Family CORIXIDAE Leach, 1815 - water boatmen
A. Jansson
The family is divided into five subfamilies (Diaprepocorinae, Stenocorixinae, Cymatiainae, Heterocorixinae and Corixinae), and includes altogether 32 genera with about 450 valid species and some 50 subspecies worldwide. In the Palaearctic Region, four subfamilies are represented by 15 genera and altogether 154 entries for species and subspecies considered valid in the present list (the validity of a few entries from Asia is questionable). The habitats of Corixidae range from small ponds to large lakes and slowly running waters. The highest species diversity is found in relatively small bodies of water without fish predation. References to the general biology of Corixidae can be found e.g. in Bosmans (1982), Henrikson & Oscarson (1985), Jastrey (1981), Macan (1954a, 1954b, 1955a, 1962, 1976), Pajunen (1970, 1977), and Savage (1994). While most species are found in fresh water, some species tolerate brackish water to some extent; only a few can live in truly saline waters (see Scudder, 1976). The food of corixids consists mainly of other aquatic animals (see Jansson, 1986a). All species have five larval instars, but the number of generations per year varies from one to several (Kaiser, 1966; Jansson & Scudder, 1974). As in many other Heteroptera, both flying and non‑flying forms of Corixidae exist. Flightlessness may result either from hind wing reduction or the absence of fully developed flight‑muscles (Jansson, 1986a). Most dispersal activity occurs in early spring, when individuals fly to new potential breeding areas, and in late fall when the population density is at its highest (Pajunen & Jansson, 1969). Many species of Corixidae can produce underwater acoustic signals which have a function in spacing out the males, as well as in aiding the sexes to find each other and in isolating closely related species (e.g. Jansson, 1972, 1973, 1974, 1979a, 1979b; Aiken, 1985).
Among the most important taxonomic works on Corixidae are the following: Hungerford (1948: the Americas), Hutchinson (1940: India), Jansson (1986a: Europe), Savage (1989: the British Isles), and Štys & Jansson (1988: Nepomorphan checklist).
The identity of two taxa from the Palaearctic Region, Corixa lacustris Stephens, 1829a: 354 and Corixa rivalis Stephens, 1829a: 354, remained unknown ever since they were published. Since they were only listed, without any description, their status would in every case remain as nomina nuda.
The following Opinions concern taxonomy and nomenclature of Palaearctic Corixidae: 281/1954, 687/1964, 739/1965, 1274/1984, 1523/1989, 1524/1989, 1555/1989, 1650/1991, 1782/1994, 1794/1995 en 1937/1999.