Chemical composition and bio-pesticidal values of essential oil isolated from the seed of Heracleum persicum Desf. ex Fischer (Apiaceae)

<p>The present investigation was aimed to analyse the chemical composition of essential oil isolated from <em>Heracleum persicum </em>Desf. ex Fischer and assess its lethal and sub-lethal effects against <em>Tribolium</em> <em>castaneum</em> (Herbst). Essential oil from hydro-distilled seeds of <em>H. persicum</em> was analyzed by gas chromatography-mass spectrometry (GC-MS), and hexyl butyrate (50.58%), octyl acetate (9.80%) and hexyl hexanoate (8.75%) were found as principal constituents. Repellent activity, contact and fumigant toxicity and antifeedant effects of this oil were assessed against the adults of <em>T.</em> <em>castaneum</em>. The essential oil strongly repelled <em>T. castaneum </em>adults even at the lowest concentration (0.035 μL cm^-2). Complete repellency (100%) occurred when the highest concentration (0.212 μL cm^-2) was applied for 8 h. <em>T. castaneum</em> was very susceptible to <em>H. persicum</em> oil at both contact and fumigant bioassays. In the fumigant toxicity, essential oil killed the larvae, pupae and adults and significantly decreased larvae emerged from treated eggs. LC₁₀ to LC₄₀ values of fumigation adult’s bioassay as sub-lethal concentrations were used to evaluate the antifeedant effects. <em>H. persicum</em> essential oil has significant antifeedant effects on <em>T. castaneum</em> adults and decrease of feeding happened when oil concentrations increased. The results of the present study indicate that essential oil of <em>H</em><em>.</em><em> persicum</em>, with wide bio-effects on <em>T</em><em>.</em><em> castaneum</em>, is a source of biologically active agents which may potentially prove to be efficient insecticides.