大豆田节肢动物群落优势种群时间生态位及营养关系分析

【目的】阐明大豆田节肢动物群落时间生态位及营养关系,为大豆害虫生态调控手段的实施提供坚实的理论依据。【方法】以大豆田节肢动物群落为研究对象,通过两年的田间系统调查分析。【结果】统计得到种类220余种,物种可分为天敌、害虫和中性昆虫3个类群,以天敌物种丰富度最高;害虫中以烟蓟马Thrips tabaci(0.36902)和大豆蚜Aphis glycines(0.13122)优势度最高,且有着较高的生态位重叠指数(0.8163),蚜小蜂Aphytis sp.和大草蛉Chrysopa septempunctata对害虫的时间生态位重叠指数很高,其他天敌如异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、黑带食蚜蝇Zyistrophe balteata和黑食蚜盲蝽Deraeocoris punctulatus等对害虫的重叠指数居中;大豆田中各类群构成错综复杂的食物网结构。【结论】综合考虑天敌的种群数量,确定捕食性天敌是控制害虫种群数量的有效天敌。研究可知不能单纯从时间生态位的重叠指数的高低来判断天敌的控制能力。

Analysis of the temporal niches of dominant species and nutritional relationships within the arthropod community in soybean fields

Objectives] To explore the temporal niches and trophic relationships of the arthropod community in soybean fields, and to provide a theoretical basis for the ecological management of soybean pests. Methods A systematic survey of the soybean arthropod community was conducted over two years. Results] More than 220 species were recorded which could divided into groups of natural enemies, pest and neutral species. The natural enemy group had the highest species richness value. Thrips tabaci and Aphis glycines, which share a relatively high niche overlap index （0.8163） were also relatively dominant （0.36902 and 0.13122）. Aphytis sp. and Chrysopa septempunctata had high niche overlap indices with pest species, wherease Harmonia axyridis, Propylaea Japonica, Zyistrophe balteata and Deraeocoris punctulatus had more moderate overlap indices. The different groups were part of a complex food web. Conclusion] Considering the large number of natural enemy species present, only predatory species were effective in controlling pest insect numbers. The biological control ability of predatory species couldn＇t be assessed by their niche overlap index.