• BEST IN STATE—Senior Courtney Schoen Lewis was named Best PR Student in Utah. Story

Bumblebees in precipitous decline: ‘Not a natural fluctuation’

February 12th, 2011 Posted in Opinion

Story and photo by Rhett Wilkinson

LOGAN–Count Jamie Strange and Jonathan Koch among those to be thanked for helping the rest of us have a better grasp on why some of our neighboring bumblebees are disappearing.

Among the eight species studied, four were found to be declining–-one in the western United States, and three in the eastern part of the country. Strange said the four species–-Bombus occidentalis, Bombus pensylvanicus, Bombus affinis and Bombus terricola–-have suffered up to a 96 percent decline in the past few decades.

Strange, a United States Department of Agriculture research entomologist and adjunct assistant professor in Utah State University’s biology department, USU biology graduate student Koch and a host of others, including entomologists from the University of Illinois, have presented a recent study of eight historically abundant North American bumblebees, known by scientific terms as the Bombus species. Three are located in regions of the western United States, while five are found east of the Mississippi.

The research began in 2007 in response to several reports from other scientists about the decline. The research has included a digitization effort of more than 70,000 museum specimens in collaboration with colleagues at the University of Illinois. More than 6,000 bees across 382 sites in 40 states have been surveyed since 2007.

Strange considers himself fortunate to be a part of the research, while explaining the hazard of losing several of the bee populations.

“Somebody has to do it,” he said. “I was just lucky enough to be there. The option is it just doesn’t get done, and maybe these bees go extinct. Certainly what keeps us excited is looking at food security, and ecosystem stability. It certainly is important for people to know.”

While Bombus occidentalis has suffered the aforementioned percentage of total loss, the other results are staggering.

Bombus affinis has experienced an 87 percent reduction; Bombus terricola, 31 percent; and Bombus pensylvanicus, 23 percent. While the three species ranged from New England to the Gulf Coast region, the bulk of the species can only be found in the northeast region.

Koch said that a variety of natural and artificial reasons abound as being a factor for a species decline, including climate change and human urbanization, which may limit the availability of suitable bee habitat.

Bombus occidentalis used to comprise 25 percent of the bumblebees in the western United States, which includes Alaska to northern Arizona and California’s coast to the Front Range of the Colorado Rockies.

Such a vast decline is not the traditional ebb-and-flow of wildlife population, Strange said. “This is not a natural fluctuation,” he said. “This is something different than everything else we’ve seen in the past.”

Such a sparse collection of species makes for sparse collecting availability, said Koch.

“It’s hard to find data [species] when the data’s hardly there,” he said. “But just because it’s hard to find, doesn’t mean it’s not there. You really need to hone in on what you know about a species’ natural history and where they have been in the past in order to find them in real time.”

But find them they have, and the results are scary.

The hypothesis of the researchers was that a fungus called Nosema bombi, a pathogen for several insects, may have caused the dramatic declines. Strange compared the pathogen’s havoc as effectual diarrhea for the bees, resulting in a wear on the various colonies.

“As the colony gets weaker, they lose their ability to reproduce for the next year,” he said.

Some colonies experienced a 100 percent infection of Nosema bombi. However, Strange said that such a density of infection doesn’t necessarily wipe out the entire species. He compared such conditions to the 1918 flu pandemic in the United States that killed millions, but didn’t utterly decimate societies or its inhabitants.

Despite the grim findings, both Strange and Koch held out hope that the critters could climb out of their endangered status. “Maybe they will rebound,” Strange said. “We will have to wait and see what’s going on.”

Koch believes that an effort to promote bee preservation through habitat conservation is well supported by the facts he, Strange and the rest of the biologists have obtained through years-long research.

“More research should go into determining the habitat requirements of bumblebees, particularly those in decline,” he said.

Studies that come with trepidation, recognizing that due to the sparseness of an insect that provides pollination services, go a long way towards providing for the availability of several nutrient-filled foods, including greenhouse plants like peppers.

“It’s good to give a voice to the voiceless,” Koch said. “Bumblebees are important pollinators of agricultural food crops and wild flowers. Their extinction could cascade to an effect that we don’t even know.”

That effect, and potential negative consequences, can hardly be ignored by the public if they expect to eat, Strange explained.

“The fact that we don’t need to worry is an archaic thought at this point,” he said.

Tags: , , , ,

Sorry, comments for this entry are closed at this time.