April 14, 2017
From: Entomology Today
By Meredith Swett Walker
A study published in March in the Journal of Economic Entomology examines whether honey bees specially bred to be “mite-resistant” might be the solution to Varroa infestations. Researchers at the USDA’s Carl Hayden Bee Research Center compared Varroa mite populations in hives of the Russian honey bee, a stock of the European honey bee (Apis mellifera) that has been selected (or bred) for its resistance to Varroa, with mite populations in hives of honey bees that have not been selected for mite-resistance. Previous studies have shown that Russian bees have lower levels of Varroa infestation than do unselected lines of European honey bees. This study measured mite populations in the hives, but it also measured the numbers of foraging worker bees with mites on them that went in and out of hives—a variable that proved to be crucial.
Varroa mite infestations wreak havoc on honey bee colonies. The mites feed on the bee’s hemolymph—a bodily fluid analogous to blood—weakening the bee. Their bites leave open wounds on bees and can transmit serious diseases. Female Varroa mites lay their eggs on developing bee larvae and young mites feed on the larvae before they emerge from their brood cells. Bees who have been parasitized as larvae may have deformities and shortened life spans.