Can a bee learn to fly over, instead of across, a busy highway? Washington State University entomologist Douglas Walsh is working with the Washington State Department of Transportation (WSDOT) to find out.

He will study alkali bees and their flight around a stretch of U.S. Highway 12 in central Washington to help WSDOT minimize the impact of a proposed highway improvement project on the native insect.

Safety improvements

WSDOT is sponsoring a four-year, $232,000 study by Walsh and his research team to survey alkali bee population density in nesting beds that potentially would be affected by the project. The team will determine flight paths between beds and nearby alfalfa fields in relation to the project’s proposed route and assess whether effective barriers can be installed along the roadway to alter vertical and horizontal flight.

The segment of WSDOT’s larger U.S. Highway 12 project, referred to as Phase 7A and 7B, proposes rebuilding the roadway as a four-lane, divided highway from the east side of Nine Mile Hill to just west of Woodward Canyon Road.

According to the department website, more than 10 million tons of cargo are transported over this section each year, and slow-moving trucks and recreational vehicles congest the two-lane highway. The bottleneck is dangerous: Since 1991, the corridor has seen roughly 1,080 collisions causing 414 injuries and 30 deaths.

Second-largest alfalfa seed producing area

The proposed new highway would cut through the Touchet-Lowden agricultural district in Walla Walla County. The 84-square-mile area supports 16 growers producing 12,000 acres of proprietary alfalfa seed varieties for six different seed companies, according to one of those growers, Mike Buckley. That acreage makes Walla Walla County the second largest alfalfa seed-producing area in the United States, he said, with retail sales exceeding $50 million in 2009.

The same area also has the world’s largest community of non-honey bee pollinators in the alkali bee, Walsh said. A 1999-2006 study published in Apidologie by U.S. Department of Agriculture entomologist James Cane showed that nearly 17 million alkali bees called the Touchet Valley home.

Valuable pollinator

Slightly smaller than the honey bee, with black and green-yellow bands on its thorax, the alkali bee is considered the most effective alfalfa pollinator. Some local alfalfa growers have relied on the bees for more than 50 years to pollinate their crops.

Unlike honey bees, female alkali bees are solitary nest builders, but many will build nest beds close to one another. Females will forage for miles to find nectar to establish their nests. They also spend six weeks of each year actively foraging - and flying - which puts them at risk in road traffic.

Walsh said alkali bees need established bee beds, between 2-10 acres, where a surface crust of salt or alkali helps preserve moisture in the below-ground nests. The bees are vulnerable to habitat loss since cultivation, grazing and disturbance by off-road vehicles can damage bee beds.