“Macrosteles”, or 'aster leafhoppers' represent a newly introduced insect pest that has invaded O'ahu watercress crops. They transmit an aster yellow pythoplasma that has cost the watercress industry hundreds of thousands of dollars in damage due to crop losses. Of even greater concern is the possibility that the leafhoppers in Hawai'i will spread and negatively impact other agricultural crops. Understanding the invasion history, e.g. the country of origin, the route of introduction, etc., is the first step in initiating efforts to control or eradicate any invasive species. The taxonomy of the genus Macrosteles is problematic due to morphological conservatism across different species, making identification cumbersome at best.