Insecticidal potential of Paenibacillus elgii HOA73 and its combination with organic sulfur pesticide on diamondback moth, Plutella xylostella

Abstract

Diamondback moth, Plutella xylostella, is one of the most destructive insect pests of several crops world-wide. Effects of Paenibacillus elgii HOA73 and its combined application with organic sulfur pesticide on Plutella xylostella were evaluated. Results showed that M3 medium composition indicated the best medium for optimization of bacterial colony growth, hydrolytic enzyme production, and insecticidal activity and was selected for culturing P. elgii HOA73 in further assays. The highest colony growth of P. elgii HOA73 was identified at 5 days after inoculation. Extracted crude enzyme and crude insecticidal compound from P. elgii HOA73 cultured in the optimized medium kill the second instar larvae of Diamondback moth in 40 and 50% at 220mg mL-1 of crude enzyme and 2% crude extract, respectively. Combined application of organic sulfur pesticide with bacterial suspension significantly killed 85% second instar larvae of Diamondback moth, when compared to use of single application: bacterial suspension (65%) and organic sulfur pesticide (38%), suggesting that P. elgii HOA73 combined with organic sulfur pesticide could be used to control P. xylostella. © 2014 The Korean Society for Applied Biological Chemistry.