In yesterday's Science Times, the Tuesday Science section of the New York Times, I found an article (Bees Vanish; Scientists Race for Reasons, bu Alexie Barrionnuevo) on the mystery of our disappearing bees. It's a progress report on the study of bees, trying to figure out why 25% of U.S bees have disappeared, as in, never returned to their hives.
My favorite line is the one which say that among the rather fanciful theories held by members of the public is that it is due to "the rapture of the bees, in which God recalled them to heaven." (Persons allergic to bees, take note, they may be there too!)
In any case, the scientists studying the problem are focusing on the three prospects they think are most likely: a virus, a fungus, or a pesticide. They have been collecting dead bees and carrying out autopsies and genetic analysis.
Here are some of their findings, as reported in the article:
--bees in declining hives have many abnormal microorganisms, as if they had weakened immune systems
--they don't seem to have any more of known hive enemies, such as the varroa mite.
--known symptoms of poisoning from feeding on Bt corn (a genetically modified crop), such as blood poisoning, haven't shown up.
--gamma ray irradiation of empty bee boxes seemed to be safe for new bee colonies (implying maybe a pathogen that the radiation killed?)
The research that continues includes more bee autopsies, to search for known pathogens; study of genes, to see if there are active genes reacting to a toxin or pathogen (they had already sequenced the genes of bees, just finishing last year); and screening for 117 chemicals.
Among chemicals, a prime suspect is one called imidacloprid, sold as Gaucho, which is a neonicotinoid. I assume this means it is a synthetic compound based on nicotine, which is one of the most poisonous of natural plant extracts. Imidacloprid was banned in France in 1999, accused of harming their bees. However, French bees haven't recovered as fully as expected, so perhaps this wasn't the cause, or at least not the only cause.
So we wait and see. I spent the afternoon watching bumblebees work a patch of phacelia, contemplating our dependence on honey bees for so much of what we eat.