Date of this Version
The only lists of Hydrophiloidae (Coleoptera: Hydrophilidae, Helophoridae, Hydrochidae, and Hydraenidae) from the mid-Atlantic region are Ulke (1902) who reported 46 species from the District of Columbia and Matta (1974) who presented keys and short descriptions for the 49 aquatic species of Hydrophilidae of Virginia.
The following checklist records 103 species (75 aquatic) from Maryland. Comparable lists of aquatic species for other states are as follows: 53 species recorded from Florida by Young (1954); 20 species recorded from Ithaca, New York by Swenson (1982); 67 species from North and South Carolina by Brigham (1982); and 47 species from Illinois by Wooldridge (1967). Hatch (1965) recorded 128 species (of all habitats, 102 aquatic) from the Pacific Northwest; and 88 species (67 aquatic) reported from New York by Leng (1928).