Strumigenys brevisetosa

Strumigenys brevisetosa
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species group:	clypeata
Species:	S. brevisetosa
Binomial name
	Strumigenys brevisetosa; Smith, M.R., 1935
Synonyms
	Strumigenys medialis Wesson, L.G. & Wesson, R.G., 1939;

Strumigenys brevisetosa is one of the more common and wide-ranging eastern USA species with a range extending into several western states. Habitats recorded by collectors for collections in Kansas, Oklahoma, and Texas were deciduous forests and bogs with workers extracted from litter and log debris (DuBois 1985). A single malaise collection from Texas suggests Fall mating flights in the western portion of its range. (Booher, 2021)

Identification

There has been much confusion about this species and until recently it has been misidentified as Strumigenys pilinasis. As of Booher (2021), there are no other published keys that reflect this recent taxonomic change (Booher 2019). This species has variable clypeal setae across its range varying from fine-filiform to slightly expanded. The most consistent character in separating Strumigenys brevisetosa from Strumigenys laevinasis is that the setae on the dorsum of the clypeus are always inclined and pointing anteriorly (Fig. 11AA). These setae are inclined anteriorly at the base, but curve evenly along their length such that their apices are pointing up or posteriorly. (Booher, 2021)

Booher (2021), Fig. 11

Strumigenys brevisetosa can be easily distinguished from most Nearctic species by the presence of a distinct peripheral groove that runs the entire free margin of the clypeus, placing it in the clypeata group. Of species in the clypeata group it is most similar to Strumigenys laevinasis and Strumigenys clypeata. Members of Strumigenys brevisetosa are distinguished from S. laevinasis by their linear-spatulate pilosity on dorsum and free margins of the clypeus (in S. laevinasis these hairs are fine and never expanded along their lengths). Strumigenys brevisetosa is distinguished from S. clypeata by the elevated positioning and elongated hairs on the clypeal dorsum (in S. clypeata, dorsal clypeal hairs are scale-like spatulate hairs that are tightly appressed), as well as the longer more linear hairs on the free margins of their clypeus (in S. clypeata, this fringe of hairs are spatulate, not linear spatulate).

Keys including this Species

Key to western Nearctic Strumigenys species

Distribution

USA; widespread in eastern USA from Florida to Pennsylvania and west to Missouri; in western USA occurs in Kansas, Oklahoma, and Texas (Booher, 2021).

Latitudinal Distribution Pattern

Latitudinal Range: 38.8946° to 31.0714°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

brevisetosa. Strumigenys (Cephaloxys) clypeata var. brevisetosa Smith, M.R. 1935: 215 (w.) U.S.A. (Mississippi).
- Brown, 1953g: 60 (q.).
- Combination in S. (Trichoscapa): Smith, M.R. 1947f: 587.
- Combination in Smithistruma (Smithistruma): Smith, M.R. 1951a: 827; Brown, 1953g: 59.
- Junior synonym of pilinasis: Brown, 1964a: 197; Bolton, 2000: 106.
- Status as species: Wesson, L.G. & Wesson, R.G. 1939: 108; Wesson, L.G. & Wesson, R.G. 1939: 108 (in key); Smith, M.R. 1947f: 587; Creighton, 1950a: 304; Smith, M.R. 1951a: 828; Brown, 1953g: 59 (redescription); Wilson, 1954: 485; Smith, M.R. 1958c: 136; Booher, 2019: 405.
medialis. Strumigenys (Cephaloxys) medialis Wesson, L.G. & Wesson, R.G. 1939: 94, pl. 3, fig. 1 (w.q.) U.S.A. (Ohio).
- Status as species: Creighton, 1950a: 307.
- Junior synonym of pilinasis: Smith, M.R. 1951a: 828; Brown, 1953g: 60; Bolton, 2000: 106.
- Junior synonym of brevisetosa: Booher, 2019: 405.

Type Material

Strumigenys clypeata brevisetosa: Holotype, worker, Lucedale, George Co., Mississippi, United States, 17 January 1932, Dietrich, USNMENT00533161, National Museum of Natural History; sifting for beetles.
Strumigenys medialis: Syntype, 4 workers, Ohio, Pike County, Beaver, United States, Museum of Comparative Zoology.
Strumigenys medialis: Syntype, 1 worker, Ohio, Pike County, Beaver, United States, National Museum of Natural History.

Taxonomic Notes

Booher (2019): There is a fairly long history of confusion in the species concept of Strumigenys brevisetosa. It has the most variable clypeal hair and clypeal shape of any North American Strumigenys. It is likely that S. brevisetosa is a single species that has hybridized or still hybridizes with both S. laevinasis and S. clypeata (Brown 1964). It is also possible S. brevisetosa contains more than one cryptic species: one or two that are more closely related to S. laevinasis and one that is more closely related to S. clypeata. Strumigenys medialis (junior synonym of brevisetosa) originally referred to species more similar to S. laevinasis and Strumigenys brevisetosa referred to species more similar to S. clypeata (Brown 1964). Another potential closely related species, mentioned as Strumigenys near Strumigenys pilinasis, represents morphological variants that are closest to S. laevinasis. However, after examining all of the type specimens, nearly all the collection material available to previous taxonomists, and additional new collections, it has become clear that there are no distinct morphological characters to distinguish S. brevisetosa from S. medialis and I retain it as combined for the same reasons as Brown (1964) combined these two species. Specimens that are most similar to S. laevinasis tend to have one scrobal hair (at apical position, but this varies within the same nest series), have a smooth non-sculptured patch on the side of the pronotum, conical and stout teeth, and a clypeus that is longer than wide. Specimens that are more similar to S. clypeata tend to have two scrobal hairs (one along midlength and one at apical position, though rarely a specimen will have only one at apicoscrobal position), the side of pronotum with punctate and striate sculpture and without a smooth patch, spiniform elongate teeth, and a clypeus that is wider than long. However, after looking at many more specimens than were available to my predecessors, it has become clear that none of these characters are stable and at this time I am reluctant to separate S. brevisetosa into more than one species.

Brown (1964: 199) mentioned a possible new species as Strumigenys sp. near brevisetosa, based on two worker collections (Karber’s Ridge, Perry County, IL [Sanderson & Standard]; and Urbana, Champaign County, IL [Tanquary]). I identify these as Strumigenys brevisetosa.

Description

References

References based on Global Ant Biodiversity Informatics

Booher D. B. 2019. Taxonomic clarification of two Nearctic Strumigenys (Hymenoptera: Formicidae). Zootaxa 4664 (3): 401–411.
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.