Cool Critters: Why the ‘flying pearls’ alkali bee deserves more buzz

Ah, the beloved honeybee. They’re fuzzy and social. They make honey and beeswax. Children draw them and backyard beekeepers dote on them.

But honeybees – brought to North America by European settlers in the 17th century – are just a tip of the apian iceberg. There’s a huge world of native bees that lives and works below our collective radar, even though they’ve inhabited our continent for millions of years and they’re primary pollinators of crops, plants and flowers.

The alkali bee is among them. And now that it’s June, these champion pollinators will soon be scouring southeastern Washington’s Touchet Valley in search of purple alfalfa flowers.

Unlike its honeybee cousin, the small, pearly striped alkali bee doesn’t dwell in colonies. It goes about life all but invisibly, nesting quietly in soil and buzzing around low to the ground.

Despite its low-key profile, the alkali bee is so economically important to Washington state that 20 mph speed limit signs were erected on backroads in Walla Walla County to reduce massive roadkill of the beneficial insect.

“One of the great things about this native bee is that it is a very efficient pollinator of alfalfa,” entomologist Richard Zack of Washington State University said. “Because of the way that alkali bee pollinates the alfalfa flower and its ability to forage and pollinate in weather that honey bees do not, it is preferred by alfalfa seed growers.”

Thanks largely to alkali bees, the Touchet Valley agricultural region is among the top producers of alfalfa seeds in the country, according to the Washington State Department of Agriculture. Growers then sell the seeds to farmers to grow alfalfa hay, the nation’s fourth-largest agricultural crop.

The half-inchlong alkali bee gets its name from the alkaline soil it thrives in. To keep its population numbers strong, area seed growers build and maintain “bee beds” of salty, moist soil where the females can build nest chambers to lay their eggs and store pollen. The bees live alone but near each other, akin to a sprawling complex of apartment units for single women only.

This week, these little workhorses should start emerging from tiny holes just as the alfalfa plants begin their seasonal bloom, said WSU entomologist Doug Walsh, who works closely with the region’s seed growers.

In a period of about six weeks, the females will mate, collect pollen, build nests in the just-right soil conditions and lay eggs before dying, Walsh said. By the time the alfalfa bloom is over, an estimated 40 million alkali bees will have dipped into the plant’s flowers, he added.

While searching for flowers to pollinate, the bees fly only 1 to 3 feet above ground, researchers have found. This makes them easy targets of vehicles speeding down roadways near alfalfa fields and bee beds. Because the slower vehicles go, the fewer number of bees are killed, each year on June 1 the speed limit is lowered to 20 mph on certain country road in Walla Walla County, Walsh said.

“The signs are up now,” he said, adding that the county also has ordinances on pesticide use and “a firm limit on how many honeybee colonies can be placed near alfalfa seed fields,” because of honeybees competing for pollen and nectar.

Although the alkali bee lacks the honey-making superpower and fame of its counterpart, North America’s ancient resident is a vital but understated pollinator of a specific plant species, biologist Thor Hanson writes in “Buzz: The Nature and Necessity of Bees.”

Among the more than 3,600 bee species native to our continent, Hanson developed a special fondness for alkali bees during a visit to the Touchet Valley, he writes in his book. He goes on to describe them as “flying pearls” for the way they shimmer – gemlike – while dutifully searching for alfalfa pollen.