New treatment against CCD

Remebee is easily administered—mixed into heavy bee syrup and fed in one feeding of one pint. Some beekeepers are trying the latest version, RemebeePro, this year.

Photo courtesy of Eyal Ben-Chanoch

Beekeepers—and the fruit growers who depend upon them for pollination ­services—may be seeing light at the end of the tunnel in their tribulations with Colony Collapse Disorder, which has been killing off a third of the nation’s ­beehives every winter for the last five years.

This year, many beekeepers are participating in trials of a new treatment, based on Nobel-prize–winning technology developed with promise for human medicine. While it has proven difficult to use in people, it appears to work in bees and other insects.

Last year, growers tried a product named Remebee, which works like a vaccination, but the vaccinelike solution is delivered by feeding it to bees in a heavy sugar syrup. Remebee targeted one primary virus, the Israeli acute paralysis virus, which is “strongly associated” with CCD, but with mixed results. Israeli acute paralysis virus is not the only virus involved in CCD.

This year they’re trying RemebeePro, an improved version of Remebee that is a “cocktail” that will target seven bee viruses. Bee researchers now believe that viruses, mostly vectored by varroa mites, are a major factor in colony losses worldwide.

Approval this year?

Keith Delaplane, an entomologist with the University of Georgia and the national director of the $4.1-million Managed Pollinator Coordinated Agriculture Project funded by the U.S. Department of Agriculture, is very enthusiastic about the technology, which may achieve U.S. Food and Drug Administration approval this year in time for hive treatment in late summer.

The vaccinelike medicine is based on ribonucleic acid interference (RNAi) technology, often called gene silencing, according to Delaplane. The first step is to identify a key gene that’s essential to the production of a protein that is essential to the survival of a virus or other pest. Then, a very specific matching piece of dual-stranded RNA is ­constructed that binds against the gene, shutting it off.

After discovery of this technology in 1998, scientists began working with it in human medicine, to silence genes that cause disease. While the technology can be applied in plants and insects, it was not so easy with humans.  The human stomach merely digests these proteins, using them as food, and human cell walls are not easily penetrated to get the synthetic parallel strands into the cytoplasm, since the body posts immune defenses to them.

But “to our everlasting surprise,” ­Delaplane said, “in bees, just feeding it to them was all that was required. We’re all shaking our heads over this. We don’t know why it’s working.”

Cause of CCD

No single cause of CCD has been found, Delaplane said. “CCD is a syndrome with an unknown number of contributors. There is an amalgamation of many contributing ­factors. But topping the list are viruses, pesticides, and the varroa mite. “Varroa mites are central. No matter what else you find, varroa will also be there.”

Dennis vanEngelsdorp, an entomologist from Pennsylvania State University, likened varroa mites to the dirty needles that spread the AIDS epidemic. The varroa’s main role is in vectoring viruses as they feed on bee fluids and brood.

Treatment protocol

In an interview with Good Fruit Grower, Eyal Ben-Chanoch, chief executive officer of Beeologics, the company that makes Remebee, said tens of thousands of doses of Remebee have been distributed to American beekeepers, who have agreed to follow an FDA-supervised treatment protocol and keep records. Others who are interested in participating—and have at least 75 hives—should contact the company, which is based in Israel and in Miami, Florida.

“We have been working on this product for over three years, and now we are really excited as finally we are able to disseminate the product to beekeepers,” he said.

One of the scientists who won the Nobel Prize for ­physiology and medicine in 2006 for the discovery of RNAi, Dr. Craig Mello, joined the Beeologics’ advisory board last year. “In bringing RNAi-based products to the field, we made his vision a reality,” Ben-Chanoch said. Mello, a professor of molecular medicine at the University of Massachusetts Medical School, discovered the concept, along with Andrew Z. Fire, in 1998.

Trade secret

While RNAi silencing sequences are expensive to construct, Ben-Chanoch said the company had developed a way to do it—“a trade secret”—that makes it less expensive for beekeepers to use. Remebee comes in 50cc bottles that treat 50 hives. The company is making it ­available at cost during the trial period.

Beekeepers who use Remebee have nothing to fear in the way of side effects, Ben-Chanoch said. “When challenged with virus, bees themselves make RNAi naturally, but for certain viruses they make too little too late to save themselves.  We instruct beekeepers to make just enough syrup for the bees to eat in one to two days.  Leftovers of syrup will start ­fermenting within a couple of weeks, breaking down Remebee, leaving zero residue in the environment.”

The Remebee bottles are kept frozen, then thawed without added heat, and one bottle is mixed with 6.5 gallons of heavy sugar syrup. One pint treats one hive one time.

Since bees live only a few weeks, it is not clear how often beekeepers might have to treat, but treating the generation that will go into winter would be a likely strategy.

The technology behind Remebee can be broadly applied. Beeologics is working on new products for bee health that target other bee viruses, the parasitic fungi Nosema ceranea, and the varroa mite. The company is hoping to deliver RemebeePro, the Nosema control, and the varroa control products within the next three years.