This species is confined to acidic habitats such as peat pools with Sphagnum moss, which usually have a high concentration of dissolved organic matter. The bug overwinters as an adult and mates and oviposits in March and April.
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. The species is fairly widespread in Ireland.
Heperocorixa castanea is one of the smaller species of the genus with a length of 4.5 – 5.5 mm. As in H. moesta (from which it was separated in 1933) there is little contrast between the light and dark markings on the elytra (cf. H. linnaei and H. sahlbergi). It can be separated from the very similar H. moesta by the length of the claw on the middle leg, which is longer than the adjoining tarsus.