Disappearing bees or rather the disappearance of bees from hives
without even leaving dead bees in many cases has been reported in
the UK recently and was commented on in "The Apiarist" (a quarterly
newsletter). The author comments that Norman Carrick from
Rothamsted believes it to be a result of virus infection vectored by
varroa. The UK is not alone in this. It has happened on a large
scale in Spain over this winter and spring. This Disappearing Bee
Syndrome is now to be the subject of a study by the CAAPE or
Andalusian Centre for Organic Beekeeping based at the University
of Cordoba. The University of Cordoba itself and the University of
Montpellier in France will also participate in this three year study
and they will look at four possible causes:
1. The action of certain groups of insecticides especially imidaclo-
prid and fipronil which are thought to cause disorientation in bees
and have been banned in France.
2. Nosema.
3. Virus diseases.
4. The lack of sufficient protein (pollen) sources which can cause
immune system deficiencies in bees.
The aim of the investigation will be to establish which of these
problems caused the depopulation of colonies, to provide solutions
for beekeepers and for Spain, to produce an epidemiological map
of the principle viruses affecting bees, similar to that carried out in
France in recent years.
The study will also study in depth the effects of Nosema on the
M.iberica with the aim of reducing the use of unnecessary treatments
and to clearly define the relationship between Nosema and colony
losses in Spain.

Source: Apis-UK June 2005.