Temnothorax marae 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 : 157-160

Temnothorax marae Alicata, Schifani & Prebus sp. nov.

urn:lsid:zoobank.org:act:CDBACBF1-90EE-47D0-B250-9B4F7D84D465

Figs 34–45

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 with a short horizontal component but no well-defined edges, subpetiolar process carinalike, sculpturing mostly areolate and weak.

Etymology

The species is dedicated to Mara La Rocca, wife of Antonio Alicata.

Material examined

We investigated 17 colony samples from 11 localities, consisting in a total of 41 ☿☿, 2 ♀♀, 4 ♂♂ from our collections, one colony under rearing in our possession, and additional workers from the personal collections of David Misfud and Stephen Schembri. A detailed list is provided in the Supp. file 1: Table S1.

Type material

Holotype ITALY • ☿; Vendicari ; 36.7814° N, 15.0894° E; 21 Sep. 2019; A. Alicata leg.; MSNG.

Paratypes (7 ☿☿, 2 ♀♀, 3 ♂♂) ITALY • 1 ☿; same collection data as for holotype; MSNG • 2 ♂♂; Isola di Capo Passero ; 36.6872° N, 15.1493° E; 10 Jul. 1997; A. Alicata leg.; MSNG • 6 ☿☿; Pineta di Vittoria ; 36.8879° N, 14.4828° E; 30 Mar. 2001; A. Alicata and A. Adorno leg.; MSNG • 1 ♀ (damaged); Pineta di Vittoria ; 36.8927° N, 14.4745° N; 25 Mar. 2019; A. Alicata and E. Schifani leg.; MSNG • 1 ♂, 1 ♀; Bosco di S. Pietro; 2 Jun. 2019; A. Alicata and S. Csősz leg.; MSNG .

Description

Worker ( Figs 34–39 )

MEASUREMENTS AND INDICES (7 specimens, 6 colonies, 5 localities). CL: 565.86 ± 35.45 (512–616); CW: 449 ± 34.46 (406–515); CS: 507.42 ± 34.31 (459–565); PoOC: 239.43 ± 11.73 (223–262); SL: 398.14 ± 23.5 (360–434); ML: 605.86 ± 43.15 (540–664); MW: 298.86 ± 22.28 (264–334); EL: 106.43 ± 6.7 (97–115); EW: 82.71 ± 7.43 (72–93); EYE: 94.57 ± 6.4 (84–99); SPST: 117.57 ± 13.24 (102–142); CL/CW: 1.26 ± 0.03 (1.19–1.30); PoOC/CL: 0.42 ± 0.02 (0.39–0.43); SL/CL: 0.70 ± 0.02 (0.67–0.72); ML/CS: 1.19 ± 0.02 (1.17–1.22); MW/CS: 0.59 ± 0.01 (0.57–0.61); EL/CS: 0.21 ± 0.01 (0.19–0.23); EW/CS: 0.16 ± 0.01 (0.15–0.17); EYE/CS: 0.19 ± 0.01 (0.17–0.20); SPST/CS: 0.23 ± 0.01 (0.21–0.25).

COLORATION. Entirely yellowish with the exception of the gaster, which is often entirely blackish (but in some colonies the black part forms a transverse band).

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. Compound eyes relatively small and ovoidal (EYE/CS: 0.19 ± 0.01).

MESOSOMA. Without a metanotal depression, straight or slightly rounded in profile. Propodeal spines notably short and thick (SPST/CS: 0.23 ± 0.01).

METASOMA. The petiole in profile view rather blunt dorsally, lacking well-defined edges; on its anteroventral part, a small carina weakly emerges in profile view. Postpetiole ordinarily roundish in profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Most of the body characterized by a variably fine areolate-rugose sculpture, the longitudinal component of which tends to be 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, mostly adpressed pilosity on all appendages, especially abundant on the antennal flagelli.

Queen ( Figs 40–42 )

MEASUREMENTS AND INDICES (1 individual). CL: 636; CW: 557; CS: 596.5; PoOC: 243; SL: 468; ML: 1032; MW: 618; EL: 174; EW: 151; EYE: 162.5; CL/CW: 1.07; PoOC/CS: 0.38; SL/CL: 0.74; ML/CS: 1.73; MW/CS: 1.04; EL/CS: 0.29; EW/CS: 0.25; EYE/CS: 0.27; SPST/CS: 0.28.

COLORATION. Entirely yellowish with the main exception of parts of the gaster: all tergites are blackish with the exception of their yellowish caudalmost part, and the first tergite is yellowish near the postpetiole. Moreover, the mesoscutellar disk is caudally darkened.

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). Compound eyes large and ovoidal (EYE/CS: 0.27); ocelli circular.

MESOSOMA. Propodeal spines very short and thick (SPST/CS: 0.28).

METASOMA. Petiole in profile view sharp, and does not include a horizontal component. On its anteroventral part, a small carina weakly emerges in profile view. Postpetiole ordinarily roundish in profile, subrectangular in dorsal view.

SURFACE SCULPTURING. Most of the body is characterized by a variably fine areolate-rugose sculpture, the longitudinal component of which tends to be more marked on the frontal side of the head. Clypeus, gaster, appendages, a variable area extending around the frons, anepisterna, katepisterna, mesoscutellar disk, and mesoscutum 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 43–45 )

MEASUREMENTS AND INDICES (3 specimens, 1 colony). CL: 472.67 ± 16.2 (454–483); CW: 419.33 ± 20.01 (396–437); CS: 445.83 ± 18.42 (425–460); PoOC: 197 ± 6.08 (190–201); SL: 252 ± 1.73 (251–254); ML: 845.67 ± 27.8 (814–866); MW: 467.66 ± 20.55 (448–489); EL: 185 ± 7.21 (179–193); EW: 157.66 ± 4.16 (153–161); EYE: 171.33 ± 4.16 (168–176); CL/CW: 1.06 ± 0.01 (1.05–1.07); PoOC/CS: 0.42 ± 0.02 (0.41–0.42); SL/CL: 0.53 ± 0.02 (0.52–0.55); ML/CS: 1.89 ± 0.03 (1.86–1.91); MW/CS: 1.08 ± 0.03 (1.03-1.06); EL/CS: 0.41 ± 0.01 (0.40–0.43); EW/CS: 0.35 ± 0.02 (0.33–0.38); EYE/CS: 0.38 ± 0.02 (0.36–0.40).

COLORATION. Whole body yellowish, appendages whitish, gaster dark.

HEAD. Subrectangular, rounded especially above the compound eyes; clypeus and mandibles rounded. Antennae of 13 segments, antennal clubs of 4 segments, antennal scapes relatively long (SL/CL: 0.53 ± 0.02). Compound eyes large and ovoidal (EYE/CS: 0.38 ± 0.02); ocelli circular.

MESOSOMA. Propodeum spineless and rounded, most of the length of its lateral profile composed by the declivious posterior margin.

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

SURFACE SCULPTURING. Sculpture relatively strong on the head, with well-developed longitudinal striae on its frontal side, very light all over the propodeum, petiole, postpetiole and in some areas near the mesosoma lateral sutures, all the remaining parts are smooth. A central longitudinal stria visible in the lower portion of the clypeus. Sparse, erect setae all over the body; fine and mostly adpressed pilosity over the appendages.

Phylogeny ( Fig. 79 )

Sister species of T. lagrecai , which together are closely related to T. flavicornis .

Distribution and biogeography ( Figs 80–81 )

Apparently restricted to SE Sicily (Hyblaean Plateau) and the Maltese islands. The Hyblean Pleateau may be the earliest sector of Sicily to have emerged from the Mediterranean Sea and has a strong biogeographic characterization ( Guarino & Pasta 2018).

Ecology and conservation

More thermophilous than any other species treated in this study, it was found at altitudes between 5 and 175 m a.s.l. (see Fig. 82 ). Mainly found in the leaf litter of phryganas or shrublands, but also within a native P. halepensis forest and under riparian vegetation. Its habitat was likely severely reduced by strong anthropization of coastal areas and agricultural activities.

Biology

Small and monogynous colonies in all documented cases.

Social parasites

One colony was found to be hosting T. muellerianus (Finzi, 1922) in the R.N.O. Vendicari.

Nesting

Nests were always found on dead twigs, either on bushes or laying on the ground, although nesting directly on the soil or in other microhabitats on the ground may also occur.

Phenology

Males were produced under rearing conditions during July.

Notes

Maltese records under Leptothorax rabaudi Bondroit, 1918 by Schembri & Collingwood (1981) are partly based on misidentified T. marae sp. nov. according to an investigation of their voucher specimens. Temnothorax aveli (Bondroit, 1918) (the senior synonym of L. rabaudi , see Casevitz-Weulersse & Galkowski 2009), a mainly arboreal-nesting species found in SW Europe may be absent from Malta as it is from Sicily (see also under T. lagrecai ).

Figures

Figs 34–45. Specimens of Temnothorax marae 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. 34–36. Holotype worker from Vendicari (Hyblaean Sicily) (ANTWEB1041541). 37–39. Paratype worker from Vendicari (Hyblaean Sicily) (ANTWEB1041542). 40–42. Queen from Bosco di Santo Pietro (Hyblaean Sicily) (ANTWEB1041543), note that the lateral image was edited to compensate for the fact that the petiole and gaster plus postpetiole were accidentally disarticulated. 43–45. Male from Bosco di Santo Pietro (Hyblaean Sicily) (ANTWEB1041544). 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.