不同干扰条件下枸杞园节肢动物群落结构与动态

The structure and dynamics of arthropod communities in Chinese wolfberry fields under different disturbances

2008年通过对宁夏银川地区不同干扰条件下枸杞园节肢动物群落的系统调查,共采集节肢动物151628头,鉴定出4纲27目76科167种,其中天敌亚群落61种,化防园23种,有机园30种,自生园61种,天敌总量的比例分别为10.87%、18.78%、70.34%。通过群落结构分析,自生园丰富度、个体数均明显高于化防园和有机园,有机园均匀度、多样性较高,而化防园丰富度、个体数指数都较低,而优势集中度高。通过主分量分析表明潜叶类害虫与刺吸类害虫是不同人工干扰条件下的主要害虫,刺吸类害虫成为发展有机枸杞的重要障碍,食花果类害虫具有较大的危害潜力;寄生类天敌、病原类天敌为自生园优势天敌,捕食类天敌是有机园、化防园的优势天敌,但化防园天敌作用较为微弱。自生园天敌亚群落与害虫亚群落第一对典型变量为V1=0.048x1-0.2533x2+0.5951x3+0.5207x4,W1=0.9021y1+0.0354y2+0.0223y3+0.1847y4-0.0591y5,相关系数为0.8635,化防园、有机园天敌亚群落与害虫亚群落第一对典型变量的相关系数分别为0.6826、0.7332。通过害虫-天敌亚群落的种群消长动态表明,天敌亚群落作为整体对害虫发挥着调控作用,自生园7-9月份寄生性天敌对刺吸式害虫的跟随作用很强,有机园较弱,化防园则不明显。

Through a systematic investigation of arthropod communities in Chinese wolfberry fields under different disturbances in 2008,151,628 arthropods from 4 classes,27 orders,76 families and 167 species were collected and 61 species of natural enemy sub-communities were identified. In the conventional field,organic field and abandoned field,the species numbers of the natural enemy sub-communities are 23,30 and 61 and their proportions to the total natural enemies are 10.87%,18.78%,70.34%,respectively. The individual numbers and richness in the abandoned field are significantly higher than in other fields. Evenness and diversity indices in the organic field are slightly high,while the dominant concentration in the conventional field is significantly higher. The principal component analysis on the arthropod community indicates that the drilling-leaf pest and the piercing sucking pest are the most important in different Chinese wolfberry fields. The piercing sucking pest is an obstacle for the development of organic Chinese wolfberry,while the flower-feeding and fruit-feeding pest has great damaging potential capacity and may be the dominant pest in the future. Moreover,the parasitic and pathogen natural enemies are the dominant species in the abandoned field,but the predatory natural enemies are the dominant species in organic field and the conventional field. The natural enemies play little role in the conventional field. The first pair of typical variables for natural enemies sub-communities and pest sub-communities are V1 = 0.048x1-0.2533x2＋0.5951x3＋0.5207x4,W1 = 0.9021y1＋0.0354y2＋ 0.0223y3＋0.1847y4-0.0591y5,and the correlation coefficient reaches 0.8635 in the abandoned field. In the conventional and organic fields,the correlation coefficients of the first pair of typical variables reach 0.6826 and 0.7332,respectively. The growth and decline curves of pest-natural enemy communities demonstrate that the natural enemy sub-communities as a whole play a role of regulating and controlling pests. Parasitic natural enemies can greatly suppress the population of piercing sucking pest in the abandoned field,and natural enemies can also control the pest in the organic field,but natural enemies performed not well in the conventional field.