有翅桃蚜蚜群中新蚜虫疠霉和烟蚜茧蜂的互作关系初探

Preliminary Study on the Interaction between Pandora neoaphidis and Aphidius gifuensis in Alate Population of Green Peach Aphid, Myzus persicae

虫霉目真菌和蚜茧蜂是蚜虫的重要专性生防因子,在田间生态系统中存在"共位共处"的现象。本文开展了以新蚜虫疠霉和烟蚜茧蜂为代表的虫霉目真菌和蚜茧蜂在有翅蚜蚜群中的互作研究。有翅蚜"孢子浴"接种新蚜虫疠霉后不同时间间隔(0d,1d,2d)再进行蚜茧蜂处理,试验结果表明:各处理间的蚜虫感病率差异显著,且均高于60%;处理间的僵蚜率则差异不显著,且均低于15%。而有翅蚜先经寄生再"孢子浴"接种的5组不同间隔时间(1d,2d,3d,4d,5d)处理试验的结果表明,组间有翅蚜的僵蚜率呈极显著差异,感病率也呈极显著差异,且僵蚜率和感病率在间隔4 d组出现明显分界。因此,在实验室条件下的有翅蚜蚜群中,新蚜虫疠霉的侵染比烟蚜茧蜂的寄生更具竞争优势,但它们之间的互作关系不是取代关系,而是迭代关系。本试验为蚜虫专性病原真菌(特别是虫霉目真菌)更好地联合蚜茧蜂在蚜虫生物防治中开展应用提供科学依据。

Entomophthoralean fungi and Aphidiidae are important obligate aphid biocontrol agents and co-exist in the field ecosystem. Here, the interaction between Pandora neoaphidis and Aphidius gifuensis, which are representatives of Entomophthoralean fungi and Aphidiidae, respectively, was studied in alate population of green peach aphid(Myzus persicae). The alates were submitted to treatments in which the aphids were inoculated with P. neoaphidis prior to expose to A. gifuensis at different time intervals. It was found that there were significant differences in the infection rate(all are greater than 60%) between the treatments. However, the parasitism rates(all are less than 15%) were not different between the treatments. To the contrary, when the alates were submitted to treatments in which aphids were exposed to A. gifuensis prior to inoculation with P. neoaphidis at different time intervals, there were significant differences in the parasitism rate and the infection rate between the treatments. In addition, the parasitism rate and infection rate of the 4-day-interval treatment showed obvious difference from other treatments. The results suggest that P. neoaphidis has certain competition advantages over A. gifuensis in the aphid population under laboratory conditions. However, their interactions are not substitutional, but iterative. This study provides a new evidence for the combination of obligate aphid-pathogenic fungi(especially Entomophthoralean fungi) with Aphidiidae in the biological control of aphids.