| Townsendia gracilis Martin, 1966 |
| Townsendia minuta Williston, 1895 |
| Townsendia nemacula Martin, 1966 |
| Townsendia triangulata Martin, 1966 |
| Trigonomiminae Enderlein, 1914 |
| Triorla Parks, 1968 |
| Triorla ambiguus (Macquart, 1846) |
| Triorla argyrogaster (Macquart, 1846) |
| Triorla concolor (Walker, 1851) |
| Triorla interrupta (Macquart, 1834) |
| Triorla lateralis (Macquart, 1838) |
| Triorla maculatus (Macquart, 1838) |
| Triorla perrumpeus (Walker, 1860) |
| Triorla rubidiventris (Macquart, 1850) |
| Triorla villosus (Bellardi, 1861) |
| Trupanea Macquart, 1838 |
| Tuberculefferia Artigas & Papavero, 1997 |
| Tuberculefferia producta (Hine, 1919) |
| Tuberculefferia setigera (Wilcox, 1966) |
| Tuberculefferia tuberculata (Coquillett, 1904) |