稻鸭共作系统中主要捕食性天敌的结构及多样性

Structure and diversity of major predatory natural enemies in rice-duck integrated farming system

为了探明稻鸭共作模式对稻田天敌群落的影响,设置稻鸭共作区、常规稻作区和空白区3个处理的田间小区试验,对早稻生长期间稻田主要捕食性天敌群落的结构及多样性特征进行了研究。结果表明:3个处理区主要捕食性天敌的优势种类均为园蛛科、微蛛科、狼蛛科和肖蛸科蜘蛛;稻鸭共作区中园蛛科、微蛛科和狼蛛科的优势度指数高于其他两个处理;在整个调查期间,常规稻作区、稻鸭共作区主要捕食性天敌的总数分别比空白区低1.7%和14.9%;除个别观测时段外,稻鸭共作区主要捕食性天敌的多样性指数均低于其他两个处理,但并不显著;多样性指数的减少以放鸭下田初期较为明显,随水稻的生长,多样性指数呈现持续上升的趋势。

A field plot experiment was conducted to study the community structure and species diversity of major predatory natural enemies in a rice-duck integrated farming system across rice growth season.Three treatments were installed,i.e.,rice-duck farming,conventional rice farming,and the control.The dominant species of major predatory natural enemies in the three treatments were all of Araneidae,Erigonidae,Lycosldae and Tetragnathidae,and the dominance indices of Araneidae,Erigonidae and Lycosldae in the rice-duck farming were higher than those in the other two treatments.In rice growth season,the total number of the major predatory natural enemies in the rice-duck farming and conventional rice farming was 14.9% and 1.7% lower than that in the control,respectively,and except in individual observation periods,the diversity index of the main predatory arthropods in the rice-duck farming was lower than those in the other two treatments.The decline of the diversity index of predatory natural enemies was more noticeable at the early stage of introducing ducklings into the experimental plot of the rice-duck farming.With the growth of rice,the diversity index of major predatory natural enemies in the rice-duck farming showed a persistent increasing trend.