Crematogaster laeviuscula

This species nests in wood, or under bark of dead logs (cottonwood), or in oak galls of the wasp Holcaspis cinerosus. Sexuals occur in nests in August. These ants are more aggressive than is typical for North American Crematogaster. (Mackay and Mackay 2002)

Identification
The workers of this species are predominantly shiny, specifically the head and side of the pronotum are shiny and glossy, the top of the pronotum is shiny, but finely sculptured. The mesopleuron and the sides of the propodeum are punctate or finely striate. The propodeal spines are well developed and long. It is generally light colored, with a pale reddish-yellow head and mesosoma and a darker gaster. (Mackay and Mackay 2002)

Morgan & Mackay (2017) - This common species is one of the most attractive, generally being bright red with a shiny black gaster. Key characteristics of C. laeviuscula are the entirely smooth and glossy head; the pronotum is lightly sculptured, and at least partially smooth and shining. Most the specimens are bicolored, mostly red with a black gaster.

There is considerable variation in C. laeviuscula in terms of color and sculpturing. Color ranges from the common bicolored individuals, completely reddish yellow, to completely dark brown. The head is mostly smooth and glossy, but the pronotum may be completely smooth and glossy (polished) to lightly sculptured (striated) and weakly shining.

Crematogaster atkinsoni
Morgan & Mackay (2017) - MacGown (pers. comm.) does not agree with our synonymizing C. atkinsoni, which makes unique and distinctive carton nests in gulf coastal grasses and is not the same thing as C. laeviuscula, that nests in stumps, cavities, etc., west of the Mississippi River. He has had considerable experience with southeastern ants, and we could be wrong.

Johnson 1988 - Crematogaster atkinsoni and Crematogaster pilosa may co-occur together in the same habitat and require care in identification.

The species typically occurs only about salt and freshwater marshes along the southern Coastal Plain and a distinct color variant having a rosy - red color over the whole body occurs in scattered localities along the salt marshes bordering the North Florida Gulf Coast. These ants are very distinct in color and the propodeal spines are slightly thicker in some specimens but no other morphological characters separate the two forms. The red variant constructs carton nests in and about the marsh, often above standing water, high enough to escape the tides. Other nests may occur within grass stems on dry land bordering the marsh, but even in these nests a carton component occurs at the base of the grass stems. Within the same marshes, the dark-colored, typical C. atkinsoni morph occurs nesting in a variety of circumstances but using a wide array of nest sites often with no carton involved.

Distribution
Central United States and south into Mexico.

Morgan & Mackay (2017) - This species is found throughout the United States, and has been collected as far south as Tabasco, México. Additional citations include Virginia (Guénard et al., 2012; Kjar, 2009), southeastern South Carolina (Davies, 2009, as C. atkinsoni), and Baja California (Johnson and Ward, 2002, as C. opaca cedrosensis, and C. hespera; Vázquez-Bolaños, 2011).

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

Habitat
Riparian Forest.

Biology
Morgan & Mackay (2017) - The habits of Crematogaster laeviuscula are diverse, mostly arboreal and relatively well known. Mackay and Mackay (unpublished) found they occasionally nest under stones, but generally live in living trees, in hollow twigs, under the bark and in branches (full of beetle burrows or termite tunnels), in completely rotten stumps with loose bark and in/under logs. They have often been taken in oak galls (Morgan, unpublished). They consistently nest in plants in Mississippi, including in dead dogwood, black willow, sumac, white ash, goldenrod, blackberry (Rubus laciniatus), common elder, mimosa, hickory, plume grass, rattan-vine, catalpa, bois d'arc, hawthorn, prickly ash, sweetgum, red oak, china-tree, pecan, black locust, and dead woody galls on red oak, often in preformed cavities (Tynes and Hutchins, 1964). They would often move the nest to logs and stumps when the colony outgrew its home (Tynes and Hutchins, 1964). They make carton nests in grass tussocks (as C. atkinsoni, Deyrup et al., 1988).

Mackay and Mackay (unpublished) collected brood in nests in March, May, June and August, sexuals in August. A founding queen with one worker was found in a hollow twig in March. Workers tend to be sluggish and escape when the nest is disturbed, but are more active under warmer temperatures, and large nests can be aggressive, and the workers attack and bite, relatively painfully for Crematogaster. Colonies have hundreds of workers and reproductives, as well as brood (Tynes and Hutchins, 1964). Brood overwinter as larvae (Tynes and Hutchins, 1964).

They forage in the vegetation as well as loose on the ground. Morgan (unpublished) noted that they utilize hollow vegetation to camouflage their trails. She found them at Squaw Spring at the UTEP Indio Mountains Research Station of Hudspeth Co., Texas, a riparian habitat in the Chihuahuan Desert, where they were traveling almost unseen on cattail stalks. Many eggs and pupae (worker and queen) were found in the hollow stalks that were exposed to the sun. Workers were seen eating a cicada thorax, others were feeding on a discarded piece of meat (Mackay and Mackay, unpublished). They were attracted to meat baits in open areas (Morrison, 2004). They tend Hemiptera and build earthen tents to protect the animals (Tynes and Hutchins, 1964).

They are generally found in mesic sites, including urban areas in arid regions, but are also found in open desert with creosote bush scrub, mesquite and acacia, mixed shrubland (mesquite, cholla, big lobed cactus), sagebrush, grassland, juniper forest, pinyon pine riparian, oak forests, oak woodland with spiny vegetation, riparian forest, riparian cottonwoods, deciduous forest, mixed pine/hardwood trees and pine/spruce/fir forest (Mackay and Mackay, unpublished). Whitford et al. (1999, as C. hespera) found them in riparian woodlands in New Mexico, and Feener (1981) reported them from semi-deciduous woodlands in eastern Texas. They are found in Florida scrub and pine flatlands in Florida upland ecosystems (King, 2007). They occur in fresh and salt water marshes, grasslands, sunflowers and mesquite, they normally nest arboreally, but can be found in logs (Jusino-Atresino and Phillips, 1992). They even occur in caves (Cokendolpher et al., 2009), and adapt to urban ecosystems (Guénard et al., 2014).

They are found in areas with soils ranging from light brown, brown to dark brown clay, light to dark brown clay/loam, dark brown loam, light brown fine sand/clay, orange sand, light brown to brown rocky-loam, and light brown rocky sand to rocky red soil.

They are codominant with the red imported fire ant Solenopsis invicta, as well as with Solenopsis geminata, and are parasitized by phorid flies, Pseudacteon sp. (Morrison et al., 2000). They are also parasitized by the strepsipteran Caenocholax fenyesis (Cook, 2009; Kathirithamby et al., 2010). Crematogaster laeviuscula are predators on egg cases and spiderlings of the spider Peucetia viridans (Oxyopidae) in South Carolina (as C. clara, Willey and Adler, 1989). They eliminate relatively few nests of the wasp Polistes exclamans (Strassmann, 1981). Hung and Vinson (1975) studied the male reproductive system.

Deyrup (2017) includes details on the biology and distribution of this species as well as comparisons with other species occurring in Florida, as C. atkinsoni.

Nomenclature

 * arborea. Oecodoma (Atta) arborea Buckley, 1867: 349 (w.q.) U.S.A.
 * [Unresolved junior secondary homonym of arboreus Smith, F. above.]
 * Junior synonym of lineolata: McCook, 1880: 187; Dalla Torre, 1893: 83.
 * Junior synonym of laeviuscula: Smith, M.R. 1951a: 809; Buren, in Smith, M.R. 1958c: 126.
 * bicolor. Oecodoma (Atta) bicolor Buckley, 1867: 350 (w.) U.S.A.
 * [Junior secondary homonym of bicolor Smith, above.]
 * Senior synonym of clara: McCook, 1880: 188; Mayr, 1886d: 463 [clara oldest synonym and hence first available replacement name.]
 * clara. Crematogaster clara Mayr, 1870b: 993 (w.) U.S.A.
 * Wheeler, W.M. 1908e: 481 (q.m.).
 * Combination in C. (Acrocoelia): Emery, 1922e: 141.
 * Combination in C. (Crematogaster): Buren, 1968b: 92.
 * Junior synonym of bicolor Buckley (junior homonym): McCook, 1880: 188; Mayr, 1886d: 463 and hence first available replacement name.
 * Subspecies of laeviuscula: Dalla Torre, 1893: 83; Wheeler, W.M. 1919g: 111; Enzmann, J. 1946c: 93.
 * Junior synonym of laeviuscula: Creighton, 1950a: 210.
 * Revived from synonymy and revived status as species: Buren, in Smith, M.R. 1958c: 126; Buren, 1968b: 92 (in key); Smith, D.R. 1979: 1378.
 * Junior synonym of laeviuscula: Johnson, C. 1988: 322.
 *  laeviuscula. Crematogaster laeviuscula Mayr, 1870b: 993 (w.) U.S.A.
 * Wheeler, W.M. 1908e: 480 (q.); Wheeler, G.C. & Wheeler, J. 1952b: 255 (l.); Petralia & Vinson, 1980: 383 (l.).
 * Combination in C. (Acrocoelia): Emery, 1922e: 141.
 * Combination in C. (Crematogaster): Buren, 1968b: 92.
 * Subspecies of lineolata: Emery, 1895c: 284; Wheeler, W.M. 1904e: 301; Emery, 1922e: 141.
 * Status as species: Wheeler, W.M. 1919g: 111; Creighton, 1950a: 210.
 * Senior synonym of clara: Mayr, 1886d: 463; Creighton, 1950a: 210; Johnson, C. 1988: 322.
 * Senior synonym of arborea: Smith, M.R. 1951a: 809 (provisional); Buren, in Smith, M.R. 1958c: 126.
 * decolorata. Crematogaster (Acrocoelia) castanea var. decolorata Santschi, 1926b: 213 (w.) SOUTH AFRICA.
 * Junior synonym of arborea: Santschi, 1930b: 69.
 * hespera. Crematogaster (Crematogaster) hespera Buren, 1968b: 98 (w.q.) U.S.A.
 * Junior synonym of laeviuscula: Morgan & Mackay, 2017: 197.
 * atkinsoni. Crematogaster atkinsoni Wheeler, W.M. 1919g: 108, fig. 16 (w.) U.S.A.
 * Wheeler, W.M. 1932a: 9 (q.m.).
 * Combination in C. (Acrocoelia): Creighton, 1950a: 207.
 * Combination in C. (Crematogaster): Buren, 1968b: 92.
 * Junior synonym of laeviuscula: Johnson, C. 1988: 322.
 * See also: Johnson, C. 1988: 316.
 * helveola. Crematogaster atkinsoni var. helveola Wheeler, W.M. 1919g: 109 (w.q.m.) U.S.A.
 * Junior synonym of atkinsoni: Creighton, 1950a: 207.
 * [atkinsoni junior synonym of laeviuscula: Morgan & Mackay, 2017: 197.]
 * [Original q.m. of helveola type-series were misidentified and are correctly ashmeadi: Smith, D.R. 1979: 1377.]
 * cedrosensis. Crematogaster lineolata subsp. cedrosensis Wheeler, W.M. 1934f: 136 (w.) MEXICO.
 * Junior synonym of laeviuscula: Morgan & Mackay, 2017: 197.

Crematogaster lineolata cedrosensis
Eight specimens from Cedros Island (VI.5.'95).

Crematogaster hespera
Phoenix, Arizona

Types: Holotype worker and eleven para type workers from Phoenix, Arizona, July 20, 1918- A. W. Morrill, with the note “attacking unripe peaches, very destructive.” I have another series from Phoenix of ten paratype workers and three females collected Dec. 25, 1895. The latter series was seen by Emery and marked by him as transitional from laeviuscula to cerasi. I have marked as paratypes also numerous specimens from these localities: Big Dalton Canyon, Glendora, Calif.- A. Mallis and J. Schwartz; Col. Desert, Calif. -A. L. Pickens; Glenville, Calif.- A. Wetmore; Pacific Grove, Calif.- W. M. Mann; Sacaton, Ariz.- F. S. Strickney; Nogales, Ruby, and Patagonia, Ariz.- L. F. Byars; Las Cruces, N. Mex.- A. C. Cole; Nogales and Patagonia, Ariz., and Ysleta and El Paso, Tex.- W. F. Buren; Sacramento, Calif.- P. H. Arnaud; Santa Ysabel and Mt. Laguna, San Diego Co., Calif.; Ft. Huachuca, Wickenberg, and Patagonia, Ariz.; and Imuris, Sonora, Mex.- Vv. S. Creighton; and Tempe, Ariz., W. M. Wheeler. A few other paratype specimens are known from "Los Angeles Riv., Calif.," Ventura and Pasadena, Calif., Tucson, Ariz., and Zion Canyon, Utah.

Holotype and many of the above paratype specimens are to be returned to the National Museum. Other para types will be returned to the California Academy of Natural Sciences and to the private collections of Dr. A. C. Cole and Dr. Wm. S. Creighton. I will retain a few paratypes from some of the series and deposit some of the paratypes in the Museum of Comparative Zoology.

Taxonomic Notes
Morgan & Mackay (2017) - Mayr described two species in 1870 from Ft. Cobb, Oklahoma: C. laeviuscula and C. clara. These two species differed by size and intensity of sculpturing on the face and mesosoma. Crematogaster laeviuscula is smaller with less intense sculpture and C. clara is larger with more intense sculpture. Dalla Torre (1893) and Wheeler (1919) made C. clara a variety of C. laeviuscula. Wheeler (1908b) found 2 nests with series of mixed sizes and sculpturing and contained ants that ranged from the largest C. clara to the smallest C. laeviuscula giving credence to synonymy. The smaller C. laeviuscula have been found in smaller nests, possibly because they are newer colonies that have been recently established. Wheeler concluded that C. laeviuscula were merely minims of C. clara, with which we agree, based on several series. Since C. laeviuscula had page preference, the species was assigned that name (Johnson, 1988).

Crematogaster lineolata var. cedrosensis has smaller spines, but the shape of the spines, pilosity and sculpture are consistent with C. laeviuscula and it is proposed as a synonym.

Crematogaster atkinsoni keys out to C. laeviuscula in both Creighton (1950) and Buren (1968) when using type material borrowed from the. We have also compared type material of C. atkinsoni and type material of C. laeviuscula. The types two species appear to be identical leading us to consider Crematogaster atkinsoni a junior synonym of C. laeviuscula.

We have compared paratypes of Crematogaster hespera Buren to syntypes of C. clara (now C. laeviuscula) and find no apparent differences. Buren’s description of C. hespera could also be applied to C. clara. In Buren’s key to eastern species, C. hespera keys out to C. laeviuscula. We did not find much variation in the Buren paratypes; however, we have seen considerable variation within nest series from CWEM leading us to consider Crematogaster hespera Buren a junior synonym of C. laeviuscula.