作 者 :李丹,赵惠燕*,胡想顺
期 刊 :生态学报 2010年 30卷 18期 页码:4986~4992
Keywords:insect population, spatio-temporal dynamics, spatial pattern, aggregation index, model,
摘 要 :种群空间格局是昆虫种群的重要属性,是为害虫防治提供动态信息的重要前提。关于种群空间格局的时空动态,前人曾建立了富立叶模型和有阻尼自由震荡模型,但忽略了生境资源和空间资源的限制,不能很好地描述昆虫种群在自然界摆布状况的动态行为。因此,在前人研究的基础上,根据蚜虫在自然界的聚集扩散行为逐步建立了描述蚜虫种群聚集扩散规律的变幅、变周期时空分布动态模型,即:y=Ae-nt\[sin(w0emtt+)+b\]+c,并应用该模型对麦长管蚜(Sitobion avenae Fabricius)、麦二叉蚜(Schizaphis graminum Rondani)、禾缢管蚜(Rhopalosiphum padi Linnaeus)和玉米蚜(Rhopalosiphum maidis Fitch)的实验数据进行了拟合。结果表明,麦蚜种群和玉米蚜种群呈现出不同的规律,3种麦蚜均为减幅减周期的变化趋势,玉米蚜则表现为减幅增周期的变化趋势。此外,该模型的拟合效果较好(R2>0.942, SSE<2.6)、生物意义明确,不仅可用于描述蚜虫以及蚜虫以外的其他昆虫和螨类种群的时空动态,还可准确描述不同年龄阶段和不同空间位置上种群的动态,具有普遍适用性。应用该模型考察不同种蚜虫在同一作物上的竞争情况和蚜虫与其天敌的空间分布动态,可为害虫的综合防治奠定基础;对不同小麦抗性品种上同一种蚜虫的聚集扩散行为进行刻画、分析,还可为小麦的抗性育种提供参考依据。
Abstract:Spatial distribution is an important property of insect populations and an important premise to provide dynamic information for pest control. A large number of papers have studied the aggregation index of various insects and mite species populations and described their spatial distributions. Most of these results indicated a similar pheromone that the behaviours of populations tend to fluctuate either from aggregation to diffusion or from diffusion to aggregation. Regarding these general phenomena of organisms′ aggregation pattern, many researchers have set up Fourier models and damp vibration models to capture the spatio-temporal distribution dynamics of populations. However, these models could not clearly describe the distributions of insect and mite populations because they ignored the constraints of resources and spaces. In this paper, we proposed a novel model based on previous studies and the aggregation-diffusion behaviours of aphids. The amplitude and cycle in this model were variable (y=Ae-nt\[sin(w0emtt+)+b\]+c). The model was utilised to express the spatio-temporal distribution dynamics of aphid populations with patchiness index as a dependent variable. We applied this model to fit with the experimental data from English green aphid (Sitobion avenae Fabricius), greenbug (Schizaphis graminum Rondani), oat bird-cherry aphid (Rhopalosiphum padi Linnaeus), corn leaf aphid (Rhopalosiphum maidis Fitch), grasshopper, and Tetranychus viennensis Zacher respectively. The fitting results of the four aphid populations showed that the dynamics of wheat aphid populations and maize aphid population were different. Decreasing amplitude and decreasing cycle were a common characteristic of all the distribution trends of the three wheat aphid species′ populations. The trends of the maize aphid population, on the other hand, showed a different characteristic: decreasing amplitude and increasing cycle. Meanwhile, according to all experimental results, we also showed the advantages of our novel model over the existing ones. First, it implied clearer biological significance, because each parameter in this model had a definite biological meaning. Second, it gave satisfying data fitting results (R2>0.942, SSE<2.6). Finally, the application fields of this model could be extended to describe the spatio-temporal dynamics of other insects and mite populations, including populations of different age-phases and populations of different positions on the same host plant. For example, the model can be used to study the spatial dynamic relationships of insect pest aphids and their natural enemies as well as to identify the dominant species of natural enemies and the competition mechanism with their enemies. Furthermore, the competition of different aphid populations on a certain plant can also be studied with this model. This will be helpful for us to demonstrate their competitive relation and find the dominant insect pest species at different periods. All these applications can provide guidance for the agricultural workers in the management of insect pest, laying a foundation for integrated pest management. The model can also be applied to describe the aggregation-diffusion behaviours of the population of a certain aphid species on wheat of different resistance varieties at the same period, which will help people to select the wheat cultivar resistant to the aphid.
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