白蜡窄吉丁幼虫及其天敌的种群空间生态位研究

Spatial population niche of Agrilus planipennis Fairmaire larvae and their natural enemies

【目的】为了明确白蜡窄吉丁Agrilus planipennis Fairmaire幼虫及其天敌在寄主树上的分布规律和相互关系。【方法】对天津和北京两个地区绒毛白蜡Fraxinus velutina和辽宁地区水曲柳F mandshurica上白蜡窄吉丁幼虫及其天敌的种群生态位进行研究。【结果】白蜡窄吉丁幼虫及其天敌的数量均随着寄主树干高度的增加而逐渐减少,但在不同寄主树种上的分布范围不同。绒毛白蜡上的分布范围较广,而在水曲柳主干上的分布高度相对较低。天敌对白蜡窄吉丁幼虫在空间资源的利用上也存在差异。在天津地区,白蜡吉丁柄腹茧蜂Spathius agrili Yang(膜翅目:茧蜂科)和啄木鸟(■形目:啄木鸟科)的跟随作用最强,且白蜡吉丁柄腹茧蜂与啄木鸟之间对空间资源的利用存在激烈竞争。在北京地区,啄木鸟的跟随作用最强,病原微生物、扁胫旋小蜂、白蜡吉丁柄腹茧蜂之间对空间和营养资源利用的竞争较激烈。而在辽宁地区,白蜡窄吉丁幼虫和天敌的分布范围较窄,各类天敌在空间上对寄主幼虫的跟随作用不是很明显,但不同天敌种类之间对空间和营养资源的利用也存在竞争。【结论】研究结果为白蜡窄吉丁的综合治理和天敌资源的保护利用提供了理论依据。

[Objectives] To explore the distribution and correlation of Agrilus planipennis Fairmaire larvae and their natural enemies on the host tree. [Methods] the spatial population niche of A. planipennis larvae and their natural enemies were studied on Fraxinus velutina in Tianjin and Beijing Cites, as well as on F. mandshurica in Liaoning Province. [Results] The results showed that the number of A. planipennis larvae and its natural enemies decreased gradually with the height of host trees, but the vertical distribution ranges of A. planipennis larvae and its natural enemies were different between different host trees, F. mandshurica and F. velutina. Distribution scope of A. planipennis larvae and its natural enemies on F. velutina was wider than that on F. mandshurica. The synchrony of varied natural enemies to A. planipennis larvae and their utilization on space and nutrition were also different. In Tianjin area, both parasitoid Spathius agrili Yang （Hymenoptera： Braconidae） and predator woodpeckers （Piciformes： Picidae） had strong synchrony to A. planipennis larvae and thus showed intensive competition for space and host resources. Woodpeckers revealed the strongest synchrony to its prey in Beijing. While the competition among pathogen, Metapelma sp. （Hymenoptera： Eupelmidae） and S. agrili was intense. In Liaoning, distribution scope of A. planipennis larvae and its natural enemies was narrower than that in Beijing and Tianjin, so the synchrony of natural enemies to host larvae were not such apparent. But competitions for space and host resources were also tense among different natural enemies. [Conclusion] These findings provide supports for the EAB management and natural enemies＇ conservation and utilization.