 

 side of the cell, presenting a flattened, melted-down appearance. 

 The back end of the dead larva is slightly elevated against the 

 bottom of the cell, while the front end flattens down on the lower 

 side of the cell, though in the earlier stages it may be slightly 

 rounded at the front and somewhat elevated. The larvae lie in a 

 fairly uniform position, stretched out on the lower sides of the 

 cells. This characteristic aids in distinguishing American foul- 

 brood from European foulbrood, in which latter disease the dead 

 larvae are found in all shapes and positions. 



Fi'ijy!r''T' 









Fig. 3. This illustration <hows a comb containing sacbrood. 



