Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 25, 2004
Publication Date: November 1, 2004
Citation: Harbo, J.R., Harris, J.W. 2004. Effect of Screen Floors on Populations of Honey Bees and Parasitic Mites (Varroa Destructor). Journal of Apicultural Research. 43(3):114-117. Interpretive Summary: Earlier work suggested the screen on the bottom of a bee hive may help control Varroa destructor, a parasitic mite of the honey bee. This study compared brood production, population growth of honey bees, and population growth of parasitic mites in hives with screen or wood as floor material. Two experiments were conducted in Baton Rouge, Louisiana; one in winter (19 colonies) and one in summer (22 colonies). In both winter and summer, hives with screen floors had fewer mites, more brood, and more adult bees at the end of the test than colonies with traditional wood floors. Colonies with screen floors also had a lower percentage of their mite population residing in brood cells where mites reproduce and a higher percentage on adult bees where mites do not reproduce. This suggests that screen floors may control mite populations by decreasing the rate that mites enter brood cells. Overall, there seem to be distinct benefits and few negative effects associated with beekeepers using screen floors on their hives.
Technical Abstract: This study compared brood production, honey consumption (in winter only), population growth of honey bees Apis mellifera), and population growth of parasitic mites (Varroa destructor) in hives with screen or wood as floor material. Two experiments were conducted in Baton Rouge, Louisiana; one in winter (19 colonies) and one in summer (22 colonies). In both tests, we established uniform colonies of honey bees by subdividing 30 kg of mite-infested bees. Each colony began with about 11,000 bees, no brood, and uniform populations of mites (127 and 480 mites per colony in winter and summer, respectively). Hives had either screen or wood floors. After the first 20 days of the tests, when no adult bees or mites had yet been produced in any of the colonies, the two treatment groups showed no differences in brood production, honey consumption, or survival of adult bees. However, colonies with screen floors had more mites on adult bees. At the ninth week (the end) of the tests, colonies with screen floors had fewer mites, a lower percentage of their mite population residing in brood cells, and more cells of capped brood. These results suggest that colonies with open screen floors may reduce the growth of mite populations by slowing the rate of entry of mites into brood cells.