10 BULLETIN 809, U. S. DEPARTMENT OF AGRICULTURE. 



FIRST STAGE 



During the second week following the infection, symptoms of Amer- 

 ican foulbrood may be seen in pupae. The cell containing a dead 

 pupa is generally found capped at this time. Upon uncapping, the 

 anterior third (PI. IV, B) of the pupa will be recognized as resembling 

 very closely that of a healthy one. The surface markings in general 

 (PI. IV, E) are not particularly unlike those of a healthy pupa. The 

 turgidity is slightly less and the body is to a slight degree more nearly 

 opaque. The body wall is easily ruptured and the tissue mass is 

 soft but not viscid. In general the consistency is similar to that of a 

 larva in the first stage of decay. 



SECOND STAGE 



The process of decay continuing, the tissues soften and the pupal 

 mass settles, distorting its form. The anterior third (PL IV, C) has 

 settled to the floor of the cell and is separated from the roof by a 

 considerable distance. The face is directed more nearly upward. 

 The surface markings (PI. IV, F) of each third are less distinct. 

 The legs and other appendages rest upon the body. The body wall 

 is at this time very easily ruptured and the tissues are soft. The 

 color and consistency are similar to those of the second stage of 

 decay of the larva. 



THIRD STAGE 



During the third stage the appendages are less easily distinguished ; 

 as they settle they merge more or less with the decaying mass of the 

 head, thorax, and abdomen. One exception should be mentioned. 

 Some of the mouthparts (PL V, A), chiefly the proboscis, adhere to 

 the roof of the cell. This condition has often been noted by the 

 beekeepers. The face of the pupa in this stage is directed still more 

 nearly upward than in the preceding stage. The head is not infre- 

 quently found to be disfigured through drying or being gnawed or 

 both. The ventral surface of the middle third (PL V, D) is still, in 

 general, convex from side to side. The color and consistency are 

 similar to those of the same stage in the larvae. When the pupal 

 mass is removed white lines may be seen in it. These are tracheae. 



FOURTH STAGE 



In the fourth stage evidence of drying is marked and pupal re- 

 mains are changed still further. The anterior third (PL V, B) 

 bears only a slight resemblance to that of the pupa. Through set- 

 tling of the mass and through drying it is now very much flattened. 

 The ventral surface of the middle and posterior thirds (PL V, E) are 

 still sHghtly convex from side to side and are roughened, due chiefly 

 to the remains of the legs and other appendages. The color of the 

 decaying mass in the fourth stage is a dark brown similar to that 



