Temnothorax poldii Alicata, Schifani & Prebus, 2022

Schifani, Enrico, Prebus, Matthew M. & Alicata, Antonio, 2022, Integrating morphology with phylogenomics to describe four island endemic species of Temnothorax from Sicily and Malta (Hymenoptera, Formicidae), European Journal of Taxonomy 833 (1), pp. 143-179 : 160-164

Temnothorax poldii Alicata, Schifani & Prebus sp. nov.

urn:lsid:zoobank.org:act:4A0D0DEF-4DCF-4D95-8D4D-43C56CBAC9D8

Figs 46–63

Diagnostic character combination

Antennal clubs concolorous and ferruginous, 12-segmented in females and 13 in males, eyes normal, metanotal groove absent, worker propodeal spines long, male propodeal spines absent, petiole upper profile usually with a clear horizontal component, subpetiolar process tooth-like, sculpturing characterized by distinct rugae, especially in larger workers, and a shiny area at the center of the frons.

Etymology

This species is dedicated to the Italian physician and amateur myrmecologist Bruno Poldi (1920–2002), which has also been a mentor and friend to Antonio Alicata in his early approach to the study of ants.

Material examined

We investigated 62 colony samples from 21 localities, consisting in a total of 820 ☿☿, 6 ♀♀, 2 ♂♂ from our collections. A detailed list is provided in the Supp. file 1: Table S1.

Type material

Holotype ITALY • ☿; Monte Arso; 37.7564° N, 14.9103° E, 14 Aug. 1992; A. Alicata leg.; MSNG.

Paratypes (30 ☿☿, 2 ♀♀, 1 ♂) ITALY • 8 ☿☿, 1 ♀; same collection data as for holotype; MSNG • 17 ☿☿, 1 ♂; Monte Ruvolo ; 37.7514° N, 14.8907° E; 18 Aug. 1992; A. Alicata leg.; MSNG • 5 ☿☿, 1 ♀; Monte Manfrè ; 37.6735° N, 14.9814° E; 24 May 1992; A. Alicata leg.; MSNG .

Description

Worker ( Figs 46–57 )

MEASUREMENTS AND INDICES (11 specimens, 5 localities, 6 colonies). CL: 694.91 ± 54.72 (636–771); CW: 626.18 ± 62.94 (529–724); CS: 660.54 ± 57.86 (585–747); PoOC: 291 ± 21.32 (268–322); SL: 538.91 ± 46.76 (481–614); ML: 784.36 ± 77.51 (671–905); MW: 384.91 ± 16.16 (324–460); EL: 137.82 ± 16.16 (111–159); EW: 102 ± 11.54 (87–120); EYE: 119.91 ± 13 (99–138); SPST: 192 ± 29.76 (148–239); CL/CW: 1.11 ± 0.04 (1.06–1.21); PoOC/CL: 0.42 ± 0.01 (0.40–0.43); SL/CL: 0.77 ± 0.02 (0.75–0.81); ML/CS: 1.18 ± 0.05 (1.10–1.28); MW/CS: 0.58 ± 0.03 (0.54–0.64); EL/CS: 0.21 ± 0.01 (0.18–0.23); EW/CS: 0.15 ± 0.01 (0.14–0.16); EYE/CS: 0.18 ± 0.01 (0.16–0.19); SPST/CS: 0.29 ± 0.02 (0.24–0.32).

COLORATION. Entirely ferruginous with the possible exception of the gaster, which varies from slightly darker than the rest of the ant to substantially black in a minority of examined colonies.

HEAD. Subrectangular with rounded margins near the four angles; clypeus and mandibles rounded. Antennae of 12 segments, antennal clubs of 3 segments, antennal scapes relatively long (SL/CL: 0.77 ± 0.02). Compound eyes relatively small and ovoidal (EYE/CS: 0.18 ± 0.01).

MESOSOMA. Without a metanotal depression, its dorsal profile being from usually rounded in lateral view. Propodeal spines relatively long and moderately thick (SPST/CS: 0.29 ± 0.02).

METASOMA. Petiole in profile view relatively high, usually presenting a clear dorsal horizontal component in profile view. On its antero-ventral part, the subpetiolar process is usually visible, consisting of a small tooth. Postpetiole ordinarily roundish in lateral profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Body sculpture relatively strong, with well-marked longitudinal rugae on the mesosoma, head sides, more variably on the dorsal surfaces of the waist segments. Development of anastomoses and variably finer areolate-rugose areas between the strong longitudinal rugae is quite variable in many areas, but usually absent in the lateral sides of the pronotum. Completely smooth areas are often observed between the larger rugae. The waist segments and some areas of the mesosoma may be entirely characterized by a finer areolate-rugose sculpture not interrupted by strong rugae. The gaster, appendages, and a long area from the clypeus to the occiput through the frons are smooth. Very sparse, occasionally suberect but usually erect setae all over the body; dense, fine, and mostly adpressed pilosity on all appendages, especially abundant on the antennal flagelli.

Queen ( Figs 58–60 )

MEASUREMENTS AND INDICES (2 specimens, 2 localities). CL: 823–841; CW: 771–784; CS: 797–812; PoOC: 325–335; SL: 635–655; ML: 1368–1408; MW: 860–904; EL: 229–239; EW: 177–179; EYE: 204–208; SPST: 280–298; CL/CW: 1.03–1.03; PoOC/CL: 0.39–0.41; SL/CL:0.77–0.78; ML/CS: 1.71–1.73; MW/ CS: 1.08–1.11; EL/CS: 0.29–0.29; EW/CS: 0.22–0.22; EYE/CS: 0.25–0.26; SPST/CS: 0.34–0.37.

COLORATION. Entirely ferruginous, gaster darker.

HEAD. Subrectangular with rounded margins near the four angles; clypeus and mandibles rounded. Antennae of 12 segments, antennal clubs of 3 segments, antennal scapes relatively long (SL/CL:0.77– 0.78). Compound eyes large and ovoidal (EYE/CS: 0.25–0.26); ocelli circular.

MESOSOMA. Propodeal spines relatively long (SPST/CS: 0.34–0.37).

METASOMA. The petiole in profile view is sharp, lacking a horizontal component dorsally. The subpetiolar process is usually visible as a small tooth. Postpetiole ordinarily roundish in lateral profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Most of the body is covered with relatively fine parallel rugae with almost no anastomoses except for parts of the head, a fine areolate sculpture is visible in parts of the propodeum and nodes. Clypeus, gaster, and appendages, a variable area extending around the frons, the lower areas of the katepisterna and partly the mesoscutellar disk smooth. A central longitudinal stria visible in the lower portion of the clypeus. Very sparse, occasionally suberect but usually erect setae all over the body; dense, fine, and mostly adpressed pilosity on all appendages, especially abundant on the antennal flagelli.

Male ( Figs 61–63 )

MEASUREMENTS AND INDICES (3 specimens, 2 localities). CL: 574.67 ± 14.01 (559–586); CW: 554.33 ± 8.38 (549–564); CS: 564.5 ± 9.26 (554–571); PoOC: 237.67 ± 3.05 (235–241); SL: 207.67 ± 3.05 (205– 211); ML: 1024 ± 14.42 (1008–1036); MW: 608 ± 15 (593–623); EL: 235.33 ± 3.78 (231–238); EW: 191.67 ± 5.03 (187–197); EYE: 213.5 ± 1.32 (212–214); CL/CW: 1.02 ± 0.01 (1.01–1.03); PoOC/CS: 0.41 ± 0.01 (0.40–0.43); SL/CL: 0.36 ± 0.01 (0.35–0.37); ML/CS: 1.81 ± 0.01 (1.80–1.82); MW/CS: 1.07 ± 0.04 (1.04–0.12); EL/CS: 0.42 ± 0.00 (0.41–0.42); EW/CS: 0.34 ± 0.01 (0.32–0.35); EYE/CS: 0.37 ± 0.00 (0.37–0.38).

COLORATION. Whole body dark reddish-brownish, appendages whitish.

HEAD. Subrectangular, rounded especially above the eyes; clypeus and mandibles rounded. Antennae of 13 segments, antennal clubs of 4 segments, antennal scapes relatively short (SL/CL: 0.36 ± 0.01). Compound eyes large and ovoidal (EYE/CS: 0.37 ± 0.00); ocelli circular.

MESOSOMA. Propodeum spineless and rounded.

METASOMA. Petiole ordinarily low and blunt. Postpetiole ordinarily roundish in profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Rugulose-areolate sculpture on head and propodeum, everything else smooth. Sparse erect setae all over the body; fine and mostly adpressed pilosity over the appendages.

Phylogeny ( Fig. 79 )

Appearing as the sister taxon of Temnothorax ibericus (Menozzi, 1922) among the sequenced species. Temnothorax ibericus is a mountain species like T. poldii sp. nov. and is endemic to Iberia ( Espadaler et al. 2017), but the two species are not particularly similar in broad morphological terms, and close relatedness appears unlikely.

Distribution and biogeography ( Figs 80–81 )

Occurs almost all over Sicily (although its ecological requirements clearly make it less widespread than T. lagrecai , e.g., absence from the westernmost section may be due to aridity and lack of suitable forests). An apparently similar niche is occupied by T. alienus in the southern Italian Peninsula (Aspromonte, Calabria).

Ecology and conservation ( Fig. 82 )

Collected between 340 and 1612 m a.s.l., mostly in hilly to mountainous conditions, always under tree coverage, usually consisting of different oak species. Massive historic deforestation of Sicily likely resulted in a huge habitat loss and fragmentation into isolated populations at least outside the mountain chains along the Tyrrhenian coast (Sicilian Apennines).

Nesting

Nests are found in the soil, probably opportunistically exploiting several kinds of microhabitats when available.

Biology

Monogynous in all documented cases.

Phenology

Males inside nests of T. poldii sp. nov. were found in August, but the time when nuptial flights occur is unknown.

Figures

Figs 46–63. Specimens of Temnothorax poldii Alicata, Schifani & Prebus sp. nov. in lateral (left), dorsal (center) and head view (right). Photos by Enrico Schifani, available on www.antweb.org, specimen identifiers in parentheses. 46–48. Holotype worker from MonteArso (Etna, Sicily) (ANTWEB1041545). 49–51. Worker from Vallone Madonne degli Angeli (Madonie, Sicily) (ANTWEB1041546). 52– 54. Paratype worker from Monte Ruvolo (Etna, Sicily) (ANTWEB1041547). 55–57. Worker from Monte Manfrè (Etna, Sicily) (ANTWEB1041548), with ergatogynes characters in the mesosoma. 58– 60. Paratype queen from Monte Arso (Etna, Sicily) (ANTWEB1041549). 61–63. Paratype male from Monte Ruvolo (Etna, Sicily) (ANTWEB1041550). Scale bars = 0.5 mm.

Fig. 79. Maximum likelihood phylogeny inferred with IQTREE ver. 2.1.2. The major clades found in Prebus (2017) are highlighted, and the focal species of the current study (all within the ‘Palearctic clade IV’) are evidenced as in Figs 75–78. Maximum likelihood bootstrap support for all nodes are 100, except where indicated.

Figs 80–81. Geographic distribution of the four taxa treated in this study. Note that the shallow water area (light grey) between Sicily and the Maltese Islands roughly corresponded to a land bridge during glaciations.

Fig. 82. Spatial characterization of the sites where the four species treated in this study were found.