Tetramorium flavidulum Santschi, 1910

Wagner, Herbert C., Cordonnier, Marion, Kaufmann, Bernard, Kiran, Kadri, Karaman, Celal, Schultz, Roland, Seifert, Bernhard & Csősz, Sándor, 2025, Delineation of species of the Tetramorium caespitum complex (Hymenoptera, Formicidae) in Anatolia with a diagnosis of related species-complexes, ZooKeys 1234, pp. 309-339 : 309-339

Tetramorium flavidulum Santschi, 1910

Note.

Based on morphological criteria ( Csősz et al. 2007; Csősz and Schulz 2010; Radchenko and Scupola 2015; Wagner et al. 2017; 2021) we place this species into the Tetramorium caespitum complex; however, we are unsure of its phylogenetic position. Future studies should investigate whether it is more closely related to species of the T. caespitum or the T. chefketi complex.

Tetramorium caespitum caespitum var. flavidula Emery, 1909: 702 (unavailable name); first available use: Tetramorium caespitum var. flavidula Santschi, 1910 ; raised to species rank: Borowiec 2014: 198. Morphology of type material investigated.

Type locality.

Lectotype: Anatolia, leg. M. Korb, 1886–1900.

Lectotype designation.

Worker with non-decapitated body (of two syntype workers on one card; the other worker is decapitated with head fixed separately), labeled “ anatolia Korb ” [—] MUSEO GENOVA coll. C. Emery (dono 1925) [—] SYNTYPUS “ Tetramorium caespitum flavidulum ”. Lectotype worker and nine paralectotype workers in Museo Civico di Storia Naturale, Genova (Italy). Morphometric data of lectotype in μm: CL = 760, CW = 731, dANC = 199, EL = 152, EW = 110, FL = 285, HFL = 596, MC 1 TG = 29.6, ML = 845, MPPL = 250, MPSP = 331, MPST = 182, MtpW = 346, MW = 459, PEH = 256, PEL = 166, PEW = 240, PLSP = 160, PLST = 165, PnHL = 182, PoOc = 301, POTCos = 8.0, PPH = 253, PPL = 111, Ppss = 9, PPW = 283, PreOc = 197, RTI = 285, SLd = 595, SPST = 156, SPWI = 213.

Redescription of worker.

Medium size, CS = 734 ± 53 [614, 855]. 76 % of workers with yellowish head and mesosoma and an often brownish gaster (which does usually not occur in other species of the complex), 21 % of workers light to medium brownish, 3 % dark brownish (n = 76 workers of 24 nests).

Head strongly elongate, CL / CW = 1.031 ± 0.018 [0.990, 1.088]. Eye medium-sized, EYE / CS = 0.176 ± 0.005 [0.167, 0.191]. Scape long, SLd / CS = 0.787 ± 0.015 [0.722, 0.815]. Mesosoma short and narrow, ML / CS = 1.110 ± 0.022 [1.057, 1.179], MW / CS = 0.619 ± 0.014 [0.580, 0.667].

Promesonotal dorsum convex, metanotal groove shallow. Head, dorsum, and occiput with longitudinal costae and costulae. Postoculo-temporal area of head with rather many costae and costulae, POTCos = 9.35 ± 2.47 [4.00, 15.50]. Mesosoma dorsum longitudinally rugulose, lateral side of propodeum with strongest sculpture of complex, Ppss = 15.7 ± 10.9 [6.0, 63.7]. Dorsum of petiolar node with strong reticulate costae, dorsum of postpetiole node with strong mostly longitudinal, sometimes reticulate costae. General surface appearance dull. Connected stickman-like or reticulate microsculpture: very large units scattered over 1 st gastral tergite, MC 1 TG = 25.93 ± 3.45 [16.30, 32.60]. Most workers with long c-shaped hairs on ventral head just posterior to buccal cavity, sinuous or crinkly hairs only in 13 % of workers.

Description of male.

Yellowish. Ten antennal segments. Paramere structure belongs to the impurum - like form sensu Wagner et al. (2017). Ventral paramere lobe with one sharp corner visible in posterior view. Clear division of ventral and dorsal paramere lobes, visible by emargination between lobes in posterior view. Relatively short dorsal paramere lobe, visible in posterior and dorsal view. Maximal paramere structure length in lateral view of four males 912 ± 27 (885, 949) μm. No corner on ventral paramere lobe between lobe top and emargination with dorsal lobe in dorsal and posterior view. Distinct different from all other species.

Distribution.

Known from 22 localities in Anatolia and Gökçeada Island (Fig. 11 ; more localities given in Kiran and Karaman 2020).

Ecology.

Rather thermophilic, TAS of 23 sites 17.1 ± 2.6 [12.1, 26.5]. More thermophilic than T. indocile , T. caucasicum , and T. impurum , less thermophilic than T. immigrans . 17 of 22 sites inhabiting woodland: Quercus forests (6), Pinus nigra forests (4), Pinus sylvestris forest (1), Pinus sylvestris - Quercus forests (2), other types of mixed forests (2), Olea stands (1), and scrublands (1). The rest in meadows (2), barren areas (1), river banks (1), and city centers (1).

Phenology.

Adult sexuals in nests on 2 July ± 12 [9 June, 13 July] (n = 7).

Figures

Figure 11. Distribution of Tetramorium hungaricum (grey) and T. flavidulum (pale yellow) in Anatolia and surrounding regions.