Bees Under Attack

Can Science Solve the Problem?

Beekeepers around
the world are reporting
unusual losses of
honeybee colonies.

During the winter of 2012-2013
colony losses of more than
10% were recorded in
11 EU Member States.

Losses of almost 30%
were reported in
the UK and Sweden.
In Belgium, the figure
was 34%.

Bees play a vital role
in the food chain
as pollinators of
plants and crops.
Honeybees also
produce food such as
honey and pollen.

What is causing the problem?

There is no
single cause of
this global trend,
although single stressors
can be identified as
culpable in certain
cases.

There is growing
evidence to suggest
that in many instances a
number of stressors are
responsible, acting
separately or in
combination.

Biological
stressors

What are the main biological stressors?

The main parasite is the Varroa mite.
Also known as Varroa destructor, it's an
invasive species from Asia that is now
found worldwide.

The varroa mite feeds on bees' circulatory
fluid and spreads viruses and bacteria.

Diseases such as Foulbrood and
Nosema can devastate bee hives.

The Asian hornet (Vespa velutina) is a
fierce predator of honeybee colonies
and other pollinators.
It is a growing threat to bees in Europe.

© Asian Hornet: Jean Haxaire

The Small hive beetle (Aethina tumida)
and Tropilaelaps mites also attack bee
colonies around the world. The small hive
beetle was first detected in Europe in 2014.

© Hive Beetle By James D. Ellis (Invasive.org)
(CC-BY-3.0-cz), via Wikimedia Commons

Chemical and
contaminant
stressors

How do chemicals reach bees?

Agriculture (through spraying
crops or coating seeds).

Gardening
(mainly through spraying).

Beekeeping (through practices
such as the use of veterinary
products on hives).

Environmental
stressors

How do environmental stressors affect bees?

Climate change is causing changes in
the growth cycle of plants through, for
example, drought or shifts in seasonal
rainfall. These changes in turn affect the
availability of the nectar and pollen on
which bees depend for food.

Modern agricultural practices
have led to habitat change and
loss, reducing sources of food
and - for wild bees - nesting areas.

Insufficient or poor-quality
diets
can weaken bees' immune
systems, making them more
vulnerable to other stressors
such as infectious agents.

There is already
evidence that multiple
stressors
acting in combination
can be more damaging to
bees than when
acting alone.

But there is more
work to be done.