Building a backup bee

The world's largest almond grower is creating a novel replacement for the embattled honeybee

Every February an extraordinary research project resumes in the southwestern corner of California’s Central Valley. It takes place inside a series of huge cages that span 20 acres by a vast pistachio grove. Each cage is shaped like a rectangular warehouse but is made entirely of extremely fine netting, pulled tight and straight along strong, narrow beams to form see-through walls and ceilings. The experiment is run by Gordon Wardell, director of bee biology for the Wonderful Company, the largest almond grower in the world. For the past eight years Wardell has been using these cages to develop an alternative insect to replace the honeybee.

The need for a backup bee has become critical, particularly in almond orchards. Almonds are California’s second-largest crop, injecting an estimated $21 billion annually into the state’s economy. In 2016 California’s almond growers needed nearly 1.9 million honeybee colonies—almost three quarters of all the commercial colonies in the country—to pollinate their 940,000 acres. Every bag of salted almonds and box of almond milk the industry produces relies on honeybees. But they are in trouble, beset by an avalanche of problems, from deadly pests and diseases to poor nutrition and pesticide exposure.

Stretched over 20 acres of soil for flowers, netting forms cages for blue orchard bees at The Wonderful Company’s facility in Lost Hills, CA.

Annual colony losses in the U.S. for the past 11 years have ranged between 29 and 45 percent. Add in the ever expanding almond acreage—from 570,000 acres in 2004 to more than a million today—and the entire system is stretched. At the National Stakeholders Conference on Honey Bee Health in 2012, Jeff Pettis, then with the U.S. Department of Agriculture, said, “We are one poor weather event or high-winter bee loss away from a pollination disaster.”

Wonderful hired Wardell in 2009 to avoid such a disaster in its orchards. The company chose to develop Osmia lignaria, a native mason bee known as the blue orchard bee, or BOB. It was an excellent almond pollinator; it had done well in small studies and had relatives that European and Japanese growers were managing successfully. And there was no alternative. Only about a dozen of the 20,000 or so bee species worldwide are managed. After the honeybee, Apis mellifera, only three species are widely used in the U.S.: two cannot be woken from their winter’s sleep in time for almond bloom, and the third is banned for open field use in California.

BOBs are nothing like honeybees, however. Honeybees are social. One queen and thousands of female workers live together in colonies that can last for years. Multiple generations of workers divvy up the jobs that keep the hive functioning. BOBs are solitary, spending their entire lives alone except when they mate. Mating is a male bee’s only job. Because they do not collect pollen for the babies, males often are not even counted in pollination work.

Each female is both queen and worker in her little domain. After a female mates, her only job for the rest of her adult life (about another 20 days) is providing for her offspring—usually between seven and 12 in orchards. She collects pollen and nectar, forms it into a wad, places it in an aboveground hole and lays an egg on the mixture. Then she walls it in with mud, never to see her offspring. The young bees eat, grow and sleep in these mud-walled nurseries and do not emerge until the following year. Any loss of a BOB female matters: it permanently reduces the current year’s pollination workforce and diminishes next year’s crew because fewer eggs are laid. The loss of one honeybee, in contrast, is trivial because a healthy colony generates tens of thousands of workers across a year.

With only one generation annually, it is not surprising that it has taken Wardell so long to figure out how to mass-produce BOBs. “If you make a mistake, you have to wait a whole year to make another mistake,” he says. “My boss doesn’t appreciate the humor in that.”

Dr. Gordon Wardell closes an access gate to cages for blue orchard bees.

Wardell has investigated all aspects of BOB life in those cages and has figured out how to do what no one else has: economically raise large numbers of BOBs on a small parcel, making them a commercially viable alternative to honeybees for almond pollination.

In 2017 Wonderful needed about 76,000 honeybee colonies to pollinate its almonds (at two colonies per acre). But that number will diminish by 320 this spring because Wardell will put 128,000 female BOBs into the orchards—the largest deployment ever. If Wardell’s experiment succeeds, the results could have far-reaching implications for the almond industry as well as a host of other early-blooming crops—from apples and cherries to apricots and peaches. All told, more than a million and a half acres could benefit from having BOBs as a backup—if they prove worthy this year. It has taken years to get this far, and problems still await.

Bringing a bee to market

Commercially managing a bee requires affirmative answers to four questions: Are the bees effective pollinators of the intended crop? Can they be awakened and transported to the field in time to pollinate? Can they be easily managed in the field? And can a critical mass of bees be produced economically?

In the 1970s Phil Torchio, a scientist at the USDA’s bee lab in Logan, Utah, investigated BOBs and found them to be excellent pollinators of early-blooming fruit and nut trees, a finding supported by later studies. On a bee-to-bee basis BOBs are vastly more efficient than honeybees. A few hundred females can do the pollination work of 10,000 honeybees. Torchio found that the bees could be woken up from diapause, a dormant state, and delivered to the crops when needed. He also developed the first protocols for managing BOBs.

Scientists have been working since Torchio’s time to find the best ways to manage BOBs in the field. They have studied mud types and the size, material and color of nest blocks, as well as the best locations for the blocks in an orchard. The progress is of little commercial value, however, if growers cannot deploy enough bees to make a difference, at a price they can afford. This is the problem Wardell has cracked.

In an ideal world, BOBs would be raised in the fields they pollinate. In Europe, farmers get a threefold to fourfold increase of European Osmia bees out of their orchards every year. Jordi Bosch, who used to work for the usda and is now at the Center for Ecological Research and Forestry Applications in Spain, says this happens because European orchards tend to be smaller, contain a mix of fruit species and have a variety of weeds that bloom around them at various times. Those factors help bees live out their full adult life span, so they can lay many eggs. In California, large, weed-free, monocrop orchards provide only two to three weeks of one type of bloom—insufficient for maximum egg laying. Fungicides and pesticides can further reduce the number of progeny that an orchard produces.

Historically, people obtained BOBs by trapping them in the wild, but this method is slow, and numbers can vary significantly from year to year. Wardell believed he could raise large numbers of BOBs consistently if he could just control the weather—which he has essentially done by locating his bees in the southern Central Valley. Reliably sunny days and appropriate temperatures during the BOBs’ flying season allow him to raise up to two million bees on a mere 20 acres of land inside his cages.

Still, Wardell has had to optimize all the past research to raise his bees. He has tested and monitored every aspect of the bees’ lives, from the plant species needed for food to the kind of mud the bees use to build the walls between their nest cells.

15 million bees a year

Wardells ultimate goal is to raise enough BOBs to cover half the 76,000 honeybee colonies used to pollinate Wonderful’s 38,000 acres of almonds. That will take 400 BOB females per acre—15.2 million female bees a year—plus all the males. Wardell has a two-pronged plan to meet that goal.

The first step is to raise a million female BOBs a year in his cages. That has to be done during a few frantic months in spring. Wardell and his crew erect the cages, put in plants, install mud pits and nest boxes, then add the bees. About 300,000 to 350,000 females from the previous year go into the cages to lay eggs. The rest go into the orchards. After the almond petals fall and the cage flowers die, the BOBs in the field and the cages metamorphose. In autumn Wardell’s workers bring the blocks inside and remove and store the cocoons. They chill the cocoons for winter and warm them when next year’s bloom time arrives. The storage phase can be perilous. Wardell says he sometimes lies awake worrying that a pest or disease will race through his cocoons. He x-rays them regularly, looking for trouble.

Wardell uses x-rays of BOB nests to check for parasites and disease.

The second step requires getting a 100 percent return from the bees put in the orchards. As noted, monocrops are not ideal for bee reproduction, but modifying pesticide regimens and planting alternative forage, as European growers do, can help. Wardell also hopes to improve returns by honing the bees’ wake-up time so that their adult life cycle lines up as closely as possible with the almond bloom. That way he may avoid “the bees hanging around hoping for handouts after the bloom.”

Last year Wardell met his 100 percent in-orchard target: 100,000 female BOBs went in and laid enough eggs so that 100,000 came out. But he was well shy of his goal of a million females from the cages because of problems with nest materials and workforce issues that led to planting delays, giving the bees a short flying season.

In 2017 the orchard BOBs supplemented the normal complement of honeybees. This year will be the first time Wonderful substitutes BOBs for some of its honeybees—those 320 colonies. If Wardell consistently meets subsequent annual goals, it would still take more than 20 years to replace half the company’s honeybees, although the process could be sped up by adding more cages. This is a long-term strategy for Wonderful, one it hopes will help spread its risk and control its pollination destiny.

Wardell with thousands of BOB nests in the temperature-controlled walk-in at the Wonderful Company’s bee development facility.

It costs Wonderful 22 cents to produce one female BOB. That means one honeybee colony can be offset with 400 females for $88, plus start-up costs. The average colony rental rate for almond growers in 2016 was $167. So Wardell has indeed shown that large numbers of bees can be raised consistently and affordably.

The tipping point

Despite Wardells success, BOB sellers and orchard growers are not rushing to build their own cages. For one thing, a project such as Wardell’s requires extensive resources. Jim Cane is a research entomologist at the USDA’s Utah bee lab and has worked with agricultural pollinators for decades. In an email to me, he wrote of Wardell’s work: “His success in mass-propagating BOBs is a landmark that can only be achieved in a commercial setting (a research lab like ours simply lacks the acreage, personnel, money, equipment and farming experience to make this work).

Moreover, sometimes the model fails. Investors started AgPollen in 2007 to develop BOBs as a commercial pollinator but never got consistent bee returns from the cages. Steve Peterson, the scientist who ran the project, blamed its failure in part on pesticide use on surrounding properties.

Another concern is that Wardell’s bees come from one site. If something goes wrong, all is lost—at least for that year. It happened once. Wardell’s plants died, and with little native forage available, most of his bees soon followed. “Growing these things is like trying to overcome the seven plagues of Egypt,” Wardell says. He has had invasions of fungi, birds, mice and even toads, which sat by the mud pits “eating blue orchard bees like candy.”

Wardell opens a blue orchard cocoon.

Other breeders have their own demons. Jim Watts runs Watts Solitary Bees. He lives in western Washington’s wet, variable climate and fears bad weather. He traps BOBs in the wild from different locales, hoping that by doing so he will avoid a weather-related catastrophe. His approach does not have hefty start-up costs, can be done wherever BOBs live and does not require the technical skills of managing BOBs in cages. Watts started selling BOBs 10 years ago, and his business has steadily grown. In 2017 he had 700,000 BOBs for sale, although only around a third were female. He expects similar numbers for 2018 because the weather in 2017 was not great for BOB reproduction, but as his pool of BOBs increases, so does the potential for growth.

Compared with this method, Wardell’s model can potentially ramp up the number of bees quickly. He started the 2016 season with 80,000 female bees and ended it with 400,000. After a disappointing 2017, he hopes to hit the mark of a million females in 2018. He could build 20 more acres of cages, put 100,000 females into them rather than into the orchards and, theoretically, within two years, be producing two million females annually.

Wardell’s bees are not currently for sale to the public, but demand for BOBs among growers of early-blooming fruit is increasing. Watts says that when he started raising BOBs a decade ago, “we were begging people to do 10 acres.” Now he has a waiting list, even though his BOBs are more expensive than honeybees. All the growers that bought bees in 2017 have signed up for them in 2018.

Theresa Pitts-Singer, who for years has studied BOBs at the USDA’s Utah bee lab, thinks the bees are finally close to becoming a managed pollinator, reaching a “tipping point” she never thought they would reach. She is convinced because BOBs are increasingly available and growers want them, even though they are not cheap. She says that for a long time only one orchard pollination model was dependable: renting honeybees. Now more people seem to accept that other models might work—from bringing more wild bees onto farms to alternatives such as BOBs.

Although the researchers working with BOBs still have a long to-do list, they have a sense of momentum. They are developing grower-friendly management plans for a variety of orchard crops. More people are selling the bees, too, mostly using some version of wild trapping where the seller works to build the number of bees where they are gathered, a kind of bee farming. Wardell thinks that for BOBs to go mainstream, growers will need to change their pest-management practices, and Watts sees glimmers of hope in that direction. He puts it down to the power of ownership. When someone owns rather than rents bees, Watts says, “they rethink how they spray.” Every bee saved means more pollinating power this year and less money spent the next.

A Wonderful Company almond orchard. The entire industry depends on honeybees—and soon, maybe BOBs, too.

Down in the Central Valley, Wardell recognizes the value of every bee, and in February 2018 his BOBs were scheduled to finally begin the job they had been bred for. But the long-term impact of Wardell’s efforts may not be from his breakthroughs in the science of mass-producing bees. Instead it may be from something more subtle. Bill Kemp recently retired from the USDA after working with BOBs and other pollinators for decades. He says that when a large organization like Wonderful takes the risk to develop something, “it gets people’s attention, and they’re going to be more inclined to take the risk themselves,” even if on a much smaller scale. “Don’t underestimate the importance of the symbolic,” he says.

*Editor’s note: Just after this story was published, The Wonderful Company announced that it was shutting down the BOB project. Paige Embry wrote an update for Scientific American, FERN’s partner on the story.

Lead image: When The Wonderful Company went looking for an alternative to the troubled honeybee, the blue orchard bee, or Osmia lignaria , was the obvious choice. Only about a dozen of the 20,000 or so bee species worldwide are managed. After the honeybee, only three species are widely used in the U.S.: two cannot be woken from their winter’s sleep in time for almond bloom, and the third is banned for open field use in California. © Laura Campbell and U.S. Geological Survey.

You made it this far so we know you appreciate our work. FERN is a non-profit and relies on the generosity of our readers so that we can continue producing incisive reporting like this story. Please consider making a donation to support our work. We appreciate support at any level. Thank you.

Produced with FERN, this article first appeared in Scientific American (paywall). All rights reserved. This article may not be reproduced without express permission from FERN. If you are interested in republishing or reposting this article, please contact