Isolation, Characterization and Insecticidal Activity of Essential Oil from Fresh Rinds of Unripe Citrus Sinensis

Fresh unripe rind (500g) of Citrus sinensis was hydro-distilled using Clevenger type apparatus. The process afforded 3.776% of essential oil. The oil was analysed using GC-MS and the analysis reveal predominance of monoterpenoids in the oil. The most abundant compound in the oil was D-limonene (96.5%), and other major compounds in the oil were sabinene (0.1%), α-pinene (0.4%), β-myrcene (1.7%), linalool (0.1%), 4R-p-mentha-2,8-dien-1-ol (0.1%), carvone (0.1%), and cis-carveol (0.1%). The insecticidal activity of the oil was tested against beans weevil (Callosobruchus maculatus) through fumigant toxicity bioassay. The oil was active against the insect and cause the insect mortality at all exposure period. Hence, the oil could serve as an environmentally friendly alternative for managing Callosobruchus maculatus in stored product.