Miridae are one of the most speciose families of true bugs, containing >11,000 species. These mostly phytophagous insects can be found in all biogeographic regions interacting closely with their plant hosts. The diverse ecosystems seen in Australia provide rich habitats for mirids and >500 species of Phylinae have been described from this continent. Casuarinaceae contains two economically important genera in Australia that are the host plants for several undescribed species of mirids. In an effort to describe new genera and species, we examined 593 specimens of Miridae collected from Casuarina and Allocasuarina species throughout Australia between 1995 and 2004. Assessments based on external morphology and genitalic dissections suggest these specimens comprise 15 undescribed species in 7 new genera of Phylinae. New genera were placed into 4 separate tribes of Phylinae based on morphological data suggesting sympatric speciation to disguise with their Casuarinaceae hosts. Phylogenetic analysis utilizing UCE data sets were used to test our preliminary assessment of the tribal assignments of new genera.