Comparative study of the effects of five Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) strains on cabbage moth Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Abstract

Food production is adversely affected by numerous biotic and abiotic factors that lead to reduction in yield and poor quality of the food products. Use of commercially synthetic pesticides was the most common method for pest control in many agricultural crops during recent decades. These synthetic chemicals have effects on all living organism when they consume such crops treated with pesticides. This research attempted is a green regulation technology as an alternative method to control cabbage moth Plutella xylostella towards the reduction of release of toxic chemical and residue. Virulence studies on different strains (Bb6, Bb11, Bb115, Bb116 and Bb362) of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) were evaluated. Various doses at 0 (control) 104, 105, 106, 107, 108 and 109 conidies ml−1 of five strains were applied topically on the third stage larvae of P. xylostella. Different parameters of larvae were measured in terms of mortality, sporulation rates, the number of pupae that emerged as adult, number of eggs laid between survived adults and the survival rate of larvae were examined at different doses, statistical analysis was performed using Cox-regression. We found that Bb11 strain of Beauveria bassiana (Balsamo) produced highest virulence compared to other strains at 109 conidia/ml while, Bb6 strains showed lower virulence effect at 109 conidia/ml as compared to control dose. Due to the larvicidal effect of different fungus strains, the percentage weight of female adult decreased significantly as compare to the control.