Genetic differentiation among six Florida populations of Diaprepes abbreviatus (L.) was determined using protein and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers. Proteins were separated by electrophoresis and stained with silver stain and for α-naphthylacetate esterase activity. No differentiation was observed among populations when egg proteins were silver stained: α-naphthylacetate esterase activity differentiated five of the six populations. RAPD-PCR data showed significant differentiation among populations, consistent with the hypothesis of three independent introductions of D. abbreviatus into Florida. Our data indicate that D. abbreviatus populations, once introduced, have generally remained in one locality with limited dispersal to new areas.