Hermann Müller was the first to discover, by following honey-bees daubed on the thorax with colored paints, that constancy is maintained not only throughout a given foraging flight but also over a period of days. He thus observed one marked bee to return repeatedly during 11 consecutive days, and another during ten days, to the same plant of Salvia aethiopis in his garden. Minderhoud subsequently demonstrated, from observations of marked honey-bees on local patches of Taraxacum offcinale, Trifolium repens and Reseda odorata, that, given an abundant supply of flowers of one species, the foraging bee instinctively visits an area about ten meters square. The experience of the British seed trade tends to confirm this view. That trade, faced during World War II with the problem of maintaining uncontaminated the pedigrees of different vegetable plants--turnips, radishes, and the like--while producing them in mass on a crowded island, turned to an experimental study of intervarietal crossing by bees. Crane and Mather concluded that if a large mass of flowers were available, bees would confine their visits to a small area. When radishes are grown in quantity, for example, an interval of 300 feet guards against contamination by intervarietal crossing. The 300 feet in this case is a conservative isolation distance. Bateman found that the first 50 feet reduced the contamination to 1%. Grant, V. (1950). The flower constancy of bees. The Botanical Review, 16(7), 379-398. *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html