Different selective pressures are expected to shape life history traits in female and male parasitoid wasps. In females a strong trade-off exists between reproduction and survival, while in males the importance of this trade-off is not known. Adult longevity of males and females of two parasitoid wasp species were measured. A preliminary theoretical framework and an outline of future research needed for interpreting the results obtained is given. Nutrition; Reproduction; Life cycle and development; Development; Abiotic factors; Physical factors Venturia canescens (Ichneumonidae); Starvation; Sex differences; Longevity, influences; Temperature Ganaspis (Cynipidae); Starvation; Sex differences; Longevity, influences none