The collapse of bee populations has been in the news lately, but a recent thread has suggested that this may be the result of genetically modified crops. Der Spiegel in Germany reports (March 22): "No one knows what is causing the bees to perish, but some expertsbelieve that the large-scale use of genetically modified plants in the US could be a factor."
How so? GM crops have been created by inserting the gene of a bacterial insecticide - Bt - so that they resist certain pests. But the pollen also contains Bt and bees pick it up. One study found a relationship between the Bt toxin and bee deaths. Der Spiegel says:
The study in question is a small research project conducted at the University of Jena from 2001 to 2004. The researchers examined the effects of pollen from a genetically modified maize variant called "Bt corn" on bees. A gene from a soil bacterium had been inserted into the corn that enabled the plant to produce an agent that is toxic to insect pests. The study concluded that there was no evidence of a "toxic effect of Bt corn on healthy honeybee populations." But when, by sheer chance, the bees used in the experiments were infested with a parasite, something eerie happened. According to the Jena study, a "significantly stronger decline in the number of bees" occurred among the insects that had been fed a highly concentrated Bt poison feed.
According to Hans-Hinrich Kaatz, a professor at the University of Halle in eastern Germany and the director of the study, the bacterial toxin in the genetically modified corn may have "altered the surface of the bee's intestines, sufficiently weakening the bees to allow the parasites to gain entry -- or perhaps it was the other way around. We don't know."
Of course, the concentration of the toxin was ten times higher in the experiments than in normal Bt corn pollen. In addition, the bee feed was administered over a relatively lengthy six-week period.
Kaatz would have preferred to continue studying the phenomenon but lacked the necessary funding. "Those who have the money are not interested in this sort of research," says the professor, "and those who are interested don't have the money."