小麦间作豌豆对麦长管蚜及其主要天敌种群动态的影响

为探索麦田物种多样性对麦长管蚜Sitobion avenae的生态调控效应，于2007年10月至2008年7月在河北省廊坊市进行田间小区试验，系统调查了豌豆与小麦分别以2∶2，2∶4，2∶6和2∶8比例行间作(分别记作2-2间作、2-4间作、2-6间作和2-8间作)种植模式下麦长管蚜种群数量的时序动态， 同时分析了麦田主要天敌种群数量的时序动态、丰富度、多样性指数及均匀度的变化。结果表明：在麦长管蚜发生高峰期，小麦与豌豆间作麦长管蚜无翅蚜的百株蚜量（平方根转换）极显著低于单作田(P<0.01)，其中小麦单作（77.38）>2-2间作（68.62）>2-4间作（68.51）>2-8间作（65.19）>2-6间作（64.94）。尽管不同种植模式下，麦长管蚜主要天敌的动态变化趋势基本一致，但间作处理的优势天敌瓢虫类和蚜茧蜂类均有较高的种群密度，天敌群落的丰富度明显提高，Shannon-Wiener多样性指数增加，但均匀度下降。总之，小麦间作豌豆不仅有效降低了麦长管蚜的种群数量，同时也增加了天敌控制害虫的稳定性和可持续性。

Effects of wheat-pea intercropping on the population dynamics of Sitobion avenae (Homoptera: Aphididae) and its main natural enemies

To study the ecological regulation effects of species diversity in wheat fields on Sitobion avenae, field experiments were carried out in Langfang Experimental Station of Institute of Plant Protection, Chinese Academy of Agricultural Sciences from October，2007 to July，2008. The intercropping patterns of wheat and pea, by the proportions of planting row of pea and wheat in 2∶2, 2∶4, 2∶6 and 2∶8 (referred to as 2-2 intercropping, 2-4 intercropping, 2-6 intercropping and 2-8 intercropping, respectively), were plotted, and the field cultivar monoculture of wheat was planted as the control. Population dynamics of apterae and alatae S. avenae, population dynamics, species richness, diversity index and evenness of main natural enemies were systematically investigated and analyzed. The results showed that, compared with monoculture of wheat, the amount of S. avenae apterae per 100 plants (square-root transformed) in aphid peak period were very significantly lower in the intercropping treatments than in the control (P<0.01), and the cascade was as wheat monoculture (77.38) > 2-2 intercropping (68.62) > 2-4 intercropping (68.51) > 2-8 intercropping (65.19) > 2-6 intercropping (64.94). Although population dynamics of main natural enemies showed a similar trend with time, wheat-pea intercropping could preserve and augment natural enemies more than monoculture of wheat, and there were higher population densities of ladybeetles and aphid parasitoids, and higher species richness and diversity index of natural enemies, but lower evenness index in every intercropping field. It is so concluded that wheat-pea intercropping system can not only reduce the population of S. avenae, but also improve the stability and sustainability of controlling wheat pests by natural enemies.