The effects of the oviposition regime on egg maturation rate in the synovigenic parasitoid, Microplitis rufiventris Kokujev were investigated. In non-ovipositing wasps, females normally reach a peak of egg maturation rate on 1 d posteclosion. Egg maturation slowed down once the maximum oviduct egg load was reached on 2 d posteclosion. In wasps manipulated for 20 ovipositions per day, the egg maturation rate during the first 3 d posteclosion was lower compared with those manipulated for 40 ovipositions per day. The rate of egg maturation in 1-d-old wasps was found to be the highest for those that experienced 60 ovipositions per day. The maturation rate in females offered unlimited hosts was not significantly greater than those manipulated for 40 ovipositions per day. The act of oviposition significantly increased the rate of egg maturation and minimized egg resorption in the female wasp. The distribution of mature eggs in the ovaries at death is apparently associated with the oviposition regime. Trade-offs between egg maturation rate and female longevity were quite evident.