Callicorixa praeusta is a common species found in a wide variety of still water habitats, often where there is some organic pollution. It readily migrates and is one of the first species to colonise new or temporary habitats. There are two generations per year, the first from eggs laid in April-May by overwintering adults and the second from eggs laid by this first generation in mid to late July. Adults of the second generation overwinter.
The map is based on records from NBN Gateway, with yellow dots showing pre 1990 records, reds dots 1990 – 2015 records and red on yellow dots overlapping records. C. praeusta is fairly widespread in Ireland.
C. praeusta is 7.0 – 8.0 mm in length. The dark rectangular mark at the apex of the hind first tarsal segment and the structure of the male pala are distinguishing features. There are a few other species of corixid that have dark marks on the hind tarsus, but the marks are differently shaped and may also be present on the second (or terminal) segment.