Leptothorax canadensis

Identification
This is apparently a species complex and is in need of clarification. The clypeus of the worker is depressed in the middle and is without a medial carina, although several lateral carinae are present. The propodeal spines are well developed. The anterior face of the petiole is weakly concave, and meets the dorsum in an angle, the posterior face is convex and rounded. The dorsum and sides of the mesosoma, petiole and postpetiole are completely covered with punctate-granulose sculpture. There are numerous short (0.01mm), blunt-tipped hairs. (Mackay and Mackay 2002)

Distribution based on Regional Taxon Lists
Nearctic Region: Canada, United States. Neotropical Region: Mexico.

Biology
Colonies of this species are found in dead Beargrass stems in Montana.

Wheeler and Wheeler (1986) - This small ant "is one of the very few truly boreal-alpine members of its family. It is known from a very wide area in the northern Palearctic" (Brown, 1955:43). "Of all ants occurring in North America, Leptothorax muscorum is the species best able to survive in extreme Arctic-alpine conditions. Throughout boreal and alpine North America within the limits of the timbered areas, L. muscorum is found in company with Camponotus herculeanus (Linnaeus) and Formica neorufibarbis Emery, the two dominant ants of the region" (Brown, 1955:47). Brown (p. 49) reported L. muscorum from an island at the mouth of the Mackenzie River, lat. 69°32'N, long. 133°47'W, which "seems to be the northernmost record for ants in the Western Hemisphere."

Colorado - Gregg (1963) reported this ant in Colorado from dry tundra and a variety of forest types; 5,345-12,000 ft.

New Mexico - This is one of the most common Leptothorax spp. in northern New Mexico. It nests in rotten logs (usually ponderosa pine) throughout the area. Logs may range from 15 cm to 1 m in diameter. Nests may also be located below stones. Brood and reproductives were found in the nests in July and August and nests may contain more than one queen. It shares nests with Myrmica fracticornis, Myrmica emeryana (=Myrmica latifrons) and Tapinoma sessile. (Mackay and Mackay 2002)

Nevada, Wheeler and Wheeler (1986) - We have 25 records from 18 localities 6,400-11,000 ft. Four records were in the Alpine Biome, 14 were in the Coniferous Forest. In the Alpine 1 nest was under a stone and 1 in dead wood; in the Coniferous Forest 7 nests were in and under rotten wood and 2 were in and under loose bark on dead trunks.

This species is a host for the slave-making species (Beibl et al., 2005; de la Mora et al., 2021).

Nomenclature

 *  canadensis. Leptothorax canadensis Provancher, 1887: 245 (w.q.m.) CANADA.
 * Wheeler, G.C. & Wheeler, J. 1955b: 21 (l.).
 * Combination in L. (Mychothorax): Ruzsky, 1904a: 288; Emery, 1924d: 261;
 * combination in L. (Leptothorax): Wheeler, G.C. & Wheeler, J. 1955b: 21.
 * Subspecies of acervorum: André, 1887: 295; Dalla Torre, 1893: 123; Wheeler, W.M. 1903c: 225; Wheeler, W.M. 1906b: 8; Wheeler, W.M. 1908f: 621; Wheeler, W.M. 1910g: 566; Forel, 1914c: 617; Wheeler, W.M. 1916m: 588; Wheeler, W.M. 1917a: 511; Wheeler, W.M. 1917e: 18; Emery, 1924d: 261; Cole, 1936a: 36; Wing, 1939: 162; Cole, 1942: 369; Wheeler, G.C. & Wheeler, E.W. 1944: 247; Buren, 1944a: 288; Smith, M.R. 1951a: 820.
 * Junior synonym of muscorum: Brown, 1955a: 47.
 * Status as species: Emery, 1895c: 318; Wheeler, W.M. in Viereck, 1903: 73; Creighton, 1950a: 274; Cole, 1953d: 27; Cole, 1954d: 240; Schar et al., 2018: 6.
 * Senior synonym of Leptothorax canadensis kincaidi: Schär et al., 2018: 6.
 * Senior synonym of Leptothorax canadensis obscurus: Schär et al., 2018: 6.
 * Senior synonym of Leptothorax muscorum septentrionalis: Schär et al., 2018: 6.
 * Senior synonym of Leptothorax muscorum sordidus: Schär et al., 2018: 6.
 * Senior synonym of Leptothorax canadensis yankee: Schär et al., 2018: 6.
 * Material of the unavailable name convivialis referred here by Creighton, 1950a: 276.
 * obscurus. Leptothorax canadensis subsp. obscurus Viereck, 1903: 72 (w.) U.S.A.
 * Junior synonym of yankee: Creighton, 1950a: 277.
 * Junior synonym of canadensis: Schar et al., 2018: 6.
 * yankee. Leptothorax (Leptothorax) canadensis var. yankee Emery, 1895c: 319 (w.q.) U.S.A.
 * Wheeler, W.M. 1917a: 513 (m.)
 * Wheeler, G.C. & Wheeler, J. 1955b: 21 (l.).
 * Subspecies of canadensis and senior synonym of obscurus, sordidus: Creighton, 1950a: 277.
 * Junior synonym of muscorum: Brown, 1955a: 47.
 * Junior synonym of canadensis: Schar et al., 2018: 6.
 * septentrionalis. Leptothorax (Mychothorax) muscorum var. septentrionalis Wheeler, W.M. 1917a: 511 (w.q.m.) CANADA.
 * Material of the unavailable name calderoni referred here by Creighton, 1950a: 276.
 * Junior synonym of muscorum: Brown, 1955a: 47.
 * Junior synonym of canadensis: Schar et al., 2018: 6.
 * sordidus. Leptothorax muscorum var. sordidus Wheeler, W.M. 1903c: 224, pl. 12, fig. 2 (w.) U.S.A.
 * Junior synonym of yankee: Creighton, 1950a: 277.
 * Junior synonym of canadensis: Schar et al., 2018: 6.
 * kincaidi. Leptothorax yankee var. kincaidi Pergande, 1900: 520 (w.q.) U.S.A.
 * Junior synonym of muscorum: Brown, 1955a: 47.
 * Junior synonym of canadensis: Schar et al., 2018: 6.

Taxonomic Notes
Schar et al. (2018): Leptothorax canadensis Provancher, 1887 stat. nov. was considered a subspecies of ''Le. acervorum by Andre (1887), a full species by Emery (1895) and a junior synonym of Le. muscorum'' by Brown (1955). Our findings support the hypothesis of ''Le. canadensis representing a full species, and it is therefore removed from synonymy with Le. muscorum''. The following junior synonyms should be moved from ''Le. muscorum to Le. canadensis: Leptothorax canadensis obscurus Viereck, 1903, Leptothorax canadensis yankee Emery, 1895, Leptothorax muscorum septentrionalis Wheeler, 1917, Leptothorax muscorum sordidus Wheeler, 1903, and Leptothorax yankee kincaidi'' Pergande, 1900. However, the North American members of the genus Leptothorax are a difficult species complex whose taxonomy remains unresolved.

References based on Global Ant Biodiversity Informatics

 * Allred D. M. 1982. Ants of Utah. The Great Basin Naturalist 42: 415-511.
 * Allred, D.M. 1982. The ants of Utah. Great Basin Naturalist 42:415-511.
 * Beck D. E., D. M. Allred, W. J. Despain. 1967. Predaceous-scavenger ants in Utah. Great Basin Naturalist 27: 67-78
 * Blacker, N.C. 1992. Some Ants from Southern Vancouver Island, British Columbia. J. Entomol. Soc. Bri. Columbia 89:3-12.
 * Blacker, N.C. 1992. Some ants (Hymenoptera: Formicidae) from Southern Vancouver Island, British Columbia. Journal of the Entomological Society of British Columbia 89:3-12
 * Borchert, H.F. and N.L. Anderson. 1973. The Ants of the Bearpaw Mountains of Montana (Hymenoptera: Formicidae). Journal of the Kansas Entomological Society 46(2):200-224
 * Brown W. L., Jr. 1955. The ant Leptothorax muscorum (Nylander) in North America. Entomological News 66: 43-50.
 * Canadensys Database. Dowloaded on 5th February 2014 at http://www.canadensys.net/
 * Choate B., and F. A. Drummond. 2012. Ant Diversity and Distribution (Hymenoptera: Formicidae) Throughout Maine Lowbush Blueberry Fields in Hancock and Washington Counties. Environ. Entomol. 41(2): 222-232.
 * Choate B., and F. A. Drummond. 2013. The influence of insecticides and vegetation in structuring Formica Mound ant communities (Hymenoptera: Formicidae) in Maine lowbush blueberry. Environ. Entomol. 41(2): 222-232.
 * Clark Adam. Personal communication on November 25th 2013.
 * Cole A. C., Jr. 1942. The ants of Utah. American Midland Naturalist 28: 358-388.
 * Cole A. C., Jr. 1953. Notes on the genus Leptothorax in New Mexico and a description of a new species. Proceedings of the Entomological Society of Washington 55: 27-30.
 * Coovert G. A. 2005. The Ants of Ohio (Hymenoptera: Formicidae). Ohio Biological Survey, Inc. 15(2): 1-207.
 * Coovert, G.A. 2005. The Ants of Ohio (Hymenoptera: Formicidae) Ohio Biological Survey Bulletin New Series Volume 15(2):1-196
 * Eidmann V. H., and H. Münden. 1933. Zur Kenntnis der Ameisenfauna von Sudlabrador. Zoologischer Anzeiger 101(7): 202-221.
 * Francoeur, A. 1983. The ant fauna near the tree-line in Northern Quebec (Formicidae, Hymenoptera). Nordicana 47: 177-180
 * Glasier J. R. N., S. E. Nielsen, J. Acorn, and J. Pinzon. 2019. Boreal sand hills are areas of high diversity for Boreal ants (Hymenoptera: Formicidae). Diversity 11, 22; doi:10.3390/d11020022.
 * Glesne R. S. 2000. Terrestrial riparian arthropod investigations in the Big Beaver Creek Research Natural Area, North Cascades National Park Service Complex, 1995-1996: Part IV, Hymenoptera: Formicidae. 48 pages
 * Gregg, R.T. 1963. The Ants of Colorado.
 * Headley A. E. 1943. The ants of Ashtabula County, Ohio (Hymenoptera, Formicidae). The Ohio Journal of Science 43(1): 22-31.
 * Higgins J. W., N. S. Cobb, S. Sommer, R. J. Delph, and S. L. Brantley. 2014. Ground-dwelling arthropod responses to succession in a pinyon-juniper woodland. Ecosphere 5(1):5. http://dx.doi.org/10.1890/ES13-00270.1
 * Higgins R. J., and B. S. Lindgren. 2012. An evaluation of methods for sampling ants (Hymenoptera: Formicidae) in British Columbia, Canada. Can. Entomol. 144: 491-507.
 * Hoey-Chamberlain R. V., L. D. Hansen, J. H. Klotz and C. McNeeley. 2010. A survey of the ants of Washington and Surrounding areas in Idaho and Oregon focusing on disturbed sites (Hymenoptera: Formicidae). Sociobiology. 56: 195-207
 * Ivanov, K. 2019. The ants of Ohio (Hymenoptera, Formicidae): an updated checklist. Journal of Hymenoptera Research 70: 65–87.
 * Johnson R. Personnal Database. Accessed on February 5th 2014 at http://www.asu.edu/clas/sirgtools/resources.htm
 * Kannowski P. B. 1956. The ants of Ramsey County, North Dakota. American Midland Naturalist 56(1): 168-185.
 * La Rivers I. 1968. A first listing of the ants of Nevada. Biological Society of Nevada, Occasional Papers 17: 1-12.
 * Lesica P., and P. B. Kannowski. 1998. Ants Create Hummocks and Alter Structure and Vegetation of a Montana Fen. Am. Midl. Nat. 139: 5868
 * Lindgren, B.S. and A.M. MacIsaac. 2002. Ant dependence on dead wood in Central Interior British Columbia. USDA Forest Service Gen. Tech. Rep.PSW-GTR-181
 * Loiselle R., A. Francoeur, K. Fischer, and A. Buschinger. 1990. Variations and taxonomic significance of the chromosome numbers in the Nearctic species of the genus Leptothorax (s.s.) (Formicidae: Hymenoptera). Caryologia 43:321-334.
 * Longino, J.T. 2010. Personal Communication. Longino Collection Database
 * Lubertazi, D. Personal Communication. Specimen Data from Museum of Comparative Zoology at Harvard
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Mackay, W., D. Lowrie, A. Fisher, E. Mackay, F. Barnes and D. Lowrie. 1988. The ants of Los Alamos County, New Mexico (Hymenoptera: Formicidae). pages 79-131 in J.C. Trager, editor, Advances in Myrmecololgy.
 * Mackay, W.P. and E. Mackay. XXXX. The Ants of New Mexico
 * Matthewman, W.G. and D.P. Pielou. 1971. Arthropods inhabiting the sporophores of Fomes fomentarius (Polyporaceae) in Gatineau Park, Quebec. Canadian Entomologist 103(6):775-847
 * Merle W. W. 1939. An Annotated List of the Ants of Maine (Hymenoptera: Formicidae). Entomological News. 50: 161-165
 * Munsee J. R. 1968. Nine species of ants (Formicidae) recently recorded from Indiana. Proc. Indiana Acad. Sci. 77: 222-227.
 * Nielsen M. G. 1987. The ant fauna (Hymenoptera: Formicidae) in northern and interior Alaska. A survey along the trans-Alaskan pipeline and a few highways. Entomological News 98:74-88
 * Paiero, S.M. and S.A. Marshall. 2006. Bruce Peninsula Species list . Online resource accessed 12 March 2012
 * Parson G. L., G Cassis, A. R. Moldenke, J. D. Lattin, N. H. Anderson, J. C. Miller, P. Hammond, T. Schowalter. 1991. Invertebrates of the H.J. Andrews Experimental Forest, western Cascade Range, Oregon. V: An annotated list of insects and other arthropods. Gen. Tech. Rep. PNW-GTR-290. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 168 p.
 * Rango J. J. 2012. A Survey of Ant Species in Three Habitats atMount St. Helens National VolcanicMonument. Psyche doi:10.1155/2012/415183
 * Shik, J., A. Francoeur and C. Buddle. 2005. The effect of human activity on ant species (Hymenoptera: Formicidae) richness at the Mont St. Hilaire Biosphere Reserve, Quebec. Canadian Field-Naturalist 119(1): 38-42.
 * Smith M. R. 1952. On the collection of ants made by Titus Ulke in the Black Hills of South Dakota in the early nineties. Journal of the New York Entomological Society 60: 55-63.
 * Talbot M. 1976. A list of the ants (Hymenoptera: Formicidae) of the Edwin S. George Reserve, Livingston County, Michigan. Great Lakes Entomologist 8: 245-246.
 * Varady-Szabo, H. 2004. Spiders and Ants Associated with Fallen Logs in Forillon National Park of Canada, Quebec. Masters Thesis, MgGill University, Montreal, Canada
 * Wheeler G. C., J. N. Wheeler, and P. B. Kannowski. 1994. Checklist of the ants of Michigan (Hymenoptera: Formicidae). The Great Lakes Entomologist 26(4): 297-310
 * Wheeler G. C., and E. W. Wheeler. 1944. Ants of North Dakota. North Dakota Historical Quarterly 11:231-271.
 * Wheeler G. C., and J. Wheeler. 1986. The ants of Nevada. Los Angeles: Natural History Museum of Los Angeles County, vii + 138 pp.
 * Wheeler G. C., and J. Wheeler. 1987. A Checklist of the Ants of South Dakota. Prairie Nat. 19(3): 199-208.
 * Wheeler J. N., G. C. Wheeler, R. J. Lavigne, T. A. Christiansen, and D. E. Wheeler. 2014. The ants of Yellowstone National Park. Lexington, Ky. : CreateSpace Independent Publishing Platform, 2013. 112 pages.
 * Wheeler W. M. 1903. A revision of the North American ants of the genus Leptothorax Mayr. Proceedings of the Academy of Natural Sciences of Philadelphia. 55: 215-260.
 * Wheeler W. M. 1905. Ants from the summit of Mount Washington. Psyche (Cambridge) 12: 111-114.
 * Wheeler W. M. 1917. The mountain ants of western North America. Proceedings of the American Academy of Arts and Sciences 52: 457-569.
 * Wheeler, G.C. and J. Wheeler. 1978. Mountain ants of Nevada. Great Basin Naturalist 35(4):379-396
 * Wheeler, G.C. and J. Wheeler. 1988. A checklist of the ants of Montana. Psyche 95:101-114
 * Wheeler, G.C. and J. Wheeler. 1988. A checklist of the ants of Wyoming. Insecta Mundi 2(3&4):230-239
 * Wheeler, G.C., J. Wheeler and P.B. Kannowski. 1994. CHECKLIST OF THE ANTS OF MICHIGAN (HYMENOPTERA: FORMICIDAE). Great Lakes Entomologist 26:1:297-310
 * Wheeler, G.C., J. Wheeler, T.D. Galloway and G.L. Ayre. 1989. A list of the ants of Manitoba. Proceedings of the Entomological Society of Manitoba 45:34-49