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



Sometimes a considerable portion of a larva is removed piecemeal 

 by the bees during the first stage of decay. The remnant (PI. VI, D), 

 consisting of the posterior third and usually much of the middle third, 

 is found occupying its normal position in the cell. The surface 

 markings are similar to those of the middle and posterior thirds in 

 the first stage of decay. The surface left by the removal of the 

 fragments is somewhat roughened and transverse to the body. 

 These larval remnants are similar to those seen in sacbrood, but in 

 American foulbrood there are fewer of them. When present they 

 form one of the earliest symptoms of the disease. 



SECOND STAGE 



By the second week after death the larva shows a slightly deeper 

 shade of brown, although still quite light. The anterior third 

 (PI. II, F) is somewhat darker than the other two thirds. The apex 

 is farther from the roof than in the first stage. The surface markings 

 (PI. II, I) are now less pronounced throughout, An attempt made 

 at this time to remove the dead larva from the cell results usually 

 in rupturing the body wall. The decaying mass can be entirely 

 removed, however. The consistency of the tissue mass in this stage 

 is somewhat similar to that of moist dough. It has not yet reached 

 the true viscid condition. 



THIRD STAGE 



By the third week after death the remains have assumed a medium 

 shade of brown, approximating that usually seen in brood cappings. 

 The apex of the anterior third (PI. Ill, D) is now widely separated 

 from the roof of the cell, exposing to view the ventral surface of the 

 remains. The transverse ridges and furrows marking the segments 

 (PI. Ill, G) are practically obliterated. The edges no longer show 

 the deep notches. The side-to-side convexity is decreased. Evidences 

 of developing head and thoracic appendages are sometimes seen. 

 Transverse tracheae can usually be observed as white lines across 

 the ventral surface of the abdomen, one in each segment. The body 

 wall is ruptured easily. The decaying mass shows some viscidity 

 and adheres to the walls of the cell. 



FOURTH STAGE 



By the fourth week after death the color of the dead larva reaches 

 a deep brown, being in shade similar to that of the average older brood 

 combs. The apex of the anterior third (PI. Ill, E) is raised only 

 slightly above the upper surface of the decaying larral mass. After 

 being uncapped this third is the first to dry, becoming dark and scale- 

 like. Surface markings practically have disappeared; tracheae 

 frequently are still visible, especially in the middle third. The ventral 



