Myrmica xavieri

Two nest collections were fairly typical for lobicornis-group species, being in soil under stones. The nest of the holotype was found at 1630 m in open pine forest (Pinus sylvestris) with moist soil and the other nest was in well-trampled grass on a mountain pass c.1500 m near pine forest. (Radchenko and Elmes 2010)

Identification
A member of the xavieri complex of the lobicornis species group. Radchenko and Elmes (2010) - tentatively placed the lobicornis-group based on the shape of scape of the female castes (it has a small vertical lobe at the bend) and on the long scape of the males. On the other hand, the shape of scape of the workers and queens is similar to that of the species of schencki-group (e.g. shield-l ike process presents on its short, vertical part). Moreover, all castes have a not-notched medially anterior clypeal margin (in contrast, the species of the lobicornis- and schencki-groups have distinctly notched clypeus). Finally, the scape of the male is even longer than that of other lobicornis-group species, in length it is similar to the rubra-group species but it is distinctly angled at its base. We suspect that M. xavieri is an Iberian endemic being a relict of a fauna isolated in Spain during recent ice ages and may typify its own separate species group. In the recent molecular phylogeny of Jansen et al. (2010) M. xavieri is most related to Myrmica sulcinodis.

Key to Myrmica of West Europe and North Africa

Distribution
Known only from the type localities in Spain.

Distribution based on Regional Taxon Lists
Palaearctic Region: Spain.

Nomenclature

 *  xavieri. Myrmica xavieri Radchenko, Elmes & Savolainen, 2008: 51, figs. 1-3 (w.q.m.) SPAIN. See also: Radchenko & Elmes, 2010: 327.

Worker
Head longer than its width with slightly convex sides and occipital margin, and broadly rounded occipital corners. Anterior clypeal margin narrowly rounded, somewhat prominent, with no medial notch. Frontal carinae fairly strongly curved, frons relatively narrow, though frontal lobes not widely extended. Antennal scape strongly angled at the base, with small vertical lobe. Alitrunk with slightly convex promesonotal dorsum; promesonotal suture clearly visible from above; metanotal groove sharp and deep. Propodeal spines long, acute, straight and divergent (seen from above) projecting backwards at an angle less than 45° (seen in profile). Petiole with distinct anterior peduncle, its anterior face slightly concave, not steep, meeting the dorsal surface at a blunt rounded angle; dorsal surface of petiolar node slightly convex, gradually sloping posteriorly. Postpetiole distinctly shorter than broad, with convex dorsum. Spurs on middle and hind tibiae well developed and pectinate.

Frons with sinuous longitudinal rugae remaining parts of head dorsum with coarse reticulation. Antennal sockets surrounded by concentric rugae. Clypeus with longitudinal rugae, frontal triangle coardely striated. Sides of alitrunk with moderately coarse rugae and reticulation. Petiole and postpetiole with fairly coarse longitudinally-concentric rugae, more sinuous on the nodes of dorsum. Surface between rugae on the body smooth and shiny.

Head margins with abundant, semierect hairs; alitrunk dorsum and waist with numerous hairs much longer than those on head margin. General colour reddish-brown, appendages somewhat lighter.

Queen
Like worker in shape of head scape, general colour and pilosity of the body, but with coarser sculpture, especially on the alitrunk, petiole and postpetiole than the worker. The main difference is a more massive petiole than in workers, with a shorter anterior peduncle. Also the propodeal spines are longer and less divergent than in workers.

Male
Head somewhat longer than broad, with slightly convex sides and occipital margin, and gradually rounded occipital corners. Anterior clypeal margin narrowly rounded and slightly prominent with no medial notch. Antennal scape very long and strongly curved at the base. Antennae 13-segmented, with 3-segmented club, second funicular segment about twice as long as the third one.

Alitrunk fairly long, scutum slightly convex, scutellum not projecting dorsally above scutum when seen in profile. Propodeum with blunt rounded tubercles. Petiole rather massive, relatively high with straight anterior face and rounded dorsum of node; postpetiole distinctly longer than its width, with weakly convex dorsum.

Head dorsum with striation and dense punctures. Scutum with dense longitudinally-concentric rugae, scutellum with coarser and less abundant rugae. Pro- and mesopleura with fine rugae, propodeum with coarser rugae. Petiole and postpetiole finely but not densely punctured, petiole additionally has fine rugulae, central part of petiolar and postpetiolar dorsum smooth and shiny. Surface on alitrunk between rugae smooth and shiny.

Head margins, alitrunk and waist with abundant, relatively short semierect hairs. Scape, tibiae and tarsi with short subdecumbent to suberect hairs. General colour of body dark brown to black, appendages somewhat lighter.

Type Material
Holotype worker: Spain, Aragon, Province ofTeruel, Sierra de Albarracin, Fuente del Canto, ca. three km WSW of Bronchales(40°30', 1°37'W, 1630ma.s.l.), 1.VII.2000, No. 334/2000 (series E-186 in the collection of G. W. Elmes), leg. R. Savolainen and K. Vepsalainen. Paratypes: 9 workers, 30 gynes and 35 males from the ne t of the holotype; 10 workers, Spain, Castilla y Leon, Province of Soria, Sierra de Urbion, ca. 25 km of Soria (from memory Elmes places it in the region 42°N, 2°30'W, 1,500 m), 7.VII.1990, series E-117, leg G. W. Elmes. The nest of the holotype was in open pine forest (Pinus sylvestris) with moist soil. The para type nest was ca. 180 km NNW of the holotype site in well-trampled grass on a mountain pass near a pine forest in the mountains of Soria Province, by a road between Soria and Logrono. Both nests were in soil under stones. The holotype is deposited in the Natural History Museum (BM 11), London, United Kingdom, and the paratypes, in the Institute of Zoology of Ukrainian National Academy of Sciences. Kiev, Ukraine, and in the collections of Graham W. Elmes, United Kingdom, and Xavier Espadaler, San Cugat, Spain.

Etymology
Radchenko and Elmes (2010) - this species was dedicated to our friend and colleague, the Spanish myrmecologist Prof. Xavier Espadaler of Barcelona.