The reduction in use of crop protection products in recent years has led to the appearance of new phytophage pests such as Nezara viridula (L.) in the greenhouses of Almería (Spain). Its biological control is, however, possible, and involves the deliberate release of the wasp Trissolcus basalis (Woll.), which parasitizes the pest's eggs. The aim of the present study was to help meet peak demand for this wasp by providing a viable reserve of material -the frozen eggs of N. viridula -for parasitization, and using stored T. basalis adults hatched from these eggs as a source for beginning wasp production in anticipation of such peak moments. The capacity of T. basalis to parasitize the eggs of N. viridula subjected to freezing and storage at -25°C was therefore assessed, and the possibility of storing (at +15°C) adult parasitoids hatched from these frozen host eggs examined. No significant differences were observed in the use of the frozen or fresh host eggs in terms of percentage parasitism, parasite hatching or parasite mortality. These results confirm that T. basalis can be raised using frozen N. viridula eggs in order to supply the varying needs of greenhouse crop growers in Almería.