Evaluation of Insecticidal Properties of Artemisia absinthium via Induced and Topical Applications Against Storage Pests

Artemisia absinthium (L.) essential oil (1.2–1.6% yield) exhibited significant insecticidal activity against three major stored-grain pests: the rice moth, Corcyra cephalonica , the red flour beetle, Tribolium castaneum , and the pulse beetle, Callosobruchus chinensis . Fumigation assays (10–50 µl/L air) demonstrated dose- and exposure-dependent toxicity, with 48-h LC₅₀ values of 18.23, 34.32, and 41.17 µl/L air for C. cephalonica , T. castaneum , and C. chinensis , respectively, indicating greater susceptibility of C. cephalonica . In topical contact bioassays (0.25–2.00 µl/insect), 72-h LD₅₀ values were 1.34, 1.76, and 1.40 µl/insect, respectively. Under induced contact exposure (2.5–20.0 µl), 96-h LC₅₀ values declined to 15.18, 12.82, and 11.12 µl, confirming increased toxicity with prolonged exposure. Across all bioassays, mortality increased significantly with both dose and exposure duration. Gas chromatographic analysis identified β-thujone (17.25%) as the predominant constituent, followed by p -cymene (13.94%), camphor (12.42%), α-terpineol (12.27%), eugenol (12.20%), terpinen-4-ol (10.10%), α-pinene (9.90%), farnesol (5.80%), myrcene (4.54%), α-thujone (1.62%), and β-pinene (0.54%). The insecticidal efficacy is primarily attributed to β-thujone and the synergistic action of these bioactive terpenoid constituents.