| Acaetoneura Brauer & Bergenstamm, 1891 |
| Acantholespesia Wood, 1987 |
| Acantholespesia texana (Aldrich & Webber, 1924) |
| Acaulona Wulp, 1888 |
| Acaulona costata Wulp, 1888 |
| Acemyini Brauer & Bergenstamm, 1889 |
| Acemyiopsis Townsend, 1915 |
| Achaetoneuropsis Townsend, 1927 |
| Acroglossa Williston, 1889 |
| Acromiodexia Townsend, 1931 |
| Acronarista Townsend, 1908 |
| Actia Robineau-Desvoidy, 1830 |
| Actia americana (Townsend, 1892) |
| Actia interrupta Curran, 1933 |
| Actinodoria Townsend, 1927 |
| Actinodoria argentata Reinhard, 1975 |
| Actinodoria argentifrons (Wulp, 1890) |
| Adejeania Townsend, 1913 |
| Adejeania aurea (Giglio-Tos, 1893) |
| Adejeania brevirostris Curran, 1947 |