M.E.A. McNeil 2020-09-17 00:26:33
Synopsis: The breeding of honey bees has had uneven success toward achieving productiveness and resistance to pathogens or pests. The first means was beekeeper preference; later were added protocols from animal breeding by Brother Adam, and from plant breeding, with the aid of refined insemination, in the later Midnite and Starline projects. Characteristics of particular subspecies have either been revived, as in Sue Cobey’s Carniolans, or integrated into lines, as with the Buckfast bee. With the aim of providing strengthened stock, the USDA imported the Yugos and Russians. The Minnesota Hygienic and USDA VSH projects selected for varroaresistant behavior. John Kefuss and, later, many others have combined subspecies and partnered with Nature to do the selection without chemicals. What’s possible?
I feel very hesitant to talk about this,” said Bob Danka. Rightly so. A bee breeding project, now in Hilo, Hawaii, is a work in progress, set back more than once in the past. It’s a story that has not yet come to a conclusion, but perhaps the time has come to tell it, ready or not, and he eases into the beginning.
“I can hardly call it new research,” he said. Danka recently retired as Research Leader and Research Entomologist at the USDA. He learned beekeeping at Penn State, moved to Louisiana in 1983 to do a dissertation on Africanized bees, and joined the Baton Rouge lab with an eye-opening initiation in the bees of Venezuela.
“It’s been an evolution over 25 years,” he said. “This program in Hawaii is what I would call phase three of all that work.” In the first phase, he and two other USDA researchers began projects in the mid-1990s in different ways to find varroa-resistant bees. Tom Rinderer investigated evolutionderived resistance in Russian bees, which had the longest association with the mite. John Harbo looked at genetically-based resistance to varroa. Danka collected colonies known to be survivor stock. “This went on for a couple of years, and I saw both John and Tom making progress, and I dropped the survivor colonies because these guys were on to something.”
Danka made multiple trips to Russia for the work that has resulted in the commercially available stock from the Russian Honey Bee Breeders Association. He also joined Harbo’s research into the resistant trait now called VSH (varroa sensitive hygiene). “It’s very confusing to people,” he said. It’s good he is here to explain, since he worked with Harbo through its development and is now involved with the latest iteration of the project.
“John is a very meticulous researcher,” said Danka. Harbo set up colonies that were genetically narrow, with every queen instrumentally inseminated with semen from a single drone — a strategy used in the Midnite and Starline breeding. Packages from a single source were shaken together to even them out further, and they were portioned into hives. Since there was only one patriline, all the worker offspring were super-sisters, 75% genetically related, a number to remember as the story unfolds. They were as close to uniform as possible, placed in the same apiary and with, presumably, the same mite levels. After about ten weeks, Harbo found the mite populations remarkably varied. In one colony, it doubled, but in the next colony the mite count halved.
Harbo, with Roger Hoopingarner at Michigan State, set up a test in 1995 with 42 single-drone-inseminated queens, from Louisiana and Michigan. Over two months, all but three of the untreated colonies were rife with mites. “But three of them, ha!” said Danka, “This was evidence of some genetically-based control effect on varroa.”
Following that breakthrough, Harbo bred those queens and produced bees that showed they could hold down mite population growth. “One or two of those colonies of the original 42 actually did have zero mite population,” said Danka. “It’s remarkable. He had no idea why. He didn’t care at the time.”
But Harbo was, after all, a scientist, and by the late 1990s he set about investigating what was happening. Danka, who was on the team, said that they looked at standard measures: hygienic behavior, grooming, post-capping duration of the worker brood. They also closely examined the mites in the brood. “It’s a very technically challenging thing to do. But it’s like everything else, if you do 10,000 of them you get the hang of it.” The answer was clear: Those colonies with low mite population growth had highly non-reproductive mites. This phenomenon had been reported in the literature as occurring in Tunisia and other places, but the USDA researchers had never seen it.
Even in the most mite-susceptible bees, some disruption of the mites’ reproductive cycle affects about 20% of them: For example, the foundress may start laying too late for daughters to be old enough to emerge, or she lays only female eggs with no male for them to mate with. But in the Harbo colonies with singledrone- inseminated queens, nearly all had highly non-reproductive mites, and that came about in fewer than a dozen generations of selection. The trait was first called SMR, suppressed mite reproduction. Then both Harbo and Marla Spivak at the University of Minnesota independently found a form of hygienic behavior in which infected brood cells are cleaned out. SMR was renamed VSH, varroa sensitive hygiene, to reflect the new understanding.
“In my opinion,” said Danka, “this was a brilliant piece of science sleuthing. I can’t tell you how much I admire this whole thing. We seemed to have struck gold,” he said, “if we could figure out how to apply this to the industry.” In 2001, commercial queen breeder Tom Glenn began to maintain VSH bees for distribution. “Tom Glenn was the biggest cheerleader for the concept of using bees like this as a sustainable answer to varroa. He was great.”
unfoRtunately, foRtunately
By the time Harbo retired in 2005, though, the promise of the program had started to unravel. It had been thought the hard-won trait would be maintained by the beekeepers buying the stock from Glenn. “It seemed like a good idea at the time,” said Danka. Not only was the required scientific rigor too much, subsequent generations of the bees were open mated.
“People were saying, ‘Oh, I got some of these bees with VSH, and they’re not so resistant.’”
Bees in general and particularly honey bees have exceedingly high recombination rates, which is to say that their genes are recombined with every mating. An individual queen, then, is like a frame in a genetic movie.
“Let’s face it,” Danka said, “Looking at it in hindsight, these guys are not going to sit with the microscope evaluating a couple thousand cells of brood to tell whether or not mites are reproducing. It was just fantasy to think that.”
When Danka was asked to take over the program, he was still committed to transferring the stock to the beekeepers, but it was a quandary. He said, “I’m not seeing bees out there that are like the bees that we produce. We haven’t treated bees for varroa in 25 years at the lab.”
He got a lucky break. “Once in a while,” he said, “a pot of money falls out of the clear blue sky.” In 2007, available USDA funds allowed him to test bees from the lab. He placed 300 queens grafted from Russian and VSH stock in the large commercial operation of Andy Card, who is from a multi-generational commercial beekeeping family in the Northeast. The lab queens were mated with the Cards’ drones, standard stock they liked except for their lack of varroa resistance. Then the researchers went on the road with the bees.
“Here’s the part that you can’t believe,” said Danka. The colonies were set up in March. In April they were shipped north from Louisiana to New York to pollinate apples, in May taken on to Maine for low bush blueberries, in June to Cape Cod to cranberries and in July to western New York to make honey. In October they were sent back to Louisiana until late January, when they were trucked to California for almond pollination and back in March to Louisiana. “If I trace the trucks right,” he said, “that’s 8100 miles, which is the diameter of the planet Earth. No wonder bees are dying, it’s amazing anything is alive. We learned a lot. Everywhere the bees went, we went.
“Here’s where the light bulb went off over my head,” he said. After that yearly cycle, some of the original queens came through looking fine. “I still can’t believe it.” He began what became the second phase of the project, integrating the genetics of those hardy bees into more large-scale commercial operations run by Ryan Lamb, who migrates between North Dakota and Texas; Jim Rodenberg, from Montana; and Kelvin Adee, “the biggest beekeeper in the known universe.” It was a challenge to monitor 300 test colonies among thousands and even tens of thousands. “It’s amazing these people put up with us, but they saw what we were doing. They would like not to be constantly worrying about the damn chemicals. It looks like a pharmacy in there, it’s ridiculous. We keep colonies [at the USDA lab] without any chemicals and do pretty well.”
That selective process, 2008-14, resulted in the stock that Tom Glenn called Pol-line — for pollination bees, from the queen mothers that sustained the Card tour into apples, cranberries, blueberries and almonds. But the project lost the expertise of Tom and Suki Glenn to retirement. BP Bees in South Carolina took over distribution of the line. The Baton Rouge lab provided queen bees and drone semen for continuing the project. Breeding was monitored, but “I guarantee you they’re not looking into microscopes to see the reproductiveness of mites,” said Danka.
Instrumentally inseminated queens were sold to queen producers across the country and then mated to unknown stock. “The end-use beekeeper buys these queens,” is told they have VSH bees and says, “‘No I don’t.’ I know what I have at the lab, but what they are getting is going through two genetic black boxes. That’s a problem. We can’t be the police.”
He determined that if he could make the resistant bees more consistent, it would be possible to deliver the genetics instead of relying on others. “We know from the first two phases of this whole thing that to have reliable resistance, the sweet spot is around two-thirds to three-fourths of the genetics of bees with VSH.” That means more than the queen alone; the drones must be selected, too.
Pause here to consider. For queen producers, it’s a seller’s market, so the motivation for the painstaking and expensive task of breeding new stock is not financial. The isolation required to restrict drones leaves out many. Although beekeepers know that mite-resistant bees would be valuable and eschew using chemicals, their livelihoods can make them risk averse: In short, they know amitraz works. They think, Danka said, “until I’m certain that some goofball breeding program in Louisiana is producing bees that work, I’m skeptical. Fair enough. And I’m not sure we’re going to change that paradigm very easily while amitraz still works. Why would you spend a lot of money, effort, tears and sweat to do this breeding when the demand is just not there?”
True, there are some reports of amitraz resistance, but it’s limited. “If there was widespread resistance, phew, the world would change,” he said. “Beekeepers would be clamoring for bees that can take care of themselves. Right? I’m not sure I’ll see it.”
Danka’s hope for the project revived when varroa invaded the susceptible bees on the Big Island of Hawaii. He sent VSH/Pol-line semen to several breeders there, including Gus Rause of Kona Queens. But Rause found that the breeding was too time-consuming and the extant Kona queens were more profitable because they produced more brood. Another impasse.
a neW beginning
When Danielle Downey became Hawaii State Apiarist in 2010, she came across what remained of Rouse’s USDA hives. “He didn’t know what to do with them,” she said, “and if I wanted to take them and work with them that was fine with him. So I took those colonies.” It wasn’t a random decision; as an undergraduate, she’d assayed the early hygienic bees at Marla Spivak’s University of Minnesota lab, and she later worked at the French national lab with Yves Le Conte, who championed varroa-resistant stock. Downey began with just eight surviving colonies, which she built up to 60 on the east, Hilo side of the island. She secured grant funding for the research that allowed her to bring Tom Glenn and then Sue Cobey to do insemination with VSH semen from the Baton Rouge lab. “For a couple of years I was working to cull the worst and improve the lines, which is great in Hawaii because you can do it all year round — there’s never a break. I was doing trials and producing queens for any beekeeper who was willing to give them a try.”
One of them was David Thomas, who, in 2012, bought Hawaii Island Honey Company, also on the Hilo side. He acquired some VSH bees from Kona Queen in that stock, and he added some F1 (first generation) VSH queens bred by Downey.
But, Downey said, “I could only do so much as one person. I had a whole job” — traveling, inspecting and educating. As it turned out, Danka knew Thomas, who also had an operation in Louisiana. So it was that the three came together at the Hawaiian Style Café in Hilo for a memorable morning meeting. A photo shows Danka with a Hawaiian breakfast called a loco moco in front of him — a pile of rice, eggs and gravy with a hamburger patty. It augured serious enterprise.
Exactly how this came about varies with the teller, but by the last cup of coffee, Danka said, “We cooked up a scheme.” On a handshake, the third phase of the project began. Thomas agreed to make 200 colonies available to develop the bees. “David was all in from day one. Unbelievable.”
Thomas and Downey created a relatively isolated mating area flooded with selected drones. The calculation was a good one: Unlike most animals, each one of a drone’s sperm is an identical clone. Sister bees with the same father share 75% of their genes, the magic number for resistance. The best offspring from that yard, about 10 percent, were bred in hopes of seeing the resistance grow. But it didn’t. “We hit a plateau,” said Downey. “Year after year only a small number were our best bees. It seemed like we were working against something that we couldn’t overcome in the natural environment — just too noisy a process to get rid of the genes that were not what we wanted. Probably because it was open mating, and you just can’t control it.”
Thomas visited the Baton Rouge lab, and he returned to Hawaii with a plan. He bought a lot adjacent to his office, honey house and wood shop, and he constructed a replica of the room where the USDA mite-counting work was done. “He built us a lab,” said Danka. “Just remarkable.”
Colleague number four was an unlikely addition. After a talk Danka gave to beekeepers in a Luxembourg beer hall about VSH bees, a Dutchman named Bartjan Fernhout introduced himself as a veterinary researcher and said he was ready to go all in. He, too, visited the Baton Rouge lab, and he brought with him Ralph Buchler, a prominent German bee breeder. Fernhout joined the Hilo team.
Danka and Downey where funded in 2015 by five of six sources of grants they applied to. They hired lab technicians and Fernhout as the breeding manager. “This thing really got rolling,” said Danka.
Fernhout knew the complex Buckfast line-breeding tradition, so he could adapt to the VSH program, which went back to single drone insemination and examination of brood cells to see if the reproductive mites were being removed. The key was that Fernhout mastered the mind-bogglingly complex family trees of the bees by developing a database called Queenbase. “It’s very impressive,” said Downey. “It keeps track of all of the legacy information.” A tool to trace lineages aids selection for genetic diversity. The program is now used at the USDA, in the Spivak lab and in Europe.
“I see it like a deck of cards,” said Downey. “You look at the [singledrone- mated] queen and the brood cells and say yes, this is a card we can keep, these are the homozygous genes that we want for resistance. As soon as you get enough of those cards your deck grows. Then you make multidrone queens because we know you can’t force those genetics without having deleterious effects.” Varroa mites are introduced into a colony and ten days later, when the mites become reproductive, hundreds of cells are examined under a microscope and the data recorded. In that way, the team produced multiple resistant lines. “Now we’re going back to a closed breeding program,” she said.
into the WoRld
In 2016, Downey left the position of state apiary inspector to become head of Project Apis m, the national organization at the interface of bee health and crop pollination. “It’s been really a boon for the project,” she said. The VSH research funding came with her, and two board members joined early commercial trials of the bees, first Zach Browning and then George Hansen. Now there are five ongoing sites across the U.S.
Downey and Danka traveled to evaluate all the trials quarterly, but last year they enlisted the Bee Informed Partnership to do the assessments as independents. “BIP already has strong trusted relationships with beekeepers,” she said. Danka will continue to analyze the numbers. And last year, the USDA included the Hilo bees in genetic studies.
Hansen is a broadly educated and thoughtful person. His Foothills Honey Company, based in California, runs 7000 hives, mainly now for pollination. About the Hilo bees, he said, “My observations are anecdotal, but we get an impression.” He got 32 Hilo queens, from two lines, and 32 controls from commercial providers divided into two yards — the same protocol at all the test sites across the country. “We didn’t treat any of them,” said Hansen. “In October my son and I went out to one yard to test what was there. The VSH queens had very low mite counts, well below any threshold, and many of them we couldn’t find any mites whatsoever. The [control] colonies, half were dead, and in the other half their mite levels were astronomical; all of those bees eventually died anyway. That’s a pretty stark comparison. It was eyeopening to us.
“We mark all of our colonies for their queen source," Hansen continues, "so we have records of [Hilo] colonies that are out in our regular operation, being moved to pollination.” He adds 100 Hilo queens a month in season to that stock. “As a general rule, those colonies have much lower mite levels than the other colonies do. But there are not enough of them available. And they are not consistent in their general quality. We’re still on a learning curve. I think Bob and Danielle and David have really worked hard to make sure that this particular breeding stock does not get out too fast.”
“I’m having to buy these queens, so when you do the arithmetic, it’s a significant contribution. It’s a commitment that I’ve made because I really believe that this is a good program.”
the Readiness is all
Thomas has dealt with disasters in his apiaries — small hive beetle, varroa. In 2018 he added molten lava to the list. Mount Kilauea did not erupt, it oozed from fissures, and Thomas’s best honey producing area was in the path of the flow. He moved some 800 colonies until the sulfuric acid fumes became too dangerous, and his last yard was overtaken and burned. Inferior locations, costs, a drop in production; it was a financial crisis for a honey producer.
Thomas had bred queens to replenish his stock in Hawaii and Louisiana. Now that the VSH queens have become a source of income, he wants to expand their distribution. His partners take a different view. “Bob and I are very cautious,” said Downey. “We don’t want a false start. We don’t want to release material that is not up to our standards, because VSH has been set back so many times already.”
Danka said, “The bees are more variable than I would like.” The goal is to get beyond treating, but Thomas still needs to treat his hives. Another variable is honey production. In some trials, the Hilo bees produced 15 to 20 percent less honey.
“There are a lot of people that believe there is a necessary trade-off with mite resistance,” said Downey. “I don’t necessarily believe that. The ones that are as productive are not uncommon. It’s just that right now we have a pretty noisy field of the selected bees. Which makes sense because it’s a very young selection. What we are comparing to has been selected for hundreds of years.”
Zach Browning has done the numbers. For overwintering and pollinating, the bottom line for the Hilo bees can be better, but for honey production, it depends on prices. For George Hansen, honey is a minor source of income. “For us having bees that are healthy and can take care of themselves without huge replacement costs or mite treatment costs would be a big benefit. If I were a big honey producer I might have a different set of standards.”
In 2019, Thomas produced several thousand Hilo queens that were distributed to ten mainland beekeepers who agreed to give feedback. “We do have high hopes,” said Downey, “but we want the data to bear out that yes, the resistance is stable and consistent enough that we are comfortable knowing what we have to share with beekeepers.”
Hansen said, “In talking to other beekeepers, there is a huge amount of interest, because they are suffering. I don’t want to give them the idea that this is perfect because we’re still not to the end line. But my sons are taking over my business, and they share my commitment to this concept. It’s not only theoretically a good idea to have a breeding program that would help solve or mitigate our varroa problem, I think that this program in particular is really worthy of that investment. We believe that breeding for mite resistance is real.”
For further information on this project, go to: HiloBees.com.
M.E.A. McNeil is a journalist and Master Beekeeper. She lives with her husband and son on a small Northern California organic farm. She can be reached at mea@meamcneil.com.
©American Bee Journal. View All Articles.