Population dynamics of queen-right, queen-less and virgin queen, honey bee colonies and their relative effectiveness as pollinators of sterile soybeans in a net room

Author of the article:LIU Qiang, YAO Hui-Min, SHEN Jin-Shan, WU Wen-Qin, SONG Huai-Lei, LEI Jia, MA Wei-Hua, JIANG Yu-Suo

Author's Workplace：Yan’an Beekeeping Experimental Station, Yan’an 716000, China

Key Words：Apis mellifera ligustica; virgin queen; queenless; soybean sterile line; net room

Abstract：[Objectives]  To investigate the effect of the queen status of honey bee colonies on their ability to pollinate sterile soybeans, and thereby find ways to increase soybean yield and reduce pollination costs. [Methods]  The population dynamics and pollen consumption of queenright (mated queen) and queen-less colonies, and those with a virgin queen, and sterile soybean yield after pollination in a net room, were investigated by counting and weighing. The frequency of bees entering and leaving hives in each of the three kinds of colonies was monitored with a camera. [Results]  The greatest decline in number of bees (58.07%) occurred in the virgin queen group, which was significantly higher than that in either the queenright group (30.83%) or the queen-less group (38.80%) (P < 0.05). The decline in the proportion of capped brood was significantly lower in the queenright group (43.40%), than in either the queen-less group or the virgin queen group (P < 0.01). The decline in egg production in the queenright group (54.2 %) was also significantly lower than that in the queen-less group (100%) (P<0.05), and was also lower, but not significantly so, than that in the virgin queen group (90.99%). The peak period of active attendance among the three groups occurred between 9:00-13:00. There were two peaks in the queenright group but just one in the queen-less group and in the virgin queen group. Groups can be ranked in frequency of attendance as follows; queenright group (38), virgin queen group (31), and queen-less group (24); these differences are statistically insignificant (P > 0.05). There was also no significant difference in the pollen consumption ratio of the three groups (P>0.05). The queenright group pollinated significantly more soybean pods and grains than that either the queen-less group or the virgin queen group (P<0.01). Soybean plants pollinated by either the queenright group or the queen-less group had a significantly higher yield per plant than those pollinated by the virgin queen group (P<0.01). [Conclusion]  Queenright and queen-less honey bee colonies were significantly better pollinators of sterile soybeans than those with virgin queens. The cost of pollinating soybean crops can, however, be reduced by using queen-less colonies or those with a virgin queen.