Helophorus aequalis


A very common water beetle, 4.5 to 6.3 mm length, it is all brown in colour with the zig-zag ridges on the thorax typical of the genus. Darker spots may be present on the elytra.

Similar Species

It is most similar to H. grandis which is also one of the larger Helophorus beetles. They can be separated by the size and shape of the 'teeth' at the end of the last abdominal segment - small and numerous in aequalis, larger and castellated in grandis.

Identification difficulty
ID guidance
  • 4.5mm - 6.3mm
  • intercalary stria present
  • elytral margin barely visible from below (not to be confused with the epipleur which is visible)
  • 'teeth' on last abdominal segment small and numerous (~15 over 0.5mm)

Helophorus aequalis is nearly always found near water, but not necessarily in it.

When to see it

All year round, but more readily recorded in summer.

Life History

The larvae live in the water and are fierce predators.

UK Status

Widespread and frequent in Britain.

VC55 Status

Common in Leicestershire and Rutland.

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map