A review of the Temnothorax anodontoides species-group (Hymenoptera, Formicidae) from Greece

Sebastian Salata; Lech Borowiec

doi:10.3897/zookeys.1091.79085

Research Article

A review of the Temnothorax anodontoides species-group (Hymenoptera, Formicidae) from Greece

Sebastian Salata^‡, Lech Borowiec^‡

‡ University of Wrocław, Wrocław, Poland

Corresponding author: Sebastian Salata ( sdsalata@gmail.com )

Academic editor: Brian Lee Fisher

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Salata S, Borowiec L (2022) A review of the Temnothorax anodontoides species-group (Hymenoptera, Formicidae) from Greece. ZooKeys 1091: 139-159. https://doi.org/10.3897/zookeys.1091.79085

ZooBank: urn:lsid:zoobank.org:pub:A67A155E-CADB-4933-9828-0E83483787A5

Abstract

A review of the Greek members of the Temnothorax anodontoides species-group revealed three species new to science: Temnothorax euboeae sp. nov. (Sterea Ellas, Euboea Island), Temnothorax arkasi sp. nov. (Peloponnese, Arcadia) and Temnothorax parnonensis sp. nov. (Peloponnese, Arcadia and Lakonia). The diagnoses of Temnothorax ikarosi Salata, Borowiec & Trichas, 2018 and T. anodontoides (Dlussky & Zabelin, 1985) are updated based of the new discoveries. Additionally, presence of the latter species in Greece is discussed and its distribution range revised. All members of the anodontoides species-group are associated with alpine and rocky habitats such as pastures and thermophilous forests. A dichotomous key to the anodontoides species-group from Greece is given.

Keywords

Myrmicinae, new species, Temnothorax anodontoides group, taxonomy

Introduction

The myrmicine genus Temnothorax Mayr, 1861, with 452 valid species and 36 valid subspecies, is one of the most speciose ant genera (Bolton 2021). Most of its members are distributed in the Northern Hemisphere, with diversity centers located in the Mediterranean region, southern parts of the USA, and the Greater Antilles (Salata and Borowiec 2019; Bolton 2021; Prebus 2021). Temnothorax species occupy a wide range of habitats, including tropical rainforests, hot deserts and boreal forests. Members of this genus nest most often in small, preformed cavities, such as rock crevices, hollow dead twigs, and dry acorns. They nest also under moss on stones and directly in ground, occasionally under cracked bark on tree trunks (Prebus 2021). Among 285 Palaearctic taxa, which consist of 59% of all known Temnothorax species, nearly 200, i.e., ~40% of all Temnothorax, are known from the Mediterranean region (sensu Vigna Taglianti et al. 1999). Due to its diversity, the Mediterranean myrmecofauna has been recently a subject of thorough studies that were partially focused on this genus (Csősz et al. 2015, 2018; Radchenko et al. 2015; Salata and Borowiec 2015; Galkowski and Lebas 2016; Catarineu et al. 2017; Galkowski and Cagniant 2017; Sharaf et al. 2017; Salata et al. 2018; Salata and Borowiec 2019; Tinaut and Reyes–López 2020; Arcos González 2021), and resulted in the description of several species new to science.

The Temnothorax anodontoides species-group was for the very first time defined by Salata and Borowiec (2019) and referred to the Balkan species characterized by the following set of characters: 12-segmented antennae, darkened club, absence of metanotal groove, overall body coloration brown to almost black, propodeal spines absent or short with wide base, rounded or at most subangulate petiolar node in profile, and very strongly sculptured head and mesosomal surface. Overall, the morphological definition of the anodontoides species-group partly overlaps with the korbi species-group defined by Radchenko (1995). However, T. anodontoides was excluded from the korbi species-group because it was the only member with distinct head sculpture, dark body colouration and unique shape of the petiole. The remaining members of the korbi group, i.e., T. korbi (Emery, 1924), T. caucasicus (Arnoldi, 1977) (now junior synonym of T. nadigi), T. anodonta (Arnoldi, 1977), and T. iranicus (Radchenko, 1994), form a separate group more closely related to the bulgaricus group (sensu Salata and Borowiec 2019). In this new sense the anodontoides species-group covers species recorded from the Apennines, Balkans and Kopet Dag Mts at the border area between Iran and Turkmenistan. Based on the literature, the Balkans hosts only two species of the anodontoides group: Temnothorax anodontoides (Dlussky & Zabelin, 1985), described from Turkmenistan close to the Iranian border, and Temnothorax ikarosi Salata, Borowiec & Trichas, 2018, described from Crete. Temnothorax anodontoides was noted from subalpine meadows and its nests were located directly in the ground (Dlussky and Zabelin 1985). Whereas T. ikarosi was described recently from the Limnakarou Plateau on Crete. A single specimen of this species was collected on a shelter wall overgrown by blackberry bush (Salata et al. 2018).

Occurrence of members of the anodontoides species-group in Greece was for the first time suggested by Schulz et al. (2007). In the paper on Italian Temnothorax, the authors compared therein described Temnothorax saxatilis Schulz, Heinze & Pusch, 2007 with a Greek taxon collected in Arcadia, Peloponnese that was tentatively identified as Temnothorax anodontoides. By courtesy of Alex Radchenko (UASK, Kiev), Petr Werner (Prague), and Claude Lebas (Canohès), we had an opportunity to study a paratype specimen of T. anodontoides, a series of specimens collected in Arcadia and identified by A. Schulz as T. anodontoides, and other material collected from Greek mountains with characters of the anodontoides species-group. Based on our research, we concluded that there are four Balkan species belonging to the anodontoides species-group: T. ikarosi known from Crete (Salata et al. 2018), two species known from the Greek mainland: Temnothorax arkasi sp. nov. and Temnothorax parnonensis sp. nov., and Temnothorax euboeae sp. nov., so far known only from Euboea Island. The literature records of T. anodontoides from Greece (Schulz et al. 2007) should be assigned to T. arkasi sp. nov. and its presence in Europe is doubtful. Also, we consider T. saxatilis as a member of the anodontoides species-group but due to its absence in Greece we did not include it in the review. However, when necessary, we included this species in the differential diagnoses of the species described as new to science. Below, we describe three species new to science, provide their photographs and a key to all members of the anodontoides species-group known from Greece.

Materials and methods

Examined specimens are housed in the following collections

MHNG Museum d’Historie Naturelle, Geneve, Switzerland;

MNHW-DBET Museum of Natural History, University of Wrocław, in temporary deposit by Department of Biodiversity and Evolutionary Taxonomy, University of Wrocław, Poland;

PWC private collection of Petr Werner, Prague, Czech Republic;

UASK Institute of Zoology, National Academy of Sciences of Ukraine, Kiev.

Specimens were compared using standard methods of comparative morphology. All measurements were made in μm using a pin-holding stage, permitting rotations around X, Y, and Z axes. A Nikon SMZ18 stereomicroscope was used at a magnification of ×100 for each character. Photographs were taken using a Nikon SMZ 1500 stereomicroscope, Nikon D5200 camera and Helicon Focus software. All given label data of type specimens are in original spelling, presented in square brackets; a vertical bar (|) separates data on different rows and double vertical bars (||) separate labels. Images of type specimens are available online on AntWeb (www.AntWeb.org) and are accessible using the unique identifying specimen codes provided in the description sections.

Pilosity inclination measurements follow Wilson (1955): adpressed (0–5°) hairs run parallel, or nearly parallel to the body surface; decumbent hairs stand 10–15°; subdecumbent hair stands 30°; suberect hairs stand 35–45°; and erect hairs stand more than 45° from the body surface. The surface sculpturing glossary follows Harris (1979).

Measurements

EL eye length; measured along the maximum diameter of the eye;

EW eye width; measured along the minimum diameter of the eye;

HL head length; measured in straight line from mid-point of anterior clypeal margin to mid-point of posterior margin in full-face view (i.e., when both maximum head length in median line and maximum head width are positioned in visual plane);

HW head width; measured in full-face view directly posterior of the eyes;

PEH petiole height; measured in lateral view, the chord of ventral petiolar profile at node level is the reference line perpendicular to which the maximum height of petiole is measured (fig. 1D in Csősz et al. 2015);

PEL petiole length; measured in lateral view, from anterior corner of subpetiolar process to dorsocaudal corner of caudal cylinder (fig. 3 in Csősz and Fisher 2015);

PNW pronotum width; maximum width of pronotum in dorsal view;

PPH postpetiole height; measured perpendicularly to a line defined by the linear section of the segment border between dorsal and ventral petiolar sclerite (fig. 1D in Csősz et al. 2015);

PPL postpetiole length; maximum length of the postpetiole measured in lateral view perpendicular to the straight section of lateral postpetiolar margin (fig. 1D in Csősz et al. 2015);

PPW postpetiole width; maximum width of postpetiole in dorsal view;

PSL propodeal spine length; measured from the centre of the propodeal spiracle to the top of the propodeal spine;

PEW petiole width; maximum width of petiole in dorsal view;

SDL spiracle to declivity length; minimum distance from the centre of the propodeal spiracle to the propodeal declivity;

SL scape length; maximum straight-line length of scape excluding the articular condyle;

WL mesosoma length; measured as diagonal length from the anterior end of the neck shield to the posterior margin of the propodeal lobe.

Indices

CI HW/HL;

EI1 EW/EL;

EI2 EW/HL;

SI1 SL/HL;

SI2 SL/HW;

MI PNW/WL;

PI PEL/PEH;

PPI PPL/PPH;

PSI PSL/SDL.

Abbreviations

w. worker

Results

Synopsis of the Temnothorax anodonotoides species-group known from Greece

Temnothorax arkasi sp. nov.

Temnothorax euboeae sp. nov.

Temnothorax ikarosi Salata, Borowiec & Trichas, 2018

Temnothorax parnonensis sp. nov.

Key to members of the Temnothorax anodonotoides species-group known from Greece

1	Head with reduced sculpture, frons medially with long and narrow smooth or indistinctly punctate area (Fig. 15). Body predominantly yellowish brown (Figs 9, 10). Mountains of Peloponnese	T. parnonensis sp. nov.
–	Head strongly sculptured, distinctly reticulate (Figs 7, 8). Body predominantly brown to almost black (Figs 1, 2, 5, 6, 17, 18)	2
2	Petiole with short peduncle (Fig. 6). Propodeal spines well marked, needle shaped (Fig. 6). Euboea	T. euboeae sp. nov.
–	Petiole with elongated peduncle (Figs 2, 18). Propodeal spines absent or short, in form of triangular denticle (Figs 2, 18)	3
3	Petiole regularly rounded in profile, with shorter peduncle (Fig. 2), petiolar and postpetiolar dorsum with distinct irregular rugae; promesonotum with denser and thinner sculpture (Fig. 1). Peloponnese	Temnothorax arkasi sp. nov. (= T. anodontoides sensu Schulz et al. 2007)
–	Petiole subangulate in profile, with longer peduncle (Fig. 18), petiolar and postpetiolar dorsum reticulate, rugae absent, promesonotum with thicker and sparser sculpture (Fig. 17). Crete	T. ikarosi Salata, Borowiec & Trichas

Species accounts

Note. Because of the partly reduced head sculpture, Temnothorax parnonensis doesn’t entirely match the characteristics of the anodontoides species-group proposed by Salata and Borowiec (2019). However, because its habitat preferences and overall morphology match most of the characters associated with this group, we decided to include it in the revision. Based on that, the definition of the anodontoides species-group should be modified as follow: 12-segmented antennae, darkened club, absence of metanotal groove, overall body coloration from yellowish brown to almost black, propodeal spines absent or short with wide base, rounded or at most subangulate petiolar node in profile, very strongly sculptured mesosomal surface; head strongly sculptured or strongly sculptured with frons with diffused sculpture and sometimes medially with narrow smooth area.

Temnothorax arkasi sp. nov.

http://zoobank.org/23D7FD80-558A-47D9-832C-B797F46B4A6B

Figs 1–2, 3, 7, 19

Type material

Holotype : worker (CASENT4015000, pin), label: “Greece, Peloponnes | Prov. Arkadia | A. Schulz & K. Vock lgt. || Parnon, | 3 km W Sitena | 37°18'N, 22°36'E | 25.4.2000 1700 m || Collection L. Borowiec | Formicidae | LBC-GR02714” (MNHW-DBET). Paratypes: 3 workers (CASENT4015001–CASENT4015003): the same data as holotype; 5 workers (CASENT4015004–CASENT4015008): the same data as holotype + “Sample Nr. | AS1”; 8 workers (CASENT4015009–CASENT4015016): the same data as holotype + “Sample Nr. | AS2”; 6 workers (CASENT4015017–CASENT4015022): the same data as holotype + “Sample Nr. | AS3” (MHNG, MNHW-DBET, PW).

Type locality

Greece, Peloponnes Province, Parnon, 3 km W Sitena, 37.3/22.6, 1375 m a.s.l.

Differential diagnosis

Temnothorax arkasi differs from T. parnonensis and T. anodontoides in very dark body coloration, with head and mesosoma predominantly dark brown to black (pale brown to yellowish brown in both relatives) and more elongate head, i.e., 1.25–1.28 as long as wide (only 1.22 in both relatives); from T. anodontoides it differs additionally in more sculptured head with rugulocostulate frontal part of head (T. anodontoides has frons entirely rugulate); from T. parnonensis it additionally differs in reduced propodeal spines and lack of smooth patch on frons (T. parnonensis has small but well-marked triangular propodeal spines and its frons sculpture is reduced on the central part); from T. euboeae it differs in almost reduced propodeal spines that are in form of small angulation of very short triangular spines, shiny interspaces between head sculpture, and longer petiole with moderately elongate pedicel (T. euboeae has propodeal spines distinct and in form of small, short, needles, more dull head surface and very short pedicel); from T. ikarosi it differs in more elongate head, shorter petiolar peduncle, denser and thinner sculpture on promesonotal dorsum and smaller propodeal spines (T. ikarosi has less elongate head, longer petiolar peduncle, sparser and thicker promesonotal sculpture and bigger propodeal spines).

Description

Worker (N = 10): HL: 0.66 ± 0.03 (0.6–0.71); HW: 0.55 ± 0.03 (0.5–0.57); SL: 0.49 ± 0.03 (0.44–0.53); EL: 0.14 ± 0.01 (0.11–0.16); EW: 0.1 ± 0.01 (0.08–0.12); WL: 0.8 ± 0.06 (0.68–0.89); PSL: 0.12 ± 0.01 (0.11–0.13); SDL: 0.11 ± 0.01 (0.1–0.12); PEL: 0.29 ± 0.03 (0.24–0.34); PPL: 0.17 ± 0.01 (0.15–0.19); PEH: 0.2 ± 0.02 (0.17–0.23); PPH: 0.19 ± 0.01 (0.17–0.21); PNW: 0.39 ± 0.02 (0.36–0.42); PEW: 0.18 ± 0.01 (0.15–0.19); PPW: 0.22 ± 0.02 (0.2–0.24); CI: 1.2 ± 0.03 (1.18–1.25); SI1: 0.74 ± 0.03 (0.68–0.77); SI2: 0.9 ± 0.03 (0.82–0.94); MI: 0.49 ± 0.03 (0.45–0.54); EI1: 0.75 ± 0.06 (0.67–0.85); EI2: 0.16 ± 0.01 (0.13–0.17); PI: 1.43 ± 0.1 (1.26–1.59); PPI: 0.87 ± 0.04 (0.8–0.94); PSI: 1.1 ± 0.03 (1.08–1.18).

Colour. Head dark brown, mesosoma, petiole and postpetiole brown to brownish black, lateral sides of pronotum with indistinct brownish areas, gaster mostly brown only base of first segment slightly brighter, in the palest specimens mesosoma partly yellowish brown; scape yellowish to yellowish brown, funicle segments 1–8 yellowish, antennal club yellowish brown to dark brown, legs mostly yellowish to yellowish brown, femora medially darkened (Figs 1, 2). Head. Slightly elongate, 1.28 times as long as wide, sides below and above eyes gently convex, occipital corners regularly rounded, occipital margin of head straight (Figs 3, 7). Anterior margin of clypeus distinctly convex, medial notch absent. Eyes moderate, short oval, 1.2 times as long as wide. Antennal scape short, in lateral view slightly curved, 0.78 times as long as length of the head, in apex gradually widened, its base without tooth, funiculus long, club 3-segmented (Fig. 3). Surface of scape finely microreticulate, shiny, covered with thin, dense, decumbent to suberect setae. Funicle longer than scape, first segment 2.1 times as long as wide at apex, segments 2–7 short, rectangular. Mandibles rounded with thick and sparse striae, shiny. Clypeus with sharp median longitudinal keel and two keels laterally, area between keels microreticulate but shiny. Frontal carinae short, slightly extending beyond frontal lobes. Antennal fossa deep, with thin circular striae and dense microreticulation. Frontal lobes narrow, microreticulate with costulae (Fig. 7). Frons, gena, malar region, vertex and temples densely reticulate with shiny interspaces; frons, gena, area behind eyes, central part of vertex, occipital area with additional costulae, malar area with costulae partly interrupted. Whole surface of head appears shiny. Sides of head with very short and sparse adpressed pubescence, sides of frons, vertex and occipital area with erect, pale, short and thick setae (Figs 3, 7). Mesosoma. Elongate, approximately twice as long as wide, distinctly arched in profile. Metanotal groove absent. Pronotum convex on sides. Propodeal spines very short, in form of triangular denticles or small angulation (Fig. 2). Whole surface of mesosoma densely reticulate with shiny interspaces. Pronotal dorsum regulate, lateral sides of pronotum rugocostulate, mesonotal dorsum reticulocostulate, propodeum rugocostulate, area below spines microreticulate with few transverse costulae. Entire mesosoma with erect, pale, moderately long and thick setae (Figs 1, 2). Petiole. In lateral view, with moderately elongate peduncle, node low, with anterior face shallowly concave and dorsum regularly rounded, whole surface rugoreticulate. Dorsal surface with sparse, short, erect setae. Postpetiole. In lateral view regularly convex, sides rounded, on the whole surface reticulocostulate, surface appears less rugose than surface of petiole. Dorsal surface with sparse, moderately long, erect setae (Figs 1, 2). Gaster. Smooth and shiny, with erect, thin, pale setae (Figs 1, 2). Legs. Moderately elongate, femora swollen in the middle, tibiae widened from base to ¾ length, surface of legs covered with sparse, adpressed to decumbent hairs.

Figures 1, 2.

Holotype worker of Temnothorax arkasi sp. nov. 1 dorsal 2 lateral. Scale bar: 1 mm.

Figures 3, 4.

Head and antennae of holotype workers 3 Temnothorax arkasi sp. nov. 4 Temnothorax euboeae sp. nov. Scale bars: 0.25 mm.

Etymology

The name is a noun in genitive case, dedicated to Arkás (ancient Greek: Ἀρκάς), a mythological hunter and King of ancient Arkadía (ancient Greek: Ἀρκαδία). His name was given to the recent Greek province Arcadia, Peloponnese, a terra typica for Temnothorax arkasi.

Biology

The type locality is placed in an alpine zone on the rocky northern slopes of Mt. Parnon overgrown with a young and sparse fir forest. The altitude indicated on the labels (1700 m) is most likely overestimated as the site indicated by the geographical coordinates given on the label gives the actual altitude of 1375 m.