白蜡窄吉丁自然种群变化的关键因子研究

为了解影响白蜡窄吉丁自然种群的关键因子,本研究对影响白蜡窄吉丁自然种群的所有生物和非生物因素进行了主成分分析,并进一步拟合了白蜡窄吉丁幼虫数量与寄主植物、树干胸径的关系。结果显示,寄主植物抗性是影响白蜡窄吉丁自然种群最主要的因素,中国本土白蜡树种水曲柳的受害情况远低于美国栽培品种绒毛白蜡,且不同寄主植物间的幼虫数量差异显著;林分结构的影响作用次之,白蜡纯林的受害程度高于混交林。年极端低温、年极端高温、幼虫期和卵期的寄生率对白蜡窄吉丁的影响作用也比较重要。研究结果为生产上采用栽培抗性树种和在合适时期释放天敌控制白蜡窄吉丁的为害提供了理论依据。

Key Factors for Population Fluctuation in the Emerald Ash Borer,Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)

To understand the key factors influencing the natural population dynamics of the emerald ash borer (EAB),Agrilus planipennis Fairmaire,the biotic and abiotic factors were evaluated for their connection with EAB population fluctuation by principal component analysis.The relationship between the number of EAB larvae and host plant,diameter at breast height (DBH) were also analyzed.The results indicated that host plant was the main factor influencing population fluctuation of EAB.The damage of Fraxinus mandshurica,a Chinese native ash species,was much less than that of F.velutina,the cultivated varieties in North America.And the number of EAB larvae differed significantly between different host plants.The influence of stand structure was only next to host plant.The damage of monoculture plantations of ash trees was higher than that of mixed forests.The influence of annual extreme low temperature,annual extreme high temperature,parasitism rate of larva and egg by natural enemies were also important.These findings provide supports for EAB management by using cultivated resistant tree species and release natural enemies in the feasible season.