Holarctic, America to Japan, North Africa to North Europe including British Isles
Prefers grassland, especially steppe and rock steppe, also urban. Nests in soil, under rocks and in small loam hills.
At 6:00pm I saw a mass of workers on the sidewalk. They were in a roughly circular patch over a sidewalk crack, a dense mass of grappling workers several ants deep, the circular mass around 20cm dia. A column of workers extended from the mass, about 1.5m long, through the grass at the side of the sidewalk to another crack. I returned at 7:30pm and found a triangular patch of more thinly spread workers, in an area of about 400 square cm. There was a low density of live workers, but most of the layer was dead workers, most of them dismembered. I counted the number of dead workers in a 2x2cm patch, got 60 workers, an estimated 6000 dead workers in the patch.
Forel, A., 1890:
Variétés diverses jaunes et noires partout, très commun. Les petites variétés claires se rapportant à peu prèsàpunicum Smith et semilaeve André sont les plus fréquentes . Ce sont elles qui servent d'esclaves àl'espèce suivante:
Emery, C., 1893:
— Fuerteventura (31), [[ worker ]], [[ queen ]], [[ male ]]; Canana (22, 61, 78, 84), Tenerife (M. Noualhier).
La plupart des exemplaires que j'ai sous les yeux se rapportent a la race depressum , decrite recemment par M. A. Forel, dont la couleur varie beaucoup. D'autres font passage a semilaeve Andre La [[ queen ]] de depressum est tres foncee, presque noire et caractensee par la forme courte du 1 er segment du pedicule. Sa taille, ainsi que celle du [[ male ]], correspond a telle des exemplaires mediterraneens de semilaeve .
Quelques [[ worker ]] de Tenerife ne different pas sensiblement de semilaeve .
Deux [[ queen ]], l'une de Lanzarote, l'autie de Canaria, ont le mesonotum en grande partie strie; elles paraissent se rapporter a une variete a sculpture plus forte.
T. caespitum est repandu dans toute la region palearctique et la race semilaeve est l'une des plus communes dans la region mediterraneenne.
Ward, P. S., 2005:
I [introduced species]
Güsten, R., 2006:
Cagniant (1997), treating this taxon as a subspecies of T. caespitum , cites records from diverse sites throughout Morocco. We have recently procured further samples, including the first known gyne ( Morocco , Middle Atlas, Reg. Meknes , in CAS ) , and regard it as a good species which may occur throughout the Maghreb. Some specimens from Tunisia (in NHMB ) are very similar , as are workers from the northeastern mountains of Teneriffa .
Species morphologically similar to T. caespitum (Linnaeus , 1758) are the dominant Tetramorium ants in temperate parts of Eurasia. Cammaerts et al. (1985) distinguished T. impurum (Foerster , 1850) from T. caespitum in central Europe based on male genitalic characters. It has recently become clear that the T. caespitum / impurum species complex constitutes in fact an assembly of cryptic species, which cannot yet be delimited clearly or assigned valid names (Steiner et al. 2002; Schlick-Steiner et al., 2006). More than one species is included within the current concepts of both T. caespitum and T. impurum . Throughout this paper we use the term “ T. caespitum s.l.” to denote species of the complex.
worker (Figs 15, 20): Spain , Prov. Huesca , Puerto de Monrepos
gyne (Fig. 9): Spain , Prov. Avila , 5 km swEl Tiemblo
Greece , Pref. Corinthia , Killini N-slope ; Germany , State Rheinland-Pfalz , Lorchhausen ; France , Dept. Gard , 15 km nnwLe Vigan ; Spain , Prov. Girona , 5 km sseCamprodon ; Spain , Prov. Granada , Puerto de la Ragua
Mayr, G., 1862:
Es duerfte interessant sein, zu erwaehnen, dass diese Art auch aus Hongkong von der Novara-Expedition mitgebracht wurde.
Forel, A., 1905:
- Kairouan. - - Faisant un peu passage a la var. semileve Andre.
Bolton, B., 1979:
(Figs 37, 49)
Formica caespitum L. , 1758: 581. Holotype female, Europe (' in Europae tuberibus') (holotype not in Linnean Society collection, London). Tetramorium caespitum (L.) ; Mayr, 1855: 426. Tetramorium caespitum var. immigrans Santschi , 1927: 54. Syntype workers, Chile: Valparaiso (Miss Edwards) (probably in NM, Basle; not seen). Syn. n. Myrmica (Myrmica) brevinodis var. transversinodis Enzmann , 1946: 47, figs 1, 2. Holotype worker, _ U. S. A.: Massachusetts, Dedham (in private coll. J. Enzmann; not seen). [Synonymy by Brown, 1949: 47; also Creighton, 1950: 291.]
Worker. With the group characters given above; the head densely and finely longitudinally rugulose everywhere. Spaces between rugulae with feeble ground sculpture, mostly shining. Head without unsculptured patches, without reticular or rugoreticular sculpture. Dorsal alitrunk longitudinally rugulose but on the posterior portion of the propodeal dorsum the rugulae being replaced by fine reticulatepunctate sculpture. Dorsal surfaces of petiole and postpetiole finely sculptured but each with a smooth median area or smooth median longitudinal strip. First gastral tergite unsculptured. Metanotal groove impressed in profile, the propodeal spines usually slightly longer than their basal width, but sometimes represented only by a pair of broadly triangular teeth. Pubescence of hind tibiae short and fine, decumbent to appressed.
During this study I have examined specimens from Massachusetts, New York and Pennsylvania, all falling within the range given by Creighton (1950). The var. transversinodis of Enzmann, noted above, is accepted as an absolute synonym of caespitum without question for, although I have not seen the holotype, the figures and description fit the species very well.
The status of var. immigrans is a little more dubious. It was first recorded from Chile by Santschi (1922) as T. caespitum but later he described it as caespitum var. immigrans (1927), both records being based on the same specimens from Valparaiso. Snelling & Hunt (1975) in their review of the Chilean ant fauna note the 1922 record but state that they had seen no material in their survey. Under these circumstances I think it best to assume that the Chilean record represents a casual introduction and to refer immigrans to the synonymy of caespitum . Sporadic introductions of caespitum in the neotropics are probably uncommon but I have seen material originating in Belize and Mexico during the course of this investigation.
Forel, A., 1910:
Forel, A., 1904:
Transcaucasie: Zakataly, Lagodechi, 1 [[ queen ]], 2. X. 1896 (MlokoseviC!).