多样化种植调控稻田天敌功能团在生境间的移动

为明确多样化种植对稻田天敌功能团在不同作物生境间的移动(或称"跨境移动")的调控作用,于2008—2009年在福建省武夷山利用双向陷阱法、双向透明粘板法和双向马氏网法监测水稻单作系统(RR?)、增种玉米的水稻多作系统(RC)和增种大豆的水稻多作系统(RS)中天敌的跨境移动规律。结果表明,2008年,RR?、RC和RS中,跨境移动的蜘蛛物种丰富度分别为9.00、6.25和8.00种,跨境移动的寄生者物种丰富度分别为57.25、42.75和48.00种。2008年和2009年,与RR?相比,RC和RS中跨境移动的天敌功能团物种丰富度均没有显著增加。2008年,RR?、RC和RS中,移入稻田的捕食性昆虫个体数量分别为6.75、9.33和2.67只,移入稻田的蜘蛛个体数量分别为43.58、13.54和18.54只。与RR?相比,除2009年的捕食性昆虫外,2008年和2009年,RC或RS中移入和移出稻田的天敌功能团个体数量无显著增加,表明玉米和大豆很可能不能为稻田天敌提供营养物质或适宜生境促进其个体数量的发展,而收获活动可能促进捕食性昆虫和寄生蜂从玉米田移动到水稻田,但这是否有利于控制害虫需要进一步验证。

Regulation of the movements of natural enemy guilds between different habitats in rice-based ecosystems by polycultural manipulation

In order to address the effect of polycultural manipulation on the composition and dynamics of natural enemy guilds moving among different crop habitats, bi-directional pitfall traps, bi-directional sticky traps and bi-directional Malaise traps were used to monitor the movement of natural enemy guilds between habitats in rice monoculture systems (RR''), rice-corn polyculture systems (RC) and ricesoybean polyculture systems (RS) in Wuyishan, northern Fujian Province during the rice-growing seasons in 2008 and 2009. The results showed that the species richness of natural enemy guilds moving between habitats in 2008 in RR'', RC and RS were, for spiders, 9.00, 6.25 and 8.00, and for parasitoids, 57.25, 42.75 and 48.00, respectively. The species richness of natural enemy guilds moving between habitats in polyculture systems was not significantly increased than that in monoculture system in 2008 and 2009. In 2008, the number of natural enemy guilds moving into rice subplots in RR'', RC and RS were, for predatory insects, 6.75, 9.33 and 2.67, and for spiders, 43.58, 13.54 and 18.54, respectively. Except for predatory insects in 2009, the movement of natural enemy guilds in both directions in RC or RS was not significantly different in number from that in RR'', indicating that neither soybean nor corn could provide nutrient foods or suitable habitats for natural enemies and both of them failed to increase the abundance of natural enemies. Harvest activity in corn fields could promote the movement of grounddwelling predatory insects and parasitoids from corn fields to rice fields, but whether insect pests will suffer a greater predation or parasitism needs further study.