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

Abstract

Essential oil extracted from the leaves of Myrtle, <em>Myrtus communis</em> L. (Myrtaceae)was tested <em>in vitro</em> for volatile toxicity against two stored-product insects (<em>Tribolium confusum</em> and <em>Callosobruchus maculatus</em>). 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. <em>C</em>. <em>maculatus</em> (LC₅₀=9.5 µl/l air) was more susceptible to the plant oil than <em>T. confusum</em> (LC₅₀=260.7 µl/l air). The results suggested that essential oil of <em>M. communis</em> L. could be used as a potential biocontrol agent for stored-product insects.