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.
Investigating the bee shortage
The New York Times has a fascinating article about the shortage of bees caused by colony collapse disorder. Bees Vanish, and Scientists Race for Reasons is that rare thing in science writing, a story about process rather than results. So there’s not a lot actually to say, other than noting that around 60 experts gathered for a two-day meeting to assess the possibilities and plan their investigations. The most likely suspects — according to these mainstream scientists — are “a virus, a fungus or a pesticide”. Not cell phones. We shall see.
Hawaiian buzz
Varroa mites have appeared on the island of Oahu. These parasites of bees are a known cause of colony death. The current worry is for the honey industry. But I expect crops may suffer too if the island loses its hives. ((Thanks Invasive Species Weblog.))
Bee immunity
We’ve spent some time on the big bee die off (although not on the mobile phones) as have many other blogs and newspaper articles. In the US, the problem has reached epidemic proportions and has raised serious concerns about the future of several crops that depend to a large degree on bee pollination. Unfortunately recent evidence seems to suggest that the problem, which has been called Colony Collapse Disorder (CCD) has been spotted in Europe, as well. The cause or causes of CCD are unknown, but the list includes the usual suspects ranging from transgenic crops and pathogens to global warming and newly developed pesticides. Oh yes, and cell phones.
So the e-publication of a paper due to appear in the Journal of Heredity ((Variation and Heritability in Immune Gene Expression by Diseased Honeybees. Laura I. Decanini, Anita M. Collins, and Jay D. Evans Journal of Heredity Advance Access published online on April 2, 2007, doi:10.1093/jhered/esm008)) (behind a paywall) is timely. It describes the heritability and genetic variation of a gene called abaecin which is a key component of the immune system of bees.
Bees, like nearly all eukaryotes, have an innate immunity, but are generally thought to lack the additional adaptive immune response, which we and most other vertebrate species have. That is to say insects can’t get the ‘flu and respond by making specific antibodies to the virus (In fairness, the notion that insects do not have an adaptive immune system has been challenged recently by studies in Drosophila. ((Extensive Diversity of Ig-Superfamily Proteins in the Immune System of Insects Fiona L. Watson, Roland Püttmann-Holgado, Franziska Thomas, David L. Lamar, Michael Hughes, Masahiro Kondo, Vivienne I. Rebel, Dietmar Schmucker. Science Vol. 309, pp. 1874 – 1878 DOI: 10.1126/science.1116887 Abstract here.)) )
To find out whether abacein expression differed between bee populations, scientists at the US Department of Agriculture crossed several unrelated males into a homogeneous maternal background and then challenged the offspring with Paenibacillus larvae. This is the bacterium that causes American foulbrood, a widespread larval disease of bees. Subsequent measurements in affected larvae showed that the level of abaecin was moderately heritable but highly variable, differing by as much as 10,000 times between different lines. Why this is variation exists at all is a matter of speculation, but it might be due to selective pressures: an arms race between hosts and different pathogen strains or species.
At any rate an understanding of the components of the immune response in bees at the molecular level and the realization that there appears to exist considerable genetic variation that could be exploited would seem to offer one of the more promising approaches to selection for pathogen resistance. Whether that will stop CCD is anyone’s guess ((From Michael Kubisch)).
First study of global pollinator value
Back in October 2006 the Royal Society published an online version of a comprehensive study that was the first attempt to put a global value on pollinators. It attracted some attention back then, at The Worsted Witch, who got it from Science Daily. We missed it at the time ((Probably because the whole site was pretty new)), but as the paper version has just been published, that’s enough reason to revisit it ((Thanks to Michael Kubisch for sending the information below and the link)).
Very briefly, the article shows that 87 of the leading 115 crops depend to varying degrees on animal pollination. These 87 crops represent 35% of the world’s food production. While a few food plants are pollinated by birds or bats, the most important pollinators are, of course, honeybees, domesticated and wild. This is particularly troublesome in light of the various threats to the domesticated bee. The authors conclude that agricultural intensification jeopardizes wild bee populations and plead for more research into landscape management practices that would enhance wild bee viability.
Interestingly, I couldn’t find an actual cash value for pollination services in the article, but maybe I didn’t look hard enough.