Chemical Composition and Insecticidal Activity of Myrtle (Myrtus communis L.) Essential Oil against Two Stored-Product Pests

Essential oil extracted from the leaves of Myrtle, Myrtus communis L. (Myrtaceae)was tested in vitro for volatile toxicity against two stored-product insects (Tribolium confusum and Callosobruchus maculatus). The chemical composition of the plant oil was examined by gas chromatography-mass spectrometry (GC-MS). The major oil components were α-pinene (10.4%), α- Terpineol (10.1%), linalool (9.0%), 1, 8-cineole (7.6%), Geranyl butyrate (6.3%), Geraniol (6.2%), Caryophyllene oxide (5.3%) and Neryl acetate (5.0%). In the fumigant toxicity test, significant differences in mortality of insects to essential oil vapor were observed in different concentrations after an exposure time of 24 hours. C. maculatus (LC50=9.5 µl/l air) was more susceptible to the plant oil than T. confusum (LC50=260.7 µl/l air). The results suggested that essential oil of M. communis L. could be used as a potential biocontrol agent for stored-product insects.