Studies were conducted to investigate the seasonal activities of larval parasitoid C. plutellae on the larvae of P. xylostella in cabbage crop. The activities of C. plutellae were on the peak during 11th and 10th standard meteorological weeks in 2000-01 and 2001-02 with 47.2 and 47.3 per cent larval parasitisation, respectively. The larval parasitoid showed a positive correlation with the host larval population in both the years. BR Parasites diseases and disorders. Parasites. Insect parasites. Hosts. Insect hosts. Habitat. Man made habitat. Abiotic factors. Physical factors. Land zones. Oriental region. Eurasia. Asia. India. Plutella xylostella (Plutellidae): Host; Cotesia plutellae (Braconidae): Parasite. Cotesia plutellae: Lepidopteran hosts, Plutella xylostella, Seasonal prevalence and influencing factors, cabbage crop, Humidity, Temperature, Rajasthan, Udaipur area; Plutella xylostella: Hymenopteran parasites, Cotesia plutellae, Seasonal prevalence and influencing factors, Cultivated land habitat, Cabbage crop, Humidity, Temperature, Rajasthan, Udaipur area. ST Insecta, Lepidoptera, Glossata, Heteroneura, Yponomeutoidea, Plutellidae; Insecta, Hymenoptera, Apocrita, Terebrantia, Ichneumonoidea, Braconidae. Arthropods; Hymenopterans; Insects; Invertebrates; Lepidopterans. none