The invasive leafhopper Balclutha rubrostriata (Melichar) was found in abundance in Bexar County, Texas. An arthropod diversity study along highway right-of-way in September and October, 2008 identified B. rubrostriata as the single most abundant species. This is the first peerreviewed published record of this invasive species in the mainland United States. Other records of this species in the U.S. are discussed. Diagnostic characters of the adults are provided and illustrated, and the nymph is described and illustrated for the first time. Genomic DNA was extracted from one adult and one nymph specimen, and the mitochondrial COI gene was sequenced for each and yielded identical sequences, thus confirming the association of the nymph and adult. Sequences are deposited in GenBank for future use in diagnostic or other studies.