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Water scavenger beetle (Laccobius)

Taxonomic group

Hydrophilidae: Laccobius

Diagnostic features

Laccobius is a hydrophilid beetle with a larva that has asymetrical mandibles (the two sickle-like jaws are not the same shape). The adults are active swimmers with a generally oval, 6-segmented abdomen. The adult antennae are 8-segmented (the last 3 segments enlarged to form a club) and usually tucked under the head.

Typical habitats

Laccobius can be found in a range of freshwater habitats including in geothermally heated waters.


The larval mouthparts suggest they are predators, but the adults may also scavenge on streambed detritus.

Indicator value

  • Hard bottom: unassigned; general hydrophilid value 5
  • Soft bottom: unassigned; general hydrophilid value 8.0

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

Species found in geothermal waters may be tolerant of some unusual conditions and so they may not be good indicators of water quality. This genus has not been assigned tolerance values but the hydrophilids have family scores of 5 (hard bottom sites) and 8.0 (soft bottom sites).