Males and females of the parasitoid wasp Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) emerge en masse from gypsy moth, Lymantria dispar dispar (L.) (Lepidoptera: Noctuidae: Lymantriinae), host egg masses. Males engage females in a brief pre‐copulatory ritual, mate, and then execute a post‐copulatory ritual. We investigated mechanisms, functions, and fitness consequences of the pre‐ and post‐copulatory ritual by high‐speed cinematography, gas chromatographic‐mass spectrometric analyses of volatile constituents on the insects’ integument, and behavioral assays. Our data indicate that the mechanisms of the pre‐ and post‐copulatory ritual are physical interactions rather than pheromone transfer. During the pre‐copulatory ritual, the males put females into a trance‐like state that persists for some time after copulation. Males attained a mating with in‐trance females 9.5 times faster than with females that had come out of trance. Mated females with post‐copulatory ritual experience did not remate, whereas females lacking that experience did. The total number of offspring and daughters did not differ between females with or without post‐copulatory ritual experience or in relation to the duration of that ritual. The post‐copulatory ritual functions as a form of mate guarding in that the male accelerates awakening of the in‐trance female, which then rejects mating attempts by other males, ensuring his paternity.