Strumigenys missouriensis

Strumigenys missouriensis is an extremely wide-ranging and morphologically variable species and probably represents a complex of species. In Ohio colonies were found nesting in soil in forested sites (Wesson & Wesson, 1939). A more thorough taxonomic treatment of S. missouriensis across its range is needed. (Booher, 2021)

Identification
Bolton (2000) - A member of the Strumigenys pulchella-group. Very closely related to Strumigenys reflexa but quickly distinguished as in missouriensis most or all of the large hairs on the lateral clypeal margins curve anteriorly, whereas in reflexa all hairs on the lateral clypeal margins are markedly reflexed, curving posterolaterally. See also under Strumigenys pulchella.

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Biology
Wesson and Wesson (1939) - Four colonies and numerous stray workers were found in a cedar thicket in western Pike County, Ohio. The first workers were seen in and around some little-used gallaries of Aphaenogaster picea under a small stone, and the colony was located about 30 cm. away just beneath the humus. Two other colonies were likewise in the soil, not more than 4 cm. below the surface. The latter, however, were not visibly associated with any other ants. Scattered, stray workers were found just under the top layer of the humus. The cedar grove was located on the gently sloping base of a hill. Mingled with the cedars were a few small oaks and an occasional maple sapling. The soil was a black clay from 5 to 15 cm. deep above the limestone bed rock. Above the clay was a thick, springy layer of loose decaying cedar needles, leaves and grass. Abounding in this debris were Ponera pennsylvanica, Myrmecina graminicola, and hordes of Collembola, as well as Strumigenys. Here, in an area of 3 by 9 meters, were found S. missouriensis, Strumigenys pilinasis (as S. manni), Strumigenys dietrichi, and Strumigenys venatrix.

On careful comparison of our specimens with 2 worker cotypes loaned by Dr. M. R. Smith, we find that, although some of the workers agree closely with the cotypes, there is quite a perceptible amount of variation both among workers from the same colony and among the 4 colonies found. This variation lies almost entirely in the direction of forms which differ from the cotypes in the following details: (1) the head is slightly more robust; (2) the clypeus is slightly depressed in the middle; (3) the antennal scapes are somewhat more angulate (4) the sculpture is distinctly coarser; (5) the hairs on the head are larger, especially on the clypeus, and are fewer in number.

Brown (1953) - Collection records indicate that it is primarily a soil and soil cover inhabitant. Mary Talbot collected the types in a nest of Aphaenogaster fulva under a stone in clay soil. The Wessons found this species abundant in the humus of a· cedar thicket in southern Ohio. Smith states that he collected workers under bark of logs and stumps, although some of the original workers were taken under objects lying on the soil surface. Miss Talbot took winged females from the type colony on August 20, 1929, the usual time of year for winged forms to occur in the nest.

Nomenclature

 *  missouriensis. Strumigenys (Cephaloxys) missouriensis Smith, M.R. 1931c: 701, pl. 4, fig. 14 (w.) U.S.A. Brown, 1953g: 72 (q.). Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 307; in Smithistruma: Smith, M.R., 1951a: 828; Brown, 1953g: 72; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 124. Senior synonym of sculpturata: Smith, M.R. 1951a: 828; Brown, 1953g: 72. See also: Wilson, 1954: 485; Bolton, 2000: 121.
 * sculpturata. Strumigenys (Cephaloxys) sculpturata Smith, M.R. 1931c: 706, pl. 4, fig. 15 (w.) U.S.A. Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 310. Junior synonym of missouriensis: Smith, M.R. 1951a: 828; Brown, 1953g: 72.

Worker
Bolton (2000) - TL 2.0-2.2, HL 0.54-0.60, HW 0.38-0.42, CI 68-72, ML 0.08-0.10, MI 13-18, SL 0.26-0.31, SI 69-75, PW 0.25-0.28, AL 0.54-0.60 (10 measured).

Anterior clypeal margin broadly shallowly convex to almost transverse. Clypeal dorsum flat to shallowly depressed, usually hairless from about centre to posterior border. Anterior clypeal margin with 1-2 pairs of hairs that curve away from the midline, directed laterally or posterolaterally; hairs on lateral clypeal margins mostly or entirely curved anteriorly. Pilosity of head and body otherwise as Strumigenys reflexa.

Type Material
Bolton (2000) - Syntype workers, U.S.A. Missouri, Columbia, 20. viii. 1929 (M. Talbot) [examined].

References based on Global Ant Biodiversity Informatics

 * Brown W. L. 1964. The ant genus Smithistruma: a first supplement to the world revision (Hymenoptera: Formicidae). Transactions of the American Entomological Society 89: 183-200.
 * Brown W. L., Jr. 1953. Revisionary studies in the ant tribe Dacetini. Am. Midl. Nat. 50: 1-137.
 * 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
 * Deyrup, M. 2003. An updated list of Florida ants (Hymenoptera: Formicidae). Florida Entomologist 86(1):43-48.
 * Deyrup, M. and S. Cover. 2009. Dacetine Ants in Southeastern North America (Hymenoptera: Formicidae). Southeastern Naturalist 8(2):191-212
 * Ivanov, K. 2019. The ants of Ohio (Hymenoptera, Formicidae): an updated checklist. Journal of Hymenoptera Research 70: 65–87.
 * Ivanov K., L. Hightower, S. T. Dash, and J. B. Keiper. 2019. 150 years in the making: first comprehensive list of the ants (Hymenoptera: Formicidae) of Virginia, USA. Zootaxa 4554 (2): 532–560.
 * Lynch J. F. 1988. An annotated checklist and key to the species of ants (Hymenoptera: Formicidae) of the Chesapeake Bay region. The Maryland Naturalist 31: 61-106
 * MacGown J. A., J. G. Hill, R. L. Brown, T. L. Schiefer, J. G. Lewis. 2012. Ant diversity at Noxubee National Wildlife Refuge in Oktibbeha, Noxubee, and Winston Counties, Mississippi. Mississippi Agricultural and Forestry Experiment Station Bulletin 1197: 1-30
 * MacGown J. A., J. G. Hill, and M. Deyrup. 2009. Ants (Hymenoptera: Formicidae) of the Little Ohoopee River Dunes, Emanuel County, Georgia. J. Entomol. Sci. 44(3): 193-197.
 * MacGown J. A., J. G. Hill, and R. L. Brown. 2010.  Native and exotic ant in Mississippi state parks.  Proceedings:  Imported Fire Ant Conference, Charleston, South Carolina, March 24-26, 2008: 74-80.
 * MacGown, J.A., J.G. Hill, R.L. Brown and T.L. 2009. Ant Diversity at Noxubee National Wildlife Refuge in Oktibbeha, Noxubee, and Winston Counties, Mississippi Report #2009-01. Schiefer. 2009.
 * Macgown J. A., S. Y. Wang, J. G. Hill, and R. J. Whitehouse. 2017. A List of Ants (Hymenoptera: Formicidae) Collected During the 2017 William H. Cross Expedition to the Ouachita Mountains of Arkansas with New State Records. Transactions of the American Entomological Society, 143(4): 735-740.
 * Smith M. R. 1931. A revision of the genus Strumigenys of America, north of Mexico, based on a study of the workers (Hymn.: Formicidae). Annals of the Entomological Society of America 24: 686-710.
 * Wesson L. G., and R. G. Wesson. 1939. Notes on Strumigenys from southern Ohio, with descriptions of six new species. Psyche (Cambridge) 46: 91-112.