Science News covers new research that suggests a plausible explanation for 'colony collapse disorder' affecting honey bees. Over 700 samples of wax and pollen were taken from honey bee hives, with test results indicating high levels of contamination by a variety of pesticides. Key finding: it's not just one or two bad actors. Several types of pesticides and break down products were reported to be concentrated in pollen and wax, though not in bees still living inside the hive so much; which means it is more about recurring field exposures generally by worker bees and less about misuse of a particular type of pesticide or unusual environmental conditions during the year.
Christopher Mullin of Pennsylvania State University in University Park and his colleagues describe widespread pesticide tainting in 749 samples of bee-dom, some of those chemicals at levels that would be toxic if they occurred alone."
Worker bees keep bringing residual pesticides back until, somewhere outside the hive, they're knocked down by especially high exposures or become disoriented due to season-long chronic exposure.
The sampling focused primarily on live bees extracted from the hives. These tended to be the queens, brood nurses and adolescents - hive residents that aren't on the chemical frontlines, foraging in pesticide treated fields. Indeed, the fact that researchers found so few healthy worker bees in many of the hives from which they received samples suggests that sickened foragers probably die before they get home.At last a study that posits a rational explanation that is not a one-off sound byte neatly packaged 'for the media.' The outlined process could be modeled and further sampling done to examine worker bee mortality as a function of regional pesticide sales records, and so on.
In fact, some of the pesticides that were detected in hive materials can disorient bees. Which suggests many foragers that had been unwittingly carrying home such contaminants at last become too confused to find their front door.
What's in a name.
Before anyone had a clue about what might be causing 'colony collapse disorder' a generic term such as CCD made sense. The media needed a handy phrase and CCD was it. Time to stop thinking of the problem as a mysterious "disorder.' Bees are insects. Insecticides kill insects.
The tern CCD reminds me of the catch-all medical term 'gastroenteritis.' Anything from bad bacteria to parasites can contribute to it. Doctors can respond to 'gastroenteritis' by suggesting the patient wait for it to go away or by prescribing a wide spectrum antibiotic - or by testing for specific underlying causes and then choosing a targeted treatment. Gastroenteritis, as a word - this is my point of analogy - tells nothing about specific cause and nothing about which specific treatments are indicated. Once the doc names a pathogen in your gut it's no longer 'gastroenteritis.'
Once hives are found full of pesticides and breakdown products it's not a disorder it's poisoning. Reduce exposures of worker bees to the point where insecticides are no longer found in the hives at toxic levels. Then we'll see if the 'disorder' abates or not.