Ranatra Absona

''Ranatra'' is a genus of slender predatory insects of the family Nepidae, known as water scorpions or water stick-insects. There are around 100 ''Ranatra'' species found in freshwater habitats around the world, both in warm and temperate regions, with the highest diversity in South America (almost 50 species) and Asia (about 30 species, reviewed in 1972Lansbury I (1972) A review of the Oriental species of ''Ranatra'' Fabricius (Hemiptera-Heteroptera: Nepidae). ''Transactions of the Royal Entomological Society of London'', vol. 124, no. 3. 287-341.). Fewer are found elsewhere, but include several African, some in North America, three from Australia and three from the Palearctic, notably the relatively well-known European '' R. linearis''. Since ''Ranatra'' belongs to the family Nepidae which in turn belongs to the order Hemiptera, ranatrids are considered "true bugs".

These brown insects are primarily found in stagnant or slow-moving water like ponds, marshes and canals, but can also be seen in streams. Exceptionally they have been recorded from hypersaline lakes and brackish lagoons.

Biology

The front legs of bugs in ''Ranatra'' are strong and used to grasp prey. They typically eat other insects, tadpoles and small fish, which they pierce with their proboscis and inject a saliva which both sedates and begins to digest their prey. They are sit-and-wait predators that reside among water plants and position themselves head-down with their grasping legs extended out to surprise passing prey. At least one species will also swim in open water at night to catch zooplanktonic organisms. Like other members in the family they have a long tail-like siphon, or breathing tube, on the rear end of their body. The adult body length is generally depending on the exact species, and females average larger than males of the same species. The siphon is typically almost the same size, but varies from less than half the body length to somewhat longer. Two of the largest species are the East Asian ''R. chinensis'' and South American ''R. magna''. ''Ranatra'' do have wings and they can fly.

The adults are active year-round, except in extreme cold. Their eggs are positioned on plants just below the water surface, but in some species they can be placed in mud. The eggs typically take two to four weeks to hatch and the young take about two months to mature.

RanatraLinearisHead.JPG, ''Ranatra linearis''
Ranatra chinensis.svg, ''Ranatra chinensis''
Water Scorpion - Ranatra species, Merrimac Farm Wildlife Management Area, Aden, Virginia.jpg, ''Ranatra'' crawling on human fingers

Among the four genera in the Ranatrinae subfamily, '' Austronepa'' and '' Goondnomdanepa'' are restricted to Australia. ''Cercotmetus'' from Asia to New Guinea resembles ''Ranatra'', although the former has a distinctly shorter siphon.

Species

The Global Biodiversity Information Facility lists:Global Biodiversity Information Facility: ''Ranatra'' Fabricius, 1790 (retrieved 12 January 2021)
/ref>

* '' Ranatra absona'' Drake & De Carlo, 1953
* '' Ranatra acapulcana'' Drake & De Carlo, 1953
* '' Ranatra adelmorpha'' Nieser, 1975
* '' Ranatra aethiopica'' Montandon, 1903
* '' Ranatra akoitachta'' Nieser, 1996
* '' Ranatra ameghinoi'' De Carlo, 1970
* '' Ranatra annulipes'' Stål, 1854
* '' Ranatra attenuata'' Kuitert, 1949
* '' Ranatra australis'' Hungerford, 1922 ^{i c g b} (southern water scorpion)
* '' Ranatra bachmanni'' De Carlo, 1954
* '' Ranatra bilobata'' Tran & Nguyen, 2016
* '' Ranatra biroi'' Lundblad, 1933
* '' Ranatra bottegoi'' Montandon, 1903
* '' Ranatra brasiliensis'' De Carlo, 1946
* '' Ranatra brevicauda'' Montandon, 1905
* '' Ranatra brevicollis'' Montandon, 1910 ^{i c g b}
* '' Ranatra buenoi'' Hungerford, 1922 ^{i c g b}
* '' Ranatra camposi'' Montandon, 1907
* '' Ranatra capensis'' Germar, 1837
* '' Ranatra cardamomensis'' Zettel, Phauk, Kheam & Freitag, 2017
* '' Ranatra chagasi'' De Carlo, 1946
* '' Ranatra chariensis'' Poisson, 1949
* ''Ranatra chinensis'' Mayr, 1865
* '' Ranatra cinnamomea'' Distant, 1904
* '' Ranatra compressicollis'' Montandon, 1898
* '' Ranatra costalimai'' De Carlo, 1954
* '' Ranatra cruzi'' De Carlo, 1950
* '' Ranatra curtafemorata'' Kuitert, 1949
* '' Ranatra denticulipes'' Montandon, 1907
* '' Ranatra digitata'' Hafiz & Pradhan, 1949
* '' Ranatra diminuta'' Montandon, 1907
* '' Ranatra dispar'' Montandon, 1903
* '' Ranatra distanti'' Montandon, 1910
* '' Ranatra doesburgi'' De Carlo, 1963
* '' Ranatra dolichodentata'' Kuitert, 1949
* '' Ranatra dormientis'' Zhang et al., 1994
* '' Ranatra drakei'' Hungerford, 1922
* '' Ranatra ecuadoriensis'' De Carlo, 1950
* '' Ranatra elongata'' Fabricius, 1790
* '' Ranatra emaciata'' Montandon, 1907
* '' Ranatra fabricii'' Guérin-Méneville, 1857
* '' Ranatra falloui'' Montandon, 1907
* '' Ranatra feana'' Montandon, 1903
* '' Ranatra fianarantsoana'' Poisson, 1963
* '' Ranatra filiformis'' Fabricius, 1790
* '' Ranatra flagellata'' Lansbury, 1972
* '' Ranatra flokata'' Nieser & Burmeister, 1998
* '' Ranatra fusca'' Palisot, 1820 ^{i c g b} (brown waterscorpion)
* '' Ranatra fuscoannulata'' Distant, 1904
* '' Ranatra galantae'' Nieser, 1969
* '' Ranatra gracilis'' Dallas, 1850
* '' Ranatra grandicollis'' Montandon, 1907
* '' Ranatra grandocula'' Bergroth, 1893
* '' Ranatra hechti'' De Carlo, 1967
* '' Ranatra heoki'' Tran & Poggi, 2019
* '' Ranatra heydeni'' Montandon, 1909
* '' Ranatra horvathi'' Montandon, 1910
* '' Ranatra hungerfordi'' Kuitert, 1949
* '' Ranatra incisa'' Chen, Nieser & Ho, 2004
* '' Ranatra instaurata'' Montandon, 1914
* '' Ranatra insulata'' Barber, 1939
* '' Ranatra jamaicana'' Drake & De Carlo, 1953
* '' Ranatra katsara'' Nieser, 1997
* '' Ranatra kirkaldyi'' Torre-bueno, 1905 ^{i c g b}
* '' Ranatra lanei'' De Carlo, 1946
* '' Ranatra lansburyi'' Chen, Nieser & Ho, 2004
* '' Ranatra lenti'' De Carlo, 1950
* '' Ranatra lethierryi'' Montandon, 1907
* '' Ranatra libera'' Zettel, 1999
* '' Ranatra linearis'' (Linnaeus, 1758) ^{i c g}
* '' Ranatra longipes'' Stål, 1861
* '' Ranatra lualalai'' Poisson, 1964
* '' Ranatra lubwae'' Poisson, 1965
* '' Ranatra machrisi'' Nieser & Burmeister, 1998
* '' Ranatra macrophthalma'' Herrich-Schäffer, 1849
* '' Ranatra maculosa'' Kuitert, 1949
* '' Ranatra magna'' Kuitert, 1949
* '' Ranatra malayana'' Lundblad, 1933
* '' Ranatra mediana'' Montandon, 1910
* '' Ranatra megalops'' Lansbury, 1972
* '' Ranatra mixta'' Montandon, 1907
* '' Ranatra moderata'' Kuitert, 1949
* '' Ranatra montei'' De Carlo, 1946
* '' Ranatra montezuma'' Polhemus, 1976
* '' Ranatra natalensis'' Distant, 1904
* '' Ranatra natunaensis'' Lansbury, 1972
* '' Ranatra neivai'' De Carlo, 1946
* '' Ranatra nieseri'' Tran & Nguyen, 2016
* '' Ranatra nigra'' Herrich-Schaeffer, 1849
* '' Ranatra nodiceps'' Gerstaecker, 1873
* '' Ranatra nodioeps'' Gerstaecker, 1873
* '' Ranatra obscura'' Montandon, 1907
* '' Ranatra occidentalis'' Lansbury, 1972
* '' Ranatra odontomeros'' Nieser, 1996
* '' Ranatra oliveiracesari'' De Carlo, 1946
* '' Ranatra operculata'' Kuitert, 1949
* '' Ranatra ornitheia'' Nieser, 1975
* '' Ranatra parmata'' Mayr, 1865
* '' Ranatra parvipes'' Signoret, 1861
* '' Ranatra parvula'' Kuitert, 1949
* '' Ranatra pittieri'' Montandon, 1910
* '' Ranatra protense'' Montandon
* '' Ranatra quadridentata'' Stål, 1862 ^{i c g b}
* '' Ranatra rabida'' Buchanan White, 1879
* '' Ranatra rafflesi'' Tran & D.Polhemus, 2012
* '' Ranatra rapax'' Stål, 1865
* '' Ranatra recta'' Chen, Nieser & Ho, 2004
* '' Ranatra robusta'' Montandon, 1905
* '' Ranatra sagrai'' Drake & De Carlo, 1953
* '' Ranatra sarmientoi'' De Carlo, 1967
* '' Ranatra sattleri'' De Carlo, 1967
* '' Ranatra schuhi'' D.Polhemus & J.Polhemus, 2012
* '' Ranatra segrega'' Montandon, 1913
* '' Ranatra signoreti'' Montandon, 1905
* '' Ranatra similis'' Drake & De Carlo, 1953
* '' Ranatra siolii'' De Carlo, 1970
* '' Ranatra sjostedti'' Montandon, 1911
* '' Ranatra spatulata'' Kuitert, 1949
* '' Ranatra spinifrons'' Montandon, 1905
* '' Ranatra spoliata'' Montandon, 1912
* '' Ranatra stali'' Montandon, 1905
* '' Ranatra sterea'' Chen, Nieser & Ho, 2004
* '' Ranatra subinermis'' Montandon, 1907
* '' Ranatra sulawesii'' Nieser & Chen, 1991
* '' Ranatra surinamensis'' De Carlo, 1963
* '' Ranatra texana'' Hungerford, 1930
* '' Ranatra thai'' Lansbury, 1972
* '' Ranatra titilaensis'' Hafiz & Pradhan, 1949
* '' Ranatra travassosi'' De Carlo, 1950
* '' Ranatra tridentata'' Poisson, 1965
* '' Ranatra tuberculifrons'' Montandon, 1907
* '' Ranatra unicolor'' Scott, 1874
* '' Ranatra unidentata'' Stål, 1861
* '' Ranatra usingeri'' De Carlo, 1970
* '' Ranatra varicolor'' Distant, 1904
* '' Ranatra varipes'' Stål, 1861
* '' Ranatra vitshumbii'' Poisson, 1949
* '' Ranatra wagneri'' Hungerford, 1929
* '' Ranatra weberi'' De Carlo, 1970
* '' Ranatra williamsi'' Kuitert, 1949
* '' Ranatra zeteki'' Drake & De Carlo, 1953

Data sources: i = ITIS, c = Catalogue of Life, g = GBIF, b = Bugguide.net

References

External links

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{{Taxonbar, from=Q1154489

Nepidae
Nepomorpha genera