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June 28, 2018 Philip Waring Leave a comment

Bumblebees Thrive in the City but Struggle on the Farm.
by Jo Anna Klein

And us, people, do we struggle in the city and if we ever do return, will we thrive on the farm?

Facing two unnatural environments, these important pollinators are finding better niches to exploit in urban areas.

June 27, 2018
A colony of Bombus terrestris bumblebees, which fared better in an experiment when placed in London than in the English countryside. Credit: Ash Samuelson

Cities are filled with buildings, people and concrete — usually not seen as the ideal place for anything wild but great for nightlife.

But then there are the bumblebees of London. They may be faring better than their relatives in the English countryside, suggests a study published Tuesday in Proceedings of the Royal Society.

“We’re not saying from this that urban areas are the solution to bumblebee declines or that urban areas are the ideal habitat,” said Ash Samuelson, a graduate student at Royal Holloway University of London in Britain and lead author of the study. “But given the choice of two unnatural situations, they’re actually able to exploit that city environment, which is very different to what they evolved in.”

Bumblebees are important pollinators for flowers and crops that benefit from their vibrating pollination style. But pesticides, disease and habitat loss are wiping out all types of bees, worldwide. Oddly, as sprawling cities and vast agricultural fields replace forests and meadows, people have noticed more bumblebees buzzing around cities. Dr. Samuelson wanted to know if these bees were simply traveling to cities when agricultural fields ran out of food or if they actually were surviving better there and having more babies.

In the past 80 years, expanding urban areas in England have been found to host more species and lose fewer pollinators than agricultural areas. City parks and gardens provide a variety of flowers and foraging opportunities for bees throughout the season. Most agricultural fields offer bees only one type of flower, for a limited time. Some biologists have suggested that cities may provide refuge for bees.

Ms. Samuelson’s team collected more than a hundred wild, foraging queen bees and took them back to the lab to build colonies. Then they transplanted the colonies to 38 different sites — from London’s city center to surrounding villages, suburbs and farms. Then they monitored how they were doing.

The country bees did not do so well. Compared to those placed in cities and villages, colonies placed in agricultural fields produced fewer reproductive offspring and fewer workers, and their queens died sooner. Their colonies, which broke down faster than city and village colonies, also had fewer nutrient reserves. It surprised Ms. Samuelson how big this difference was.

A nest box containing some country bumblebee colonies. By multiple measures they performed more poorly than colonies in urban settings. Credit Ash Samuelson

But even more remarkable was that suburban colonies were no better off than city colonies:

The bees did really, really well, even in the absolute center of London.”

In bumblebee colonies, sterile female offspring forage, bring in food for the nest, clean and help rear the brood. Once a colony makes enough of these workers, they start making bees capable of reproducing and carrying on the genetic line. Perhaps modern farm life — with fewer floral resources and potentially more pesticides — may be too stressful for the bees, preventing them from growing big colonies and making babies that make babies.

Can You Pick the Bees Out of This Insect Lineup?

How can we save the pollinators if we don’t even recognize them?

Some of the insects pictured below are bees, and some are not. Can you tell which are which? Select each insect you think is a bee.

Here are the two bees of my youth. I used to raise the honey bees for their honey. I would try not to be stung by the bumblebees. Six of the above are bees. And the others?

The survey had more than 1,000 respondents recruited by word of mouth and on social media, and may have been biased toward people with an interest in bees. Perhaps the Velvet Ant (No. 8) fooled you — it threw off about half of respondents, according to the survey, which was published Tuesday in the journal Frontiers in Ecology and the Environment.

For the record, that furry ant isn’t even an ant — it’s a wingless wasp.

Just like the rest of the world, the United States has a bee problem. Bees pollinate our plants, which make the food that humans and nearly everything else relies on for sustenance.

Since 2006, when researchers coined the phrase “colony collapse disorder” to describe the losses to commercial honeybee colonies, scientists, conservation groups, the government and news media have issued warnings of declining bee populations and the necessity of conserving these economically and ecologically significant pollinators.

By now, we understand their importance: 99 percent of respondents in the survey said as much. But, however much we may value bees, we don’t know much about their diversity.

“We realized there was a huge misunderstanding or lack of knowledge about most kinds of bees,” said Joseph S. Wilson, an evolutionary ecologist at Utah State University, Tooele, who helped lead the survey. “Everyone knew that bees were good, but even though they know that they’re good, most people had no idea how many kinds of bees live here.”

Do you? Tell us approximately how many different bee species you think there are in the United States. 100, 850, 4,000, 20,000? Actually About 4,000 bee species live in this country. If you were off, you weren’t alone: Only 14 percent of survey respondents were able to get within 1,000 of this number.