Agriculture Reference
In-Depth Information
The larvae appear to 'melt down' and to lose definition.
The bees do not usually cap infected cells, but larvae that are capped
may
die of
the disease and, in this case, the cappings are sunken and often perforated (pepper
pot).
The later stages of the disease produce a foul smell - often worse than AFB. In
both diseases this smell depends on which secondary bacteria infest the larval
remains after death.
Treating EFB
Treatment may not be necessary in an otherwise healthy colony, although you may
have to report an infestation to the statutory authorities in your area. The bacteriostat
oxytetracycline will prevent and cure the problem and many texts advocate this, but its
use is not really recommended unless a bee-inspection officer advises it and then only
under their direct guidance. Personally, I wouldn't employ it at all. Its overuse can cause
resistance and, without doubt, it can contaminate the honey.
Try to remove the cause of stress, and boost the colony's efforts to build up, perhaps
with a frame of brood and bees, if possible. If the disease is not too far gone, then all
should be well. There is no need for chemicals.
Remember that, because this disease is caused by the starvation of the larvae, it can
be hidden in, for example, queen-rearing colonies where high levels of feeding are
undertaken. If this is the case, the larvae are able to overcome the parasitic nature of
the bacteria.
The name EFB bears no relationship to its geographical spread, and very few areas
of the world have escaped it. At the time of writing, New Zealand has no EFB. It is
important you know the rules in your area concerning the reporting and treatment of
EFB.
Sacbrood
Sacbrood is a viral disease
(
Morator aetatulae)
that does not usually cause severe losses.
It mainly occurs early in the brood-rearing season when the ratio of brood to bees
