Temnothorax vivianoi Schifani, Alicata & 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 : 164-171

Temnothorax vivianoi Schifani, Alicata & Prebus sp. nov.

urn:lsid:zoobank.org:act:F873BCD2-E771-48D1-9871-F23CFA6C7EE6

Figs 64–74

Diagnostic character combination

Antennal clubs concolorous yellowish, antennae 12-segmented in females and 13 in males, eyes normal, metanotal groove absent, worker propodeal spines short, male propodeal spines absent, petiole upper profile usually without a horizontal component, subpetiolar process carina-like, sculpturing mostly areolate and weak.

Etymology

The species is dedicated to our friend Roberto Viviano, who donated to us most of the material of this species we had the opportunity to examine, collected by him during malacological surveys.

Material examined

We investigated 20 colony samples from 11 localities, consisting in a total of 111 ☿☿, 14 ♀♀, 1 ♂ from our collections. A detailed list is provided in the Supp. file 1: Table S1.

Type material

Holotype ITALY • 1 ☿; Monte Pellegrino ; 38.1866° N, 13.3539° E; 9 Oct. 2016; R. Viviano leg.; MSNG.

Paratypes (30 ☿☿, 2 ♀♀) ITALY • 10 ☿☿; same collection data as for holotype; MSNG • 10 ☿☿, 1 ♂; Monte Pellegrino ; 38.1580° N, 13.3664° E; 15 Mar. 2016; R. Viviano leg.; MSNG • 5 ☿☿, 1 ♀; Monte Pellegrino ; 38.1641° N, 13.3466° E; 20 May 2016; R. Viviano leg.; MSNG • 5 ☿☿; Monte Pellegrino , 38.1558° N, 13.3544 ° E; 6 May 2018; R. Viviano leg.; MSNG .

Description

Worker ( Figs 64–69 )

MEASUREMENTS AND INDICES (21 specimens, 6 colonies, 2 localities). CL: 610.25 ± 26.66 (546–642); CW: 509.27 ± 27.02 (449–554); CS: 559.2 ± 26.09 (498–598); PoOC: 255.5 ± 11.6 (229–270); SL: 451.05 ± 30.02 (395–496); ML: 643.33 ± 36.03 (548–683); MW: 323.5 ± 23.74 (281–361); EL: 110.75 ± 6.64 (97–124); EW: 84.05 ± 7.49 (71–98); EYE: 97.4 ± 6.8 (84–110); SPST: 114.19 ± 12.55 (92–145); CL/CW: 1.19 ± 0.02 (1.11–1.23); PoOC/CL: 0.42 ± 0.01 (0.39–0.44); SL/CL: 0.74 ± 0.02 (0.70–0.79); ML/CS: 1.14 ± 0.03 (1.08–1.18); MW/CS: 0.58 ± 0.02 (0.54–0.61); EL/CS: 0.19 ± 0.01 (0.18–0.21); EW/CS: 0.15 ± 0.01 (0.13–0.17); EYE/CS: 0.17 ± 0.01 (0.16–0.18); SPST/CS: 0.20 ± 0.01 (0.18–0.24).

COLORATION. Entirely yellowish with the exception of a black transverse band on the first gaster tergite.

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 short (SL/CL: 0.74 ± 0.02). Compound eyes relatively small and ovoidal (EYE/CS: 0.17 ± 0.01).

MESOSOMA. Without a metanotal depression, straight or slightly rounded in profile. Propodeal spines notably short and thick (SPST/CS: 0.20 ± 0.01).

METASOMA. The petiole in profile view usually presents no dorsal horizontal component. Subpetiolar process carina-like. Postpetiole ordinarily roundish in profile, subrectangular in dorsal view.

SURFACE SCULPTURING. The body is almost entirely meticulously covered with a relatively fine areolaterugose sculpture, the longitudinal component of which tends to slightly more marked on the frontal side of the head. Clypeus, gaster, and appendages smooth; a variable area extending around the frons. 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 70–72 )

MEASUREMENTS AND INDICES (5 specimens, 4 colonies, 1 locality). CL: 732.4 ± 36.48 (672–769); CW: 646.6 ± 33.98 (588–670); CS: 689.83 ± 34.80 (630–719); PoOC: 283.8 ± 13.6 (264–301); SL: 527.8 ± 28.2 (482–552); ML: 1150.2 ± 53.66 (1062–1204); MW: 693.6 ± 37.15 (630–723); EL: 190.8 ± 14.16 (171– 210); EW: 154.8 ± 6.38 (144–160); EYE: 172.8 ± 10.02 (157–184); SPST: 212.6 ± 9.61 (200–227); CL/ CW: 1.06 ± 0.01 (1.05–1.07); PoOC/CL: 0.39 ± 0.00 (0.38–0.39); SL/CL: 0.72 ± 0.02 (0.71–0.73); ML/ CS: 1.67 ± 0.02 (1.63–1.70); MW/CS: 1 ± 0.00 (1.00–1.01); EL/CS: 0.28 ± 0.01 (0.26–0.29); EW/CS: 0.22 ± 0.00 (0.22–0.23); EYE/CS: 0.25 ± 0.00 (0.24–0.26); SPST/CS: 0.31 ± 0.01 (0.29–0.33).

COLORATION. Entirely yellowish with the exception of black transverse bands on each gaster tergite. 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 short (SL/CL: 0.72 ± 0.02). Compound eyes large and ovoidal (EYE/CS: 0.25 ± 0.00); ocelli circular.

MESOSOMA. Propodeal spines very short and thick (SPST/CS: 0.31 ± 0.01).

METASOMA. The petiole in profile view sharp dorsally and rather high; on its antero-ventral part, a small carina weakly emerges in profile view. Postpetiole ordinarily roundish in lateral profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Most of the body is covered with moderately marked longitudinal rugae, which are stronger on head. Very fine areolate sculpture is also present on propodeum and waist segments. Clypeus, gaster, and appendages smooth; a variable area extending around the frons, anepisterna, katepisterna, mesoscutellar disk and mesoscutum. 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 73–74 )

MEASUREMENTS AND INDICES (1 individual - unfortunately, only a single damaged specimen of this species was found so far, solely consisting of the mesosoma, wings and legs). ML: 765; MW: 385.

COLORATION. Entirely yellowish.

MESOSOMA. Propodeum spineless and rounded, in profile view propodeal declivity clearly shorter than the propodeal dorsum.

SURFACE SCULPTURING. Sculpture very weak, most areas smooth with exception of a fine areolate-rugose sculpture on the propodeum. Few sparse erect setae.

Phylogeny ( Fig. 79 )

Sister taxon to all species in ‘Palearctic subclade IV’ sensu Prebus (2017), which consists of a large radiation of species with Mediterranean, Middle Eastern and northern Afrotropical distributions.

Distribution and biogeography ( Figs 80–81 )

Restricted to NW Sicily and neighboring Aegadian Islands in the drepano-panormitan biogeographic sector that is constituted by a very old carbonatic platform. The area is known to have a significant zoogeographic relevance for ants, hosting some species that are either unique or absent from the rest of Sicily, as discussed by Schifani et al. (2020).

Ecology and conservation

Found from 75 to 1080 m a.s.l. (see Fig. 82 ). Most of our sites are characterized by forest or shrubs of Quercus ilex / Fraxinus ornus L. growing on rocky landslides or very rocky substrates, usually at the base of hundred meters-high north-facing cliffs hosting relatively wet and cool conditions compared to the surroundings. At least twice it was found in more open habitats characterized by rocky outcrops with sparse shrubs, in one case surrounded by agricultural areas. Populations may be fragmented due to anthropogenic fragmentation of forested areas and shrublands, but further assessment are required.

Biology

Small and monogynous colonies in all documented cases.

Nesting

Nests are found in the soil, probably opportunistically exploiting several kinds of microhabitats when available. The large number of the samples we examined consisted of colonies living entirely within abandoned shells of gastropods. In Monte Pellegrino, on several occasions entire colonies were found inside the abandoned shells of Marmorana (Murella) sicana (Férussac, 1822) , a short-range endemic species which is locally very abundant. In Monte Pecoraro, a colony was found under a stone inside an abandoned shell of another short-range endemic of Palermo mountains, Chilostoma macrostoma (Rossmässler, 1837) . It has also been found within shells of Rumina decollata (Linnaeus, 1758) . However, these repeated findings may not indicate a true specialization in the use of abandoned gastropod shells, but a reflection of the nesting opportunities offered by many of the collecting sites, as well as the malacological nature of the sampling efforts during which it was found.

Phenology

Nuptial flights observed in late August in Mondello (Palermo), where queens were attracted by artificial lights.

Notes

Specimens from Favignana (Aegadian Islands) mentioned as unidentified or related to T. lagrecai by Mei (1995) and Scupola (2009) represent T. vivianoi sp. nov. based on our investigation of vouchers at the MSNG.

Figures

Figs 64–74. Specimens of Temnothorax vivianoi Schifani, Alicata & Prebus sp. nov. in lateral (left), dorsal (center) and head view (right). Photos by Enrico Schifani, available onwww.antweb.org, specimen identifiers in parentheses. 64–66. Holotype worker from Monte Pellegrino (Palermo Mountains, Sicily) (ANTWEB1041551). 67–69. Paratype worker from Monte Pellegrino (Palermo Mountains, Sicily) (ANTWEB1041552). 70–72. Paratype queen from Monte Pellegrino (Palermo Mountains, Sicily) (ANTWEB1041553). 73–74. Damaged male from Palermo Mountains (Sicily) (ANTWEB1041554). 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.