苹果园周围生境对凹唇壁蜂种群的维持作用

Effect of maintaining surrounding habitat near apple orchards on Osmia excavata(Hymenoptera:Megachilidae)

【目的】凹唇壁蜂Osmia excavata Alfken是我国重要授粉昆虫之一,在北方苹果树授粉有极其重要的作用。如何通过管理措施,维持壁蜂种群成为急需解决的重要问题之一。【方法】以苹果园和周围生境为研究区域,在四类不同生境类型中(苹果园中心区与边缘区,苹果周围生境中心区和边缘区),共选取18个点,采用粘虫板(白板和黄板)和蜂巢(芦苇管和塑料巢箱)两种不同调查方式监测凹唇壁蜂及其天敌叉唇寡毛土蜂种群数量动态,重点分析苹果园周围生境对凹唇壁蜂种群的维持作用。【结果】粘虫板调查结果表明:整体上凹唇壁蜂的数量在苹果园周围生境(65%±17%)高于苹果园生境(35%±12%)。芦苇巢管调查表明:凹唇壁蜂筑巢数量在苹果园周围生境(69%±26%)高于苹果园生境(31%±9%);塑料巢管调查表明,凹唇壁蜂筑巢数量在苹果园周围生境(48%±13%)与苹果园生境(52%±13%)基本相同。苹果园的周围生境可以为释放在果园内的壁蜂提供稳定觅食筑巢条件,起到有效维持凹唇壁蜂种群的作用。【结论】苹果园景观中的凹唇壁蜂种群受生境类型的影响,果园周围的生境可以为凹唇壁蜂等授粉昆虫提供栖息空间与食物资源,具有重要价值。在苹果园实际生产与管理时,应考虑在其周围生境中保护与种植更多的开花植物,为以凹唇壁蜂为代表的授粉昆虫提供适宜的栖息环境和补充食物,维持其种群。

[Objectives] To investigate the effect of maintaining sutiable habitat around apple orchards on populations of Osmia excavata, an important pollinator of apple trees in northern China. [Methods] We compared O. excavata abundance at eighteen sites in four habitats types(core and edge of apple orchards, and core and edge of surrounding habitat). Plastic nests, reed nests and stickytraps were used to monitor numbers of O. excavata and those of its natural enemy Sapyga coma[Results] The stickytrap survey results indicate that the population of O. excavata was higher in the surrounding habitat(65%±17%) than in apple orchards(35%±12%). More nests were found in reed nest tubes placed in surrounding habitat(69%±26%) than in apple orchards(31%±9%) but there was no significant difference in the number of nests found in plastic nest tubes in apple orchards(48%±13%) and those in the surrounding habitat(52%±13%). The habitat around apple orchards can provide stable foraging and nesting sites for O. excavata released in orchards. [Conclusion] O. excavata populations are affected by the habitat around apple orchards. Wild habitat around apple orchards provides pollinator insects such as O. excavata with habitat space and food resources. Consideration should therefore be given to protecting and planting more flowering plants around apple orchards to provide more suitable habitat and supplementary food sources for O. excavata.