This study evaluated the fumigant toxicity of Thymus munbyanus subsp. coloratus essential oil against adult Ephestia kuehniella (Zeller). To determine sublethal effects, we integrated biochemical biomarkers with assessments of reproductive performance and locomotor activity. Adults were exposed via fumigation to concentrations between 0.05 and 0.8 ?L/mL of air, with lethal concentrations calculated after 24 h of exposure. The essential oil showed strong fumigant activity, with LD25 and LD50 values of 0.153 and 0.26 ?L/mL of air, respectively. Sublethal exposure at these concentrations was associated with changes in biomarker responses in adults, including increased glutathione S-transferase (GST) and catalase (CAT) activities, along with decreased acetylcholinesterase (AChE) activity. In addition, fumigation affected adult reproductive performance by reducing oviposition, as reflected by a decrease in the number of eggs laid and hatched. Locomotor activity was also impaired, with reductions in distance traveled, movement duration, and movement speed. Overall, these findings suggest that T. munbyanus essential oil has potential as a botanical fumigant against E. kuehniella adults.
Hamida et al. (Thu,) studied this question.