For Sam Droege, bees aren't just a job.
Not every bee may count, but Sam Droege is counting every bee.
On Saturdays, the head of the landmark Native Bee Inventory and Monitoring Program at the U.S. Geological Survey leaves his straw-bale house, where bees burrow in the walls, and goes to his office—for pleasure. From his desk, a recycled segment of a lane from a bowling alley, he pores over bee specimens with a microscope.
Pesticides, fungicides, and viruses, among other factors, have contributed to the honeybees' decline. Though they lack a traditional vertebrate circulatory system, they're vulnerable to parasites, such as the bloodsucking varroa mite, which deforms their bodies and shortens their life span.
Little is known about the hardiness of the honeybee's native counterpart, the mostly solitary wild bee. Many scientists believe that wild bee populations were once greater, but have dwindled as land was developed and agriculture intensified.
Home gardeners may also be contributing to the bees' habitat loss. Gardeners with a love of exotic plants often uproot native ones, not realizing that this deprives most pollinators of their food. Other factors limiting the bees' food supply include the effects of climate change, droughts, floods, and flowers blooming prematurely as the days grow warmer.
"People were collecting bees in the early 1900s, but they weren't doing quantitative analyses," said Georgetown University biologist Edd Barrows.
In 1998, Barrows gathered bees in Dyke Marsh Wildlife Preserve in Alexandria, Virginia, using mesh, tentlike structures called Malaise traps. The bees he collected then—still awaiting examination due to lack of time and funds—could serve as a historical reference point to show scientists how the preserve's bee fauna is changing due to water and air pollution, erosion, and invasive plants.
"We need to have some way of measuring whether native bees are increasing or decreasing," said Droege.
Workers from New Horizons Supported Services, an organization that helps adults with developmental disabilities in Maryland gain employment, paint the cups to mimic the colors bees prefer in flowers. Then the cups are filled with propylene glycol—the same substance used to maintain moisture in food, medicine, and cosmetics. Its low surface tension means that insects will sink to the bottom. Every two weeks, the traps are emptied by volunteers.
After that the bees are washed, dried, and stored at the USGS lab in repurposed pizza boxes. Their deaths serve as a chance to learn about, and monitor, potentially endangered native bee species.
"[They're] not something someone like a birder could look at, and say, 'That's a robin,'" said biologist Daniel Kjar of Elmira College in New York.
So Droege spends hours trying to identify species. His team captures the pitting on their skin, the striations of hair on their abdomens, and other physical traits with a macro lens camera—a sort of insect portraiture. Droege says these body features may help bees avoid predation and attract mates.
Today, scientists will go to great lengths to study the small insects.
Sean Brady, head of the Smithsonian Institution's Department of Entomology, is studying evolutionary relationships between different bee species. He's sequencing their genetic material, which can cost between $10,000 and $50,000 for a complete genome.
He's also interested in understanding why, among certain bee species that produce offspring twice in a season, the first brood spends its lifetime caring for the second hatching instead of reproducing. The work may help him understand the social behavior and pollination strategy of wild bees.
"The unknown can be a good thing," said Brady. "There is a lot to learn in the next 10 to 20 years."
In 2010 and 2011, Brady and Droege set up traps in the cacti and thorn scrub of Guantanamo Bay, where the native habitat is preserved in the midst of the prison camp. They collected more than a third of the bee species that live on the entire island of Cuba. A new species they discovered was quickly named—Megachile droegei, after Droege.