Honeybee on rose bloom. |
And they couldn't find 'em
They left before the sun came up that day
They just drove off
And left it all behind 'em
But where were they going
Without ever knowing the way?
A number of explanations have been posited, with a strong indication that the neonicotinoid insecticide imidacloprid plays a key role. Imidacloprid is considered safe for general use, however, recent research indicates that imidacloprid builds up in the bee's body until it reaches a lethal level. Bees are exposed when they consume contaminated pollen, and exposure also increases if bees are fed corn-based syrup by their keepers when blooms are not available (corn is often treated with the pesticide).
An article in Wired magazine characterizes pesticide's effects as follows:
"Honeybees are clearly exposed to [pesticides] throughout the year and through multiple environmental routes. At certain times, especially in spring, death often follows exposure, and even non-lethal exposures may disrupt bee learning and navigation. Neonicotinoids also appear to make bees especially vulnerable to certain parasites and may interact similarly with other stressors."The European Union is taking the threat very seriously, going so far as to issue a Honeybee Health report. In the US, a similar report on bee health was prepared for Congress, and includes this figure:
A recent study emphasizes that wild pollinators enhance fruit set regardless of honeybee abundance. According to The Guardian's summary of the report,
"Wild pollinators perform better than honeybees because they deploy a wider range of pollinating techniques, such as "buzz" pollination. They also visit more plants, meaning much more effective cross-pollination than honeybees, which tend to carry pollen from one flower to another on the same plant."The bad news is that wild pollinators are in world-wide decline too, due to the double threat of insecticides and habitat loss.
Try a wildflower mix. It's fun to see what grows, and you benefit from both a crop of fresh flowers to enjoy indoors or out and increased fruit set in your garden. |
Party @ Black-Eyed Susan's! Rudbeckia hirta is a hearty native that is sometimes a biennial, and reseeds itself quite well. |