Morphological, molecular and virulence characterisation of six Cordyceps spp. isolates infecting the diamondback moth, Pluttela xylostella

摘要

Entomopathogenic fungi are widely distributed and well described within the fungal kingdom. Different species of fungi belonging to the Genus Cordyceps are well known pest control agents. This study reports the isolation, characterisation as well as virulence of six fungal isolates belonging to three different species of Cordyceps genus including three C. farinosa isolates; two C. fumosorosea isolates; and one C. tenuipes isolate against P. xylostella. The newly identified strains proved pathogenic to P. xylostella under laboratory conditions. In addition, the C. fumosorosea isolate SCFU-1 was virulent against eggs, 1st, 2nd, 3rd, 4th instar larvae and pupae of P. xylostella having LC50 values of 1.27 x 10(9), 2.78 x 10(6), 2.59 x 10(6), 2.87 x 10(6), 1.22 x 10(7), and 1.71 x 10(9) conidia/mL, respectively 7 days post application. The newly isolated strains can be developed as potential biopesticide for P. xylostella although extensive field bioassays as well as development of proper formulation is still required.