Honeybee decline decisively linked to pesticide use

Posted on April 1, 2012 by Bob Berwyn

Sub-lethal doses affect queen reproduction, homing ability

A bumblebee feeds on a fireweed in Summit County, Colorado. PHOTO BY BOB BERWYN.

By Bob Berwyn

SUMMIT COUNTY — Bumblebee and honeybee populations have declined dramatically in recent years, and while researchers have suspected that insecticides are at least part of the problem, they haven’t been able to pinpoint exactly how the bees are affected by the poisons.

But a pair of new studies from Europe link the use of neonicotinoid insecticides, introduced in the early 1990s, with impacts to bees’ central nervous system and show how the chemicals spread to to the nectar and pollen of flowering crops. Neonicotinoid insecticides have been favored because of a lower toxicity to mammals.

One study showed that bumblebees exposed to a widely used insecticide produced 85 percent fewer queen bees, which are critical to the establishment of new colonies following the winter die-off.

In the second study, the researchers found that bees exposed to a second type of neonicotinoid insecticide were two to three times as likely to die while away from their nests, possibly because the toxin interfered with the bees’ homing systems. (more…)

Filed under: agriculture, biodiversity, Environment | Tagged: , , , , , | 3 Comments »

Environment: Bumblebees in decline

Posted on February 13, 2011 by Bob Berwyn

Populations of some bumblebee species have declined by as much as 96 percent in recent decades.

Research suggests genetic factors and parasites are factors

By Summit Voice

SUMMIT COUNTY — The buzzing of bumblebees during summer is a comforting sound, but it’s also an economic factor in multibillion dollar tomato and berry crops, as the insects intentionally use those vibrations to shake loose pollen. Their robust size and long tongues also help them pollinate efficiently, but recent studies have documented an alarming decline in bumblebee populations in North America and the U.S.

Altogether, bees pollinate about 90 percent of the world’s commercial plants, so the decline has spurred environmental and economic concerns, along with more studies, and the results are not good. Most research is pointing toward a significant loss, possibly due to the introduction of a tiny parasite that’s common in Europe. In one of the most significant research efforts, scientists at the University of Illinois said populations of four common species of bumblebees have dropped by 96 percent in recent decades. (more…)

Filed under: Colorado, Environment, Summit County Colorado, Summit County news | Tagged: , , , , , , | 1 Comment »

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