12 



than does American foulbrood, but it is less destructive and easier 

 to control. 



European foulbrood is a bacterial disease caused by Bacillus 

 pluton, though other organisms are present. The larvae are 

 attacked at an earlier stage than in American foulbrood. They 

 may be affected as early as the fourth day and most of them die 

 before being capped. The dead larvae take on a yellow color 

 •^vhich later becomes brownish. These dead larvae are often coiled 

 up in the bottom of the cells, and white tracheal lines may be seen 

 radiating outward from the center. However, one of the chief 

 characteristics of this disease is the irregularity of shape and 

 position of the larvae. They may be twisted in any shape or form 

 and may be in any position in the cell. 



As decay continues the dead larvae dry down into dark scales. 

 These scales do not adhere to the cell-walls as tightly as do the 

 scales of American foulbrood. They can be removed easily. It 

 often happens that considerable numbers of larvae die after being 

 capped. These capped larvae, dead from European foulbrood, may 

 be confused with American foulbrood. Some of the larvae that 

 die at this stage maj^ lie flat on the floor of the cells, but the 

 majority of them occupy various positions in the cells and may 

 assume most any shape. When they apparently lie flat, a close 

 inspection will often reveal a slightly twisted position. At certain 

 stages a ropiness may be present, but the rope is shorter and more ■ 

 granular than that of American foulbrood, and does not snap 

 with a rubbery consistency, on breaking, as does that of American 

 foulbrood. When the larva dries down it has the consistency of 

 dead burned rubber. The color is dark, and at the rubbery stage 

 may be almost black. In the early stages little odor is detected, 

 but in the later stages of bad eases, a foul repulsive odor is 

 present. 



Treatment 



Since European foulbrood is primarily a disease of weak colonies 

 and of black bees, the best method of treatment is preventive 

 measures. Black colonies should be requeened with a vigorous 

 strain of Italians. All colonies should be kept strong by better 

 beekeeping methods. This will usually serve to keep the disease 

 well under control. However, in some seasons and in some localities 

 the disease gives more trouble. Weak colonies should be united. 

 In bad cases it may be necessary to take away some of the badly 

 diseased combs or separate them from the brood-chamber by means 

 of a queen excluder. 



SACBROOD 



Sacbrood is an infectious disease of the larvae, caused by a 

 filterable virus. The larvae are usually attacked soon after the 

 cells are capped. At first the larva becomes yellowish, then a 

 grayish mottled to brownish color. The front end is often darker, 

 sometimes even black. The dead larva usually lies on its back and 

 often the front end is pointed and extended toward the roof of 



