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Water boatman (Diaprepocoris)

Taxonomic group

Corixidae: Diaprepocoris

Diagnostic features

Diaprepocoris bugs are similar in appearance to the common water boatman Sigara, having long hair-fringed hind legs designed for swimming, and having forelegs ending in a trowel-like segment. Unlike Sigara however, Diaprepocoris have two small dark spots (ocelli) between the large compound eyes.

Typical habitats

Diaprepocoris can be common in ponds and lakes, including coastal lakes with tidal influence.


It is likely that Diaprepocoris has a similar diet to the related Sigara, which feeds on algae and organic detritus.

Indicator value

  • Hard bottom: 5
  • Soft bottom: 4.7

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

An abundance of Diaprepocoris is likely to be the result of pond-like habitat conditions (at the site or upstream) rather than any particular water quality condition. They have medium tolerance values of 5 (hard bottom sites) and 4.7 (soft bottom sites).