1950 年 19 巻 1-2 号 p. 165-167
This study was planned to determine whether co-existence of other nectar plants has influence upon the pollenizing activity of bees in the cage. Nectar plants, the alsike clover (Trifolium hybridum L.) and the white clover (Trifolium repens L.) were used for this experiment. When the other nectar plants bloomed simultaneously with the red clover, pollenizing activity of Bombus wustneii chinganensis Reinig 〓, ♀ and Eucera sociabilis Smith upon the red clover decreased slightly as compared with the case when the red clover was cultivated alone. In the case of Apis indica japonica Radoszkowski the seed production of red clover was decreased also some extent by the co-existence of those competitive plants. The seed setting ability of red clover by Andrena spp. was most decreased in the same condition mentioned above.