none Enter A study was conducted to determine the prevalence of Nosema hombycis infection in the highland populations of diamondback moth (DBM) and its two parasitoids, Diadegma semiclausum and Cotesia plutellae. Insects were collected from two vegetable farms in the highland area (Sri Juliana Farm, Brinchang, and MARDI, Cameron Highlands, Pahang). Results showed that Nosema spores were abundant in DBM and its two parasitoids. There was a significant (p < 0.05) difference in the means of prevalence rate, spore concentrations and infection intensities between DBM and its parasitoids at both locations. Although results from both location was somewhat vary, the parasitoids seemed to have lower rate of Nosema infection (prevalence), spore concentrations and infection intensities than its host, DBM. The potential of N. hombycis to be used as a biological control agent of DBM are discussed. Cotesia plutellae (Braconidae): [Host, Parasite]. Diadegma semiclausum (Ichneumonidae): [Host, Parasite]. Plutella xylostella (Plutellidae): [Host]. Nosema bombycis (Microspora): [Parasite]. noneEmailOc13