. Diseases of bees. Bees. Fig. 3.âHealthy prepupa approximately 8 days old, having reached the quies- cent stage. This is the age at which the majority of larvSD die from Ameri- can foulbrood. End view. (White (55)) the larval intestine, which up to this time has been a blind sac, is connected with the end gut, allowing defecation to take place. There is then two days of quies- cence, during which the larva extends in the cell and lies motionless, while internal preparatory to metamorphosis occur (figs. 3 and 4). These changes (7) consist of the almost complete histolysis of the fat b
. Diseases of bees. Bees. Fig. 3.âHealthy prepupa approximately 8 days old, having reached the quies- cent stage. This is the age at which the majority of larvSD die from Ameri- can foulbrood. End view. (White (55)) the larval intestine, which up to this time has been a blind sac, is connected with the end gut, allowing defecation to take place. There is then two days of quies- cence, during which the larva extends in the cell and lies motionless, while internal preparatory to metamorphosis occur (figs. 3 and 4). These changes (7) consist of the almost complete histolysis of the fat body of the larva in order to furnish nutriment for the formation of imaginal tissues. This is made possible by the physiological and morphological changes occurring Tn this stage of the development of the larva. Extended investigations have been made of these physiological and morphological changes, but they need not be summarized further here, since the present work has been solely of a biochemical character. It is noticeable, however, that the intestines of mature larvse even for a short time after cap- ping are full of material colored by the pollen content, while the intestines of the prepupae, after they have extended in the cell, are colorless. It is during the latter two-day prepupal period that according to Maassen {28) the invasion of the fat body by Bacillus larvae occurs and that according to White (SS) the majority of the brood dies in American foulbrood. In European foulbrood, on the contrary, the majority of the larvae in typical cases of this disease die before sealing and after reaching an age of Si to 4 days from the time of hatching of the egg (56) (fig. 5). In certain abnormal cases in European foulbrood death may occur after capping (46), but this almost always occurs during the first two days of the prepupal stage, when the larva in most cases is still moving about in the cell, usually causing a gross appearance quite different from that of dead of America
Size: 1089px × 2296px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisher, booksubjectbees
