Evaluation of biological activities of Piper nigrum oil against Tribolium castaneum

Abstract

The essential oil of Piper nigrum (L.) was evaluated for its repellent, insecticidal and developmental inhibitory activities against an important wheat grain pest Tribolium castaneum (Herbst). Adults of T. castaneum were repelled significantly by P. nigrum at 0.2 % concentration (v:v) and above in filter paper test. The LC50 values for larvae and adults were calculated to be 14.022 µl and 15.262 µl respectively. The oil had shown a dose response relationship as the larval and adult mortality increased while the larval survival and adult emergence decreased with increase in the concentration of essential oil. Effective concentration (EC50) of P. nigrum oil to reduce the number of larvae transformed to pupae to 50 % was found to be 6.919 µl. Key words: essential oil, Piper nigrum, Tribolium castaneum.