The Beekeeper's Lament (9 page)

A
S
A
USTRALIA’S PREEMINENT BEE PATHOLOGIST,
A
NDERSON
is keenly involved in his nation’s efforts to prevent that destruction from spreading to Australia’s shores, striving to keep any foreign bee that could harbor the mite well away from the island continent. This is no easy task in an era of slapdash mobility. Bees have crossed all the great oceans. They arrive on all variety of conveyances: in the pockets of bee collectors looking for the next great queen; in the holds and spars of ships; in airplane baggage compartments. The problem is compounded by the fact that the world is no longer dealing with only one dangerous species of mite. Since Anderson observed and named
Varroa destructor
, another variant has jumped from Asian to European bees. As luck would have it, it has done so in the very population Anderson first became familiar with, in the very location where he first studied the mite.

In 2008, reports emerged from New Guinea about beekeepers losing
Apis mellifera
colonies at an alarming rate. Anderson went to look at the situation. “The first colony I opened,” he says grimly, “there were reproducing mites in nearly every cell.” He couldn’t be certain, without access to sophisticated technology not available in New Guinea, which species of mite was causing the problems. So he improvised: he retrieved some
Varroa jacobsoni
from an Asian bee colony and compared them to the ones that had infested the European colonies, taking photos of both with his digital camera and uploading the images on a laptop. They were exactly the same size and shape. He shipped a sample to a lab in Australia for genetic testing. “Sure enough,” he says, “it was a population of Java mites.” The
jacobsoni
mites had, for the first time, begun reproducing in European colonies. The prospect is unsettling, because like
Varroa destructor,
these newly pathogenic
jacobsoni
mites could carry unfamiliar viruses that could cause even more problems for already-embattled bee populations across the world. In addition, Anderson doesn’t know yet whether the
jacobsoni
mites that can now reproduce on European bees can still reproduce on Asian ones. If they can, it only hastens the inevitable moment when the varroa mite will reach Australia: “The way that mite will get out of New Guinea,” Anderson says, “is on the Asian honey bee.”

The European honey bee doesn’t fare well in the tropical lowlands of New Guinea. It needs lots of care and tending to survive. The Asian honey bee has no such problems; it is considered an invasive species there. It swarms easily and travels long distances. Since its introduction in Irian Jaya, it has spread across the island to the former Australian territory of Papua New Guinea, and east to the island of New Britain, and 1,300 miles farther to the Solomon Islands. It has also made incursions onto Australian soil: in May 2007, a beekeeper from Cairns, in far northeastern Australia, was called to remove a swarm from the mast of a yacht in drydock. He realized that the bees were unusual and called officials from the local agriculture authority. The officials recognized the bees as
Apis cerana
and promptly declared an emergency. Queensland biosecurity officials restricted all movements of managed Australian bees and sent three surveillance teams racing through the continent’s lightly populated north country in search of swarms. They put out a call for citizens to report any unusual bee sightings, combed the area with sweep nets, and tested the pellets of bee-eating birds for
Apis cerana
DNA. They also used a process called “beelining”—capturing and marking foraging Asian bees that had been lured to strategically placed sugar feeding stations, then releasing and tracking them back to their nests.

When the teams found and destroyed three colonies within a one-kilometer radius of the yacht harbor, it became clear that the bees had been living there long enough to swarm and spread. Authorities reckoned that they could have been onshore for as long as three months. The search widened, and by July 2010 they had found more than one hundred Asian beehives. It seemed unlikely that they could stop its spread: the Asian honey bee had probably become endemic to northern Queensland. Tests on the bees and comb from the nests showed that all the nests were related and had descended from a single colony—probably a swarm that hitched a ride on a boat from New Guinea, eluding quarantine inspection. The tests also confirmed that there were no mites on the bees. Although the risk remained that the Asian bees would rob and attack European bees or outcompete them for food, Australia had dodged the varroa bullet for the time being. Still, Anderson knows that it is only a matter of time before varroa mites arrive on Australian shores. It might be the newly destructive New Guinea variety, the Korean variant, or another damaging genotype newly cooked up in the global bee melting pot. “It’s not a matter of if it will arrive,” he says, “but when.” Anderson’s knowledge of varroa mite genetics will do little in the short term to stanch its spread or control the devastation. For in addition to being a remarkably destructive creature, the varroa mite is also a tremendously adaptive one.

T
HIS IS A LESSON
J
OHN
M
ILLER LEARNED THE HARD WAY IN
the winter of 2005. In the initial period after American beekeepers first encountered the varroa mite, treatment was easy. A beekeeper simply placed an Apistan strip in each hive in the fall and forgot about it. The Apistan killed the mites, which never grew numerous enough to overwhelm the hives. But after about ten years the medicine stopped working. Apistan, it turned out, killed most of the mites, but small numbers survived, and over the years the surviving mites reproduced, replicating the genetic capacity that resisted the miticide and growing in population until, finally, the resistant survivors’ offspring made up the majority of mite populations. The medication had selected for stronger, more resistant mites. Fortunately, a second compound, called coumaphos, was in the process of EPA approval and was rushed to market. Coumaphos was also effective against mites, but it was much harder on bees. Soon after Miller began applying it, he noticed that his queens were less fertile, and that they failed, and died, sooner. Miller’s friend Kevin Ward—who produces some of the best star thistle honey on the planet—likes to joke that coumaphos “killed everything but the mite.”

Beekeepers had resorted to protecting their frail charges with the very thing they had been fighting against since the dawn of industrial agriculture: pesticides. Starting in the 1950s and ’60s, lethal chemicals like methyl parathion and Furadan had been sprayed on crops nationwide and nearly indiscriminately, killing birds, wild insects, and managed bees. The effects were dramatic: when foragers were inadvertently caught in a spray of pesticides, they would fall out of the air as they were flying. If bees survived the initial dusting or visited a flower that had recently been sprayed, they might bring back contaminated nectar that would doom the whole hive. For weeks after chemicals were applied, fields remained lethal, their fences pasted with placards warning “Peligro”—danger.

For beekeepers, the danger was more than hypothetical: their livelihood could be destroyed with one poorly timed spray or wrongly placed pass of a crop duster. Miller remembers being “popped” by a stray plume of Furadan that drifted over his hives from alfalfa fields near Tracy, California. Dead bees piled up not only in the “customary puddle o’ death” outside the hives, but also, more disturbingly, inside the hives. “I was fighting tears,” he says, “bagging up bees.” When he sent them to a state lab for analysis, the techs told him they had never measured Furadan levels that high in bees. In California and some other states, farmers are required to inform beekeepers when they treat crops with insecticides; in others, the onus falls on the beekeeper to keep abreast of farmers’ pesticide plans. That was next to impossible. Treatments applied miles away could kill entire bee yards when a drift traveled unexpectedly on the prevailing breeze.

Beekeepers hated everything about insecticides. Before the onslaught of the varroa mite, the strongest thing any self-respecting beekeeper would put in his hive was an antibiotic called Terramycin to treat American foulbrood. Now they were forced to dose their own hives with chemicals. “It ran counter to everything we believed about good husbandry,” Miller says. But the only other choice was not to treat for varroa mites—and guarantee the loss of 80 to 90 percent of their operation. Few beekeepers were willing to do that. So Miller swallowed his pride and continued to use the coumaphos. For three or four years, it did the trick.

But in the late summer of 2004, he realized, too late, that it was no longer working. He was in a bee yard in rural Lehr, North Dakota, on the farm of Wilbur Hauff, a “cool old bachelor” in his eighties, a gifted gardener with a soft spot for honey. Hauff’s yard was on sandy soil, and Miller’s hives sat in an area that was relatively free of grass, making it easier to work the hives (no hidden badger holes) and to see what was going on at the base of them. The colonies were not doing well, and Miller couldn’t understand why the bees weren’t making honey. Then he examined the base of the hives. “I looked down, onto the sand,” he writes, “and there they were . . . ANTS!”

Ants are what Miller and Ryan Elison, his right-hand man, call worker bees that have been parasitized by varroa mites. They are undersized bees with deformed wings—infants, barely hours old but already ejected by the housekeeping bees. Exiled, they crawled in front of the hive entrances, confused and underweight, riddled with deformed wing virus, a destructive pathogen that mites carry with them into a hive. Miller got down on the ground to observe the ants more closely—just, perhaps, as young Lorenzo Langstroth had, wearing out the knees of his pants in pursuit of insect knowledge—and experienced a distinctly unpleasant flash of recognition. “Eureka, Jeeves, I’ve got it!” The mites were adapting. The coumaphos was failing. So were his hives. “The outfit was crashing, right before my very eyes.” It was too late to stop the conflagration. The hives were too heavily infested, and the last bees of the summer harvest were too sick to forage. They would not produce enough honey for the winter. It was too late to restock with healthier bees; there was nothing to be done. Miller put his hives away for the winter sick and hungry, and hoped against all his years of accrued wisdom that they would recover.

They wouldn’t. The varroa mite, once a frightening but manageable problem, had become a wily adversary, a daunting foe, a small, red great white whale. The next January, Miller saw the fruits of its handiwork. He unloaded an early semi of bees in a large orchard in Los Banos, California, in preparation for the almond bloom and discerned immediately that they were “garbage.” Most had only two frames of healthy bees instead of the usual eight; whole semitruck loads were dead. The honey crop had been bad that year, so his hives had headed into winter light. He had less honey, fewer bees, ineffective coumaphos, a high mite load, and a high virus load. It was, he says, a “darn near perfect storm.” By spring Miller had lost four thousand hives; his life’s work had diminished by more than a third. The same was true for many of his colleagues. “In the old days we were shouting and spitting and swearing if we had an eight percent dud rate. Now people would be happy with that,” he says. “We hauled semi loads of dead bees and equipment from the orchards.”

It was a lesson Miller didn’t need to learn twice. From then on, he took no chances with the varroa mite. As is typical of beekeepers, Miller blamed himself. He didn’t see it coming, he wrote, “because I wasn’t doing the work INSIDE the hive, taking sticky board samples, opening brood, LOOKING, LOOKING, LOOKING . . . I was neglecting about the most important thing a beekeeper can do; to monitor hive health issues.” After the “dope slap” of 2004, he began inspecting his bee yards far more frequently and monitoring the gossip grapevine among bee guys and bug guys to learn what could kill mites without killing hives. He began spending nearly every free moment in his “Frankenstein yard”—an apiary stocked with non-honey-producing colonies where he performs daily counts of mites and treats different hives with different EPA-approved and not-so-approved medicines.

In his Frankenstein yard, Miller tinkers with materials like formic acid, which, he learned, is reasonably effective at killing mites, but only if temperatures stay between 60 and 80 degrees for two weeks. At colder temperatures it doesn’t emit sufficient fumes to kill the mites; at warmer temperatures it becomes volatile, and although it doesn’t appear to harm bees, it can harm humans, who must wear a respirator while applying it. The grapevine conveyed stories of beekeepers who neglected the respirator and ended up puking blood in their bee yards. Thymol, a plant extract that is the main component of thyme oil, is also approved for use in beehives and effective against varroa mites, but the bees don’t like it, and if there’s a firestorm of varroa mites in a hive, a beekeeper can’t count on thymol to put it out. Oxalic acid is a natural wood-bleaching compound that can, with regular, conscientious application every three days for the varroa’s twenty-one-day breeding cycle, disrupt the mite’s progress. It’s less dangerous to humans than formic acid—it only causes temporary blindness—and works better, nuking the hemolymph of the mites without damaging the bees. But it is not EPA-approved, and it doesn’t work nearly as well as Apistan and coumaphos once did.

It is difficult to find a material that will kill bugs on bugs.Miller compares it to having a chimpanzee on your back, grabbing you by the throat and biting you on your neck. You are bleeding profusely, and you have to find something in your medicine cabinet, quick, to splash on the chimp that will kill it but not you. In the case of the varroa mite, beekeepers need materials that will kill acarids—ticks and mites—without harming bees or contaminating the honey. “We don’t have a lot to work with,” says Miller, “and by the way, I’m trying to protect honey’s good name.” Many of the approved natural miticides require a level of intervention that is not possible for large-scale beekeepers. Apistan and coumaphos were easy—plastic strips coated with low doses could be placed in the hives and forgotten. Other treatments require beekeepers to remove each frame from a hive and spray a light mist on the bees. This has to happen once or twice a week for three weeks during the brief time in late fall when there are few capped brood cells that can hide the mites and no surplus honey being produced for sale to humans. For hobbyists with a few backyard hives, it is possible, but for commercial beekeepers with a thousand or more colonies, it’s not.