Stenus
Stenus is a genus of semiaquatic rove beetles in the subfamily Steninae, and one of the largest genera in the kingdom Animalia, with some 3100 known species worldwide. They are predators of Collembola and other small arthropods. Adults have a protrusible labium with a sticky tip used in prey capture. To overcome the rapid escape of Collembola, the labium is protruded at high speed by hemolymph pressure, and immediately withdrawn, pulling the prey within the range of the mandibles. However, the labium tip does not easily stick to prey covered in scales or setae or that have a large body size. Stenus comma is more likely to catch such prey 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 that act as a surfactant and rapidly propel the beetle fast forward, a phenomenon known as the Marangoni effect. 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, 1884Stenus adspector Maklin, 1852Stenus advena Stenus agnatus Stenus alacer Casey, 1884Stenus alpicola Fauvel, 1872Stenus alveolatus Casey, 1884Stenus amabilis Stenus amicus Casey, 1884Stenus amplifacatus Benick, 1921Stenus angustus Casey, 1884Stenus animatus Casey, 1884Stenus annularis Erichson, 1840Stenus arculus Casey, 1840Stenus argus Gravenhorst, 1806Stenus arizonae Casey, 1884Stenus artus Casey, 1884Stenus austini Casey, 1884Stenus bakeri Bernhauer, 1910Stenus biguttatus Stenus bilentigatus Casey, 1884Stenus bipunctatus Erichson, 1839Stenus biwenxuani Tang & Li, 2013Stenus caenicolus Notman, 1919Stenus californicus Casey, 1884Stenus callosus Erichson, 1840Stenus canadensis Stenus canaliculatus Gyllenhal, 1827Stenus capucinus Boheman, 1858Stenus cariniceps Maklin, 1852Stenus carinicollis Casey, 1884Stenus carolinae Casey, 1884Stenus carolinus Bernhauer, 1917Stenus chalybeus Boheman, 1858Stenus chapini Blackwelder, 1943Stenus colon Say, 1834Stenus colonus Erichson, 1840Stenus comma LeConte 1863Stenus convictor Casey, 1884Stenus corvus Casey, 1884Stenus costalis Casey, 1884Stenus croceatus Stenus cubanus Blackwelder, 1943Stenus cubensis Bernhauer, 1910Stenus curtus Casey, 1884Stenus delawarensis Casey, 1884Stenus dispar Casey, 1884Stenus dissentiens Casey, 1884Stenus dives Casey, 1884Stenus dolosus Casey, 1884Stenus dyeri Blackwelder, 1943Stenus edax Notman, 1920Stenus ellipticus Casey, 1884Stenus eriensis Casey, 1884Stenus erythropus Melsheimer, 1844Stenus exasperatus Benick, 1925Stenus exploratus Fall, 1926Stenus falli Scheerpeltz, 1933Stenus femoratus Say, 1834Stenus flavicornis Erichson, 1840Stenus floridanus Casey, 1884Stenus fraternus Stenus frigidus Falls, 1926Stenus fulvoguttatus Notman, 1920Stenus gemmeus Casey, 1884Stenus gibbicollis Sahlberg, 1880Stenus gilae Casey, 1884Stenus gratiosus Casey, 1884Stenus gravidus Casey, 1884Stenus haitiensis Blackwelder, 1943Stenus hirsutus Casey, 1884Stenus hispaniolus Blackwelder, 1943Stenus hubbardi Casey, 1884Stenus immarginatus Mäklin, 1853Stenus incertus Casey, 1884Stenus incultus Casey, 1884Stenus indigens Casey, 1884Stenus ingratus Casey, 1884Stenus inornatus Casey, 1884Stenus insignis Casey, 1884Stenus integer Casey, 1884Stenus intrusus Casey, 1884Stenus juno Stenus juvencus Casey, 1884Stenus laetulus Stenus leviceps Casey, 1884Stenus limatulus Benick, 1928Stenus liupanshanus Tang & Li, 2013Stenus luctuosus Casey, 1884Stenus luculentus Casey, 1884Stenus lugens Casey, 1884Stenus lutzi Notman, 1920Stenus maritimus Motschulsky, 1845Stenus megalops Stenus mendax Casey, 1884Stenus meridionalis Stenus militaris Casey, 1884Stenus minor Casey, 1884Stenus montanus Casey, 1884Stenus monticola Casey, 1884Stenus morio Gravenhorst, 1806Stenus mundulus Casey, 1884Stenus murphyanus Bernhauer, 1917Stenus nanus Stephens, 1833Stenus neglectus Casey, 1884Stenus nimbosus Casey, 1884Stenus nitescens Stenus noctivagus Casey, 1884Stenus obstrusus Casey, 1884Stenus occidentalis Casey, 1884Stenus odius Blackwelder, 1943Stenus pacificus Casey, 1884Stenus palposus Zetterstedt, 1838Stenus papagonis Stenus parallelus Casey, 1884Stenus pauper Casey, 1884Stenus pauperculus Casey, 1884Stenus perexilis Notman, 1920Stenus personatus Benick, 1928Stenus pertinax Stenus pettiti Casey, 1884Stenus pinguis Stenus placidus Casey, 1884Stenus plicipennis Stenus pluto Casey, 1884Stenus pollens Stenus pterobrachys Gemminger & Harold, 1868Stenus pudicus Casey, 1884Stenus pugetensis Casey, 1884Stenus pumilio Erichson, 1839Stenus punctatus Erichson, 1840Stenus punctiger Casey, 1884Stenus ranops Casey, 1884Stenus renifer LeConte, 1863Stenus retrusus Stenus rugifer Casey, 1884Stenus sayi Stenus scabiosus Casey, 1884Stenus schwarzi Casey, 1884Stenus sculptilis Casey, 1884Stenus sectator Casey, 1884Stenus sectilifer Casey, 1884Stenus semicolon LeConte, 1863Stenus shoshonis Casey, 1884Stenus similiatus Blatchley, 1910Stenus simplex Casey, 1884Stenus solutus Erichson 1840Stenus sphaerops Casey, 1884Stenus strangulatus Casey, 1884Stenus stygicus Say, 1834Stenus subtilis Casey, 1884Stenus tacomae Casey, 1884Stenus tahoensis Casey,1884Stenus tarsalis Ljungh, 1804Stenus tenuis Casey, 1884Stenus terricola Casey, 1884Stenus teter Notman, 1920Stenus texanus Casey, 1884Stenus torus Benick, 1925Stenus trajectus Stenus tristis Casey, 1884Stenus tuberculatus Casey, 1884Stenus utenis Casey, 1884Stenus vacuus Casey, 1884Stenus venustus Casey, 1884Stenus verticosus Casey, 1884Stenus vespertinus Casey, 1884Stenus vestalis Casey, 1884Stenus vexatus Casey, 1884Stenus vicinus Casey, 1884Stenus villosus Casey, 1884Stenus vinnulus Casey, 1884Stenus vista Sanderson, 1946Stenus zunicus Casey, 1884