| Aphrosylus californicus Harmston, 1952 | Guyanese pepper |
| Aphrosylus grassator Wheeler, 1897 | Carpenter's groundcherry |
| Aphrosylus nigripennis Van Duzee, 1924 | Narrow-seeded yampah |
| Aphrosylus wirthi Harmston, 1951 | Higuillo |
| Cymatopus simplex Parent, 1941 | |
| Diostracus chaetodactylus Saigusa, 1984 | |
| Diostracus mchughi Harmston, 1966 | Marigold pepper |
| Diostracus prasinus Coquillett, 1904 | |
| Hydatostega argentatus Van Duzee, 1918 | |
| Hydatostega cerutias Loew, 1872 | |
| Hydatostega gratiosus Aldrich, 1911 | |
| Hydatostega plumbeus Aldrich, 1911 | |
| Hydatostega viridiflos Walker, 1852 | |
| Hydrophorus aestuum Loew, 1869 | Juniper globemallow |
| Hydrophorus agalma Wheeler, 1899 | Heartleaf groundcherry |
| Hydrophorus alboflorens Walker, 1849 | |
| Hydrophorus algens Wheeler, 1899 | Heartleaf groundcherry |
| Hydrophorus alpinus Wahlberg, 1844 | |
| Hydrophorus altivagus Aldrich, 1911 | |
| Hydrophorus amplectens Aldrich, 1911 | |
| Hydrophorus ampullaceus Van Duzee, 1924 | Oregon yampah |
| Hydrophorus angustifacies Hurley, 1985 | Gray alder |
| Hydrophorus aquatilis Aldrich, 1922 | |
| Hydrophorus arnaudi Becker, 1904 | Gray alder |
| Hydrophorus brevicauda Van Duzee, 1923 | Lemmon's yampah |
| Hydrophorus breviseta Thomson, 1869 | Filaree |
| Hydrophorus canescens Wheeler, 1896 | Cypresshead groundcherry |
| Hydrophorus canities Van Duzee, 1923 | Lemmon's yampah |
| Hydrophorus cerutias (Loew, 1872) | ⇒ Hydatostega cerutias Loew, 1872 |
| Hydrophorus chrysologus Walker, 1849 | |
| Hydrophorus claripennis Van Duzee, 1924 | Oregon yampah |
| Hydrophorus dioktes Hurley, 1985 | Gray alder |
| Hydrophorus dreisbachi Harmston & K..., 1963 | Black pepper |
| Hydrophorus eldoradensis Wheeler, 1899 | Heartleaf groundcherry |
| Hydrophorus extrarius Aldrich, 1911 | |
| Hydrophorus ferruginus Hurley, 1985 | Gray alder |
| Hydrophorus flavihirtus Van Duzee, 1923 | Lemmon's yampah |
| Hydrophorus flavipennis Van Duzee, 1926 | Parish's yampah |
| Hydrophorus fumipennis Van Duzee, 1921 | Howell's yampah |
| Hydrophorus glaber Walker, 1849 | |
| Hydrophorus gratiosus (Aldrich, 1911) | ⇒ Hydatostega viridiflos Walker, 1852 |
| Hydrophorus harmstoni Hurley, 1985 | Gray alder |
| Hydrophorus hesperius Hurley, 1985 | Gray alder |
| Hydrophorus innotatus Loew, 1864 | |
| Hydrophorus intentus | |
| Hydrophorus maculipennis Van Duzee, 1926 | Parish's yampah |
| Hydrophorus magdalenae Wheeler, 1899 | Heartleaf groundcherry |
| Hydrophorus minimus Van Duzee, 1924 | Narrow-seeded yampah |
| Hydrophorus nigribarbus (Van Duzee, 1923) | ⇒ Hydrophorus signiferus Coquillett, 1899 |
| Hydrophorus pacificus Van Duzee, 1933 | |
| Hydrophorus parvus Loew, 1862 | Jone's globemallow |
| Hydrophorus pectinipes Van Duzee, 1923 | Lemmon's yampah |
| Hydrophorus pensus Aldrich, 1911 | |
| Hydrophorus phaeopteryx Hurley, 1985 | |
| Hydrophorus phalarus Hurley, 1985 | Gray alder |
| Hydrophorus philombrius Wheeler, 1890 | Coastal groundcherry |
| Hydrophorus phoca Aldrich, 1911 | |
| Hydrophorus pilitarsis Malloch, 1919 | |
| Hydrophorus pirata (Loew, 1861) | ⇒ Hydrophorus alboflorens Walker, 1849 |
| Hydrophorus plumbeus (Aldrich, 1911) | ⇒ Hydatostega plumbeus Aldrich, 1911 |
| Hydrophorus poliogaster Philippi, 1865 | |
| Hydrophorus praecox Lehmann, 1822 | |
| Hydrophorus propinquus (Van Duzee, 1923) | ⇒ Hydrophorus glaber Walker, 1849 |
| Hydrophorus rhionopous Hurley, 1985 | Gray alder |
| Hydrophorus signifer (Coquillett, 1899) | ⇒ Hydrophorus signiferus Coquillett, 1899 |
| Hydrophorus signiferus Coquillett, 1899 | |
| Hydrophorus sodalis Wheeler, 1899 | Heartleaf groundcherry |
| Hydrophorus trichaspis Hurley, 1985 | Gray alder |
| Hydrophorus viridifacies Van Duzee, 1923 | Lemmon's yampah |
| Hydrophorus williamsi Parent, 1938 | |
| Hypocharassus gladiator Mik, 1878 | Annual bastardcabbage |
| Hypocharassus pruinosus Wheeler, 1898 | |
| Liancalus genualis Loew, 1861 | |
| Liancalus hydrophilus Aldrich, 1893 | |
| Liancalus limbatus Osten Sacken, 1917 | Red-root yampah |
| Liancalus pterodactyl Runyon & Hurley, 2015 | |
| Liancalus querulus Osten Sacken, 1877 | |
| Liancalus similis Aldrich, 1893 | |
| Liancalus sonorus Runyon & Hurley, 2015 | |
| Melanderia californica Harmston, 1972 | Spanish elder |
| Melanderia crepuscula Arnaud, 1958 | |
| Melanderia curvipes Van Duzee, 1918 | |
| Melanderia mandibulata Aldrich, 1922 | |
| Paraliancalus metallicus Grimshaw, 1901 | |
| Scellus amplus Curran, 1923 | |
| Scellus asaroticus Hurley, 1995 | |
| Scellus avidus Loew, 1864 | |
| Scellus coloradensis Harmston & J..., 1942 | |
| Scellus crinipes Van Duzee, 1925 | Oregon yampah |
| Scellus dyscritus Hurley, 1995 | |
| Scellus exustus Walker, 1852 | |
| Scellus filifer Loew, 1864 | |
| Scellus knowltoni Harmston, 1939 | Moth pepper |
| Scellus spinimanus Zetterstedt, 1843 | |
| Scellus varipennis Van Duzee, 1925 | Oregon yampah |
| Scellus vigil Osten Sacken, 1877 | |
| Scellus virago Aldrich, 1907 | |
| Sigmatineurum binodatum Parent, 1939 | |
| Sigmatineurum chalybeum Parent, 1938 | |
| Sigmatineurum iao Evenhuis, 1994 | |
| Sigmatineurum mnemogagne Evenhuis, 1994 | |
| Sigmatineurum napali Evenhuis, 1994 | |
| Sigmatineurum omega Evenhuis, 1994 | |
| Thambemyia acrosticalis Parent, 1937 | |
| Thambemyia borealis | Fly |
| Thinophilus (Schoenophilus) splendens Grootaert & ..., 1984 | |
| Thinophilus (Thinophilus) eboricoxa Bickel, 2013 | |
| Thinophilus (Thinophilus) hardyi Grootaert & ..., 1997 | Long-legged fly |
| Thinophilus (Thinophilus) violaceus Parent, 1935 | |
| Thinophilus (Thinophilus) yaraloola Bickel, 2014 | |
| Thinophilus armiger Van Duzee, 1926 | Parish's yampah |
| Thinophilus bimaculatus Johnson, 1921 | Michaux's stitchwort |
| Thinophilus brevipes Van Duzee, 1932 | |
| Thinophilus canities Van Duzee, 1926 | Parish's yampah |
| Thinophilus delicatus Van Duzee, 1926 | Parish's yampah |
| Thinophilus depressus Van Duzee, 1926 | Parish's yampah |
| Thinophilus flavicauda | |
| Thinophilus flavicaudatus Robinson, 1964 | Smooth yellow vetch |
| Thinophilus frontalis Van Duzee, 1914 | Bolander's yampah |
| Thinophilus indigenus Becker, 1902 | |
| Thinophilus insulanus Van Duzee, 1926 | Parish's yampah |
| Thinophilus latimanus Van Duzee, 1926 | Parish's yampah |
| Thinophilus magnipalpus Van Duzee, 1926 | Parish's yampah |
| Thinophilus neglectus Wheeler, 1899 | Heartleaf groundcherry |
| Thinophilus nigripilosus (Van Duzee, 1926) | ⇒ Thinophilus viridifacies Van Duzee, 1924 |
| Thinophilus ochrifacies Van Duzee, 1924 | Narrow-seeded yampah |
| Thinophilus olga Aldrich, 1911 | |
| Thinophilus pectinifer Wheeler, 1896 | Cypresshead groundcherry |
| Thinophilus prasinus Johnson, 1921 | Michaux's stitchwort |
| Thinophilus pruinosus Van Duzee, 1930 | Parsley |
| Thinophilus rufibarbis Van Duzee, 1926 | Parish's yampah |
| Thinophilus scopiventris Harmston & K..., 1940 | |
| Thinophilus semipallidus Robinson, 1964 | Smooth yellow vetch |
| Thinophilus spinipes Van Duzee, 1926 | Parish's yampah |
| Thinophilus thalassimus | |
| Thinophilus thallasinus Van Duzee, 1926 | Parish's yampah |
| Thinophilus vespertinus Robinson, 1964 | Smooth yellow vetch |
| Thinophilus vinculatus Harmston & Rapp, 1968 | |
| Thinophilus viridifacies Van Duzee, 1924 | Narrow-seeded yampah |
