Diving beetle (Hyphydrus)

Taxonomic group

Dytiscidae: Hyphydrus

Diagnostic features

Hyphydrus is one of the dytiscid “diving beetles” having larvae and adults that are active swimmers. The larvae have a spoon-like “nose” that has no side barbs (unlike Antiporus). The adults are oval and streamlined, up to 5mm long, with 11-segmented antennae, and the last segment of the foreleg is shorter than the other tarsal segments.

[Hyphydrus] adult with short 4th segment of fore tarsus. Image: Stephen Moore Image — Hyphydrus adult with short 4th segment of fore tarsus. Image: Stephen Moore

[Hyphydrus] larva with spoon-like “nose” lacking side barbs. Image: Stephen Moore Image — Hyphydrus larva with spoon-like “nose” lacking side barbs. Image: Stephen Moore

Typical habitats

Hyphydrus are most common in ponds, wetlands and slow-flowing weedy streams

Feeding

The dytiscid beetles are predators, feeding on other pond invertebrates.

Indicator value

Hard bottom: unassigned; general dytiscids value 5
Soft bottom: unassigned; general dytiscids value 0.4

The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species

The presence of Hyphydrus is more likely to reflect pond-like habitat conditions rather than any particular water quality conditions. This genus has not been assigned tolerance values but the dytiscids have family scores of 5 (hard bottom sites) and 0.4 (soft bottom sites).