Research was conducted to evaluate the possibility that a plant bug damaging cotton, Gossypium hirsutum L., in south Texas is actually green mirid, Creontiades dilutus Stål, which is the primary plant bug pest of cotton in Australia. Molecular comparisons targeting a fragment of the CO1 region of mitochondrial DNA were made on Creontiades specimens collected from the Lower Rio Grande Valley of Texas and specimens of green mirid and brown mirid, C. pacificus Stål, collected from Queensland, Australia. The emerging south Texas cotton pest is neither of the species tested from Australia; rather it is a closely related, possibly indigenous species. Further morphological systematics work is needed to identify the Creontiades species from Texas, and collection of additional specimens from several locations where it is known to occur is ongoing.