They also benefit many native plant species. Beekeepers can kill varroa mites by using a chemical miticide, Apistan, within affected colonies. But some don't want to use chemicals, either for environmental or economic reasons, Caron reported. And, mites inevitably develop resistance to chemicals, prompting beekeepers to boost the dosage. Too much miticide can kill the bees as well as the mites, since both are arthropods.
Young bees are particularly vulnerable to the miticide.
Strategies for addressing these problems may include breeding hardier bees and improved mite treatments, he said. Formic acid, legalized for mite treatment in Canada, does kill mites, but it evaporates quickly and, therefore, must be reapplied frequently. A formic acid gel may provide beekeepers with an important new alternative to Apistan, as it slows the rate of release of the chemical. Meanwhile, Camazine said his group is studying essential oils, such as eucalyptus, as possible natural mite repellents in the northeastern region. This knowledge could help us to develop new control strategies or to identify desirable traits to select for in breeding programs.