マルハナバチ類の訪花性

Abstract

Flower-visiting habits of 3 species of the genus Bombus were examined during from spring to autumn of 1951-1959. Nesting or flower-visiting activities were observed till early summer in B. ardens, and till autumn in B. ignitus and B. diversus, respectively. The number of flower-visiting workers became maximum during the periods of April-May in B. ardens, and June in B. diversus and B. ignitus.The workers of B. diversus visited flowers of 76 species belonging to 31 families. Particularly, the flowers of Leguminosae, Labiatae and Liliaceae were visited predominantly by this workers. Moreover, they preferred mostly the flowers of Cirsium japonicum, Rosa multiflora, Vicia unijuga, Prunella vulgaris, Trifolium repens, Salvia chinensis, Impatiens textori, Pertya ovata, Astragalus sinicus and Styrax japonica.The workers of B. ignitus visited flowers of 24 species belonging to 14 families. The flowers of Leguminosae were visited predominantly by them. These workers preferred mostly the flowers of Trifolium pratense and Vicia unijuga.The workers of B. ardens visited flowers of 32 species of 18 families, especially, the flowers of Leguminosae, Rosaceae and Caprifoliaceae predominantly. And these workers rather preferred the flowers of Rosa multiflora, Rhododendron sp., Styrax japonica, Rubus parvifolius and Diospyros Kaki.