This is a highly contagious affection which, as it mainly affects the
developing brood in the cells, is commonly known as "foul brood." It is
due to a microbe (_Bacillus alvei_) whose spores are easily transported
from hive to hive by the bees themselves, by the operator, in honey,
or in combs changed from one hive to another. Once established in an
apiary, it usually spreads, unless speedily and energetically checked,
until all of the colonies in the neighborhood are ruined and even
exterminated. The most apparent symptoms are the turning black of
larvæ in open cells, many sealed cells with sunken caps, frequently
broken in and containing dead larvæ or pupæ in a putrid condition,
brown or coffee-colored, jelly-like or ropy in consistency, and giving
off an offensive odor. The disease, though known to exist in nearly
all countries, can hardly be said to be common. The writer, in an
experience of over thirty years in bee keeping in several States of
the Union, as well as in a number of foreign countries, has met the
disease but rarely, and has had but one experience with it in his own
apiary, it having been in this instance brought in by a neighbor who
purchased bees at a distance. It was easily cured, without great loss.
Thus the beginner's risks of disaster in this direction are, if he be
forewarned, comparatively small. He may, furthermore, gain assurance
from the fact that, should the disease invade his apiary, prompt and
intelligent action will prevent serious loss.
The following is the treatment for a colony which still has sufficient
strength of numbers to be worth saving: The bees are to be shaken from
their combs just at nightfall into an empty box, which is to be removed
at once to a cool, dark place. They are to be confined to the box, but
it must be well ventilated through openings covered with wire cloth.
During the first forty-eight hours no food should be given to them, and
during the second forty-eight hours only a small amount of medicated
sirup--a half pint daily for a small colony to a pint for a strong
one. This food is prepared by adding one part of pure carbolic acid or
phenol to 600 or 700 parts of sugar sirup or honey. At the end of the
fourth day the bees are to be shaken into a clean hive supplied with
starters of comb foundation. This hive is to be placed outside on a
stand some distance from all other colonies, and moderate feeding with
medicated sirup or honey should be continued for a few days thereafter.
The combs of diseased colonies which contain brood may be assembled
over a single one of these colonies, or, if the amount of brood be too
great for one colony to care for, over several such diseased colonies,
until the young bees have emerged. All of the honey is then to be
extracted. While it is wholesome as food, it should not be offered
for sale, lest some of it be used in feeding bees or be inadvertently
exposed where foraging bees might find it and carry to their hives the
germs of this disease, harmless to other creatures but so fatal to bee
life. A good use for this honey is to employ it in making vinegar. One
and one-third pounds added to each gallon of rain water or soft spring
water and allowed to ferment for three months in a warm place makes a
quality of vinegar quite equal to the best cider vinegar. Provision for
the free circulation of air through the cask should be made. This is
easily secured by placing the cask, not completely filled, on its side
and boring an auger hole in each end near the upper side, the holes to
be covered with cheese cloth or fine gauze, to keep out insects.
If the honey containing the germs is to be used for feeding bees, it is
to be diluted with half its own quantity, by measure, of water and kept
at the boiling point for three hours in a water bath--a vessel within
another containing water.
The combs from which the honey has been extracted, as well as all of
the pieces built by the bees during their four days' confinement, may
be melted into wax, by thorough boiling in soft water. This wax should
be kept liquid for 48 hours or longer, to allow all impurities to
settle. These will include the foul brood spores, which may then be
removed with, the impure wax by scraping or cutting away the bottom of
the cake. These scrapings should be burned. The same disposition had
better be made of the frames from which the combs containing germs were
removed.
In all of this work the utmost care should be exercised to avoid the
dripping of honey about the apiary or the exposure of implements,
receptacles, or combs smeared with or containing honey from the
diseased colonies. It may even be better, in order to save time and
possible risk, where but few combs and a comparatively small amount
of honey are involved, to destroy all of these immediately after
their removal from the hive. The old hive and all utensils used about
the diseased colony should be disinfected by washing in a solution
of corrosive sublimate--one-eighth ounce in one gallon of water--and
should afterwards be exposed to the air and sun for some time. If
healthy colonies are to be manipulated immediately after handling
diseased ones the hands of the operator must also be disinfected by
washing in the solution just mentioned.
Those who care to try and save combs and brood should employ the
remedial method developed by the late Professor Cheshire. This is
explained in full in his work on bee keeping,[C] and a brief statement
of it may also be found in "The Honey Bee," Bulletin No. 1, new series,
of the Bureau of Entomology, United States Department of Agriculture.
Notwithstanding these remedies, some will prefer, where healthy
colonies of bees can be bought at moderate prices, to burn diseased
bees, combs, and frames rather than spend time to effect a cure, and
risk, as they fear they may, the further spread of the pest. To kill
the bees thus is, however, neither profitable, humane, nor necessary,
for if confined as described above and separated at once from the other
colonies, this work being done at nightfall, when all of the bees are
in their hives, the risk of spreading the disease will not thereby be
increased, nor is the labor much greater than that involved in the
removal of combs and bees for burning. And if it be found that the
diseased colonies are weak in numbers and seem, therefore, individually
hardly worth saving, this need not be taken as an excuse for the death
sentence, as several colonies may be smoked and shaken together into
the same box to make a single strong colony, the best queen of the
lot having been selected and caged in the box in such a way that the
workers can release her within a few hours by eating through candy.
[C] "Bees and Bee keeping," by Frank K. Cheshire, F. L. S., F. E. M.
S., London, 1888, Vol. II, pages 554-575.