Chemical Constituent and Insecticidal Activity of Essential Oil from Dried Unripe Citrus Reticulata

Pulverized dried peels of Citrus reticulata (500g) were subjected to hydrodistillation for
four hours using a Clevenger-type apparatus. The resulting essential oil was analyzed
using Gas Chromatography-Mass Spectrometry (GC-MS), and its insecticidal properties
were evaluated through a contact toxicity bioassay against adult bean weevils
(Callosobruchus maculatus). The distillation process yielded 1.272% (w/w) of essential
oil. GC-MS analysis revealed that monoterpenoids constituted the major portion of the
oil, making up 99.6% of its composition. The dominant compounds identified D-
limonene (93.3%) and sabinene (2.1%). The oil demonstrated significant insecticidal
activity, causing mortality in the exposed insects. These findings suggest that the oil may
serve as a potential natural alternative to synthetic insecticides for controlling storage
pests.