FOUL BROOD 
363 
FOUL BROOD. —The term foul brood 
covers two brood diseases—one known as 
American, or the old-fasbioned diseased 
brood, caused by Bacillus larvae, and one 
the European, a disease of comparatively 
recent introduction, caused by Bacillus plu- 
ton. There is some evidence to show that 
European foul brood was present in this 
country as early as 1890; but it was not 
until 1899 that the author discovered that 
there are two distinct foul brood diseases 
here. (See Gleanings in Bee Culture, 
page 858, for 1899.) Shortly after, others, 
including the foul-brood inspectors of New 
York (where the European foul brood was 
first found), also recognized the difference. 
AMERICAN FOUL BROOD. 
The American foul brood, often called 
“ropy” foul brood, because the dead mat¬ 
ter assumes a gluey, sticky, tenacious char¬ 
acter, was well known in Europe, and has 
been referred to by Dzierzon and other 
writers. But Moses Quinby of St. Johns- 
ville, N. Y., was the first one to recognize 
it in the United States and prescribe for 
its cure. The Quinby cure is the basis of 
the only successful mode of treatment 
known and recognized today. 
As a general rule, the beekeeper will 
not discover it in its incipient stages. He 
is not expecting it, and, if it comes, does 
not see it. His first intimation of its pres¬ 
ence will be occasional cells of sealed brood 
showing sunken, greasy cappings and cells 
with irregular perforations. American foul 
brood is confined mainly to brood that has 
died after the cells have been sealed; but 
25 or 30 per cent of unsealed cells will 
show dead brood, and the dead larvae in 
both sealed and unsealed will vary in color 
from a yellowish brown to a dark brown, 
and finally to a brownish black. The larva 
that has just died holds its shape. As the 
disease advances it begins to shrink, and 
the dead matter becomes so rotten and 
putrid that the skin breaks, and on the 
lower side of the cell is seen a melted-down 
mass of matter that is very ropy—that is 
to say, sticky and tenacious. As this dries 
down it forms a hard scale that sticks 
tightly to the cell wall. These scales are 
not readily seen by looking straight into 
the cells; hut if the top of the comb is 
tilted toward the observer and held so the 
light will shine into the cells, the scales can 
be seen on the lower cell wall. In American 
foul brood the scales lie in uniform posi¬ 
tion (Figs, e, i, p, s, page 368), while in 
European foul brood their position is some¬ 
what irregular. The scale of European foul 
brood does not adhere so tightly and may 
be removed. The worst specimens of Amer¬ 
ican foul brood are usually found in the 
cells that have been sealed, altho the melted 
broken-down form of larvae will be found 
in some unsealed cells. 
The initial stages of American foul brood 
are usually confined to the sealed cells. 
After the disease has advanced so that 75 
per cent of all the sealed brood in a comb 
is affected, there will be found quite a 
sprinkling of stray cells of young larvae 
that have never been capped over that are 
dead. But usually the grub will be almost 
fully grown before it dies in the unsealed 
cell, tending to show that American foul 
brood does not usually kill the larva until 
after it is sealed in the cell, or just before 
that sealing. 
European foul brood in its first stages is 
usually confined to the unsealed cells. The 
dead larva will have a light-yellow color 
instead of a brownish-dirty one verging 
on to very nearly black. The American 
may be found at any time of the year 
when brood-rearing can take place; hut 
the European usually shows up at its 
worst early in the season, and before the 
main honey flow. 
One may find occasional dead larvae just 
before sealing that do not indicate disease 
of any sort. A few such scattered over the 
combs may he due to starvation — that is, 
improper feeding. This occurs occasion¬ 
ally when there is too much brood for the 
number of nurse bees to the hive. One 
will occasionally find dead brood, due to 
chilling or overheating. When the brood 
area expands too fast in the spring, an oc¬ 
casional cold night will cause the cluster 
to contract, leaving some of the brood un¬ 
covered. This chills and dies, and is car¬ 
ried out and deposited at the entrance. The 
larvae will be white or slightly grayish, but 
not brown or yellow as in either of the 
foul broods. All such dead brood should 
be carefully distinguished from brood af¬ 
fected with either European or American 
foul brood. If, after a week or two, no 
