Biological Activity of Ethanol Extracts and Essential Oils fromCurcuma longa(Zingiberaceae),Cymbopogon nardus(Gramineae), andAcorus calamus(Acoraceae) againstPlutella xylostella(Lepidoptera: Plutellidae)

Abstract

The diamondback moth, Plutella xylostella (L.), is a major pest that has developed resistance to many groups of synthetic insecticides. Natural plant products present reliable alternatives for its management. In this study, the activities of essential oils and ethanol extracts from three medicinal plants, i.e., Curcuma longa L. (Zingiberaceae), Cymbopogon nardus (L.) Rendle (Gramineae), and Acorus calamus L. (Acoraceae), from Thailand against P. xylostella were evaluated. Four concentrations of the extracts (i.e., 0.625, 1.25, 2.5, and 5%) were tested. The essential oils and ethanol extracts of Cu. longa, Cy. nardus, and A. calamus exhibited different degrees of activity against P. xylostella. Of these, both the essential oil and ethanol extract of A. calamus at 5% (v/v) concentration exhibited feeding toxicity for P. xylostella larvae, resulting in 100% mortality 1 d after treatment, with a median lethal concentration of 0.528% for the essential oil and 1.074% for the ethanol extract. Furthermore, all concentrations of A. calamus ethanol extract exhibited contact toxicity to the larvae, resulting in >75% mortality 3 d after treatment. All tested extracts, except A. calamus ethanol extract at the 0.625% concentration, exhibited high repellent activity against P. xylostella larvae, while Cu. longa and Cy. nardus ethanol extracts at 5% (w/v) concentration and A. calamus essential oil at 2.5% (v/v) concentration deterred oviposition by P. xylostella adults with an effective repellency >70%. These results indicate that both essential oils and ethanol extracts of these plants have the potential to be developed as insecticides for use in integrated pest management of P. xylostella.

Exploring the chemical characterization and insecticidal activities of Curcuma angustifolia roxb. leaf essential oils against three major stored product insects

“…It shows the better activity of C. angustifolia essential oil. Curcuma essential oils also showed great insecticidal activities against insects like Sitophilus oryzae ( Visakh et al, 2023 ), and Plutella xylostella ( Phukhahad and Auamcharoen, 2021 ). The LC 50 value was 35 mg/cm 2 for the oil extracted from the rhizomes of C. zeodaria and 45 mg/cm 2 for Alpinia conchigera rhizome oil, which also had lower activity compared to C. angustifolia oil ( Suthisut et al, 2011 ).…”

Inhibition Effect of Non-Host Plant Volatile Extracts on Reproductive Behaviors in the Diamondback Moth Plutella xylostella (Linnaeus)

“…The inhibition effect of the calamus EO from A. gramineus on reproductive behaviors in both sexes has not been reported. An EO from another closely related species, A. calamus, has been documented as an effective repellent on the oviposition of P. xylostella female moths [46,54].…”