【作者】 王波；

【导师】 刘同先； 冯毅；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2020， 硕士

【摘要】 捕食关系是生态系统中普遍存在的影响生物群落结构和稳定性的重要因素,捕食性天敌对猎物种群动态及数量起着十分重要的调控作用。捕食者不仅可通过直接取食影响猎物的种群数量和分布,也可以通过非取食效应间接影响猎物的形态、行为、生长发育或生理状态。非取食效应是指捕食者降低猎物的适应力,但与直接取食引起的死亡无关的效应。瓢虫的非取食效应可引起蚜虫个体和种群的适应性的变化,并且在瓢虫对蚜虫产生非取食效应作用过程中,蚜虫报警信息素((E)-β-法尼烯,EBF)起着重要的作用。本研究以异色瓢虫(Harmonia axyridis(Pallas))作为天敌,以豌豆蚜(Acyrthosiphon pisum(Harris))作为猎物,探究不同密度捕食者的非取食效应及不同浓度的蚜虫报警信息素对蚜虫适应性的影响,研究内容主要有:(1)通过设置低、中、高3种不同的异色瓢虫密度,来探究不同密度捕食者的非取食效应对连续三代豌豆蚜发育历期、体重、产蚜量的影响;(2)使用不同浓度的EBF对豌豆蚜进行处理,通过建立蚜虫生命表的方法,来探究不同浓度的蚜虫报警信息素对连续两代豌豆蚜适应性的影响。主要的研究结果如下:(1)不同密度捕食者产生的非取食效应对蚜虫适应性有显著影响,并且其影响与豌豆蚜的世代有关。低密度的瓢虫对多代豌豆蚜的适应性均没有显著影响,中密度的瓢虫可以使第二代和第三代豌豆蚜的发育历期延长,并使第二代豌豆蚜体重差下降,高密度瓢虫可使第二代豌豆蚜的产蚜量上升。(2)不同浓度的EBF对蚜虫适应性均有显著影响,并且其影响与豌豆蚜的世代有关。第一代豌豆蚜的三龄若蚜发育时间,寿命和平均世代周期在1000 ng/μL的EBF处理后均会显著缩短,内禀增长率和周期增长率在受到250 ng/μL的EBF作用时会显著降低;第二代豌豆蚜的一龄若蚜发育时间在50 ng/μL、250 ng/μL和1000 ng/μL的EBF处理后会显著延长,寿命在受到10 ng/μL的EBF处理后会显著缩短。第二代豌豆蚜的净增殖率和繁殖力在受到10 ng/μL、500 ng/μL和1000 ng/μL的EBF处理后显著降低。综上,不同密度捕食者的非取食效应和不同EBF浓度对豌豆蚜适应性都存在显著影响。不同密度瓢虫的非取食效应和低浓度的EBF对第一代豌豆蚜的适应性均没有显著影响,中密度瓢虫的非取食效应可以使第二代和第三代豌豆蚜的发育历期延长,并使第二代豌豆蚜体重差下降,高密度瓢虫可使第二代豌豆蚜的产蚜量上升。不同浓度EBF对豌豆蚜的影响并不是线性相关的,并且高浓度的EBF可使豌豆蚜的适应性显著降低。更多还原

【Abstract】 Predation relationship is a common interaction in ecosystem and it play an important role in regulating community structure and stability.Predators not only directly affect the prey population and distribution through consumptive effects(CEs),but also indirectly influence the behavior,development or physiological state of prey through non-consumptive effects(NCEs).The effect which reduce prey fitness,but not directly result in the death of prey is defined NCEs.The NCEs of coccinellid have the potential to further differentiate their relative impacts on aphid populations.Moreover,aphid alarm pheromone((E)-β-farnesene,EBF)is an important factor when ladybirds produce non-consumptive effects on aphids.In this study,a system that consisted of Harmonia axyridis(Pallas)and Acyrthosiphon pisum(Harris)was used to study the effect of NCEs on the performance of A.pisum.The main research contents include two aspects:(1)The effect of NCEs of ladybird with low,medium and high densities on the nymph development duration,weight grown and the number of offspring of three generations of aphid.(2)The effect of five concentrations of EBF on the fitness of two generations of aphid were investigated through the establishment of the aphid life table.The main findings are as follows:(1)The NCEs of different densities of ladybird could affect the fitness of A.pisum,and its influence is related to the generation of A.pisum.The low-density ladybird had no significant effect on the fitness of the multiple generation of A.pisum.The mid-density ladybird could prolong the nymph development duration of the second generation and the third generation of A.pisum,and reduce the weight grown of the second generation of A.pisum.Finally,the high-density ladybird could increase the number of offspring of the second generation of A.pisum.(2)The EBF of different concentrations could affect the fitness of A.pisum,and its influence is related to the generation of A.pisum.The development time of the third instar nymph,lifetime,and generation time of the first-generation of A.pisum significantly shortened in 1000 ng/μL EBF treatment.The intrinsic rate of increase and finite rate of increase of the first generation of A.pisum were significantly reduced in the 1000 ng/μL EBF treatment.The development time of the first instar nymph of the second-generation of A.pisum was significantly increased after 50 ng/μL,250 ng/μL and 500 ng/μL EBF treatment,and lifetime was significantly reduced after 10 ng/μL EBF treatment.The net reproductive rate and fecundity of the second generation of A.pisum was significantly reduced after 10 ng/μL,250 ng/μL and 500 ng/μL EBF treatment.In conclusion,the NCEs of different density predators and different EBF concentrations have an impact on the fitness of A.pisum.The NCEs of ladybirds of different densities and low concentration of EBF have no effect on the fitness of the first generation of A.pisum.The NCEs of the mid-density ladybirds can prolong the nymph development duration of the second and third generation of A.pisum,and reduce the weight grown of the second generation of A.pisum.NCEs of high-density ladybirds can increase the number of offspring of the second generation of A.pisum.The concentrations of EBF was not linearly related with the development of A.pisum,and high concentration of EBF can significantly reduce the fitness of A.pisum.更多还原