Today I stood beside a row of Christmasberry trees in North Kohala, listening to the buzzing of bees around newly opened blossoms. Some were gathering pollen, others, nectar. I leaned in close to inspect their bodies for that dreaded and all too prevalent parasite, the varroa mite. I was pleased to find not a one among the hundred or so bees I examined!
Last week in class, Ethel Villalobos from the UH Manoa Honeybee Project spoke about the research being conducted on diseases spread by varroa, various methods of controlling the mite, and ongoing outreach and education efforts. It seems the battle against the eight-legged pest is never-ending and laborious. Synthetic chemicals find their way into honey, so the use of more earth friendly organic chemicals like thyme oil and formic acid is preferable. Biomechanical methods of mite control include removing drone (male) brood as they are developing. As the drone larvae are larger than worker (female) larvae, mites find them more attractive and feed upon them in greater numbers. Thus, by removing developing drones, the mite population can also be greatly reduced. Ethel warned that without proper management and intervention, infected colonies can die within a year.
Tom Glenn, a bee breeder from Southern California, has yet another approach to varroa control. He selects for a remarkable trait–bees carrying the Varroa Sensitive Hygiene (VSH) gene that can sense if a capped cell holds mite-infested larvae. Workers will chew through the beeswax caps and eat or discard these larvae, reducing the number of mites in the colony. Since introducing VSH queens into his hives, Tom has not had to treat his bees for mites in ten years.
Accelerating the process of natural selection for desirable traits through artificial insemination of queen bees seemed advantageous to many in class. Others found the idea distasteful, suggesting that instead of tinkering with Mother Nature, we should allow bees and mites to achieve a balance where the two could live together without the bees being decimated. It was argued that the use of toxic chemicals and selective breeding might cause the mites to adapt, becoming even stronger, more formidable foes!
Later that afternoon I watched as Tom anesthetized a queen with carbon dioxide, delicately pulled open her “bottom end” and injected 8 micro liters of semen (collected from 100 drones) into her. An identifying number was then super-glued to her thorax, and one wing-tip clipped to prevent her from flying and mating again. I felt an anthropomorphic pang of sadness. She would never zoom 600 feet up into the sky on a glorious and dizzying flight – never merge in ecstatic union with drones on the wing.
My wild swing from VSH enthusiasm to a sense of having betrayed the queen was purely in the realm of emotion, and I hadn’t even begun to understand the scientific consequences and ethical concerns of artificially inseminating queen bees! But, despite my inner qualms, I must admit that if I acquired a hive tomorrow, I would introduce a VSH queen. I don’t want to watch a colony struggle with varroa and I’d hope that greater diversity in the Hawaiian bee gene pool would outweigh any possible negatives of selective breeding.
Posted by Monika Hennig
This project was funded by a grant from the Western Sustainable Agriculture Research and Education Program.