Characterization and Toxicity of Crude Toxins Produced by Cordyceps fumosorosea against Bemisia tabaci (Gennadius) and Aphis craccivora (Koch)

Cordyceps fumosorosea, an insect pathogenic fungus, produces different toxins/secondary metabolites which can act as pest control agents. This study reports the extraction and characterization of crude mycelial extracts of C. fumosorosea isolate SP502 along with their bio-efficacy against Bemisia tabaci and Aphis craccivora. Fourier transform infrared spectroscopy, liquid chromatography, mass spectrometery and nuclear magnetic resonance analysis of C. fumosorosea isolate SP502 extracts showed the presence of five major compounds-Trichodermin, 5-Methylmellein, Brevianamide F, Enniatin and Beauvericin-which all may potentially be involved in insecticidal activity. The HPLC analysis of C. fumosorosea mycelial extracts and Beauvericin standard showed similar chromatographic peaks, with the content of Beauvericin in the crude toxin being calculated as 0.66 mg/ml. The median lethal concentrations of C. fumosorosea mycelial extracts towards first, second, third and fourth instar nymphs of A. craccivora were 46.35, 54.55, 68.94, and 81.92 mu g/mL, respectively. The median lethal concentrations of C. fumosorosea mycelial extracts towards first, second, third and fourth instar nymphs of B. tabaci were 62.67, 72.84, 77.40, and 94.40 mu g/mL, respectively. Our results demonstrate that bioactive compounds produced by C. fumosorosea isolate SP502 have insecticidal properties and could, therefore, be developed into biopesticides for the management of B. tabaci and A. craccivora.

Automated summary

The insect pathogenic fungus Cordyceps fumosorosea produces toxins that act as pest control agents. The study extracted crude mycelial extracts of C. fumosorosea isolate SP502 and identified five compounds potentially involved in insecticidal activity. The bioactive compounds have insecticidal properties and could be developed into biopesticides for managing Bemisia tabaci and Aphis craccivora.