The honeycomb above is not "entombed". Image credit: Will Luo, used under Creative Commons license.
During our live chat with bee expert and Tyler Prize laureate Professor May Berenbaum, she cautioned against over simplistic arguments regarding the link between colony collapse disorder, bees and pesticides. While there has been research to suggest bees living with pesticides in their hives, and certain pesticides have been shown to be particularly harmful to bees, nobody has shown a direct causal link between the still-difficult to diagnose Colony Collapse Disorder and pesticide use or misuse. However, some new research is casting an even clearer light on just how many chemicals our bees are being asked to live with, and on what looks like their own tragically futile attempts to limit the damage.
>> WATCH SLIDESHOW: Bee Hives: Nature's Architectural WonderContaminated Pollen is Sealed Off
According to Fiona Harvey over at The Guardian, honeybees may be sealing off or "entombing" cells in which conatminated pollen is stored—that is pollen with unusually high levels of pesticides or chemicals used to treat varroa mites. (Yet another indication that a combination of stress factors is contributing to the plight of our bees.)
The research, conducted by Jeff Pettis of the US Department of Agriculture, shows that bees are taking the unusual step of sealing off cells containing pollen with wax in what looks like an attempt to keep contaminants away from the hive population. (Bees do not usually seal off cells containing pollen.) Unfortunately, however, Harvey reports that the evidence shows such efforts largely resulting in failure:
"This is a novel finding, and very striking. The implication is that the bees are sensing [pesticides] and actually sealing it off. They are recognising that something is wrong with the pollen and encapsulating it," said Jeff Pettis, an entomologist with the US Department of Agriculture. "Bees would not normally seal off pollen."
But the bees' last-ditch efforts to save themselves appear to be unsuccessful - the entombing behaviour is found in many hives that subsequently die off, according to Pettis. "The presence of entombing is the biggest single predictor of colony loss. It's a defence mechanism that has failed." These colonies were likely to already be in trouble, and their death could be attributed to a mix of factors in addition to pesticides, he added.
Fascinating, tragic stuff. And just one more inconclusive chapter in the ongoing saga of Colony Collapse Disorder and the plight of our honeybees.
More on Honeybees and Colony Collapse Disorder
Live Chat with Honeybee Expert Professor May Berenbaum
The Cooperative Group Launches Plan Bee to Save the Honey Bees
Colony Collapse Disorder and the Epic Fight to Save the Bees
Beekeeping Alternatives: Top-Bar Hives, Warre Hives and Natural Approaches to Honey Bees