Proceratium melinum

A wide ranging Palaearctic species. In Albania (Purkart et al., 2019) it was found near a canyon of the river Lengaricës, where rocky slopes are covered with small areas of forest-steppe, from a sample of rotten wood, leaf litter and soil taken from a decaying tree, and the collected material was then heat extracted from the sample using Tullgren funnels. Carebara oertzeni was also found in this same sample.

Identification
A member of the pergandei clade. Differing from its ingroup species, Proceratium confinium, in the worker, mainly by the frontal carinae separate instead of very close to each other, by the antennal scapes shorter and by the fore basitarsi longer than the mid basitarsi instead of subequal; and from its outgroup, Proceratium morisitai, in the worker and gyne, by the head rugosopunctate instead of granulate and by the second tarsomere of hind leg about 1/5 longcr than the pretarsus instead of about as long as the pretarsus, and, in the male, by the IGR = 0.62 instead of IGR 0.68. (Baroni Urbani and de Andrade 2003)

Distribution
Central and Southern Europe from South Spain to Russia, Turkey, and Israel.

The known distribution of this species in the Iberian Peninsula is detailed by Tinaut & Martinez-Ibanez (1998). Kugler (1988) reports this species from Israel, a country from which we did not see any specimen. The account, however, represents the southernmost record for this species and appears as biogeographically plausible. The northernmost distributional record for P. melinum appears to be from southern Poland (Cracow).

Distribution based on Regional Taxon Lists
Palaearctic Region: Albania, Austria, Bulgaria, Czech Republic, Greece, Hungary, Iberian Peninsula, Israel, Malta, Montenegro, Republic of Macedonia, Romania, Russian Federation, Slovenia, Spain, Turkey, Ukraine.

Nomenclature

 *  melinum. Ponera melina Roger, 1860: 291 (w.q.m.) EUROPE (not U.S.A.; see Baroni Urbani, 1977d: 91). Combination in Proceratium: Mayr, 1886d: 438; in Sysphincta: Emery, 1895c: 263; in Proceratium: Brown, 1958g: 248. Senior synonym of europaea, fialai, rossica: Brown, 1958g: 248. See also: Atanassov & Dlussky, 1992: 64; Baroni Urbani & De Andrade, 2003b: 251.
 * europaea. Sysphingta europaea Forel, 1886e: clxiii, fig. 2 (w.) GREECE. Forel, 1889: 259 (q.); Forel, 1905b: 177 (m.). Combination in Proceratium: Forel, 1889: 258; in Sysphincta: Emery, 1909c: 359. See also: Emery, 1916b: 103; Lomnicki, 1922: 1; Menozzi, 1925d: 24. Junior synonym of melinum: Brown, 1958g: 248.
 * rossica. Sysphincta europaea subsp. rossica Arnol'di, 1930b: 144, figs. 1-3 (w.q.) RUSSIA. [Also described as new by Arnol'di, 1930d: 157.] Junior synonym of melinum: Brown, 1958g: 248.
 * fialai. Sysphincta fialai Kratochvíl, in Kratochvíl, Novák & Snoflák, 1944: 54, figs. 1-4 (w.q.m.) CZECHOSLOVAKIA. Junior synonym of melinum: Brown, 1958g: 248.

Worker
Baroni Urbani and de Andrade (2003) - Head longer than broad, its sides gently convex in the two anterior thirds and weakly converging in the posterior third. Anteromedian part of the clypeus narrow, triangular and protruding anteriorly, with a variably markcd longitudinal carina dorsally. Frontal carinae diverging posteriorly, poorly raised and not close to each other. Lateral expanfions of the frontal carinae narrow. Genal carina absent. Gular area not impressed. Eyes small and represented by a dark dot below the integument. Eyes on the midline of the head. First funicular joint slightly longer than broad. Funicular joints 2-10 about as broad as long or slightly broader than long. Last funicular joint about as long as the sum of joints 7-10. Scapes much shorter than the vevtexal margin and gently thickening apically. Masticatory margin of the mandibles with 4-5 denticles before the pointed apical tooth. Palp formula 4,3.

Mesosoma as long as or slightly shorter than maximum head length (mandibles included). Propodeal suture dorsally poorly impressed in some specimens. Basal face of the propodeum gently declivous posteriorly. Area between basal and declivous faces of the propodeum superficially concave and separated laterally by a small denticle. Declivoirs face of the propodeum flat and with superficially marginate sides. Propodeal lobes subround. Propodeal spiracle round and above the mid height in lateral view.

Petiole about as long as broad, convex in side view and with the sides diverging on the anterior fourth and convex posteriorly in dorsal view. Anterior border of the petiole concave and carinate, the carina forming a denticle on each side. Ventral process of the petiole lamelliform, truncate anteriorly and pointed posteriorly. Postpetiole anteriorly broader than the petiole; its sides diverging or gently convex. Postpetiolar sternite anteromedially with a marked subtriangular projection. Posterior half of the postpetiolar sternite strongly convex. Constriction between postpetiole and fist gastral segment impressed. Gastral tergite I strongly convex on the curvature. Remaining gastral tergites and sternites curved ventrally.

Legs slender but not very elongate. All tibiae with a pectinate spur. Spurs of fore legs with basal spine. Fore basitarsi longer than the mid ones. Hind basitarsi about 1/5 shorter than hind tibiae. Second tarsomere of hind leg about 1/5 longer than the pretarsus. Pretarsal claws simple. Arolia large.

Sculpture. Head rugosopunctate. Mesosoma granulopunctate. Petiole and postpetiole granulate. Gaster superficially shining and covered by piligerous impressions. Legs punctate.

Pilosity. Body covered by hairs of three main types: (1) short, dense, subdecumbent on the whole body, sparse and suberect on the funicular joints, absent on the funiculi; (2) longer than type (1), sparse and suberect on the whole body; (3) shorter than hair type (1), dense and decumbent on the funicular joints only. In addition the funicular joints bear whitish, thick, appressed, short, sparse hairs, and the scapes with sparse hairs shorter than hair type (2).

Colour yellowish to light brown.

Measurements in mm and Indices: TL 3.30-4.15; HL 0.76-0.91; HW 0.69-0.82; EL 0.03-0.05; SL 0.53-0.69; WL 0.93-1.15; PeL 0.28-0.37; PeW 0.29-0.35; HFeL 0.58-0.73; HTiL 0.51-0.67; HBaL 0.40-0.56; LS4 0.30-0.45; LT4 0.68-1.01; CI 88.6-91 .O; SI 69.2-74.4; IGR 0.42-0.44.

Queen
Baroni Urbani and de Andrade (2003) - Differing from the worker in the following details: eyes large, about 1/4 of the head length and with well defined ommatidia. Ocular pilosity present. Ocelli developed. Mesosoma robust. Scutellum large, slightly longer than the length of the basal face of the propodeum; its sides gently converging into a convex posterior border. Metanotum with or without traces of a minute denticle. Spiniform ventral process of the petiole longer.

Fore wings of our type 2, hind wings of our type 1 as defined in the description of the genus.

Measurements in mm and Indices: TL 4.37-4.64; HL 0.87-0.90; HW 0.79-0.83; EL 0.21-0.22; SL 0.61-0.64; WL 1.24-1.30; PeL 0.37-0.38; PeW 0.36-0.38; HFeL 0.78; HTiL 0.67; HBaL 0.52-0.53; LS4 0.45-0.50; LT4 1.08-1.16; GI 91.0-92.2; SI 70.1-71.1; IGR 0.42-0.43.

Male
Baroni Urbani and de Andrade (2003) - Head slightly broader than long. Vertex in full face view convex. Vertexal margin carinate. Clypeus subround or triangular; its dorso-median part with a superficial longitudinal carina. Frontal carinae thin, low, parallel or slightly diverging posteriorly. Frontal area with a sulcus. Ocelli large. Compound eyes large and placed mostly on the anterior part of the head sides. Scapes reaching the vertexal margin. First funicular joint about 1/4 longer than broad, thicker and about 1/4 shorter than second joint. Joints 2-11 longer than broad. Last funicular joint as long as the sum of joints 10-11. Mandibles with a minute, median denticle before a pointed apical tooth. Palp formula 4,3.

Mesosoma robust. Pronotum and anterior third of mesonotum almost perpendicular to the posterior two thirds of the mesonotum. Posterior two thirds of mesonotum almost flat. Parapsidal furrows marked. Scutellum about as high as the mesonotum; posterior border of scutellum round. Basal face of the propodeum declivous posteriorly. Sides of the basal face of the propodeum gently converging posteriorly. Sides between basal and declivous face of the propodeum subangulate. Declivous face of propodeum flat. Metanotum with a median, minute, carinate denticle. Propodeal lobes round. Propodeal spiracles small.

Petiole about as long as broad, declivous in the anterior third and convex in the two posterior thirds in profile. Sides of the petiole in dorsal view subparallel in the anterior third and convex posteriorly. Anterior border of the petiole concave, carinate and laterally angulate. Subpetiolar process as in the worker. Postpetiole anteriorly broader than the petiole; postpetiolar sides diverging posteriorly or gently convex. Anterior border of the postpetiolar sternite with a superficial triangular "lip". Posterior half of the postpetiolar sternite gently convex. Gastral tergite 1 slightly round. Gastral sternite I large. Remaining gastral tergites and sternites slightly curved ventrally. Legs slender and elongate. Spurs of fore legs with a basal spine. Fore basitarsi as long as the mid ones. Hind basitarsi about 1/7 shorter than hind tibiae. Second tarsomere of hind legs 1/5 longer than the pretarsus. Pretarsal claws simple. Arolia present.

Fore wings of our type 2, hind wings of our type 1 as defined in the description of the genus.

Sculpture. Head, mesosoma, petiole and postpetiole minutely granulopunctate, the punctation less marked and sparser on the postpetiole. In addition thin, irregular rugosities may be present on the head, scutellum, propodeum and metapleurae. Gaster smooth and with sparse, minute piligerous impressions. Legs superficially smooth and minutely punctate.

Pilosity similar to the one of the worker.

Colour. Black with lighter antennae and legs.

Measurements in mm and Indices: TL 3.53-4.00; HL 0.61-0.67; HW 0.66-0.72; EL 0.29-0.30; SL 0.47-0.52; WL 1.22-1.36; PeL 0.3 1-0.33; PeW 0.32-0.33; HFeL 0.68-0.79; HTiL 0.65-0.70; HBaL 0.55-0.60; LS4 0.50-0.60; LT4 0.81-0.97; CI 107.5 -108.2; SI 77.0-77.6; IGR 0.62.

Type Material
Baroni Urbani and de Andrade (2003):

Worker, gyne and male. Type locality: Carolina (probably a labelling error, see Brown, 1958a). Type material a worker and a gyne (syntypes) labeled: "Carolina, Proceratium melinum Rog., Type, melina Roger, Zool. Mus. Berlin" in ZMBC, examined.

Sysphingta (sic) europaea Type locality: Greece. Type material: holotype worker labelled "Albanien, Avlona, v Oertzen., 88, Sysphincta, P. europaeum, Forel, Typus" in, examined.

Sysphincta europaea rossica Type locality: Don steppe, Russia. Type material: not available for the piesent study.

Sysphincta fialai Type locality: Mohelno Reserve, Czech Republic. Type material: not available for the present study.