8 Wisconsin Bulletin 333 



In American foulbrood there may be two or three very 

 small punctures ; and the cap may be gnawed but not entirely 

 removed except in minute spots. In sacbrood the larvae ob- 

 served soon after death have a slight yellowish tinge with the 

 front end slightly darker. The back part of the body may re- 

 main yellowish for some time, and gradually become darker 

 while the head portions turn almost black. Often the larvae, 

 observed through the punctured cappings, appear brown with 

 a reddish tinge. The body wall of the larvae does not break 

 so easily as in the other diseases and the larvae may be re- 

 moved from the cell intact: The body when ruptured appears 

 as a granular mass with a more or less watery appearance. 

 The larvae require a much longer time to dry down and the 

 scales do not remain fast to the cell wall as in. American foul- 

 brood. 



How THE Diseases are Spread 



Little is known about the method of spread for European 

 fpulbrood or sacbrood, but both of these diseases may appear 

 suddenly in every colony in a yard. Package bees placed on 

 empty drawn combs may develop thd disease as severely as 

 old colonies. In 1920, package bees shipped from Texas and 

 placed on sheets of foundation developed both diseases be^ 

 tween May 1 and June 1. The season of 1920 was favorable 

 to these diseases and strong colonies sufifered in the same 

 propibrtion as weaker ones. European foulbrood disappeared 

 as soon as the honey flow began, but the; sacbrood did not dis- 

 appear until the honey flow was nearly over. 



The spread of American foulbrood^ from one state to an- 

 other, or over widely separated areas, is due to shipping dis- 

 eased bees and infected equipment or honey. 



Aside from buying diseased bees and bringing them into 

 a disease-free territory, the buying of, used hives and old conabs 

 is one of the most dangerous things a beekeeper can do. As a 

 rule, beekeepers who have, old hives or combs to pell without 

 bees have lost their bees through disease. Old combs from 

 such sources are almost sure to carry disease, especially if 

 there is honey in them. 



Old combs from a region in which foulbrood is known to 

 occur should never be given to disease-free bees. 



De^f-^o? A°gr.^*^*^ Entomologist for 1917 and 1918. Bui. 20, Wis. State 



