The varroa destructor mite is a parasite that can take down entire bee colonies by spreading diseases and sucking the bees’ hemolymph (blood-like fluid). Because they play such a large part in colony collapse disorder, scientists all over the world are searching for ways to combat these parasites. There are pesticides that work against them, but they aren’t very good for the bees, either. No new chemical treatments have been registered in over 20 years.
Now, an accidental discovery in Germany may point the way to a new weapon in beekeepers’ fight against the varroa mite.
While attempting to replicate results from The Hebrew University of Jerusalem’s work with RNA interference, German scientists stumbled on a new possibility. In their experiments, they found that mites feeding on bees who were fed a lethal strain of RNA died quickly, just as the Israeli experiment showed. But in the German lab, they found that the mites in their control group, which were fed a harmless form of RNA, died just as quickly. Through rigorous testing, they determined that it was lithium chloride, which was used in producing the RNA and therefore was in the sugar solution, that was killing the mites.
Naturally, the German scientists launched into a new series of tests, this time using lithium chloride. They found that feeding bees incredibly tiny amounts of the lithium salt over a one-to-three-day period killed 90%-100% of varroa mites, without causing appreciable harm to the bee population. Of course, more tests are necessary, particularly in looking for lithium residue in the honey of a treated hive, but lithium chloride has promise as a cost-effective, easily available, easily applied, safe, and effective means of protecting bees from a dangerous parasite.