Sustainable alternative for the control of heritage pests:insecticidal action of essential oils against Tenebrio molitor L.

Abstract

This study focused on evaluating the insecticidal efficacy of essential oils (EOs) of Thymus mastichina (white thyme) and Cannabis sativa (cannabis) from local strains CAT ₁ and CAT ₃ against the pest insect Tenebrio molitor. The trial was extended for 30 days, monitoring the mortality and development of larvae in each treatment group. The results show significant variability in the effectiveness of the oils. Thyme oil proved to be the most effective, achieving 100 % mortality. In contrast, CAT ₃ oil did not present any insecticidal effect, since all larvae survived and reached the adult stage. Finally, CAT ₁ oil showed an intermediate effect: although mortality was low (20 %), 40 % of the larvae were affected in their development, failing to complete their life cycle during the trial period. These results make the tested EOs a promising option for use in wall and furniture coatings against insect damage, contributing to the conservation of cultural heritage.