Hydrophilidae

Hydrophilidae, also known colloquially as water scavenger beetles, is a family of beetles. Aquatic hydrophilids are notable for their long maxillary palps, which are longer than their antennae. Several of the former subfamilies of Hydrophilidae have recently been removed and elevated to family rank; Epimetopidae, Georissidae (= Georyssidae), Helophoridae, Hydrochidae, and Spercheidae. While the majority of hydrophilids are aquatic, around a third of described species are terrestrial, mostly belonging to the subfamily Sphaeridiinae.

With rare exceptions, the larvae are predatory while the adults may be herbivores or predators in addition to scavenging. Many species are able to produce sounds.

Species of Hydrophilus are reported as pests in fish hatcheries. Other species are voracious consumers of mosquito larvae, and have potential as biological control agents.

This beetle family contains 2,835 species in 169 genera.