Research Article
Research Article
Unrecognized for centuries: distribution and sexual caste descriptions of the West European Aphaenogaster species of the subterranea group (Hymenoptera, Formicidae)
expand article infoEnrico Schifani§, Antonio Alicata|, Lech Borowiec, Fede García#, Vincenzo Gentile¤, Kiko Gómez#, Elia Nalini«, Fabrizio Rigato», Sämi Schär˄, Antonio Scupola˅, Roger Vila§, Mattia Menchetti§
‡ University of Parma, Parma, Italy
§ Institut de Biologia Evolutiva (CSIC-Univ. Pompeu Fabra), Barcelona, Spain
| University of Catania, Catania, Italy
¶ University of Wroclaw, Wroclaw, Poland
# Unaffiliated, Barcelona, Spain
¤ Unaffiliated, Naples, Italy
« University of Milan “La Statale”, Milan, Italy
» Museo Civico di Storia Naturale, Milan, Italy
˄ Unaffiliated, Zürich, Switzerland
˅ Natural History Museum, Verona, Italy
Open Access


There are only two Aphaenogaster species from the subterranea group in the western Mediterranean: A. ichnusa Santschi, 1925, from south-western Europe, and A. subterranea (Latreille, 1798), also occurring in central and eastern Europe. Historically, the two species have been widely misunderstood: A. ichnusa was long considered a Sardinian endemic subspecies of A. subterranea, while its continental populations were misidentified as A. subterranea s. str. Recently, A. ichnusa was elevated to species rank and its worker caste was redescribed with that of A. subterranea, allowing for their correct identification. Yet their distribution was documented in detail only for France and Sardinia. Furthermore, no morphological characters were described to distinguish the males and queens of the two species. By investigating private and museum collections, 276 new records of A. ichnusa are provided here and 154 of A. subterranea from the western Mediterranean. Additionally, qualitative and quantitative morphological characters were combined to identify their males and queens. We present the new southernmost, easternmost, and westernmost distribution limits for A. ichnusa. Based on our results, this species is widely distributed in Italy and Catalonia (Spain), also occurring on several Mediterranean islands, avoiding areas with continental climate and high altitudes. Sicily is the only island to host the less thermophilous A. subterranea, which otherwise extends westward to Galicia (Spain). Sympatric occurrence is not rare along the contact zone. Additional natural history observations are reported regarding foraging habits, associated myrmecophiles, habitat preferences, and colony structure in the two species.


Ants, Aphaenogaster ichnusa, biogeography, Mediterranean, Myrmicinae, Stenammini


The genus Aphaenogaster Mayr, 1853 belongs to the myrmicine tribe Stenammini Ashmead, 1905 (Ward et al. 2015) and currently counts 206 valid species and 16 valid subspecies (Bolton 2023). The true genus Aphaenogaster is almost exclusively Holarctic, while the tropical species belong to the “Deromyrma” clade that awaits formal separation (Branstetter et al. 2022). Most Aphaenogaster ant species inhabit the West Palearctic, where six species groups have been identified (Schifani et al. 2022a).

The subterranea group currently includes eight species [A. epirotes (Emery, 1895), A. holtzi (Emery, 1898), A. ichnusa Santschi, 1925, A. kurdica Ruzsky, 1905, A. lesbica Forel, 1913, A. maculifrons Kiran & Aktaç, 2008, A. subcostata Viehmeyer, 1922, A. subterranea (Latreille, 1798)], mostly residing in the eastern Mediterranean and Caucasus region, where several putative undescribed species also exist (Borowiec and Salata 2017; Schifani et al. 2022a). Ten taxa formerly included in this group that are distributed in the Maghreb region and around Sicily, were recently assigned to the distinct crocea group according to morphological and genetic evidence (Alicata and Schifani 2019; Schifani et al. 2022a). The only three North African records of A. subterranea are based on outdated taxonomy (Forel 1890; Bernard 1967; Cagniant 1970; Henine-Maouche et al. 2022), and most likely represent misidentifications of species of the crocea group (Alicata and Schifani 2019; Schifani et al. 2022a). For instance, a worker labeled A. subterranea in the Forel’s collection of Geneve Natural History Museum (AntWeb identifier CASENT0907686) is in fact A. strioloides (see Schifani et al. 2021a).

Only two species belonging to the subterranea group are recognized in West Europe: A. subterranea (Latreille, 1798) (terra typica: mainland France) and A. ichnusa Santschi, 1925 (terra typica: Sardinia). The first was described using the spelling “subteranea” (Latreille 1798), which was later corrected by Latreille himself (Latreille 1802).

Aphaenogaster subterranea has a wide distribution, from Iberia to Anatolia, and north to central Europe, while the range of A. ichnusa is restricted to West Europe and does not occur in the Balkans (Borowiec and Salata pers. comm., 2022; MM unpublished data). Until recent years A. ichnusa was considered as a Sardinian endemic and a subspecies of A. subterranea. Their separation as two distinct species was only recently demonstrated based on worker morphology and mitochondrial DNA (Galkowski et al. 2019). The recent recognition implies that reliable data over the distribution of the two species is scarce in the sympatric range, where they were historically confused. Apart from Sardinia, Galkowski et al. (2019) reported the presence of A. ichnusa in Corsica and southern mainland France. More recently, only a few scattered records were published from mainland Italy, Sicily, and mainland Spain (Schifani and Alicata 2018; García et al. 2020; Schär et al. 2020; Zara et al. 2021; Bazzato et al. 2022; Scupola et al. 2022). However, a detailed picture of the distribution of A. ichnusa and A. subterranea in these regions is lacking.

The investigation of specimens from private and museum collections allowed us to gather reliable distribution data of A. ichnusa and A. subterranea from the west Mediterranean basin, and to fill the current gaps of knowledge. Among them, we investigated several complete nest samples allowing us to morphologically characterize the sexual castes of the two species and provide tools for their identification.

Materials and methods

In this study, we focused our investigation on the West European region, where A. ichnusa is present and co-occurs with A. subterranea. We re-identified worker specimens belonging to the subterranea species group found in the authors’ personal collections and the Natural History Museum of Milan. Specimen identification was performed using the morphological characters illustrated by Galkowski et al. (2019): A. ichnusa differs from A. subterranea in the shorter and thicker propodeal spines, which are triangular, the feebler surface sculpturing of the pronotal sides, and paler pigmentation (Fig. 1).

Figure 1. 

Workers of Aphaenogaster ichnusa (on the left, sample from Monte Petroso, Sicily) and of A. subterranea (on the right, sample from Parma, Italian peninsula). Cropped images highlight the differences in surface sculpturing of the pronotal sides and in the shape of the propodeal spines.

Queens and males associated with identified workers were examined to detect further distinctive morphological features. In total, we studied 16 queens from nine colonies and 17 males from seven colonies of A. ichnusa, as well as 16 queens from eight colonies and 19 males from nine colonies of A. subterranea. Samples were chosen from across the study region and included specimens from their terrae typicae (see Suppl. material 1). Due to the unknown, but possibly significant, dispersal capabilities, queens and males unassociated with workers as proof of successful colony establishment were not considered informative for the distribution range of the two species. Morphometric data for the descriptions was produced by taking pictures with a Carl Zeiss Stemi 2000-C stereomicroscope equipped with a CMEX PRO-5 DC.5000p digital camera and measurements taken with ImageFocus 4 software. Three quantitative morphological characters were defined for this study based on those presented by Wagner et al. (2017) and Seifert (2019) (Fig. 2):

Figure 2. 

Diagnostic quantitative morphological characters recorded on males (A) and queens (B) of Aphaenogaster ichnusa and A. subterranea.

PrW Males only. In dorsal view, maximum width of the dorsal plate of the propodeum at the level of the propodeal spiracles.

SPWI Males only. In dorsal view, maximum width of the dorsal plate of the propodeum at the level of the propodeal spiracles.

MCMssctm Queens only. In dorsal view, quantification of stickman-like or reticulate microsculpture units on the mesoscutum: the number of connected lines building units and being separated by line intersections and by flections angled > 30° is counted. Very short lines are also considered full counts. Arithmetic means of three units per specimen are taken.

In addition to means to distinguish males and queens of A. ichnusa from those of A. subterranea, we provide identification keys that tell them apart from the other Aphaenogaster species occurring in the study area (i.e., A. cardenai, A. italica, A. ovaticeps, and species from the crocea, gibbosa, pallida, splendida, and sardoa groups; see Schifani et al. 2022a).

All characters are given in μm as mean ± sd (min, max). A complete list of the investigated material and of the morphological data is provided in the Suppl. material 1.


Male diagnosis (Figs 3, 4)

Compared to A. subterranea, A. ichnusa is characterized by a different propodeal shape with relatively well-developed dentiform spines, as opposed to slight edges. This difference can be appreciated both in lateral view (as the spines protrude backwards from the propodeal profile and are often preceded by a gibbous form in the distalmost part of the propodeal dorsum) and in dorsal view (as the spines are wider than the remaining propodeum). Consequently, the SPWI/PrW ratio was found to be very different between the two species, with no overlap: 1.36 ± 0.14 (1.12, 1.58) in A. ichnusa, 0.911 ± 0.06 (0.80, 0.99) in A. subterranea (Fig. 4). Furthermore, A. ichnusa males are normally substantially darker than those of A. subterranea.

Figure 3. 

Males of Aphaenogaster ichnusa (on the left, sample from Monte Petroso, Sicily) and of A. subterranea (on the right, sample from Parma, Italian peninsula). Cropped images highlight the differences in the shape of the propodeum.

Figure 4. 

Quantitative morphological differences distinguishing A. ichnusa and A. subterranea males (A) and queens (B).

Compared to other sympatric species of the same genus, A. ichnusa and A. subterranea can be distinguished based on the following combination of characters: shiny integument, mesosoma lacking a pronounced contrast between the anterior gibbosity of the mesosoma and the flat propodeum, the dorsal profile of the propodeum in lateral view relatively short and horizontal, forming approximately a 90° angle with the posterior profile, the rather elongated head shape, the body pigmentation pale to dark brownish.

The following traits are shared by the two species: the head, including mandibles, forms a subtriangular shape; its edges are rounded, and the head capsule is clearly longer than wide. Very large ovoidal compound eyes (~ ½ length of the head capsule) that significantly protrude out of the head capsule, well-distanced from three large ocelli. Mandibles dentate, ~ ½ length of the head capsule, their external side mostly straight for more than ¾. Clypeus medially slightly emarginated. Mesosoma clearly wider than the head, characterized by a well-developed anterior gibbosity. Propodeum much shorter than the remainder of the mesosoma. The horizontal section of the propodeal profile is shorter than its two vertical sections (anterior and posterior), which both form angles of ~ 90° with it. A ventral cuticular process protrudes from the metasternum. Long pedunculate petiole, globose postpetiole, the petiole and postpetiole have a similar heigh, while the postpetiole is wider than the petiole. The legs are long, with hind femurs approximately the same length as the entire mesosoma. The antennae comprise of 11 flagellomeres, the scapi are short, measuring ca. twice the pedicel, and approximately extending slightly beyond the eyes if aligned perpendicularly to the head length axis. Body color pale to dark brown, appendages whitish. Surface sculpturing mostly weak, most of the ant is smooth and shiny, with at most isolated stickman-like units, very feeble rugae or reticulate microsculpture near the sutures, and feeble reticulate microsculpture on the head. Sparse erect and suberect setae mostly occur dorsally over the head, mesosoma and nodes, and both dorsally and ventrally on the first gastral segment and on the distalmost margins of the remaining segments, while shorter suberect or appressed setae cover the appendages.

The following key is meant to facilitate this distinction in the examined region. However, the intraspecific morphological variation of several species is still little known, so we recommend a careful approach in its use.

1 Notably pronounced contrast between the anterior gibbosity of the mesosoma and a long and relatively flat propodeum, as better observed in lateral view; head less elongated A. italica Bondroit, 1918, A. sardoa (Mayr) (only Sardinia and Sicily), A. splendida (Roger, 1859), A. gibbosa (Latreille, 1798) or crocea group (only Sicily and southern Italian peninsula), i.e., A. fiorii Emery, 1915, A. sicula Emery, 1908, A. strioloides Forel, 1890, or A. trinacriae Alicata & Schifani, 2019 (see Emery 1908; 1916; Santschi 1932; Gómez et al. 2018; Alicata and Schifani 2019)
Propodeum much shorter and not as flat 2
2 Body color blackish; integument either most extensively matt, or mostly smooth and shiny and paired with a wide subrectangular head, or with reticulate microsculpture on the head and visible striae on the mesosoma and petiole remaining A. sardoa group species (see Boer 2013), the Iberian endemic A. ulibeli (Gómez et al., 2018), or A. epirotes (in the study area only near the Italian border with Slovenia, see Müller 1923)
Body color ferruginous to dark brownish, integument largely smooth and shiny, without strongly developed surface sculpturing 3
3 Iberia only, very large size (approximate body length 6–6.8 mm) A. cardenai Espadaler, 1981 (see Tinaut 1986)
Combination not as above 4
4 Propodeal dorsum in profile view longer and inclined at ~ 45° before reaching the propodeal spiracle, lacking a clearly horizontal component A. dulcineae Emery, 1924, A. finzii Müller, 1921, A. ovaticeps (Emery, 1898), or A. pallida (Nylander, 1849) (Emery 1898; 1916; Müller 1923; Santschi 1932)
Propodeal dorsum shorter and more vertical, with a clear horizontal component A. ichnusa or A. subterranea (discrimination possible based on propodeal shape, see characters illustrated in the second paragraph of this section and Figs 3, 4)

Queen diagnosis (Figs 4, 5)

Queens of A. ichnusa and A. subterranea are much more difficult to tell apart based on their general shape as compared to workers and males. However, a subtle but very reliable character was found in the surface microsculpture of the dorsal mesosoma: in A. ichnusa, stickman-like reticulations occur sparsely and are modestly developed, while in A. subterranea they are visibly more developed and sometimes single stickman-like complexes may connect to each other covering very large areas. MCMssctm ranges do not overlap between the two species, while A. subterranea shows a high variation in the upper range: 4.33 ± 0.78 (3.00, 5.33) in A. ichnusa, 24.68 ± 22.97 (8.67, 87.67) in A. subterranea (Fig. 4).

Figure 5. 

Queens of Aphaenogaster ichnusa (on the left, sample from Monte Petroso, Sicily) and of A. subterranea (on the right, sample from Parma, Italian peninsula). Cropped images highlight the differences in the microsculpture of the mesoscutellum.

Compared to other sympatric species of the same genus, A. ichnusa and A. subterranea can be distinguished based on the following combination of characters: large mesosoma with wide smooth and shining patches, dark brown to ferruginous pigmentation with blackish areas, body setae relatively sparse, thick propodeal spines and mostly vertical propodeum lateral profile.

The following traits are shared by the two species: The head capsule forms a subrectangular shape, with rounded edges, and is as approximately as long as wide or slightly longer than wide. Large compound eyes (their length ~ ⅓–¼ of the head length) slightly protruding out of the head capsule. The distance between the central among the three ocelli and the level of the compound eyes is ca. the length of the ocellus itself. Mandibles dentate, ~ ½ length of the head capsule, their external side mostly straight for over ¾. Clypeus medially slightly emarginated. Massive mesosoma, slightly wider than the head. Propodeal spines well developed and straight, in profile view the of the propodeum is steep, with the section above the spines slightly inclined and the section below entirely vertical. Long pedunculate petiole, globose postpetiole, the petiole and postpetiole have a similar heigh, while the postpetiole is wider than the petiole. The antennae comprise ten flagellomeres, the scapi are moderately long, surpassing the posterior margin of the head if aligned parallel to the head length axis, while the antennal club consists of four flagellomeres and the flagellomeres 3–8 are only slightly longer than wide. Body color normally not uniform, ferruginous to very dark brown, with blackish patches usually occurring on the frons and paler orangish areas near the sutures of the mesosoma. Appendages pale orange to ferruginous. Rugose sculpture on most of the head, partly on the sides of the mesosoma including the entire propodeum, and on the nodes. The remainder of the body is smooth and shiny, except for stickman-like microsculpture. Abundant erect or suberect setae cover the head, the dorsum of the mesosoma and nodes, the first gastral segment, and the distalmost margins of the remaining segments, while shorter suberect or appressed setae cover the appendages.

The following key is meant to facilitate this distinction in the examined region. However, the intraspecific morphological variation of several species is still little known, so we recommend a careful approach in its use.

1 Mesosoma matt and smaller, not hosting properly developed flight muscles, all species suspected to be incapable of normal flight dispersal sardoa group (see Boer 2013; Schifani et al. 2022a)
Mesosoma with wide smooth and shining patches and larger 2
2 Propodeum longer, its dorsal profile inclined at ~ 45°, propodeal spines thinner, body color uniformly ferruginous A. ovaticeps (see Salata et al. 2021)
Character combination deviating 3
3 Body color blackish, striate sculpture on the posterior part of the mesoscutellum and on the metanotum, only near the Italian border with Slovenia A. epirotes (Müller, 1923)
Color paler, mesoscutellum without striae 4
4 Body color uniformly very dark brown to blackish, flagellomeres more elongated, head with more parallel sides giving the impression of a more rectangular shape A. italica, A. gibbosa, A. ulibeli (see Santschi 1932; Gómez et al. 2018)
Body color paler, head sides not as parallel and more convergent frontad 5
5 Very hairy, comparatively dense setae at least on the gaster and postpetiole A. pallida group (A. dulcineae, A. finzii, or A. pallida, see Schifani et al. 2022a)
Setae sparser 6
6 Body pigmentation yellowish or uniform ferruginous with at most a darkened area on the frons either crocea group (only Sicily and southern Italian peninsula), i.e., A. fiorii, A. sicula, and A. trinacriae, or A. splendida which is normally also characterized by a black transversal band on the first gastral tergite (Alicata and Schifani 2019; Salata et al. 2021)
Body pigmentation overall darker and more irregular, blackish patches on the mesosoma and frons A. ichnusa or A. subterranea (discrimination possible based on microsculpture, see characters illustrated in the second paragraph of this section and Figs 4, 5)

Note: The queens of A. cardenai and A. strioloides are currently unknown and, therefore, they are not included in this key. The first only occurs in Iberia and, considering that its workers are unique among West Palearctic Aphaenogaster and that queens usually retain a number of characters of workers, they are highly unlikely to be confusable with species of the subterranea group (Schifani et al. 2022a). In West Europe, A. strioloides only occurs on the island of Pantelleria, where neither A. ichnusa nor A. subterranea exist (Schifani et al. 2021a).

We recovered a total of 274 new records of A. ichnusa, and 154 of A. subterranea from the study area. We increased the know number of cells of 0.2 decimal degrees (ca. 22 km) occupied by A. ichnusa by 145% (103 new compared to 71 from literature) and of those occupied by A. subterranea by 64% (130/202). The two species showed a parapatric distribution, with only 4.5% of the cells (22/484) occupied by both species (Fig. 6). The westernmost record of A. ichnusa occurs at 0.74 longitude (Catalonia, Spain), the easternmost at 18.46 longitude (Apulia, Italy), the southernmost at 36.94 latitude (Sicily, Italy) and the northernmost at 44.48 latitude (mainland France). For A. subterranea, the westernmost record is at -8.46 longitude (Galicia, Spain) and the southernmost at 37.64 latitude (Sicily, Italy).

Figure 6. 

Distribution map showing the locations of the records here newly reported (black border) and retrieved from literature (no border) in a cell grid of 0.2 decimal degrees. Cells are blue for A. subterranea, yellow for A. ichnusa, and pink if the two species co-occur.

We report A. ichnusa for the first time for several islands and archipelagos: some of the Aeolian Islands (Lipari, Vulcano, Salina, Filicudi, Panarea), the Balearic Islands (Mallorca), the Maddalena Archipelago (Caprera), the Phlegrean Islands (Ischia, Procida), Tavolara island, the Tremiti islands (San Domino), and the Tuscan Archipelago (Capraia, Elba, Giglio, Montecristo).


The morphological distinction of the subterranea group species in the region is relatively easy (Schifani et al. 2022a), and male-based separation of A. ichnusa from A. subterranea is normally straight-forward as demonstrated by our data. While distinction of queens and workers can be more difficult at first sight, queens are safely separable at adequate magnification and workers are normally easy for a trained eye. Colony samples of A. ichnusa with longer spines and colony samples of A. subterranea with shorter ones may occur, always requiring a certain attention to other characters such as spine shape, pronotal sculpture and pigmentation. The different ecological requirements of the two species are often helpful but the two may occur sympatrically. While Galkowski et al. (2019) reported a possible introgression event, we did not encounter colony samples with intermediate morphological characters based on subjective evaluation.

While A. ichnusa inhabits areas with a Mediterranean climate, A. subterranea in the same region occurs only at higher elevations or in specific microclimates. However, A. subterranea is frequent at the sea level in continental climatic zones where A. ichnusa is absent (e.g., most of mainland France, the Po Plain). We show that A. ichnusa is frequent across a vast region of the western Mediterranean (Wang et al. 2023, including Italy’s Tyrrhenian and Ionian coasts, and part of the Adriatic one. Moreover, it is the sole species found on all investigated islands with the only exception of Sicily, where A. subterranea is found at higher elevations in the Etna and the Sicilian Apennines alongside other continental species (Schifani et al. 2021b, 2022b).

Notably, both A. ichnusa and A. subterranea seem to have a more limited distribution in Iberia, where they seem to be restricted to northern Spain. The reliability of few old records from southern Spain appears doubtful in the absence of more recent findings (e.g., Santschi 1919). No historic records exist from Portugal (Arcos et al. 2022), yet our data suggest that targeted investigations may discover A. subterranea near the northern border with Spain. The wide distribution of A. ichnusa is apparently reflected in the fact that in some old keys, descriptions and drawings attributed to A. subterranea were found to depict A. ichnusa instead (e.g., Emery 1916 key to the Italian fauna with a drawing of an A. ichnusa male). Aphaenogaster subterranea may have been temporarily introduced to Madagascar (Csősz et al. 2021).

Colonies of A. ichnusa and A. subterranea are often found nesting under rocks, and both species may be especially abundant in shady forest habitats with sufficient humidity and leaf litter (Castracani et al. 2010, referring at least part of the records to A. ichnusa based on voucher checked; Seifert 2018, assuming Central-European records to represent A. subterranea; Zara et al. 2021; Bazzato et al. 2022). Albeit rarely, at least A. ichnusa may adapt significantly to urban environments: in summer days, we observed workers foraging in a shady courtyard entirely made of concrete within a historic palace of Florence.

However, despite their ecological success and wide distribution, still relatively little is known ca. the habits of these species besides anecdotal reports. They are probably mostly predators and scavengers, but at least A. ichnusa was also observed by the authors to tend root aphids, suggesting that trophobiosis may also play an important role in the diet of both. In addition, we observed isopods (Platyarthrus sp.), oribatid mites, silverfish, leaf beetle larvae (Chrysomelidae: Clytrinae), and planthoppers nymphs (Cixiidae) in A. ichnusa nests, and isopods (Platyarthridae in A. subterranea nests, in which also Cixiidae were reported by Lörinczi (2012). In shady habitats, we observed minimal daytime foraging by both species. However, on other occasions, workers of A. ichnusa mostly started to forage outside the nest at dusk. Perhaps the foraging activity is often conducted within the leaf litter or in endogean microspaces, but none of these species is truly subterranean (Ortuño et al. 2014).

Some of us also observed cooperative food transport in A. subterranea at least. Furthermore, A. subterranea workers are known to use tools: they drop small debris into liquid food and transport food-soaked tools back into their nest (Lőrinczi et al. 2018; Módra et al. 2022). This behavior is deemed to be a complex strategy developed to compensate for the inability to ingest and carry into the body large quantities of liquid food (Lőrinczi et al. 2018; Módra et al. 2022). Notably, we found multiple times numerous dealate queens (up to five) in some colonies of A. ichnusa and A. subterranea, suggesting at least occasional polygyny in both species.

An integrative approach is needed to clarify whether hybridization or introgression between the two species have a significant role as observed in other ants (Seifert 2018). Nuptial flights of A. subterranea and A. ichnusa seemingly overlap in late summer/early autumn. However, the relatively large size of the contact zone compared to the distribution range of A. ichnusa, and the consistent morphological differentiation from A. subterranea, suggest some adaptation to counter hybridization. At the same time, the data we are providing could facilitate future studies focused on the ecology and niche partitioning of these species.


We are grateful to Rumsaïs Blatrix for sharing with us the raw species distribution data used by Galkowski et al. (2019), as well as to all the collectors who contributed to gather specimens relevant to this paper (see the list in the Suppl. material 1). We also thank the referees Alexander Wild and Sebastian Salata as well as the editor Brendon Boudinot for their comments on an earlier version of this manuscript.

Support for this research was provided by “la Caixa” Foundation (ID 100010434) to Mattia Menchetti (grant LCF/BQ/ DR20/11790020).


  • Alicata A, Schifani E (2019) Three endemic Aphaenogaster from the Siculo-Maltese archipelago and the Italian Peninsula: part of a hitherto unrecognized species group from the Maghreb? (Hymenoptera: Formicidae: Myrmicinae). Acta Entomologica Musei Nationalis Pragae 59(1): 1–16.
  • Arcos J, Chaves D, Alarcón P, Rosado A (2022) First record of Temnothorax convexus (Forel, 1894) in Portugal (Hymenoptera: Formicidae) with an updated checklist of the ants from the country. Sociobiology 69(2): e7623.
  • Bazzato E, Lallai E, Caria M, Schifani E, Cillo D, Ancona C, Pantini P, Maccherini S, Bacaro S, Marignani M (2022) Land-use intensification reduces multi-taxa diversity patterns of Small Woodlots Outside Forests in a Mediterranean area. Agriculture, Ecosystems & Environment 340: e108149.
  • Bernard F (1967) Faune de l’Europe et du Bassin Méditerranéen. 3. Les fourmis (Hymenoptera Formicidae) d’Europe occidentale et septentrionale. Paris: Masson, 411 pp.
  • Branstetter MG, Longino JT, Reyes‐López JL, Brady SG, Schultz TR (2022) Out of the temperate zone: A phylogenomic test of the biogeographical conservatism hypothesis in a contrarian clade of ants. Journal of Biogeography 49(9): 1640–1653.
  • Cagniant H (1970) Deuxième liste de fourmis d’Algérie récoltées principalement en forêt. (1re partie). Bulletin de la Société d’Histoire Naturelle de Toulouse 105: 405–430.
  • Castracani C, Grasso DA, Fanfani A, Mori A (2010) The ant fauna of Castelporziano Presidential Reserve (Rome, Italy) as a model for the analysis of ant community structure in relation to environmental variation in Mediterranean ecosystems. Journal of Insect Conservation 14(6): 585–594.
  • Csősz S, Loss AC, Fisher BL (2021) Taxonomic revision of the Malagasy Aphaenogaster swammerdami group (Hymenoptera: Formicidae). PeerJ 9: e10900.
  • Emery C (1898) Beiträge zur Kenntniss der palaearktischen Ameisen. Öfversigt af Finska Vetenskaps-Societetens Förhandlingar 20: 124–151.
  • Emery C (1908) Beiträge zur Monographie der Formiciden des paläarktischen Faunengebietes. (Hym.) (Fortsetzung.) III. Die mit Aphaenogaster verwandte Gattungengruppe. Deutsche Entomologische Zeitschrift 1908: 305–338.
  • Emery C (1916) Fauna entomologica italiana. I. Hymenoptera. – Formicidae. Bollettino della Società Entomologica Italiana 47: 79–275.
  • Forel A (1890) Fourmis de Tunisie et de l’Algérie orientale. Annales de la Société Entomologique de Belgique 34: 61–76.
  • Galkowski C, Aubert C, Blatrix R (2019) Aphaenogaster ichnusa Santschi, 1925, bona species, and redescription of Aphaenogaster subterranea (Latreille, 1798) (Hymenoptera, Formicidae). Sociobiology 66(3): 420–425.
  • García F, Espadaler X, Roig X, Serrano S, Cuesta-Segura AD (2020) Nuptial flights in ants: a study of the drowned sexuals in four Iberian water surfaces (Hymenoptera: Formicidae). Boletín de la Sociedad Entomológica Aragonesa (S.E.A. ) 10: 255–268.
  • Gómez K, Martinez D, Espadaler X (2018) Phylogeny of the ant genus Aphaenogaster (Hymenoptera: Formicidae) in the Iberian Peninsula, with the description of a new species. Sociobiology 65(2): 215–224.
  • Latreille PA (1798) Essai sur l’histoire des Fourmis de la France. F. Bourdeaux, Brive, 50 pp.
  • Latreille PA (1802) Histoire Naturelle des Fourmis, et Recueil de Mémoires et D’observations sur les Abeilles, les Araignées, les Faucheurs, et Autres Insectes. Impr. Crapelet (chez T. Barrois), Paris, 445 pp.
  • Lörinczi G (2012) A novel association between Aphaenogaster subterranea (Hymenoptera: Formicidae) and the nymphs of Reptalus panzeri (Hemiptera: Cixiidae). European Journal of Entomology 109(4): 509–515.
  • Lőrinczi G, Módra G, Juhász O, Maák I (2018) Which tools to use? Choice optimization in the tool-using ant, Aphaenogaster subterranea. Behavioral Ecology 29: 1444–1452.
  • Módra G, Maák I, Lőrincz Á, Lőrinczi G (2022) Comparison of foraging tool use in two species of myrmicine ants (Hymenoptera: Formicidae). Insectes Sociaux 69(1): 5–12.
  • Müller G (1923) Le formiche della Venezia Guilia e della Dalmazia. Bollettino della Società Adriatica di Scienze Naturali in Trieste 28: 11–180.
  • Ortuño VM, Gilgado JD, Tinaut A (2014) Subterranean ants: the case of Aphaenogaster cardenai (Hymenoptera: Formicidae). Journal of Insect Science 14(1): e212.
  • Santschi F (1919) Fourmis d’Espagne et des Canaries. Boletín de la Real Sociedad Española de Historia Natural 19: 241–248.
  • Santschi F (1925) Fourmis d’Espagne et autres espèces paléarctiques (Hymenopt.). EOS. Revista Española de Entomología 1: 339–360.
  • Santschi F (1932) Études sur quelques Attomyrma paléarctiques. Mitteilungen der Schweizerische Entomologische Gesellschaft 15: 338–346.
  • Schär S, Menchetti M, Schifani E, Hinojosa JC, Platania L, Dapporto L, Vila R (2020) Integrative biodiversity inventory of ants from a Sicilian archipelago reveals high diversity on young volcanic islands (Hymenoptera: Formicidae). Organisms, Diversity & Evolution 20(3): 405–416.
  • Schifani E, Alicata A (2018) Exploring the myrmecofauna of Sicily: Thirty-two new ant species recorded, including six new to Italy and many new aliens (Hymenoptera, Formicidae). Polish Journal of Entomology 87(4): 323–348.
  • Schifani E, Costa S, Mei M, Alicata A (2021a) A new species for the Italian fauna: Aphaenogaster strioloides, not A. crocea, inhabits Pantelleria Island (Hymenoptera: Formicidae). Fragmenta Entomologica 53: 21–24.
  • Schifani E, Csősz S, Viviano R, Alicata A (2021b) Ant diversity on the largest Mediterranean islands: On the presence or absence of 28 species in Sicily (Hymenoptera, Formicidae). Natural History Sciences : Atti della Societa Italiana di Scienze Naturali e del Museo Civico di Storia Naturale in Milano 8(1): 55–70.
  • Schifani E, Alicata A, Menchetti M, Borowiec L, Fisher BL, Karaman C, Kiran K, Oueslati W, Salata S, Blatrix R (2022a) Revisiting the morphological species groups of West-Palearctic Aphaenogaster ants (Hymenoptera: Formicidae) from a phylogenetic perspective: toward an evolutionary classification. Arthropod Systematics & Phylogeny 80: 627–648.
  • Schifani E, Alicata A, Menchetti M (2022b) Following the Apennines: Updating the distribution of Formica clara and Formica rufibarbis in Italy (Hymenoptera, Formicidae). Biogeographia 37(1): a014.
  • Scupola A, Durante A, Giannuzzi F (2022) The ant fauna (Hymenoptera, Formicidae) of Salento (Apulia, South East Italy): First reports, new occurrences, and an updated species list. Thalassia Salentina 44: 107–146.
  • Seifert B (2018) Ants of Northern and Central Europe. Lutra Verlags- und Vertriebsgesellschaft, Tauer, Germany.
  • Seifert B (2019) A taxonomic revision of the members of the Camponotus lateralis species group (Hymenoptera: Formicidae) from Europe, Asia Minor and Caucasia. Soil Organisms 91: 7–32.
  • Tinaut A (1986) Descripción del macho de Aphaenogaster cardenai Espadaler, 1981 (Hymenoptera, Formicidae). Miscel·lània. Zoològica 9: 245–249.
  • Wagner HC, Arthofer W, Seifert B, Muster C, Steiner FM, Schlick-Steiner BC (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.
  • Wang R, Kass JM, Galkowski C, Garcia F, Hamer MT, Radchenko A, Salata S, Schifani E, Yusupov ZM, Economo EP, Guénard B (2023) Geographic and climatic constraints on bioregionalization of European ants. Journal of Biogeography 50(3): 503–514.
  • Ward PS, Brady SG, Fisher BL, Schultz TR (2015) The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae). Systematic Entomology 40(1): 61–81.
  • Zara L, Tordoni E, Castro-Delgado S, Colla A, Maccherini S, Marignani M, Panepinto F, Trittoni M, Bacaro G (2021) Cross-taxon relationships in Mediterranean urban ecosystem: A case study from the city of Trieste. Ecological Indicators 125: e107538.

Supplementary material

Supplementary material 1 

Distribution data of Aphaenogaster ichnusa and A. subterranea

Enrico Schifani, Antonio Alicata, Lech Borowiec, Fede García, Vincenzo Gentile, Kiko Gómez, Elia Nalini, Fabrizio Rigato, Sämi Schär, Antonio Scupola, Roger Vila, Mattia Menchetti

Data type: table (excel document)

This dataset is made available under the Open Database License ( The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (122.68 kb)