Chemical composition and larvicidal activity of Zanthoxylum armatum against diamondback moth, Plutella xylostella

Abstract

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) is the most serious pest of cruciferous crops grown in the world causing economic yield loss. Several synthetic insecticides have been used against P. xylostella but satisfactory control was not achieved due to development of resistance to insecticides. Therefore, the present study was carried out to screen different fractions of Zanthoxylum armatum for their insecticidal activities against second instar larvae of P. xylostella. Results indicate, all the fractions showed activity to P. xylostella. However, n-hexane fraction of Z. armatum showed maximum larvicidal activity with minimum LC₅₀ value of 2988.6 ppm followed by ethanol (LC₅₀ = 12779.7 ppm) and methanol fraction (LC₅₀ = 12908.8 ppm) whereas chloroform fraction was least toxic (LC₅₀ = 16750.6 ppm). The GC–MS analysis of n-hexane fraction of leaf extract showed maximum larvicidal activity, which may be due to two major compounds i.e. 2-undecanone (19.75%) and 2-tridecanone (11.76%).

Keywords:

• Zanthoxylum armatum
• fractions
• insecticidal activity
• Plutella xylostella

Acknowledgements

The authors are grateful to Dr. P.S. Ahuja, Director, CSIR-IHBT, Palampur for encouragement and support. Mr. VK is grateful to UGC for Senior Research Fellowship. This work was supported by Council of Scientific and Industrial Research, New Delhi, India [BSC 0213, BSC 0110].

Disclosure statement

No potential conflict of interest was reported by the authors.