椰子织蛾高毒力金龟子绿僵菌菌株的筛选

椰子织蛾是为害热带地区棕榈科植物的重要害虫,本试验对从海南省陵水县采集的椰子织蛾僵虫上分离得到的4株金龟子绿僵菌进行了分子生物学鉴定,并测定了其对椰子织蛾3龄幼虫的室内生物活性,筛选出了高毒力菌株LS-Y1。试验结果表明,经NCBI BLAST比对,4株菌株的rDNA-ITS序列与GenBank中已知基因序列相似性分别为99%、100%、99%、99%。菌株LS-Y1处理椰子织蛾3龄幼虫后6d的LC50为4.41×106个/mL。6.25×106、1.25×107、2.5×107、5×107和1×108个/mL浓度处理下,金龟子绿僵菌LS-Y1对椰子织蛾3龄幼虫的LT50分别为5.77、4.88、4.43、3.82和3.36d。该菌株对椰子织蛾幼虫具有较高毒力,具有较好的生防潜力。

Screening of highly toxic strains of Metarhizium anisopliae against Opisina arenosella Walker

Opisina arenosella Walker is an important insect pest on palm plants in the tropical area of China. In order to find efficient biocontrol agent against O. arenosella, four Metarhizium anisopliae strains with good cultural characters were obtained from dead overwintering O. arenosella larvae collected from Lingshui, Hainan Province. The strains were identified by molecular method and their toxicities against the 3rd instar of O. arenosella were investigated in laboratory. Strain LS-Y1 demonstrated high toxicity against O. arenosella. NCBI BLAST with the rDNA-ITS fragments from the four tested strains revealed that the nucleotide sequences of these genes have the similarity of 99%, 100%, 99% and 99% with the sequences of JN377427.1, NR132017.1, FJ545278.1, FJ545294.1, respectively. LC50value of LS-Y1 on the 3rd instar larvae of O. arenosella was 4.41×106 conidia/mL 6 days after treatment. The LT50 values of LS-Y1 on the 3rd instar larvae of O. arenosella at the spores concentrations of 6.25×106, 1.25×107, 2.5×107, 5×107 and 1×108 conidia/mL were 5.77 d, 4.88 d, 4.43 d, 3.82 d and 3.36 d, respectively. These results showed that the strain LS-Y1 was highly toxic against O. arenosella larvae, which was the promising candidate in the biological control of O. arenosella.