棉花生境面积及其破碎化对烟粉虱种群的影响

Effects of varying the proportion of cotton habitat area and their fragmentation on the abundance of Bemisia tabaci

【目的】阐明棉花生境面积变化及其破碎化对烟粉虱Bemisia tabaci种群的作用规律,为合理利用作物布局进行害虫生态调控提供理论支撑。【方法】采用国际流行的微景观试验模型系统(Experimental model landscape system,EMLS)进行试验设计,田间条件下连续两年研究了棉花生境面积变化(20%、40%、60%、80%和100%;其他为玉米生境面积)及2种极端破碎化(完全连通C clumped:H=1.0;完全破碎F fragmented:H=0.0)下烟粉虱种群数量变化,采用广义线性模型(GLM)分析各因素对烟粉虱种群数量的影响。【结果】棉花生境面积及其破碎化单独作用时均对烟粉虱种群数量无显著影响,而取样时间则有显著影响。烟粉虱种群数量也没有受到取样时间与棉花生境面积、取样时间与破碎化以及三者交互作用的显著影响。但是,棉花生境面积与破碎化的互作效应则存在年度变化,2014年无显著作用,2015年显著影响烟粉虱种群。当棉花生境面积较小(20%)或较大(80%)时,破碎化程度高,烟粉虱种群数量少;棉花生境面积中等(40%和60%)时,破碎化程度低,烟粉虱种群数量少。【结论】烟粉虱种群对棉花生境面积变化有较强的适应性,而生境破碎化只能在一定程度上产生影响。

[Objectives]To determine the effects of varying the proportion of cotton habitat area and their fragmentation on Bemisia tabaci populations and thereby investigate the effectiveness of controlling insect pests by changing crop planting patterns.[Methods]The experimental model landscape system(EMLS)was adopted to assess the effects of varying the proportion of cotton habitat area(20%,40%,60%,80%,100%),and of two levels of fragmentation(C clumped:H=1.0;F fragmented:H=0.0),on B.tabaci populations in a 2-year field trial.A generalized linear model(GLM)was used to analyze the effects of various factors on B.tabaci populations.[Results]The proportion of cotton habitat area and the level of fragmentation had no significant effects on B.tabaci populations,whereas survey time had a significant effect.B.tabaci abundance was also not significantly affected by the interactions between survey time and cotton habitat area,survey time and fragmentation,and among these three variables.However,the significance of the interaction between cotton habitat area and fragmentation depended on the year,with no significant effects in 2014 and significant effects in 2015.When the area planted in cotton was 20%or 80%,B.tabaci abundance was lower if there was a high degree of fragmentation.However,when the area planted in cotton was 40%and 60%,B.tabaci abundance was lower with less fragmentation.[Conclusion]B.tabaci can adapt to different proportions of cotton habitat area and the effects of fragmentation were subtle.