[Objective] In this study,the natural enemies of the invasive pest Sirex noctilio (Hymenoptera:Siricidae) in China were identified,and the dominant parasitoids and their biology were determined to provide a basis for determining the optimal control period and biological control agents.[Method] The sampling sites were set in the Scotch pine stands infested by Sirex noctilio,and continuous field surveys were conducted in combined with laboratory rearing and observation in this study from 2015 to 2016.[Result] 1) The result showed that there were 3 types of natural enemies in Sirex noctilio,including parasitic wasps,pathogenic fungi and nematode.Of which there were 5 species of parasitic wasps:Rhyssa persuasoria persuasoria (Hymenoptera:Ichneumonidae),Ibalia leucospoides leucospoides (Hochenwarth),Ibalia rufipes drewseni Borries (Hymenoptera:Ibaliidae) and Pseudorhyssa nigricornis (Ratzeburg) (Hymenoptera:Ichneumonidae),2 species of pathogenic fungi (Trichoderma atroviride Bissett and Trichoderma viride Persoon) and a nematode Deladenus siricidicola Bedding.2) Rhyssa persuasoria persuasoria was determined as a dominant species of parasitoid,and its natural parasitism rate was 9.3％.The wasp had one generation a year,ovipositing in young larvae or older instar larvae of its host.It was primary monoparasites and overwintered as larvae within tunnels of Sirex noctilio.Its pupal stage was 10-15 d and the peak period of the adult emergence was in the early May.The adult had a longer life span.It had a strong ability of rainwash resistance and a good adaptability to natural environment.3) Through anatomical observation of Sirex noctilio under the microscope,the infection rate of larvae of Sirex noctilio caused by nematode was 32.1％,and the infection rate of the adult was up to 70.9％.[Conclusion] The above-mentioned result showed that Rhyssa persuasoria persuasoria (L).was an important insect species of natural enemies for control Sirex noctilio and the most appropriate control period was larvae or older instar larvae (i.e.from late April to middle May in local time).Moreover,based on the parasitism rate and effect,D.siricidicola Bedding would be considered the primary biological control means,which should futher focus on the study and utilization in biological control of the pest.%[目的]探明入侵害虫松树蜂在我国的天敌种类,确定优势寄生蜂及其生物学特性,为确定最佳防治时期和防治技术提供理论依据.[方法]2015-2016年,在松树蜂危害的樟子松林区布点,采用林间调查结合室内饲养观察,对松树蜂的自然天敌种类及寄生蜂优势种进行研究.[结果]1)共发现松树蜂天敌3类,包括寄生蜂、病原真菌和线虫,其中:寄生蜂5种,分别为黑背皱背姬蜂指名亚种、枝跗瘿蜂、黑色枝跗瘿蜂指名亚种、红足枝跗瘿蜂、黑角拟皱背姬蜂;病原真菌2种,分别为深绿木霉和绿色木霉;寄生性线虫1种,为Deladenus siricidicola Bedding.2)确定了松树蜂的寄生蜂优势种为黑背皱背姬蜂指名亚种,林间自然寄生率为9.3％.室内观察黑背皱背姬蜂指名亚种1年发生1代,主要寄生松树蜂幼虫或老熟幼虫,为单寄生天敌,以幼虫在松树蜂蛀道内越冬,蛹期10-15天,羽化高峰期在5月上旬,寿命较长,耐雨水冲刷能力较强,对自然环境有着良好的适应性.3)通过在显微镜下对松树蜂的解剖观察,发现线虫对松树蜂幼虫的侵染率达32.1％,对成虫的侵染率高达70.9％.[结论]黑背皱背姬蜂指名亚种是防治松树蜂的重要天敌昆虫,松树蜂幼虫或老熟幼虫期(即当地时间4月下旬-5月中旬)是防治的最佳时期.另外从寄生率和寄生效果来看,线虫可能成为一种主要的防治松树蜂的手段,有待下一步重点研究与利用.
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