Malte Baesler's 'take' on CCD - Hamburg

I. Worldwide Situation
In 2006 beekeepers reported for the first time a weird situation: large
populations of bees had abruptly disappeared. The hives were abandoned
by the worker bees. Since then, every year colony losses above average
are reported from countries all over the world. The term colony collapse
disorder (CCD) was introduced and scientists in many countries are
searching for the cause of this ecological and economical disaster. Till
this day, the reason could not be identified. But it is assumed that CCD
is the symptom of a complex problem due to a harmful environment for
bees caused by agriculture, diseases, and beekeepers.
Agriculture: Since end of World War II a diverse amount of different
pesticides have been developed and applied. Fortunately, some of them
have been prohibited again but, nevertheless, most of the nowadays
permitted pesticides are harmful to bees. Even if chemical companies
attest nontoxic to bees, these tests cannot eliminate risks because they
only determine the lethal dose of toxic for isolated adult bees. These
tests do not analyze the impact on the brood, on fertility, on the
orientation of the bees, and on accumulation in food and wax.
Furthermore, genetically modified crops are cultivated on our fields
that are suspected to be toxic for bees, too. Genetically modified crops
that are resistant to novel classes of highly potent pesticides and
plants that produce toxics by themselves primarily benefit the chemistry
companies.
Moreover, modern agriculture prefers mono cultures. Wild flowers with a
continuously and diverse flow of nectar and pollen are eliminated by
herbicides so that for the bees the environment appears like a desert
with some peaks of nectar and pollen flow, but unbalanced nutrition.
These malnourished bees are prone to parasites and diseases.
Diseases: Several parasites, bacterias, viruses, and fungal pathogens
are suspected to cause CCD or at least stress that contributes to CCD.
The usual suspect is varroa destructor mite, the world's most
destructive honey bee killer, that spread viruses such as deformed wing
virus, acute bee paralysis virus, and Israel acute paralysis virus.
Other scientists have suggested that diseases such as nosema apis and
nosema cerana are contributors to CCD, too.
Beekeepers: The beekeepers might also be a factor of influence of CCD.
Not only the bees carry in pesticides that might accumulate in honey,
pollen and wax, but also the beekeepers do. Medications to fight varroa
mite and other diseases are applied. Furthermore, the colony management
causes stress to bees leading to a weakened immune system. The beekeeper
uses frames with foundation to specify the cell types and cell sizes and
to suppress drone cells. But naturally the bees build different cell
sizes for brood and storage. A natural swarm knows at best which type of
cells are required and does not need any guideline. It is suspected that
during the past century the honeybee was accustomed to larger cell size
(from 4.9 mm to 5.4 mm diameter), supporting varroa mite. The growth of
drones is suppressed by foundations, too. In spring and summer time
drones are an integral part of the colony and are important for the
colony's harmony. Moreover, the beekeeper suppresses an other integral
instinct of the bees: swarming. Swarming is the only natural way of
reproduction. It is important, because both, the swarm and the remaining
colony, have a period with absence of brood and the colony can recover.
During colony management the brood nest is often torn by the beekeeper
and frames are interchanged. This management also causes stress to the
colony. Furthermore, in most regions wrong races of the European
honeybee are kept. Due to extensive queen breeding the bees are selected
for maximum honey production, gentleness, no propolis accumulation, and
a strong swarm sluggishness. As a result, thousands of queens are
daughters of the same mother, the gene pool depletes, and diseases might
spread easily. In addition, propagation of diseases is boosted by
national and international bee transports and package bees.