Jason Gibbs collected the first specimen of this new species of sweat bee from a front garden on Brunswick Avenue in downtown Toronto on his way to the Spadina subway station. ((Jason Gibbs/York University))

Bees found in downtown Toronto and the Okanagan desert are among 19 new species discovered by a university graduate student while he was working on his PhD.

Jason Gibbs found one species while walking up Brunswick Avenue to the Spadina subway station in Toronto one morning in the fall of 2006.

As usual, Gibbs, who has since graduated from York University in Toronto, had his net ready in case he spotted any bees among the flowers.

"People have some really nice front gardens on Brunswick Avenue," Gibbs said Wednesday. "I just stop anywhere that looks like good bee habitat and I collect as many as I can."

Have you seen a sweat bee?

Sweat bees are dark-coloured and most are just half a centimetre long.

"I imagine most people have probably seen them, but they may not have recognized them as bees," researcher Jason Gibbs said.

When he's shown sweat bees to friends, they tell him they would have mistaken the insects for flying ants.

While sweat bees can sting, they're so small that their stingers can't penetrate human skin, Gibbs said. "I usually pick them up with my fingers without any problems."

The sweat bee he popped into his jar that morning turned out to be one that had never been identified, even though it later proved to be common throughout Eastern Canada and the United States.

Gibbs found other new species in the arid Okanagan region of southeastern B.C.

Gibbs's exhaustive descriptions of 84 sweat bees, including the new species, were published Wednesday in the journal Zootaxa. They also won him the 2010 dissertation prize from York University.

Sweat bees are tiny black or iridescent green bees known for their attraction to perspiring humans.

Over five years, Gibbs peered through a microscope at thousands of specimens. He collected some of them in and near the Rockies of B.C. and Alberta, and from the western U.S. Others were provided by other people, including co-workers in his lab.

While sweat bees are very diverse and can be found from deserts to mountaintops around the world, different species tend to look very similar.

Many of them could only be told apart by subtle characteristics like the appearance of their skin under high magnification — how smooth it was or how dense their pores were, Gibbs said.

DNA barcoding

He sorted the bees into what he believed to be different species, and then confirmed his findings by sending samples to the University of Guelph for DNA "barcoding" — where a short sequence of DNA from a standard segment found in all animals is used to identify species.

A bee named Nightmare

Sweat bees are hard to identify at the best of times because they look very similar to one another, but the new kind of bee that Jason Gibbs found in Toronto was particularly tricky to distinguish.

"It doesn't have any recognizable characteristics," Gibbs said, adding that the bee's features are part way between the features of a lot of other species.

That made identification downright horrifying — hence Gibbs gave the species the scientific name Lasioglossum ephialtum. Lasioglossum is the group that the species belongs to, and ephialtum is Greek for "nightmare." 

Gibbs said sweat bees are important pollinators because they are so abundant.

Scientists are also interested in using them to study the evolution of bee social behaviour because some are solitary, some live in colonies and others behave like cuckoos, laying their eggs in other bees' nests so their young will be cared for by other bees.

But in order to begin studies of pollination or social behaviour, researchers need to know what species they're dealing with, and that's where Gibbs's work comes in.

"Whole avenues of research open up after a study like this," he said.

Gibbs is doing postdoctoral research, which he will continue shortly at Cornell University in Ithaca, N.Y.