| Summary: | The aim of this research was to determine the chemical composition and insecticidal activity of the essential oils derived from flowering aerial parts of <em>Artemisia giraldii </em>Pamp. and <em>A. subdigitata</em> Mattf. (Family: Asteraceae) against the maize weevil (<em>Sitophilus zeamais</em> Motsch.). Essential oils of aerial parts of <em>A. giraldii</em> and <em>A. subdigitata</em> were obtained from hydrodistillation and investigated by GC and GC-MS. A total of 48 and 33 components of the essential oils of <em>A. giraldii</em> and <em>A. subdigitata</em> were identified, respectively. The principal compounds in <em>A. giraldii</em> essential oil were β-pinene (13.18%), <em>iso</em>-elemicin (10.08%), germacrene D (5.68%), 4-terpineol (5.43%) and (<em>Z</em>)-β-ocimene (5.06%). 1,8-Cineole (12.26%) and α-curcumene (10.77%) were the two main components of the essential oil of <em>A. subdigitata</em>, followed by β-pinene (7.38%), borneol (6.23%) and eugenol (5.87%). The essential oils of <em>A. giraldii</em> and <em>A. subdigitata</em> possessed fumigant toxicity against the maize weevils with LC<sub>50</sub> values of 6.29 and 17.01 mg/L air, respectively. The two essential oils of <em>A. giraldii</em> and <em>A. subdigitata</em> also exhibited contact toxicity against <em>S. zeamais</em> adults with LD<sub>50</sub> values of 40.51 and 76.34 µg/adult, respectively. The results indicated that the two essential oils show potential in terms of fumigant and contact toxicity against grain storage insects.
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