Technical Abstract: Larvae of closely related parasite taxa often lack morphological differences that can be used to easily separate different species. Determining the parasite species present in a host population then requires rearing to obtain adult parasites, often a time-consuming process. To monitor field parasitism rates by several species of Peristenus wasps (Hymenoptera: Braconidae) that are natural enemies of Lygus (Heteroptera: Miridae), we have developed a two-step molecular approach. PCR with wasp- targeting primers is performed on DNA extracted from a Lygus nymph and the parasite larvae (if any) therein. A positive reaction indicates parasite presence. Next, a restriction digest on the PCR product will indicate which parasite species is present among known alternatives, and a diagnosis is achieved in days rather than weeks or months.