Tetramorium fusciclava

Nests in grasslands, cornfield reins, beaches, pine forests; especially on sandy soil.

Identification
A member of the Tetramorium caespitum complex. The species can be determined with a discriminant analysis of a set of morphological measurements. See Wagner et al. (2017) and https://webapp.uibk.ac.at/ecology/tetramorium/

Distribution based on Regional Taxon Lists
Palaearctic Region: Italy.

Biology
Wagner et al. (2017) - More thermophilic than all species except Tetramorium hungaricum, Tetramorium breviscapus, and Tetramorium immigrans; TAS of 13 sites 21.3 ± 1.6 °C [16.1, 21.8]. Preference for to sea. Nests in grasslands, cornfield reins, beaches, pine forests; especially on sandy soil.

No adult sexuals found, records of sexual larvae and pupae from 13 and 14 May.

Nomenclature

 *  fusciclavum. Tetramorium caespitum var. fusciclavum Consani & Zangheri, 1952: 42.
 * [First available use of Tetramorium caespitum subsp. caespitum var. fusciclava Emery, 1925c: 187 (w.) ITALY; unavailable (infrasubspecific) name (Bolton, 1995b: 408).]
 * Subspecies of caespitum: Baroni Urbani, 1971c: 138.
 * Junior synonym of caespitum: Sanetra, et al. 1999: 320; Radchenko, 2016: 244.
 * Status as species: Wagner, et al. 2017: 118 (redescription)

Worker
Wagner et al. (2017) - Lectotype in μm: CL = 701, CW = 697, dAN = 199, EL = 150, EW = 109, FL = 273, HFL = 584, MC1TG = 19.9, ML = 777, MPPL = 228, MPSP = 298, MPST = 190, MtpW = 336, MW = 422, PEH = 244, PEL = 148, PEW = 217, PLSP = 168, PLST = 186, PnHL = 186, PoOc = 275, POTCos = 9, PPH = 252, PPL = 98, Ppss = 23, PPW = 279, PreOc = 167, RTI = 309, SLd = 564, SPST = 133, SPWI = 170.

Rather small, CS = 724 ± 42 [667, 829] μm. Dark brown to blackish.

Shortest head of complex, CL / CW = 0.996 ± 0.012 [0.976, 1.029]. Largest eye of complex, EYE / CS = 0.188 ± 0.004 [0.183, 0.196]. Scape moderately long, SLd / CS = 0.774 ± 0.006 [0.763, 0.784]. Mesosoma short and narrowest in complex, ML / CS = 1.136 ± 0.021 [1.101, 1.175], MW / CS = 0.615 ± 0.012 [0.596, 0.646].

Promesonotal dorsum convex, metanotal groove shallow. – Head dorsum and occiput with longitudinal costae and costulae. Postoculo-temporal area of head with a moderate number of longitudinal costae and costulae, POTCos = 6.76 ± 2.12 [4.63, 13.50]. Mesosoma dorsum longitudinally rugulose, lateral side of propodeum with pronounced sculpture, Ppss = 30.8 ± 10.5 [15.5, 47.3]. Dorsum of petiolar node typically with few strong costae, sometimes smooth or microreticulated. General surface appearance moderately smooth and shiny compared with other species. – Connected stickman-like or reticulate microsculpture: large units scattered over 1st gastral tergite, MC1TG = 20.57 ± 1.85 [16.34, 23.74]. – Some workers with long c-shaped, crinkly, or sinuous hairs on ventral head posterior to buccal cavity.

Type Material
Wagner et al. (2017) - Riccione (Italy), 43.999° N, 12.656° E, 11 m a.s.l., leg. C. Emery, 1925. Lectotype designation. Top worker of two syntype workers (of two cards on one needle), labeled "Riccione" [–] SYNTYPI Tetramorium caespitum c. var. fusciclava C. Emery, 1925 [–] "var fusciclava Emery" [–] MUSEO GENOVA coll. C. Emery (dono 1925) [–] ANTWEB CASENT 904802, designated as lectotype (Fig. 17). Lectotype worker and one paralectotype worker in Museo Civico di Storia Naturale, Genova (Italy).

References based on Global Ant Biodiversity Informatics

 * Consani M., and P. Zangheri. 1952. Fauna di Romagna. Imenotteri - Formicidi. Mem. Soc. Entomol. Ital. 31: 38-48.
 * Steiner F. M., B. Seifert, K. Moder, and B. C. Schlick-Steiner. 2010. A multisource solution for a complex problem in biodiversity research: description of the cryptic ant species Tetramorium alpestre sp. n. (Hymenoptera: Formicidae). Zoologischer Anzeiger 249: 223-254.
 * Wagner H. C., W. Arthofer, B. Seifert, C. Muster, F. M. Steiner, and B. C. Schlick-Steiner. 2017. Light at the end of the tunnel: Integrative taxonomy delimits cryptic species in the Tetramorium caespitum complex (Hymenoptera: Formicidae). Myrmecological News 25: 95-129.