Hygrotus artus (Fall, 1919)

Mono Lake diving beetle



Taxonomy & Nomenclature

Synonym/s: Coelambus artus Fall, 1919 [Leng & Mutchler, 1927:17] (basionym); Hygrotus (Coelambus) artus (Fall, 1919) [Nilsson, 2001:205]


See Challet & Fery (2020:52) for a complete synonymy. Most recent authors place the species in the subgenus Leptolambus (Challet & Fery, 2020:52 and references therein), with the exception of Nilsson (2001:205) who placed it in Coelambus.


Conservation Status

Rediscovered in August 2017 (Challet & Fery, 2020)

IUCN RedList status: Extinct


Poor preservation of the holotype, combined with neglect of a second historical locality in the literature (Challet & Fery, 2020), resulted in the species often being regarded as an extinct endemic of Mono Lake (World Conservation Monitoring Centre, 1996a,b; Robischon, 2007:259; Bouchard et al., 2009; Foster, 2020). It was rediscovered by Gil Challet in August 2017 in two counties (Inyo & Mono) after several unsuccessful attempts (Challet & Fery, 2020).



Inyo County & Mono County, California, USA


Although the common name suggests that the species is endemic to Mono Lake, it occurs more widely across two counties (Inyo & Mono) (Challet & Fery, 2020).


Biology & Ecology

The species does not appear to inhabit the highly alkaline (pH 9.8) water of Mono Lake itself (Challet & Fery, 2020), but has been found in a spring (pH 8.3) on Paoha Island in Mono Lake (Brues, 1932:215; Challet & Fery, 2020:57)



Holotype: MCZ* 23892

*Museum of Comparative Zoology, Harvard University


For more recent specimens, see (Challet & Fery, 2020).






Original scientific description:

Fall, H. C. (1919). The North American species of Coelambus. John D. Sherman, Jr. Mount Vernon, NY.


Other references:

Anderson, R. D. (1983). Revision of the Nearctic species of Hygrotus groups IV, V and VI (Coleoptera: Dytiscidae). Annals of the Entomological Society of America 76(2): 173-196.

Anderson, R. D. (1985). Proposed faunal affinities of the Great Basin Dytiscidae (Coleoptera). Proceedings of the Academy of Natural Sciences of Philadelphia 137(1): 12-21.

Anonymous. (2020). A register of extinct beetles. Latissimus 45: 26-28.

Baillie, J. and Groombridge, B. (eds). (1996). 1996 IUCN Red List of Threatened Animals, pp. 378. International Union for Conservation of Nature, Gland, Switzerland and Cambridge, UK.

Bouchard, P., Grebennikov, V. V., Smith, A. B. T. and Douglas, H. (2009). Biodiversity of Coleoptera, pp. 265-301. In: Foottit, R. G. and Adler, P. H. (eds.). Insect Biodiversity. Science and Society. Oxford: Blackwell Publishing. 632 pp.

Brues, C. T. (1932). Further studies on the fauna of North American hot springs. Proceedings of the American Academy of Arts and Sciences 67: 185-303.

Challet, G. L. and Brett, R. (1998). Distribution of the Dytiscidae (Coleoptera) of California by county. The Coleopterists Bulletin 52(1): 43-54.

Challet, Gil and Fery, Hans. (2020). Rediscovery of Hygrotus (Leptolambus) artus (FALL, 1919), description of Hygrotus (L.) yellowstone nov.sp. and notes on other species of the genus (Coleoptera, Dytiscidae, Hydroporinae, Hygrotini). Linzer biol. Beitr. 52(1): 37-79.

Evans, A. V. and Hogue, J. N. (2006). Field Guide to Beetles of California. University of California Press.

Foster, G. N. (2020). A register of extinct beetles. Latissimus 45: 26-28.

Foster, G. N. and Bilton, D. T. (2014). The conservation of predaceous diving beetles: Knowns, unknowns and anecdotes, pp. 437-462. In: Yee, D. A. (ed.). Ecology, systematics, and the natural history of predaceous diving beetles (Coleoptera: Dytiscidae). Dordrecht, Heidelberg, New York, London: Springer.

Groombridge, B. (ed.). (1994). 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.

IUCN. (1990). IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.

Larson, D. J., Alarie, Y. and Roughley, R. E. (2000). Predaceous diving beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska. Ottawa: National Research Council of Canada Monograph Publishing Program. [suggested H. artus as synonymous with H. sharpi]

Leech, H. B. and Chandler, H. P. (1956). Aquatic Coleoptera, pp. 293-371. In: Usinger, R. L. (ed.). Aquatic insects of California. Berkeley: University of California Press. 508 pp.

Leng, C. W. and Mutchler,  A. J. (1927). Supplement 1919 to 1924 (inclusive) to catalogue of the Coleoptera of America, north of Mexico. Mount Vernon, N.Y.: J.D. Sherman (Jr.). 78 pp.

NatureServe. (2011). NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available (Accessed: September 18, 2011).

Nilsson, A. N. (2001). World catalogue of insects. Vol. 3. Dytiscidae Coleoptera. Stenstrup: Apollo Books. 395 pp.

Nilsson, A. N. and Hájek, J. (2020). A world catalogue of the family Dytiscidae (Coleoptera, Adephaga). 311 pp. Internet version 1.I.2020. Available from: (Accessed 16 May 2023)

Robischon, M. (2007). Das heimliche Sterben der Insekten. Entomologische Zeitschrift 117(6): 256-262.

Villastrigo, A., Fery, Hans, Manuel, M., Millán, A. and Ribera, I. (2018). Evolution of salinity tolerance in the diving beetle tribe Hygrotini (Coleoptera, Dytiscidae). Zoologica Scripta 47: 63-71.

Villastrigo, A., Ribera, I., Manuel, M., Millán, A. and Fery, Hans. (2017). A new classification of the tribe Hygrotini Portevin, 1929 (Coleoptera: Dytiscidae: Hydroporinae). Zootaxa 4317(3): 499-529.

World Conservation Monitoring Centre. (1996a). Hygrotus artus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. ( Downloaded on 06 February 2013.

World Conservation Monitoring Centre. (1996b). Hygrotus artus. The IUCN Red List of Threatened Species 1996: e.T10345A3195883. Downloaded on 01 August 2020.


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