Some biological data of the phytoseiid mite species Euseius metwallyi Basha & Yousef and Typhlodromips capsicum Mostafa were investigated to evaluate their ability in controlling the two-spotted spider mite, Tetranychus urticae Koch under laboratory conditions of 29+3 °C and 73+5 % R.H. Adult females of the two predatory mite species were provided daily during their adulthood with constant number of T. urticae adult females (5 preys/ predator female). It was noticed that, both phytoseiid

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... fed well and successfully reproduce on the introduced prey, with significant differences in their longevity, fecundity and prey consumption rates. T. capsicum has significantly longer longevity compared to E. metwallyi. These values averaged 18.5 and 13.55 days for the former and later species, respectively. Adult females of T. capsicum showed higher fecundity, where they deposited a significantly greater number of eggs (17.67 eggs) during a significantly longer oviposition period (14.33 days) with a daily mean of 1.33 eggs. On the other hand, E. metwallyi adult females continued depositing eggs for a shorter oviposition period averaged 11.17 days, where they laid a total average of 12.33 eggs, with a daily men amount of 1.11 eggs. Adult females of T. capsicum showed higher rate of predation during adulthood, where they attacked a significantly greater number of 63.00 preys as a total average with a significantly greater daily mean of 3.41 preys. For E. metwallyi adult females, these values were 41.5 and 2.71 preys, respectively. Average daily prey consumption and oviposition rates of both phytoseiid species during their longevity were discussed also. Generally, these results indicated that, both E. metwallyi and T. capsicum may be considered as biological control agents against the two-spotted spider mite T. urticae but the former species was more efficient predator against the investigated prey pest.