264 MARYLAND AGRICULTURAL EXPERIMENT STATION. 
DISEASES. 
Of the diseases which attack bees the greatest losses arise from the 
two infectious diseases of the young brood, viz., American Foul Brood 
and European Foul Brood. 
American Foul Brood is characterized by a ropiness of the affected 
brood, manifested by thrusting a wooden splinter into the dead brood 
and removing it. In some cases the ropy mass can be drawn out to 
the extent of 3 or 4 or more inches. Later this ropy mass dries and 
forms a dark brown scale on the lower cell wall usually adhering 
tightly. The color of this decayed mass in the earlier stages before 
drying down is a light brown. The dead brood may be either capped 
or uncapped and the cappings are often sunken and perforated. The 
odor in American Foul Brood is usually marked and perhaps more 
noticeable after the mass has dried down to form the scale. This 
odor is not always unpleasant. It has been likened to that of a glue 
pot, which perhaps is as descriptive a comparison as can be made. 
This disease rarely attacks drone larve. 
In European Foul Brood there is not the tendency toward ropiness, 
as in American Foul Brood, although a slight degree of ropiness does 
sometimes occur. The scale that forms in this disease does not adhere 
as a rule very closely to the cell wall and is more usually found at the 
base of the cell. These scales often show lines running around the 
dead grub, marking it off into divisions. The color of the scales is a 
yellowish brown or gray, sometimes quite dark brown. In the earlier 
stages before drying down the larva is of a yellowish or gray color and 
has what might be called a “melting” appearance, by which it is under- 
stood that the larva becomes a moist collapsed mass. The brood in this 
disease is not so often capped as it is in American Foul Brood, since 
it is the younger larva that are more often attacked. The disease at- 
tacks queen and drone larve as well as worker brood. 
The adult bees of a colony affected with either of these diseases do 
not seem to work with their usual activity, and the bee keeper will 
probably note a general listlessness about the hive. Owing to the large 
amount of brood dying, the colony constantly dwindles in strength, 
often becoming so weak that robbers enter and spread the infection to 
other hives in the apiary. 
In these two diseases there is great variation, so that it is not a sim- 
ple matter to give a general description applicable in every detail to all 
cases. Variation occurs in both of these diseases, and they may be- 
come so much alike in appearance that in some cases the distinguishing 
of the one from the other requires considerable care. In case there is 
any doubt in the mind of the bee keeper about diagnosis the Bureau of 
Entomology, United States Department of Agriculture, Washington, 
D. C., is always willing to aid the bee keeper by examining samples of 
brood suspected of being diseased. Neither of these diseases can be 
diagnosed from empty comb, honey, or dead adult bees. Hence, in sus- 
pected cases larve of the age at which the disease has been described as 
attacking the brood should be sent. A piece of comb four or five 
inches square is sufficient. 
