American foulbrood (AFB) is the most serious, contagious
notifiable bacterial disease of honeybee brood of international
proportion. The causative organism is a virulent spore-forming
bacterium, Paenibacillus larvae var. larvae. AFB can
appear and spread quickly through a colony and if left
untreated may result in the death of the hive in a short
space of time.
European foulbrood (EFB) is a serious, notifiable bacterial
disease of honeybee brood of international proportion.
Its incidence is apparently increasing and there is considerable
pressure from beekeepers to improve EFB control. European
foulbrood is sometimes not regarded as such an important
disease as American foulbrood yet the two are often confused
or mis-diagnosed.
In the UK around 50% of EFB-infected colonies per year are destroyed, with costs
to beekeepers also posed by standstill notices on infected apiaries (in place
for years in some areas), losses of honey yields, pollination contracts and sale
of bees.
The parasitic mite Acarapis woodi Hirst is not visible
with the naked eye; microscopic examination is necessary
as they vary in size between only 125 and 174 microns
(Delfinado-Baker and Baker 1982). They are basically
oval in shape and translucent-white in colour. The mite
infests the breathing tubes or tracheae and the air sacs
of honeybees, often in large numbers, where they pierce
the trachea walls to feed on the bee haemolymph.
Ascophaera apis, a fungus, causes the disease known
as chalkbrood in honeybee larvae.
Nosema apis is a parasitic Microsporan organism that
can cause Nosema disease and dysentery in honeybees.
The group Microspora are unicellular and spore-forming
in nature. They are not visible with the naked eye; microscopic
examination is necessary.
The varroa mite, Varroa destructor (Anderson and Trueman)
is a voracious parasite of the European honeybee, Apis
mellifera. It feeds on the bee haemolymph causing grave
physical damage and is a catalyst for viral infections
within the colony. Untreated, colonies are destroyed
by this pest in just a few years and many, many thousands
of hives have already been lost throughout the world
to attack from this mite. Varroa is without doubt the
most serious threat to honeybee health worldwide.
| Miscellaneous
Disease Agents |
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Viruses are commonly present in the honeybee colony.
However infection of honeybees and the appearance of
disease symptoms seems to depend to a large extent on
other stress factors on the colony, such as lack of space,
food or water, weather pattern or infection by other
means be they bacterial, fungal or mite.
The greater wax moth Galleria mellonella is estimated to cause upwards of $5 million worth of damage a year in the United States alone.
The adult wax moth is greyish brown and has a wingspan of around 3 cm. The adult female moth penetrates the hive and lays her eggs directly on the comb. The wax moth larvae feed on the wax, the pollen, and even, if there are many larvae, on the host's brood.
