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WATER SCAVENGER BEETLES

HYDROPHILIDAE

HYDROPHILIDAE

family

Hydrophilidae

known species

3,400

distribution

Worldwide except Antarctica

habitat

Many species are common in and around

wetland habitats, especially in slow-moving

fresh water with muddy banks, and in decay

situations such as dung, compost, and fungi

size

1.5–55 mm

diet

Larvae of some genera are predators. Adults

feed on a range of decaying organic matter

and some vegetation

T

he Hydrophilidae, known as the water

scavenger beetles, are the second-most

species-rich group of aquatic beetles after the

Dytiscidae, and can be found in freshwater bodies,

especially weedy, slow-moving waters with muddy

banks, throughout the world. In contrast to

Dytiscidae, most hydrophilids are not very powerful

swimmers, and many species spend much of their

time clinging to water plants. They are called

“water scavenger beetles” because adults of

most species are detritivores feeding on

dead plant matter, rather than active

predators like the dytiscids. The

larvae, on the other hand, often

feed on other invertebrates, with

several species being specialized

consumers of water snails.

Adults collect air from

the water surface, which they

usually carry as a bubble on

the underside of the abdomen.

Hydrophilids can be distinguished

from dytiscids by their shape, which

is less streamlined and usually widest

toward the back, rather than the

characteristic oval shape of the diving beetles,

below | Berosus signaticollis One of

the exceptions to the “crawling” rule:

from Europe, it is a fast and powerful

swimmer.