The Virulence of Nomuraea rileyi Nr0815 against the Different Instars of Spodoptera litura Larvae

Purpose The aim of this study was to explore the virulence of Nomuraea rileyi strain Nr0815 against different instars of Spodoptera litura larvae.

Method The mortalities of 2-5 instars of S. litura larvae infected by N. rileyi suspension were respectively measured by impregnation method.

Result From the perspective of the corrected mortality rate, of the same age when the moth larvae vaccination, calibration of larval mortality increased with the rising of the inoculation concentration, the calibration of larval mortality between different inoculation concentration has significant difference (P<0.05). During the age of corrected mortality in 10⁷ concentrations inoculated with spore/mL there was no significant difference (P>0.05), 10³-10⁶ and 10⁸ concentrations were inoculated with spore/mL exist significant difference (P<0.05), and with 2 instars correction rates were the highest.

Conclusion N. rileyi strain Nr0815 had certain pathogenic effect against 2-5 instars of S. litura larvae, and it had the strongest virulence against 2 instars of S. litura larvae.