Conservation Guardians of Northwest Illinois
We Are What We Eat
Ever since my daughter became an entomologist, I have been interested in bees. While she was at the University of Illinois, she met Dr. Cedric Alaux, who was a postdoctoral research assistant doing research on the molecular basis of social behavior in honey bees in Gene Robinson’s laboratory. In Dec of 2008 he returned to France, where he now researches honey bee response to environmental stressors at INRA Avignon, France (French National Institute for Agricultural Research). He just recently sent us a BBC article on his work he is doing. I think the findings are very interesting and reinforce the mission of the Conservation Guardians to protect as much biodiversity around us as possible. The following is a reprint of the article.
Plant loss 'leads to fewer bees'
The decline of honeybees seen in many countries may be caused by reduced
plant diversity, research suggests.
Bees fed pollen from a range of plants showed signs of having a healthier
immune system than those eating pollen from a single type, scientists
found.
Writing in the journal Biology Letters, the French team says that
bees need a fully functional immune system in order to sterilize food
for the colony.
Other research has shown that bees and wild flowers are declining
in step.
Two years ago, scientists in the UK and The Netherlands reported that
the diversity of bees and other insects was falling alongside the
diversity of plants they fed on and pollinated.
Now, Cedric Alaux and colleagues from the French National Institute
for Agricultural Research (INRA) in Avignon have traced a possible
link between the diversity of bee diets and the strength of their
immune systems.
"We found that bees fed with a mix of five different pollens
had higher levels of glucose oxidase compared to bees fed with pollen
from one single type of flower, even if that single flower had a higher
protein content," he told BBC News.
“You’ve now got large areas of monoculture; and that's
been a fairly major change in what pollinating insects can forage
for”
David Aston British Beekeepers' Association
Bees make glucose oxidase (GOX) to preserve honey and food for larvae
against infestation by microbes - which protects the hive against
disease.
"So that would mean they have better antiseptic protection compared
to other bees, and so would be more resistant to pathogen invasion,"
said Dr Alaux.
Bees fed the five-pollen diet also produced more fat than those eating
only a single variety - again possibly indicating a more robust immune
system, as the insects make anti-microbial chemicals in their fat
bodies.
Other new research, from the University of Reading, suggests that
bee numbers are falling twice as fast in the UK as in the rest of
Europe.
Forage fall
With the commercial value of bees' pollination estimated at £200m
per year in the UK and $14bn in the US, governments have recently
started investing resources in finding out what is behind the decline.
In various countries it has been blamed on diseases such as Israeli
Acute Paralysis Virus (IAPV), infestation with varroa mite, pesticide
use, loss of genetic diversity among commercial bee populations, and
the changing climate.
The most spectacular losses have been seen in the US where entire
colonies have been wiped out, leading to the term colony collapse
disorder.
However, the exact cause has remained elusive.
A possible conclusion of the new research is that the insects need
to eat a variety of proteins in order to synthesize their various
chemical defences; without their varied diet, they are more open to
disease.
David Aston, who chairs the British Beekeepers' Association technical
committee, described the finding as "very interesting" -
particularly as the diversity of food available to UK bees has declined.
"If you think about the amount of habitat destruction, the loss
of biodiversity, that sort of thing, and the expansion of crops like
oilseed rape, you've now got large areas of monoculture; and that's
been a fairly major change in what pollinating insects can forage
for."
As a consequence, he said, bees often do better in urban areas than
in the countryside, because city parks and gardens contain a higher
diversity of plant life.
Diverse message
While cautioning that laboratory research alone cannot prove the case,
Dr Alaux said the finding tied in well with what is happening in the
US.
There, collapse has been seen in hives that are transported around
the country to pollinate commercially important crops.
"They move them for example to [a plantation of] almond trees,
and there's just one pollen," he said.
"So it might be possible that the immune system is weakened...
compared to wild bees that are much more diverse in what they eat."
In the US, the problem may have been compounded by loss of genetic
diversity among the bees themselves.
In the UK, where farmers are already rewarded financially for implementing
wildlife-friendly measures, Dr Aston thinks there is some scope for
turning the trend and giving some diversity back to the foraging bees.
"I'd like to see much greater awareness among land managers such
as farmers about managing hedgerows in a more sympathetic way - hedgerows
are a resource that's much neglected," he said.
"That makes landscapes much more attractive as well, so it's
a win-win situation."
The French government has just announced a project to sow nectar-bearing
flowers by roadsides in an attempt to stem honeybee decline.
Richard Black
Environment Correspondent, BBC News website
If you find pollinators as interesting as I do or want to find out
more information and help with research, go to /beespotter.mste.uiuc.edu/.
BeeSpotter is a partnership between citizen-scientists and the professional
science community designed to educate the public about pollinators
by engaging them in a data collection effort of importance to the
nation. It is a web-based portal at the University of Illinois for
learning about honeybees and bumblebees and for contributing data
to a nationwide effort to baseline information on population status
of these insects.
An interesting museum is the pollinatarium, which was established
by the University of Illinois – Entomology Department to further
educate the public on the importance of pollinators (http://www.life.illinois.edu/pollinatarium/).
The University of Illinois Pollinatarium is the first free-standing
science center in the nation devoted to flowering plants and their
pollinators.
Pam Johnson
