雌雄木蜂对活血丹盗蜜的行为差异及原因

通过近三年的野外观察和实验揭示了活血丹的盗蜜者为中华木蜂．但其雌雄个体具有不同的访花特性和影响．雄蜂的体形稍小，访花频率是雌蜂的4倍，单花访问时间较雌蜂短（2．18s／7．48s），但在一个居群的单次访花数印是雌蜂的5倍（42．48／8．81），对被盗蜜花的损伤也较雌蜂低；在开放条件下，被雌雄小蜂访问过的花的座果率有明显差异（34．72％／73．59％）．结果表明，体形大小的差异可能是活血丹的花冠管长度、硬度及单花产蜜量仪能适成雄蜂的盗蜜，小适心雌蜂盗蜜的主要原因，对食物资源的合理利用可能导致了中华木蜂雌雄个体在对活血丹的取食行为上发生了分化，并对其花部进化施加了不同的选择压力．

Preliminary Study of the Causes and Pattern of Behavioural Differences Between Male and Female Carpenter Bees (Xylocopa sinensis) during Nectar Robbing in Glechoma longituba (Lamiaceae)

Studies over three years in natural population shown that as nectar robbers of Glechoma longituba,male carpenter bee of Xylocopa sinensis is smaller than the female one.Moreover,detailed studies indicated that male and female bees have different behavior and effects when visiting flowers.For example,the visit frequency in a certain population for male bees was 4 times than that of female ones;average duration of single visit was shorter for male bees than female bees(2.18 s vs.7.48 s),and the visited flower number during a bout for male individuals is significantly more than that of female individual(42.48 vs.(8.81).) Consequently,the female bee resulted in higher extent of destruction on the corolla,ovule and nectary in comparison with male bee;fruit set from visited flowers due to male bees is significantly higher than female ones under opening condition(34.72% vs.73.59%).We therefore postulated that the length,rigidity of corolla and nectar production of flower in G.longituba must be an adaptive consequence of its nectar robbing visitors;The behavior differentiation of Xylocopa sinensis during foraging may result from the difference pattern of distribution of the food resource for the male and female individuals.