玉米田草地贪夜蛾卵寄生蜂(黑卵蜂)的形态特征观察及分子生物学鉴定

Morphological characteristics and molecular identification of egg parasitoids(Telenomus remus Nixon)of Spodoptera frugiperda Smith from maize field

【目的】明确在云南省瑞丽市玉米田间发现的一种寄生于草地贪夜蛾卵块的黑卵蜂种类,为其人工扩繁及利用本地寄生蜂等天敌开展草地贪夜蛾生物防治提供理论依据。【方法】2020年7—9月,选择云南省瑞丽市德宏热带作物研究所基地的玉米田,采用普查方法调查寄生于草地贪夜蛾卵块的黑卵蜂寄生率,在人工气候箱中建立黑卵蜂实验种群,通过体视显微镜观察其形态特征,结合分子生物学方法对其进行种类鉴定,并分析其在室内对斜纹夜蛾卵粒的寄生率和寄生后的羽化率。【结果】通过形态学特征观察及分子生物学方法鉴定,将寄生于玉米田草地贪夜蛾卵块的黑卵蜂确定为夜蛾黑卵蜂(Telenomus remus Nixon),其在遗传上与巴基斯坦种群(T._remus_Pakistan_KY835081)更接近。在田间观察的15 d中,夜蛾黑卵蜂对草地贪夜蛾的卵块寄生率和卵粒寄生率有2 d均为0,其余各观察日的卵块寄生率和卵粒寄生率中最低均为57.1%,最高分别为100.0%和99.9%,平均分别为84.7%和83.6%。室内养殖观察结果表明,夜蛾黑卵蜂对斜纹夜蛾卵块的平均寄生率在95.00%以上,寄生后的平均羽化率为70.91%。【结论】在云南省瑞丽市玉米田间发现寄生于草地贪夜蛾卵块的黑卵蜂经鉴定为夜蛾黑卵蜂,在自然条件下对草地贪夜蛾寄生效果较好,具有开发为防控田间草地贪夜蛾种群天敌寄生蜂的潜力。

【Objective】Identified the species of Telenomus sp.that was parasitic on Spodoptera frugiperda Smith in maize field in Ruili,Yunnan,in order to provide theoretical basis for artificial propagation of the Telenomus sp.species and using local natural enemies such as local parasitic wasp in the biological control of S.frugiperda.【Method】The parasitic rate of Telenomus sp.was investigated in a maize field which belonged to Dehong Institute of Tropical Agriculture in Ruili,Yunnan,from July to September 2020.In the artificial climate box,Telenomus sp.test population was established,observed the morphological characteristics of the Telenomus sp.through the body visual microscope,identified the species in combination with molecular biology methods,and analyzed the parasitism rate and eclosion rate of Telenomus sp.after parasitism of S.litura.【Result】The Telenomus sp.that was parasitic on S.frugiperda was identified as Telenomus remus Nixon by morphological characteristics and molecular biological methods.It was genetically more similar to the Pakistani population(T._remus_Pakistan_KY835081).In the 15 d of field observation,the egg mass parasitism rate and egg particle parasitism rate of T.remus to S.frugiperda were 0 on 2 d.The lowest egg mass and egg particle parasitism rate on the other observation days were 57.1%.The highest parasitic rate of T.remus were 100.0%and 99.9%,respectively.The average parasitism rate of S.frugiperda egg mass and egg granulation was respectively 84.7%and 83.6%.The results of indoor culture observation showed that the average parasitic rate of T.remus to S.frugiperda egg mass was more than 95.00%,and the average eclosion rate of T.remus to S.frugiperda was 70.91%.【Conclusion】The Telenomus sp.which was found from maize field in Ruili,Yunnan is identified as T.remus Nixon,and the parasitism effect is good unedr natural condition.It has the potential to develop and utilize the local T.remus Nixon for the control of S.frugiperda population in the field.