Category: Pollinators

What’s Killing American Honey Bees? by Benjamin P. Oldroyd, an Australian entomologist, is without a doubt the best summary of the current state of play on Colony Collapse Disorder. I know I’m biased, being — gasp — a scientist, but Oldroyd’s paper is the bees’ knees. It has hypotheses (wot, no mobile phones?), facts, and interpretations. And one rather interesting conclusion. I’ll let Oldroyd explain:

Remarkably, honey bees maintain the temperature of their brood nest within ± 0.5 °C of 34.5 °C, despite major fluctuations in ambient temperature. If the brood is incubated a little outside this range, the resulting adults are normal physically, but show deficiencies in learning and memory. Workers reared at suboptimal temperatures tend to get lost in the field, and can’t perform communication dances effectively. Although entirely a hypothesis, I suspect that if colonies were unable to maintain optimal brood nest temperatures, CCD-like symptoms would be apparent.

… snip …

I suggest that another possible cause of CCD might simply be inadequate incubation of the brood. Thus any factor—infections, chronic exposure to insecticides, inadequate nutrition, migration in adult population, and inadequate regulation of brood temperature might cause CCD-like symptoms.

My hypothesis could be easily tested by removing brood from several colonies and incubating some of it at optimal temperature and some at suboptimal temperature. The brood would then be used to constitute new colonies in which some colonies comprise workers raised at low temperature and some comprise workers raised at optimal temperature. I predict that the colonies comprising workers reared at suboptimal temperature will show signs of CCD. Moreover, I would not be surprised if they showed higher levels of stress-related viral infections. These effects could act synergistically—more virus leads to shorter-lived, less efficient workers, that in turn leads to suboptimal temperature regulation, and more short-lived bees.

See, kids, that’s the way science is done. But really, go read the article. And if there’s anything in it you honestly don’t follow, ask.

Over at The Daily Kos Devilstower has produced an entertaining and (I think) fair and honest appraisal of the hypotheses swirling around colony collapse disorder. What I found most interesting about the summary is that Devilstower gives his/her own estimates of each one being right or wrong and then offers a poll where readers can give their own estimates. When I voted, the results were:

• The way commercial hives are handled 10% 785 votes
• Infection & Infestation 22% 1731 votes
• Pesticides 19% 1487 votes
• GM Foods 9% 741 votes
• Drought & Bad Weather 4% 324 votes
• Global Warming 12% 946 votes
• Electromagnetic pollution 14% 1134 votes
• Other 6% 499 votes

That strikes me as eminently sensible (because it fits with my own prejudices, obviously). But what would have been really neat — though perhaps impossible to do on Daily Kos — would have been a before and after poll. Give and estimate before reading the piece, then after reading the piece, and see whether all that fine work by Devilstower had any impact. I would hope it did, but a skeptical voice deep within whispers “no”.

On Gristmill, a brief answer to the question “are organically managed bees faring any better” in the current outbreak of Colony Collapse Disease. My summary: maybe.