Bumblebees... Four Species have Sharply Declined by 96 Percent and are Disappearing in US

Submitted by SadInAmerica on Fri, 08/19/2011 - 10:55am.



Researchers say four bumblebee species are nearly disappearing in the United States as a result of what is widely called colony collapse disorder.

According to the study published in the Proceedings of the National Academy of Sciences, the number of the four species has decreased 96 percent and their range shrunk by as much as 87 percent.

"We provide incontrovertible evidence that multiple Bombus species have experienced sharp population declines at the national level," the researchers reported, calling the findings "alarming."

"These are one of the most important pollinators of native plants," Sydney Cameron of the University of Illinois, Urbana, and leader of the study told Reuters.

Bees have been disappearing in recent years as a result of parasites, fungi, stress, pesticides and viruses among many other factors.

While many studies have been concentrated on honeybees, Cameron believes bumblebees are also important pollinators.

Bumblebees pollinate tomatoes, blueberries and cranberries, she said, adding "the 50 species (of bumblebees) in the United States are traditionally associated with prairies and with high alpine vegetations."

"Just as important -- they land on a flower and they have this behavior called buzz pollination that enables them to cause pollen to fly off the flower."

The study by Cameron and her colleagues is the first large national study conducted on bumblebees in the Americas.

The team studied 382 sites in 40 states in a period of three years and looked at more than 73,000 museum records.

"We show that the relative abundance of four species have declined by up to 96 percent and that their surveyed geographic ranges have contracted by 23 percent to 87 percent," they wrote in their report.

Results showed that pollinators such as bees and bats often have specific tongue lengths and their pollination behaviors have evolved along with the species of various plants.

Although no crops are in immediate danger, Cameron says experts need to pay attention.

Compared to other species, bumblebees can fly in colder weather and are therefore the key to pollinating native species in the tundra and at high elevations, she added.

Genetic tests showed that the four affected bumblebee species are inbred and other tests implicate a parasite called Nosema bombi.

"This is a wake-up call that bumblebee species are declining not only in Europe, not only in Asia, but also in North America," Cameron said.


January 4, 2011 - PressTV


Tag this page!
Submitted by SadInAmerica on Fri, 08/19/2011 - 10:55am.