Scientists have found that wild bees enhance the production of a number of crops, including watermelon and canola. They are the primary pollinators of squash and pumpkins. But scientists have also pointed to a larger truth: If wild pollinators are going to work for agriculture, agriculture will also have to work for them.

“Bees need a few different things,” said Sarah Greenleaf, a post-doctoral scientist at UC-Davis who found that when wild bees join honeybees on hybrid sunflowers, production is doubled. “They need flowers for food, nest sites and protection from things that kill them. Farmers can plant flowers to provide food when crops are not blooming, modify pesticide applications, and provide nest sites for bees,” Greenleaf said. “And they can leave some natural habitat near farms. There are lots more bees on farms that are close to natural habitat.”

Scientists have estimated that honeybees add $15 billion to the value of American agriculture each year, while native bees add about $3 billion — a figure considered by some to be an underestimate. But wild bees play an essential part in the health of ecosystems beyond our farm fields. In fact, the Logan bee lab gets about $200,000 in annual funding from federal land-management agencies to research pollination and pollination diversity on public lands.

Providing uncultivated habitat for wild bees flies in the face of Secretary of Agriculture Ezra Taft Benson’s 1950s advice to farmers, “Get big or get out’’ — advice the California almond growers have apparently taken to heart. The $3 billion a year industry is four times bigger than it was 20 years ago. California now grows more than 80 percent of the world’s supply; nearly 70 percent of the crop is shipped overseas.

“If you’re doing small-scale agriculture, it’s relatively easy to provide uncultivated habitat for bees,” said Strickler. “It’s more difficult for large-scale agriculture. That’s something large-scale agriculture is going to have to think about.”

A cautionary tale is offered by the fate of the alkali bee — the one that caught the attention of Utah alfalfa farmers nearly 70 years ago. In response to an increase in demand for alfalfa seed, some farmers started plowing into the adjacent bee habitat.

“I recall hearing a farmer from Delta, Utah, describe huge flocks of seagulls that followed his plow to feed on the overwintering bee larvae which were strewn behind him like popcorn as he plowed,” wrote Ned Bohart, founder of the Logan bee lab, in Stephen L. Buchmann and Gary Paul Nabhan’s 1996 book The Forgotten Pollinators.

Insecticides on neighboring crops apparently decimated newly created nesting aggregations of alkali bees in California, says Jim Cane. Such situations contributed to the fact that most alfalfa seed farmers have turned to the easily obtained alfalfa leafcutting bee, which originated in Europe. American growers buy them from Canadian suppliers in five-gallon plastic containers, each containing about 50,000 bees — “as convenient as buying fertilizer,” says Cane. But they aren’t a magic bullet. Alfalfa leafcutting bees aren’t very hardy south of Canada, a good portion of their progeny succumbing to maladies like a fungus called chalkbrood.

“The message is clear,” write Buchmann and Nabhan in The Forgotten Pollinators. “The remaining wildlands and the animals that inhabit them are playing an increasingly important role in maintaining the stability of the world’s food, fiber and beverage supply. We cannot let wildness become too remote from the lives of pollinators, or from our own lives.”

The author writes from Boulder, Colorado.