<i>Ruta Angustifolia</i> Essential Oil: Behavioral and Insecticidal Effects Against Larvae and Adults of <i>Tribolium castaneum</i>

Abstract

Abstract The study aims to evaluate the behavioral and insecticidal effects of Ruta angustifolia EO (RAEO) against larvae and adults of a major pest insect, Tribolium castaneum . RAEO exhibited a strong repellency against both adults and larvae where percentages as high as 74 and 72 % of PR (Percentage of Repellency) were recorded respectively, at 0.47 μL/cm 2 after 2 h. Regarding the antifeedant bioassay, no feeding deterrence was recorded in adults while an increase in appetite was registered in larvae exhibiting −80 % of FDI recorded at 0.2 μL/pellet. In terms of feeding preference, the response significantly depended on the developmental stage (F=97.19, P&lt;0.05) and larvae were attracted to treated pellets recording percentages of 84 and 73 % of PI (Preference index) after 5 and 30 min at 0.05 μL/pellet; on the other hand, adults expressed a repulsive behavior at 0.2 μL/pellet with a PI of −81.1 (20 min), and −69.2 % (30 min). Regarding topical application toxicity, a significant difference was observed between larvae and adults (p&lt;0.05 F=174.56). The study promotes the use of RAEO as a repellent and bioinsecticide for the control of larvae and adults of T. castaneum .