Five phytoseiid species were tested to evaluate their potential as predators of Phthorimea operculella and Spodoptera littoralis eggs as an alternative food substance in the laboratory. For Typhlodromips swirskii, the development was faster and reproduction was higher, when fed on P. operculella eggs, while the developmental time increased and reproduction decreased when Neoseiulus californicus fed on both eggs respectively. Females of T. swirskii consumed a higher number of P. operculella and S. littoralis eggs than N. californicus did. The number of eggs deposited per day by T. swirskii was higher (2.1 and 1.3 eggs / female / day) than for N. californicus (1.1 and 0.9 eggs /female/day) on eggs of P. operculella and S. littoralis respectively. Immatures survival of Typhlodromus balanites, Paraseiulus talbii and Typhlodromus transvaalensi were low on P. operculella and S. littoralis eggs and all failed to develop to adulthood.