This is the smallest corixidae easily identifiable by its plain pronotum with no lines and also it's small size (3.7mm). It occurs in ponds and ditches with thick masses of Chara, water milfoil or hornwort interspersed with clear water.

This is a predator and rests upon vegetation, which it protectively resembles in life, facing towards clear water. From time to time it dashes out to catch water fleas, corixid larvae, mayfly or chironomid larvae, etc., these being held in the head groove by the front limbs whilst feeding proceeds; apparently in optimum habitats it kills far more than it requires as food.

They mate in mid-June and lay long-stalked eggs upon vegetation. Egg batches normally contain 8 eggs, 1 from each ovariole, and up to 4 or 5 batches may be laid spread over a month. The first instar larvae are as large as those of Corixa punctata, a bug which, when adult, is four or five times longer than C. coleoptrata. In the first two instars the larvae, predacious from the start, breathe dissolved air but at the third instar major changes occur, the spiracles opening and the buoyancy increasing. By the end of July new adults are present and a further generation occurs to mature during autumn and overwinter as adults. (S&L, 1959)

In Germany, DNA research (H, 2018) has found that there could be another lineage for this species. It may be a bit eastern for this species but worth looking out for.

Distribution:

In Northants this found in 13 10km squares and therefore the status is Un-common. Also in 27 sites mainly down the Nene Valley in the Gravel pits ( Stortons, Delta/Slab Pit), Clay pits (Orton Brick Pit), canals (Grand Union), ponds (Woodston ponds, Abington Meadows), lakes (Stanwick and Irthlingborough Lakes), Streams (Scaldwell stream, Grendon Brook), Rivers ( River Tove, River Nene), and ditches (Barnes Meadow, Stanground Lode).

Across the country it is common in the South East and the Midlands but rare in Wales and above the Humber estuary.

Habitat:

Found in Gravel Pits, Clay pits, ponds, lakes, rivers, canals and ditches with thick submerged vegetation over exposed substrate. Can be found in conjunction with C. bonsdorffii (RM, 2006)

Identification:

The pronotum is a uniform yellowish-brown with no spots or stripes. It also has a narrower pronotum than C.Bonsdorffii and is much smaller than the other two species.