梨园芳香植物间作区蚜虫与天敌类群的相互关系

The relationship among aphids and natural enemies in the different aromatic plants intercropping plots of pear orchard

在梨园中设置不同种类的芳香植物间作处理区、自然生草区和清耕区(对照),研究不同芳香植物间作区蚜虫及其天敌类群组成、种群时序动态与时间生态位指数的变化,并进行灰色关联分析。结果表明,不同芳香植物间作处理区蚜虫及其天敌类群数量、时序特征、时间生态位宽度与重叠指数存在明显差别。在梨树年生长周期中,薄荷、孔雀草和罗勒间作区的梨黄粉蚜、绣线菊蚜、梨二叉蚜与天敌类群的时序变化趋势相似,但发生的时段及数量与对照区存在显著差异。各个处理区中3种蚜虫的时间生态位宽度指数均较小,而天敌类群的时间生态位宽度指数较大;芳香植物间作区中蚜虫(孔雀草间作区的绣线菊蚜除外)及捕食性天敌的生态位宽度指数均大于对照区。各个处理区中蚜虫及(与)天敌之间的时间生态位重叠指数差异明显。各处理区中不同的天敌类群对某一特定的蚜虫的关联度相似,而不同间作处理区某一特定的天敌类群对3种蚜虫的关联度存在明显差异。芳香植物间作改变了梨园生态环境中的蚜虫及其天敌类群数量和组成,害虫种群数量明显减少,益害比(1∶1)明显大于自然生草区(1∶2.1)和清耕区(1∶3.3)。结论:芳香植物间作能有效降低蚜虫种群数量,是一种农业防治蚜害的优选方法。

With the development of a sustainable agriculture,especially in fruit production,researchers have known more and more effects of applied organic materials in eco-orchard on the increasing of ecosystem productivity,nutrient cycling,and ecosystem stability.Cover crops is one of the important conventional management measures in eco-orchards,and is widely believed to increase soil organic matter and soil fertility,conserve soil moisture,and increase habitat productivity,habitat complexity,and local biodiversity besides maintaining ecological equilibrium and improving fruit.And also many have reported positive relationships between intercropping in orchards and arthropod communities,but the details of the interactive effects of the aromatic plants used as intercrops on relationship of aphids and natural enemies are not well documented.During March 10 to September 30 in 2006 to 2007,we conducted a systematic survey about the population compositions,dynamics as well as time niche of aphids and their natural enemies under five treatments toward the pear trees that were all in 20-years old in full fruit production in pear plantation that is located of Daxing District in Beijing,China.Treatments were designed as the intercropping mint（Mentha haplocalyx B.）,maidenhair（Tagetes patula L.） and basil（Ocimum basilicum L.）,natural sward plots and clean tillage plot as control in pear orchard.The results showed that there were significant differences in aphids and natural enemies＇ population numbers,compositions,time series characteristics,time niche breadth and overlap among different intercropping treatments：（1） The temporal characters trend of three aphids（Aphanostigma jakusuiense Kishida,Aphis citricola van der Goot,Toxoptera piricola Matsunmra） and their natural enemies were similar to that in mint,maidenhair and basil intercropping plots,but the occurring numbers and time of the aphids and natural enemies were remarkably different from that in control.Compared with natural grass plot and clean tillage plot,the number of three aphids at intercropping aromatic plants plots decreased remarkably.All aphid peaks occurred at about 10d or earlier at intercropping aromatic plants plots than that in natural grass plot and clean tillage plot.（2） In all treatment regions,the time niche breadth index was small for aphids while it was large for its enemies.（3） All aphids except Aphis citricola,and predatory enemies had larger time niche breadth index in aromatic intercropping region than control;（4） The time niche overlap index varied significantly between aphids and natural enemies;（5） In all treatment regions,the correlation degree between different natural enemy groups and a certain specific aphid was similar,while it was different between a specific natural enemy and the three aphids among intercropping regions.We proved that changed quantity and constitution of aphid and its natural enemies,and decreased the group number of pest in the ecological environment of pear orchard.Moreover,intercropping aromatic plants can increase predator： prey ratio at 1∶1,and it is obviously larger than that in natural grass plot（1 ∶ 2.1） and clean tillage plot（1 ∶ 3.3）.In conclusion,intercropping aromatic plants can efficiently depress group quantity of aphid,which is a preferred agricultural prevention and control method of aphid damage.