Chemical composition and larvicidal activities of the Himalayan Cedar, Cedrus deodara essential oil and its fractions against the diamondback moth, Plutella xylostella

Abstract

Plants and plant-derived materials play an extremely important role in pest management programs. Essential oil from wood chips of Himalayan Cedar, Cedrus deodara (Roxburgh) Don (Pinales: Pinaceae), was obtained by hydrodistillation and fractionated to pentane and acetonitrile from which himachalenes and atlantones enriched fractions were isolated. A total of forty compounds were identified from these fractions using GC and GC-MS analyses. Essential oils and fractions were evaluated for insecticidal activities against second instars of the diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae), using a leaf dip method. All samples showed promising larvicidal activity against larvae of P. xylostella. The pentane fraction was the most toxic with a LC 50 value of 287 μg/ml. The himachalenes enriched fraction was more toxic (LC 50 = 362 μg/ml) than the atlantones enriched fraction (LC 50 = 365 μg/ml). LC 50 of crude oil was 425 μg/ml and acetonitrile fraction was LC 50 = 815 μg/ml. The major constituents, himachalenes and atlantones, likely accounted for the insecticidal action. Present bioassay results revealed the potential for essential oil and different constituents of C. deodara as botanical larvicides for their use in pest management.