Investigating alternatives to synthetic chemicals in pest management is essential. The bioactivity of Artemisia absinthium and A. dracunculus essential oils (EOs) was evaluated against two stored-product insect pests (Sitophilus granaries and Tribolium castaneum) and two root-knot nematodes (Meloidogyne incognita and M. chitwoodi). EOs were hydrodistilled and analyzed by GC-MS: A. absinthium consisted mainly of myrtenyl acetate (47.10%) and β-thujone (11.41%); A. dracunculus of methyleugenol (26.02%), β-asarone (14.04%), and elemicin (10.95%). In contact bioassays, A. absinthium caused 93.2–96.8% mortality against S. granarius, but minimal effect on T. castaneum. A. dracunculus caused 66.3–73.5% mortality against S. granarius, no effect on T. castaneum, yet reduced progeny by 87%. Both EOs strongly repelled T. castaneum but weakly affected S. granarius. A. dracunculus exhibited 100% nematicidal efficacy against M. incognita and 94.9% against M. chitwoodi; A. absinthium showed limited effect. A. dracunculus showed minimal hatching inhibition (<30%), whereas A. absinthium increased hatching. Sparse Partial Least Squares (sPLS) prioritized pulegone, methyleugenol, β-asarone, β-thujone, myrtenyl acetate, and β-phellandrene as constituents co-varying with AChE/BChE responses, with docking identifying pulegone as the top ligand. These findings demonstrate species-specific bioactivity patterns: A. dracunculus shows strong nematicidal and reproductive inhibitory effects, whereas A. absinthium shows potent acute toxicity and repellency against S. granarius, supporting multi-target biopesticide strategies to mitigate risks of synthetic chemical treatments.