''Stenus'' is a genus of semiaquatic

rove beetle The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra (wing covers) that typically leave more than half of their abdominal segments exposed. With roughly 63,000 species in thousands of genera, the ...

s in the subfamily

Steninae Steninae is a subfamily of Staphylinidae.Newton, A. F., Jr., M. K. Thayer, J. S. Ashe, and D. S. Chandler. 2001. 22. Staphylinidae Latreille, 1802. p. 272–418. In: R. H. Arnett, Jr., and M. C. Thomas (eds.). American beetles, Volume 1. CRC Pres ...

, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''

Agrilus ''Agrilus'' is a genus of jewel beetles, notable for having the largest number of species (about 3000) of any single genus in the animal kingdom. '' Agrilus aureus'' Species * '' Agrilus abantiades'' Descarp ...

'' is comparable in size). They are predators of

Collembola Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Ento ...

and other small arthropods. Adults have a protrusible labium with a sticky tip used in prey capture. To overcome the rapid escape of

, the labium is protruded at high speed (1-3 ms in ''Stenus comma'') by hemolymph pressure, and immediately withdrawn (withdrawn in 30-40 ms in ''Stenus comma''), pulling the prey within the range of the mandibles. However, the labium tip does not easily stick to preys covered in scales or

setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

or that have a large body size. ''Stenus comma'' is more likely to catch such preys by lunging forward and grabbing them directly with its mandibles rather than using its labium. ''Stenus'' species are also known for "skimming" on the water surface using their pygidial gland

secretions 440px Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classica ...

that act as a

surfactant Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming ...

and rapidly propel the beetle fast forward, a phenomenon known as the

Marangoni effect The Marangoni effect (also called the Gibbs–Marangoni effect) is the mass transfer along an interface between two phases due to a gradient of the surface tension. In the case of temperature dependence, this phenomenon may be called thermo-capill ...

. ''Stenus comma'' has been seen to achieve a velocity of 0.75 m/s, and to cover a distance of up to 15 m if the secretion is continuous.

Selected Species

* '' Stenus adelops'' Casey, 1884 * ''

Stenus adspector ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are preda ...

'' Maklin, 1852 * '' Stenus advena'' (Casey, 1884) * ''

Stenus agnatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' (Casey, 1884) * '' Stenus alacer'' Casey, 1884 * '' Stenus alpicola'' Fauvel, 1872 * ''

Stenus alveolatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Casey, 1884 * ''

Stenus amabilis ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' (Casey, 1884) * ''

Stenus amicus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are preda ...

'' Casey, 1884 * ''

Stenus amplifacatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Benick, 1921 * ''

Stenus angustus ''Stenus angustus'' is a species of water skater in the beetle family Staphylinidae The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra (wing covers) that typically leave more than half of t ...

'' Casey, 1884 * ''

Stenus animatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Casey, 1884 * ''

Stenus annularis ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Erichson, 1840 * ''

Stenus arculus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Casey, 1840 * ''

Stenus argus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Gravenhorst, 1806 * ''

Stenus arizonae ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Casey, 1884 * ''

Stenus artus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Casey, 1884 * ''

Stenus austini ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are preda ...

'' Casey, 1884 * '' Stenus bakeri'' Bernhauer, 1910 * ''

Stenus biguttatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' (Linnaeus, 1758) * '' Stenus bilentigatus'' Casey, 1884 * '' Stenus bipunctatus'' Erichson, 1839 * '' Stenus biwenxuani'' Tang & Li, 2013 * '' Stenus caenicolus'' Notman, 1919 * '' Stenus californicus'' Casey, 1884 * '' Stenus callosus'' Erichson, 1840 * '' Stenus canadensis'' (Casey, 1884) * '' Stenus canaliculatus'' Gyllenhal, 1827 * '' Stenus capucinus'' Boheman, 1858 * '' Stenus cariniceps'' Maklin, 1852 * '' Stenus carinicollis'' Casey, 1884 * '' Stenus carolinae'' Casey, 1884 * '' Stenus carolinus'' Bernhauer, 1917 * '' Stenus chalybeus'' Boheman, 1858 * '' Stenus chapini'' Blackwelder, 1943 * '' Stenus colon'' Say, 1834 * '' Stenus colonus'' Erichson, 1840 * '' Stenus comma'' LeConte 1863 * '' Stenus convictor'' Casey, 1884 * '' Stenus corvus'' Casey, 1884 * '' Stenus costalis'' Casey, 1884 * '' Stenus croceatus'' (Casey, 1884) * '' Stenus cubanus'' Blackwelder, 1943 * '' Stenus cubensis'' Bernhauer, 1910 * '' Stenus curtus'' Casey, 1884 * '' Stenus delawarensis'' Casey, 1884 * '' Stenus dispar'' Casey, 1884 * '' Stenus dissentiens'' Casey, 1884 * '' Stenus dives'' Casey, 1884 * '' Stenus dolosus'' Casey, 1884 * '' Stenus dyeri'' Blackwelder, 1943 * '' Stenus edax'' Notman, 1920 * '' Stenus ellipticus'' Casey, 1884 * '' Stenus eriensis'' Casey, 1884 * '' Stenus erythropus'' Melsheimer, 1844 * '' Stenus exasperatus'' Benick, 1925 * '' Stenus exploratus'' Fall, 1926 * '' Stenus falli'' Scheerpeltz, 1933 * '' Stenus femoratus'' Say, 1834 * '' Stenus flavicornis'' Erichson, 1840 * '' Stenus floridanus'' Casey, 1884 * '' Stenus fraternus'' (Casey, 1884) * '' Stenus frigidus'' Falls, 1926 * '' Stenus fulvoguttatus'' Notman, 1920 * '' Stenus gemmeus'' Casey, 1884 * '' Stenus gibbicollis'' Sahlberg, 1880 * '' Stenus gilae'' Casey, 1884 * '' Stenus gratiosus'' Casey, 1884 * '' Stenus gravidus'' Casey, 1884 * '' Stenus haitiensis'' Blackwelder, 1943 * '' Stenus hirsutus'' Casey, 1884 * '' Stenus hispaniolus'' Blackwelder, 1943 * '' Stenus hubbardi'' Casey, 1884 * ''

Stenus immarginatus ''Stenus'' is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genus in the kingdom Animalia, with some 2700 known species worldwide (only the beetle genus ''Agrilus'' is comparable in size). They are predato ...

'' Mäklin, 1853 * '' Stenus incertus'' Casey, 1884 * '' Stenus incultus'' Casey, 1884 * '' Stenus indigens'' Casey, 1884 * '' Stenus ingratus'' Casey, 1884 * '' Stenus inornatus'' Casey, 1884 * '' Stenus insignis'' Casey, 1884 * '' Stenus integer'' Casey, 1884 * '' Stenus intrusus'' Casey, 1884 * '' Stenus juno'' (Paykull, 1789) * '' Stenus juvencus'' Casey, 1884 * '' Stenus laetulus'' (Casey, 1884) * '' Stenus leviceps'' Casey, 1884 * '' Stenus limatulus'' Benick, 1928 * '' Stenus liupanshanus'' Tang & Li, 2013 * '' Stenus luctuosus'' Casey, 1884 * '' Stenus luculentus'' Casey, 1884 * '' Stenus lugens'' Casey, 1884 * '' Stenus lutzi'' Notman, 1920 * '' Stenus maritimus'' Motschulsky, 1845 * '' Stenus megalops'' (Casey, 1884) * '' Stenus mendax'' Casey, 1884 * '' Stenus meridionalis'' (Casey, 1884) * '' Stenus militaris'' Casey, 1884 * '' Stenus minor'' Casey, 1884 * '' Stenus montanus'' Casey, 1884 * '' Stenus monticola'' Casey, 1884 * '' Stenus morio'' Gravenhorst, 1806 * '' Stenus mundulus'' Casey, 1884 * '' Stenus murphyanus'' Bernhauer, 1917 * '' Stenus nanus'' Stephens, 1833 * '' Stenus neglectus'' Casey, 1884 * '' Stenus nimbosus'' Casey, 1884 * '' Stenus nitescens'' (Casey, 1884) * '' Stenus noctivagus'' Casey, 1884 * '' Stenus obstrusus'' Casey, 1884 * '' Stenus occidentalis'' Casey, 1884 * '' Stenus odius'' Blackwelder, 1943 * '' Stenus pacificus'' Casey, 1884 * '' Stenus papagonis'' (Casey, 1884) * '' Stenus parallelus'' Casey, 1884 * '' Stenus pauper'' Casey, 1884 * '' Stenus pauperculus'' Casey, 1884 * '' Stenus perexilis'' Notman, 1920 * '' Stenus personatus'' Benick, 1928 * '' Stenus pertinax'' (Casey, 1884) * '' Stenus pettiti Casey, 1884 * '' Stenus pinguis'' (Casey, 1884) * '' Stenus placidus'' Casey, 1884 * '' Stenus plicipennis'' (Casey, 1884) * '' Stenus pluto'' Casey, 1884 * '' Stenus pollens'' (Casey, 1884) * '' Stenus pterobrachys'' Gemminger & Harold, 1868 * '' Stenus pudicus'' Casey, 1884 * '' Stenus pugetensis'' Casey, 1884 * '' Stenus pumilio'' Erichson, 1839 * '' Stenus punctatus'' Erichson, 1840 * '' Stenus punctiger'' Casey, 1884 * '' Stenus ranops'' Casey, 1884 * '' Stenus renifer'' LeConte, 1863 * '' Stenus retrusus'' (Casey, 1884) * '' Stenus rugifer'' Casey, 1884 * '' Stenus sayi'' (Casey, 1884) * '' Stenus scabiosus'' Casey, 1884 * '' Stenus schwarzi'' Casey, 1884 * '' Stenus sculptilis'' Casey, 1884 * '' Stenus sectator'' Casey, 1884 * '' Stenus sectilifer'' Casey, 1884 * '' Stenus semicolon'' LeConte, 1863 * '' Stenus shoshonis'' Casey, 1884 * '' Stenus similiatus'' Blatchley, 1910 * '' Stenus simplex'' Casey, 1884 * '' Stenus solutus'' Erichson 1840 * '' Stenus sphaerops'' Casey, 1884 * '' Stenus strangulatus'' Casey, 1884 * '' Stenus stygicus'' Say, 1834 * '' Stenus subtilis'' Casey, 1884 * '' Stenus tacomae'' Casey, 1884 * '' Stenus tahoensis'' Casey,1884 * '' Stenus tarsalis'' Ljungh, 1804 * '' Stenus tenuis'' Casey, 1884 * '' Stenus terricola'' Casey, 1884 * '' Stenus teter'' Notman, 1920 * '' Stenus texanus'' Casey, 1884 * '' Stenus torus'' Benick, 1925 * '' Stenus trajectus'' (Casey, 1884) * '' Stenus tristis'' Casey, 1884 * '' Stenus tuberculatus'' Casey, 1884 * '' Stenus utenis'' Casey, 1884 * '' Stenus vacuus'' Casey, 1884 * '' Stenus venustus'' Casey, 1884 * '' Stenus verticosus'' Casey, 1884 * '' Stenus vespertinus'' Casey, 1884 * '' Stenus vestalis'' Casey, 1884 * '' Stenus vexatus'' Casey, 1884 * '' Stenus vicinus'' Casey, 1884 * '' Stenus villosus'' Casey, 1884 * '' Stenus vinnulus'' Casey, 1884 * '' Stenus vista'' Sanderson, 1946 * '' Stenus zunicus'' Casey, 1884

References

{{Taxonbar, from=Q148654 Steninae Beetles described in 1796