Chemical Composition and Insecticidal Activity of <i>Pastinaca sativa</i> L. Essential Oils Against Two Storage Insects

Essential oils (EOs) derived from certain medicinal plants present a potential alternative to synthetic insecticides for managing stored-product insects. Two major insects, Tribolium castaneum (TC) Herbst (Coleoptera: Tenebrionidae) and Lasioderma serricorne (LS) (Coleoptera: Ptinidae), are key targets for EO control. Pastinaca sativa L. has medicinal and industrial uses and shows potential as a biopesticide. EOs were extracted from P. sativa aerial parts (A1) and fresh roots (R1-R3 obtained sequentially) via hydrodistillation. Gas chromatography-mass spectrometry (GC-MS) analysis showed 3-carene, 2,6-dimethyl-1,3,5,7-octatetraene, E,E-, and myristicin as dominant components in A1 EO, R1 EO and R2, R3 EOs. Four EOs exhibited both contact toxicity and repellent activity. R1-R3 EOs demonstrated strong efficacy compared to A1, showing the LD₅₀ values: 8.25 µL/adult for R1 EO against TC and 14.31 µL/adult for R3 EO against LS. EO's repellent effects were comparable to N,N-diethyl-3-methylbenzamide (DEET) at the highest concentrations. As the concentration decreased, the repellent effect gradually turned into an attractant effect. Generally, four EOs exhibited stronger repellent effects against TC than LS. This research confirmed that P. sativa EOs possessed insecticidal potential and offered scientific guidance for its efficient extraction, demonstrating its promise as a novel eco-friendly insecticide.