次生共生菌Rickettsia对丽蚜小蜂 寄主选择潜能的影响
Effects of the Rickettsia endosymbiont on the host preferences and parasitism rate of Encarsia formosa, a parasitoid of the whitefly Bemisia tabaci
刘 媛；栗 颖；彭 晶； 陈心怡；凡泽云；邱宝利
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DOI：10.7679/j.issn.2095-1353.2019.146
作者单位： 广东省生物农药创制与应用重点实验室，广州 510640；生物防治教育部工程研究中心，广州 510640； 华南农业大学昆虫学系，广州 510640
中文关键词：Rickettsia；烟粉虱；丽蚜小蜂；寄主选择性；寄生率
英文关键词：Rickettsia; Bemisia tabaci; Encarsia formosa; host preference; parasitism rate
中文摘要：【目的】 研究次生共生菌Rickettsia感染对烟粉虱Bemisia tabaci防御丽蚜小蜂Encarsia formosa寄生能力的影响，为探索新的害虫防治技术提供策略与思路。【方法】 以Rickettsia阳性与阴性烟粉虱（B生物型）为实验材料，研究分析丽蚜小蜂在不同烟粉虱寄主上的寄生率、发育历期、羽化率、体型（体长、体宽、头长、头宽）及其寄主选择性。【结果】 Rickettsia 阳性烟粉虱寄主对丽蚜小蜂的寄生率、发育历期有显著影响，但对羽化率、体型无显著影响。丽蚜小蜂对Rickettsia阳性与阴性烟粉虱若虫的寄生率分别为32.52%和41.50%，丽蚜小蜂F1代发育历期分别为14.5 d和15.0 d，羽化率分别为79.02%和83.71%；丽蚜小蜂寄生 Rickettsia 阳性烟粉虱若虫时，其F1代成虫的体长、体宽、头长、头宽比阴性烟粉虱寄主上羽化的虫体略大。在实验室烟粉虱寄主可选择的条件下，丽蚜小蜂对Rickettsia阳性与阴性烟粉虱若虫的平均寄生率分别为35.26%和50.22%，两者差异显著；而在田间笼罩条件下，丽蚜小蜂对Rickettsia阳性与阴性烟粉虱若虫的平均寄生率分别为35.03%和57.79%，两者差异极显著。【结论】 Rickettsia可提高烟粉虱对丽蚜小蜂寄生的防御能力，丽蚜小蜂更倾向于寄生Rickettsia阴性的烟粉虱若虫，以提高其后代的存活率。
英文摘要：[Objectives] To investigate the impact of Rickettsia infection on the resistance of the whitefly Bemisia tabaci to the parasitoid wasp Encarsia formosa, and provide new strategies for whitefly management. [Methods] The parasitism rate, developmental period, eclosion rate, body size (body length, body width, head length and head width) and the host preferences of E. formosa for different B. tabaci hosts, were investigated in both Rickettsia positive and negative populations of B. tabaci (B-biotype) and its parasitoid E. formosa. [Results] Rickettsia infection had a significant effect on the parasitism rate and developmental period of E. formosa, but no significant effects on the eclosion rate and body size of F1 generation adults. The average parasitism rates of E. formosa on Rickettsia positive and negative B. tabaci nymphs was 32.52% and 41.50%, respectively, and the developmental periods of these two populations were 14.5 d and 15.0 d, respectively. The eclosion rates of F1 generation E. formosa adults raised on either Rickettsia positive or Rickettsia negative B. tabaci nymphs, were 79.02% and 83.71%, respectively; the body length, body width, head length, and head width of F1 generation E. formosa adults raised on Rickettsia positive hosts were slightly larger than those of wasps raised on Rickettsia negative hosts. In laboratory choice experiments, the average parasitism rates of E. formosa on Rickettsia positive vs Rickettsia negative B. tabaci hosts were 35.26% and 50.22%, respectively. Under semi-field conditions, the average parasitism rates of E. formosa on Rickettsia positive populations was 35.03% in choice experiments; significantly lower than that on Rickettsianegative populations (57.79%). [Conclusion] Rickettsia infection reduces the susceptibility of B. tabaci to parasitism by E. formosa because E. formosa females prefer to parasitize Rickettsia negative B. tabaci, a preference that potentially increases the survival of their offspring.