茶角胸叶甲高毒力球孢白僵菌菌株的筛选

Screening of the Beauveria bassiana Strain with High Virulence to Basilepta melanopus (Coleoptera:Chrysomeloidea)

茶角胸叶甲(Basilepta melanopus Lefevre)是一种茶树上常见的食叶性害虫,其发生为害严重影响茶叶的产量和品质。近年来,该虫在局部茶园,尤其是有机茶园中常爆发成灾。如何有效防治该害虫,已成为亟待解决的问题。本研究选择原寄主为茶园鞘翅目害虫的9个球孢白僵菌(Beauveria bassiana)菌株,依据菌落形态、菌株生长速率、产孢量、孢子萌发率、耐热力和抗紫外能力等生物学性状初步筛选出Bb338、Bb346和Bb2-1等3个生物学性状优良的菌株;在此基础上,利用浸虫法研究了3个菌株对茶角胸叶甲成虫的杀虫毒力。生测结果表明,用每毫升1×10~7个孢子的孢悬液处理后,球孢白僵菌Bb2-1对茶角胸叶甲成虫的累计校正死亡率达100%,僵虫率达86.11%;LT_(50)仅为3.32 d。综合上述各生物学特性和杀虫毒力表明,筛选到的Bb2-1菌株具有生长速率快、产孢量大、耐热力和抗紫外能力强,以及对茶角胸叶甲杀虫毒力最强和杀虫速率最快等优点,在今后茶角胸叶甲的生物防治中将发挥重要的作用。

The beetle(Basilepta melanopus)is one of the most serious leaf-feeding insects in tea garden,whichseriously affects both tea yield and quality.In recent years,the beetle often caused serious damage in some teagardens,especially organic tea gardens.How to effectively control this pest has become a serious problem.In orderto screen high virulence strains of Beauveria bassiana to B.melanopus,9strains of B.bassiana isolated from thecoleoptera pests in tea gardens were selected as candidates.In the preliminary screening,the biologicalcharacteristics of these9strains,including colony morphology,growth rate,sporulation,spore germination rate,thermotolerance and UV radiation resistance were detected.According to the above biological characteristics,three strains Bb338,Bb346and Bb2-1were selected for further bioassay against the adult of B.melanopus.Bioassayresults showed that the strain Bb2-1was the most virulent strain to the adults of B.melanopus,which had the highestcorrected mortality rates of100%,highest cadaver rates of86.11%and shortest LT50of3.32d at a concentration of1.0×107conidia per milliliter.The strain Bb2-1has the best biological characteristics and the highest virulent againstthe adults of B.melanopus,which would play a very important role in biocontrol of B.melanopus.