4 CIRCULAR 3 9 2, U. S. DEPARTMENT OF AGRICULTURE 



of the disease through robbing. Under no circumstances should 

 colonies be permitted to remain in the apiary until they have become 

 seriously weakened by or die of American foulbrood. 



Figure 1. — Symptoms of American foulbrood: A, Normal capping over healthy 

 larva; B-F, stages in the discoloration and removal of cappings; G, capping 

 removal to show healthy larva; H-L, stages in the decay and drying of larvae 

 killed by American foulbrood; oral views. 



