Considering the importance of sustainable pest control, this study evaluated the insecticidal and antifeedant properties of medicinal plants from arid regions against Tribolium castaneum. The methodology involved extracting bioactive compounds from four selected plant species: Atriplex halimus L. (saltbush), Sonchus oleraceus L. (sowthistle), Lavandula multifida L. (fernleaf lavender) and Globularia alypum L. (globe daisy), and conducting antifeedant and insecticidal bioassays, along with phytochemical screening tests, to assess their effects on adult beetles. The primary findings indicated that Lavandula multifida and Sonchus oleraceus manifested notable insecticidal activity, underscoring their promise as efficacious natural pest management agents, despite their modest antifeedant activities. Notably, Atriplex halimus demonstrated remarkable antifeedant activity, achieving a 31.37% effect, though its insecticidal activity was somewhat modest. Globularia alypum showed minimal insecticidal and antifeedant activity. However, the utilization of Lavandula multifida as a bioinsecticide may be limited by the plant’s small size, which necessitates the production of a considerable quantity of plant material to produce a sufficient extract. Phytochemical analysis indicated that these plants are rich in bioactive compounds, including flavonoids, terpenoids, and tannins. The observed differences between insecticidal and antifeedant activities suggest the presence of different underlying mechanisms. This study underscores the potential of these plant extracts as environmentally friendly alternatives to synthetic pesticides and lays the groundwork for future research into their role in sustainable pest management strategies.