Cannibalizing Honey Bees Target Deadly Mite that Kills Colonies

Delta Farm Press   By Hembree Brandon   August 2, 2016

Colony collapse disorder has wiped out hundreds of thousands of honey bee colonies in the U.S. and worldwide. Bee breeders at the USDA Honey Bee Laboratory at Baton Rouge, La., have developed a line of bees with resistance to the varroa mite, which vectors viruses that lead to colony collapse.Bees with the VSH gene are able to detect bee pupae within the brood nest that have mite families, and they cannibalize those bees. “The bee nest can tolerate losing individual bees,” Harris says, “because they’re producing thousands per day from the queen, but the mite family can’t tolerate the interruption. The bees eat the mite offspring as they cannibalize an infested pupa. The female mite will attempt to reproduce only three to five times in her life. If every time she tries to reproduce the VSH bees interrupt the cycle, the mite population declines.”

The bee lab team produced stocks of the VSH bees that are still maintained at Baton Rouge. A cooperator Tom Glenn, in California, who Harris says was “probably the biggest seller of instrumentally inseminated queens in the world,” entered into an agreement with the USDA to disseminate the VSH stock. He then produced breeder queens and sold them across the U.S., helping to distribute the resistance gene. “There’s now an entire body of work to support that this works in the field,” Harris says.

The VSH honey bee can detect pupae infested with varroa mites; they then cannibalize the infected pupae and eat the mites in the process.“This is definitely a first step, and where I think where we need to be going for controlling the varroa mite. But all the activist and media focus on pesticides and bees has sort of taken attention away from these unique bees.”

Because honey bees are quicker to inbreed than most animals, the challenge, he says, is how to sustain a breeding program that focuses on certain traits without inbreeding too rapidly.

 “One of the things I’m trying to do here at Mississippi State is establish a breeding plan that is more long term and designed to avoid inbreeding. I’m trying to develop a VSH bee that will be good for Mississippi beekeepers and isn’t inbred.