Biocontrol of tamarisk in the southwestern United States, in the form of species belonging to the genus Diorhabda, has been the subject of much research in the past few years in terms of efficacy and impact to native wildlife. This study documents the northern tamarisk beetle's (Diorhabda carinulata) arrival to the Las Vegas Wash in southern Nevada, and its impact on two other nonnative phytophagous invertebrate species that also feed on tamarisk. Our research indicates a negative correlation between the arrival of the northern tamarisk beetle and a population of tamarisk leafhoppers (Opsius stactogalus). There was no significant influence on a population of the splendid tamarisk weevil (Coniatus splendidulus). The arrival of the northern tamarisk beetle resulted in substantial defoliation of tamarisk whereas the two other species had minimal impacts on tamarisk foliage.