The news began in 2007 with a number of reports by beekeepers that their bees had just vanished from the hive, usually during over-wintering. The press began beating the drum for the “serious new problem.”
The only thing is, it wasn’t new. Bee colonies have been disappearing since as early as 950, with reports also unearthed from 993, and 1443. More recently there were reports from 1853, 1891, 1896 and 1903, as well as 1960 and 1975. You can read about that history in Joe Ballenger’s article on the Biofortified site and in a shorter treatment in the Ottawa Citizen “There is no Bee Crisis.”
These bee collapses got more attention starting in about 2000, and have been reported frequently ever since. Something must be causing these collapses and considering the wide range of dates and geographical locations, there must surely be more than one something.
There was some suggestion the Bt corn might be contributing, but in 2007 this was disproved. Corn, of course, is wind-pollinated in any case, but the amount of Bt detected in corn pollen is simply too small to be of any concern to bees, especially since Bt is toxic only to Lepidoptera (butterflies and moths) and not to bees. Randy Oliver discusses all of this in great detail in this article from scientificbeekeeping.com.
So what is causing all these bee deaths? Are we going to run out of bees? Well actually the US bee population is pretty stable. Beekeepers can and do respond to these conditions and grow their hive populations. But it is not completely clear which combinations of things are causing these deaths.
Obvious candidates seem to be insecticides and diseases. The varroa mite is a little tick-like bug that attaches to the honey bee, and can do great damage if not controlled. It is, of course, tricky to kill a bug that lives on a bug, and some of the original insecticides, such as fluvalinate are no longer effective. Attempting to kill these mites with newer insecticides can kill some of the bees as well. Bees are also susceptible to Nosema: one celled parasites.
But what we are really concerned with stopping is called Colony Collapse Disorder (CCD). In that disorder, the entire hive is empty except for the queen and there are few bee bodies remaining. This usually happens during the winter. In addition to Ballenger’s article there is a pretty good one on CCD in the Huffington Post.
Recently, blame has been focused on neonicotinoid pesticides (also called neonics). There is no doubt that neonics are toxic to bees and should not be sprayed when bees are active. This is clearly set out on the label, and when this is ignored you will see reports of huge piles of dead bees. And neonics are used because they are considerably less toxic to humans than the organophosphates they replaced.
But it is not clear that neonics are the major cause of CCD. When such collapses occur, the hives and pollen residues show a mixture of agricultural chemicals, including traces of neonics. But here are the kickers:
1. Beekeepers in Canada, Europe and Australia use neonics and little CCD is observed.
2. Beekeepers in France continue to experience CCD and neonics have been banned since 2008.
So while petitioners and governments have been urgently discussing the banning of neonics, we really don’t know what is causing CCD. It is probably a combination of factors which may include a number of pesticides, the varroa mite, and Nosema.
This problem is summarized by Jon Entine in Forbes, where he urges us not to act precipitously, when we really don’t yet understand what is causing CCD. There really are no safe alternatives to neonics, and banning them could cost farmers (and us) a great deal of money, but not help the bees in any significant way.
To summarize, be skeptical about petitions to ban neonics that are going around. The science is as yet completely unclear.