Temnothorax variabilis

Specimens of this species have been observed in material collected on an entomological umbrella and a few workers collected from litter in deciduous forests.

Identification
Salata et al. (2018) – A member of the T. luteus group characterized by: a uniform bright yellow body colouration except for a dark band on the apical margin of the first gastral tergite, the absence of a metanotal groove, and big eyes. According to Seifert et al. (2014) there are two cryptic species of this group: Temnothorax luteus and Temnothorax racovitzai distributed in the western part of the Mediterranean basin east to Switzerland. Morphometrics can be used to differentiate T. variabilis (data provided in the following order: T. variabilis vs T. racovitzai vs T. luteus): CL/CW: 1.235 ± 0.02 vs 1.130 ± 0.012 vs 1.135 ± 0.015; ML/CS (CS=CL+CW/2): 0.781 ± 0.008 vs 1.171 ± 0.014 vs 1.241 ± 0.017 and PNW/CS: 0.388 ± 0.007 vs 0.597 ± 0.01 vs 0.616 ± 0.01.

Distribution based on Regional Taxon Lists
Palaearctic Region: Greece.

Nomenclature

 *  variabilis. Temnothorax variabilis Salata, Borowiec & Trichas, 2018: 798, figs. 80-88 (w.) GREECE (Crete).

Worker
(n=15): HL: 0.598 ± 0.03 (0.556-0.654); HW: 0.485 ± 0.02 (0.447-0.525); SL: 0.426 ± 0.02 (0.391-0.466); EL: 0.128 ± 0.006 (0.123-0.14); EW: 0.097 ± 0.007 (0.089-0.109); ML: 0.657 ± 0.03 (0.609-0.726); PSL: 0.153 ± 0.01 (0.123-0.168); SDL: 0.107 ± 0.007 (0.095-0.117); PL: 0.246 ± 0.01 (0.223-0.277); PPL: 0.153 ± 0.01 (0.14-0.17); PH: 0.181 ± 0.009 (0.168-0.201); PPH: 0.177 ± 0.006 (0.168-0.19); HTL: 0.39 ± 0.02 (0.346-0.425); PNW: 0.326 ± 0.02 (0.302-0.357); PW: 0.143 ± 0.01 (0.128-0.159); PPW: 0.192 ± 0.01 (0.176-0.212); HI: 81.0 ± 1.1 (78.8-82.9); SI1: 71.3 ± 1.3 (69.0-73.7); SI2: 88.0 ± 1.6 (84.8-90.9); MI: 59.5 ± 1.8 (54.9-61.7); EI1: 75.7 ± 5.6 (66.9-86.4); EI2: 16.2 ± 1.3 (14.6-18.6); TI: 124.2 ± 3.0 (120.9-132.3); PI: 136.2 ± 3.0 (131.3-143.3); PPI: 86.9 ± 5.6 (76.9-98.3).

Whole body uniformly bright yellow. Only apical margin of the first tergite of gaster with a narrow, black band.

Head oval, 1.2 times as long as wide, lateral surfaces below and above eyes slightly convex, posterior edges convex, occipital margin of head slightly concave. Anterior margin of the clypeus slightly convex, without median notch. Eyes small, oval, 1.3 times as long as wide. Antennal scape short, in lateral view slightly curved, 0.7 times as long as length of the head, in apex gradually widened, its base with small, triangular tooth, funiculus long, club 3 segmented. Surface of scape with very fine microreticulation, shiny, covered with thin, dense, adpressed to subdecumbent setae. Mandibles rounded with thick sparse, longitudinal striae, shiny. Clypeus shiny, with gentle and sparse striation, area between striae smooth. Frontal carinae short, not extending beyond frontal lobes. Antennal fossa deep, with a few roundly curved striae, area between striae shiny, with sparse and slight reticulation. Frontal lobes narrow, smooth and shiny. Frons shiny, with thin, sparse longitudinal striation and reticulation, area between striae smooth or microreticulate, sometimes sculpture reduced or absent on the center. Rest of head shiny, with sparse, thick reticulation, area between striation smooth, sometimes posterior part of head and genae, on whole surface of partly, with reduced sculpture or smooth areas. Whole head surface bearing suberect to erect, pale, short and thick setae.

Mesosoma elongate, 1.7 times as long as wide, slightly arched in profile. Pronotum convex on sides. Propodeal spines long or medium length, narrow, with wide base, directed upward, tips sharp. Dorsal surface of mesosoma shiny, with sparse, thin reticulation, sometimes reticulation co-occurs with a few, thin longitudinal striae, area between sculpture smooth. Dorsal surface of pronotum sometimes with reduced sculpture and with smooth area on its center. Lateral surfaces of propodeum with thin, sparse longitudinal striation, area between striae with scarce reticulation or smooth. Lateral surfaces of mesonotum and propodeum with dense but gentle reticulation, area between reticulation smooth. Entire mesosoma bearing suberect to erect, pale, short and thick setae.

Petiole, in lateral view, with short peduncle, node high, with anterior face straight or concave, posterior face straight, its dorsal surface aculate, sharply arched. Postpetiole, in lateral view, regularly convex, apical half with gently convex sides. Peduncle and petiolar node and postpetiole dorsum shiny, with thin, dense reticulation, area between reticulation smooth, sometimes petiole with a few wrinkles.

Gaster smooth and shiny, bearing erect, thin, pale setae. Legs short, shiny, with fine microreticulation. Tibiae 0.7 times as long as head length, bearing adpressed to documbent setae on the whole surface. Inner margins of tibia without a row of erect setae.

Type Material
Holotype (w.) (CASENT0845936): Collection L. Borowiec, Formicidae, DBET-GR00995 ; Greece, Crete, Rethymno Prov., n. Argiroupolis, 35°17.583 N/24°20.588 E, 13 V 2013, 197 m, L. Borowiec ; Paratypes (8w.) (CASENT0845937-CASENT0845944): the same data as holotype. and

Etymology
Name refers to high variability in body sculpture (lat. variabilis – variable).

References based on Global Ant Biodiversity Informatics

 * Salata S., L. Borowiec, and A.Trichas. 2018. Taxonomic Revision of the Cretan Fauna of the Genus Temnothorax Mayr, 1861 (Hymenoptera: Formicidae), with Notes on the Endemism of Ant Fauna of Crete. Annales Zoologici (Warsaw) 68(4): 769-808.
 * Salata S., and L. Borowiec. 2018. Taxonomic and faunistic notes on Greek ants (Hymenoptera: Formicidae). Annals of the Upper Silesian Museum in Bytom Entomology 27: 1-51.