The primary parasitoid wasp, Diaeretiella rapae (M'Intosh), is used as a biological control agent in insect pest management strategies to combat aphid pests, mainly on cruciferous plants. To investigate the spatial scales over which this beneficial parasitoid wasp moves within an agricultural landscape, we developed five polymorphic microsatellite markers. The number of alleles per locus ranged from 11 to 21. Cross-species amplification indicated that these loci may be useful in some other members of the Aphidiinae. Biochemistry; Genetics; Evolution; Variation Diaeretiella rapae (Aphidiidae); Nucleic acids; Molecular genetics; Microsatellite DNA loci; Isolation & characterization, polymorphism; Biochemical variation; Polymorphic microsatellite DNA loci none