
Effects of ethanol extracts of Curcuma longa L., Myristica fragrans Houtt. and Piper nigrum L. on the mortality of red flour beetle were investigated. In the current study, ethanol plant extracts showed that the mortality rate increased with increasing concentration as well as the length of exposure times. On the other hand, results of this study point out that the three plants of this study might be useful as potent insect control agents. The results showed that Myristica fragrans had the best effect on the mortality of adults and Larvae (100%) in 8% concentration, followed by Curcuma longa and Piper nigrum extracts of mortality were achieved. After 24-hour exposure, the LD50 values of ethanol extract of Piper nigrum, Curcuma longa and Myristica fragrans against adult Tribolium castaneum were found to be 0.73, 0.79 and 0.45 mg/cm2, respectively, while in larvae found 0.34, 0.27 and 0.12 mg/cm2 respectively. No mortality was observed in control. The LD50 values for fifth instar larvae were 0.34, 0.27 and 0.12 mg/cm2 in Piper nigrum, Curcuma longa, and Myristica fragrans respectively.