Contact Toxicity and Repellency of the Essential Oil from Bupleurum bicaule Helm against Two Stored Product Insects

Abstract

Essential oils obtained from many plants showed various kinds of insecticidal properties; some of them have been considered as alternative insecticides for pest control. The present study was aimed at determining the chemical composition of the essential oil from the roots of Bupleurum bicaule Helm, as well as evaluating the contact and repellent activities of the oil and four identified compounds against Lasioderma serricorne and Liposcelis bostrychophila adults. The essential oil was extracted by hydrodistillation, and its components were analyzed by gas chromatography-mass spectrometry (GC-MS). 26 components were determined and the main compounds included trans-2-isopropylbicyclo[4.3.0]non-3-en-8-one (25.9%), 4,5-dimethyl-1,2,3,6,7,8,8a,8b-octahydrobiphenylene (23.5%), and 1,4-dimethoxy-2-tert-butylbenzene (4.3%). It was found that the essential oil exhibited contact toxicity against L. serricorne (LD 50 = 11.91 g/adult), but the contact toxicity against L. bostrychophila could not be observed. The essential oil also showed strong repellent activity against L. serricorne with percent repellency of 100% at 78.63 nl/cm 2 . Four chemical compounds, 1,4-dimethoxy-2-tert-butylbenzene, bornyl acetate, (2E,4E)-2,4-nonadienal, andbisabolene, exhibited various levels of bioactivities. The experimental results indicated that the essential oil of B. bicaule and its individual compounds could be used in insecticidal and repellent strategies for stored product insects.

Insecticidal and repellent activity of essential oil from Amomum villosum Lour. and its main compounds against two stored-product insects

“…Consulting the past literature, borneol acetate also showed similar attraction effect to L. serricorne. [51] At almost all tested concentration, the essential oil and the constituents show the weak repellency at 4 h after exposure. And at 3.15 nL/cm 2 , camphor and bornyl acetate showed insect attractant properties (PR = −42% and −52%).…”

Contact toxicity of Essential Oils from Tithonia diversifolia against Aphis gosypii, Thrips tabaci and Bemisia tabaci

“…Essential oils from T. diversifolia were diluted with a 1:4 mixture of pure n-hexane (non-polar solvent) and Dichloromethane (DCM-polar solvent) 2% v⁄v for GC-MS analysis sample solution (Wei et al, 2018) and a sample solution of 1 µL was injected into GC-MS equipment using an auto-injector. Calibration of the equipment was done prior to analysis and time and temperature were determined and programmed at the time of analysis.…”

“…The application of synthetic pesticides is by far the most widely used approach of agricultural pests, and it entails the use of various pesticides (Wei et al, 2018). Pesticides are categorised based on a variety of factors, including chemical components, target pests, formulation, mechanism of action, and source (Pandya, 2018;Gogi et al, 2017).…”

Efficacy of Essential Oils from Ocimum kenyense as a Biopesticide against Aphis gosypii, Thrips tabaci and Bemisia tabaci.

“…The treated and untreated half discs were then enjoined using cello tape and placed in Petri dishes. A commercial repellent containing 20-30% DEET was used as a positive control and was applied on the filter papers as the essential oils (Wei et al, 2018). 10 pests of each species were released at the centre of the filter papers and the responses were observed after one hour.…”

“…Chemical control is the most commonly used method of pest management that involves the use of different types of pesticides (Wei et al, 2018). Pesticides are classified using different criteria such as the chemical composition, the target pests, formulations, mode of action, and source (Pandya, 2018;Gogi et al, 2017).…”