Developing sustainable strategies for the protection of stored legumes is essential due to the extensive damage caused by the dried bean beetle ( Acanthoscelides obtectus ). In this study, an innovative green bioformulation based on thymol loaded into cellulose acetate beads (CAB-T) using supercritical CO 2 was tested, aiming to achieve prolonged release of the active compound and provide dual biological action: protection of bean seeds from insect damage and enhancement of seed physiological quality during long-term storage. Material characterization confirmed efficient thymol loading (∼26 wt%) and revealed slight pore narrowing combined with weak polymer–thymol interactions, indicating successful incorporation into the matrix. Thymol release from CAB-T exhibited markedly reduced volatilization compared to neat thymol, with only ∼58% released after 40 days in air, demonstrating effective gradual-release performance. Insecticidal assays demonstrated a strong and concentration-dependent effect of CAB-T on adult mortality, reduction in longevity, and complete inhibition of progeny production at concentrations of ≥20 mg (equivalent to 5.12 mg thymol). CAB-T also displayed high repellency (80–88%, class V) across a broad concentration range, whereas neat thymol showed only moderate repellence and rapid loss of activity. Beyond pest control, CAB-T significantly improved bean seed quality after 90 days of treatment. Seed germination, root and shoot growth, seedling dry mass, and vigor indices increased substantially, indicating a strong biostimulatory effect. • Cellulose acetate beads impregnated with thymol (CAB-T) have a long-lasting effect. • CAB-T showed high repellency and insecticidal effect on dried been beetle. • CAB-T displayed biostimulatory effect on common bean seed. • CAB-T is an innovative and perspective pest control material in storage condition.
Lazarević et al. (Mon,) studied this question.