Fumigant toxicity of menthol was investigated against different stages of Tetranychus urticae Koch and two associated predators. Recorded LC50 values were 0.76, 0.279 and 0.269 mg/l against eggs, protonymphs and adults, respectively. Increase in efficiency was detected with increasing temperature, as LC50 values was decreased from 0.356 to 0.269 and 0.217 mg/l when temperature increased from 20° to 25° and 35°C; respectively. The two predators, Phytoseiulus persimilis A. H. and Neoseiulus californicus (McGr.) proved to be more tolerant to mentol vapor than T. urticae. Subjecting T. urticae proto-nymphs to LC50 of menthol vapor reduced mite productivity as finite rate decreased from 1.37 to 1.29 female per female per day. No significant change was recorded in total proteins, alkaline phosphatase and acid phosphatase between survived-treated and non-treated mites; while significant reduction was recorded in survived-treated mites in α-esterases, β-esterases and G. S-transferase.