Repellency of essential oils against Nephotettix cincticeps: Laboratory and glasshouse assays

Abstract

Four oils from Piper nigrum, Litsea cubeba, Zanthoxylum bungeanum and Curcuma longa were obtained by ethanol extraction. The repellency of these oils and two major compounds (linalool and piperine) was evaluated against female adult and third-instar nymphs of the rice pest, Nephotettix cincticeps, under laboratory and glasshouse conditions. Paired-choice and no-choice assays were used for each treatment, with essential oils evaluated after 24 and 48 hr of exposure and chemical compounds evaluated after 12 and 24 hr of exposure. The potential effects of essential oils on activities of glutathione S tranferase (GST), carboxyl esterase (CarE) and acetyl cholinesterase (AchE) were also evaluated after 48 hr of exposure to leafhoppers. The constituents of the essential oils were determined using GC-MS. The results showed that the major components in the oils were piperine (34.75%) for P. nigrum, 9,12-octadecadienoic acid (Z,Z) (18.74%) for L. cubeba, ethanone, 1-(2-hydroxy-4,6-dimethoxyphenyl) (18.51%) for Z. bungeanum and turmerone (15.89%) for C. longa. In all cases, the essential oils repelled female adults and third-instar nymphs of N. cincticeps. The repellency of the tested oils and chemicals compounds in the paired-choice assay was higher than in the no-choice assay. In all experimental conditions, P. nigrum and C. longa oils were the most and the least potent, respectively. Linalool was the best repellent among the single-tested compounds under laboratory conditions. In the glasshouse study, the highest repellency was observed in the mixture of linalool and piperine. GST and CarE activities of leafhoppers were significantly enhanced by exposure to the four essentials oils; AchE activity increased significantly only in the P. nigrum and L. cubeba assays. Ourresults clearly indicate that the tested oils and chemical compounds are promising agents for developing plant-based pesticides to control N. cincticeps. K E Y W O R D Senzyme activity, essential oils, leafhopper, repellent

The function of spineless in antenna and wing development of the brown planthopper, Nilaparvata lugens

“…The selection index was calculated using the following formula: selection index = [(TR − CK)/(TR + CK)] × 100%, where TR is the number of insects that were attracted to the treated chemical compounds and CK is the number of insects that were attracted to the control. Positive values indicate an attractant effect, whereas negative values represent a repellent effect (Toloza et al , ; Chakira et al , ).…”

The composition, pharmacological and economic importance of essential oil of Litsea cubeba (Lour.) Pers

“…The repellency of L. cubeba oil was higher in the choice assay than in the no-choice assay, and L. cubeba oil showed acetylcholinesterase activity. The results indicated that L. cubeba oil is a potent N. cincticeps control agent (Chakira et al, 2017). Huang et al (2013) reported the potential cosmeceutical properties of L. cubeba essential oil.…”

Evaluation of the chemical composition and bioactivity of essential oils from Cinnamomum camphora (L.) J.Presl. (Lauraceae), Piper nigrum L. (Piperaceae) and Stemona japonica (Miq.) (Stemonaceae) against Oryzaephilus surinamensis (Linnaeus, 1758) (Coleoptera: Silvanidae)

“…These environmental issues have changed thinking among scientists and persuaded them to consider alternative methods (KOUL et al 2008) of controlling insect pests. The use of plant extracts as alternatives to chemical pesticides has been found effective in managing many insect species (PINO et al 2013): they are bioactive against many insect species, providing maximum repellency and toxicity as well as retarding feeding, oviposition and growth in crop fields, greenhouses and stores (ISMAN 2000, KOUL et al 2008, CHAKIRA et al 2017.…”