(3 major workers, 5 minor workers (CASENT0906368)) same data as the neotype; 6 major workers, 6 minor workers, SAUDI ARABIA, Wadi Bagara, 10.xi.2012, 18.79287°N, 42.01857°E, 436m, by leaf litter sifting (M. R. Sharaf leg.); 1 major worker, 9 minor workers, SAUDI ARABIA, Wadi Aljora, near Abadan, 12.xi.2012, 17.29263°N, 43.07010°E, 465 m, by leaf litter sifting (M. R. Sharaf leg.); 12 minor workers, SAUDI ARABIA, Fayfa, Agriculture Research Station, 6.iv.2013, 17.28671°N, 43.14390°E, 879m, (M. R. Sharaf leg.); 5 minor workers, SAUDI ARABIA, Fayfa, Agriculture Research Station, 5.iv.2013, 17.28671°N, 43.14390°E, 879m, (M. R. Sharaf leg.) [KSMA]; 1 major worker, SAUDI ARABIA, Al Bahah, Al Mukhwah, Zei Ein Archaeological Village, 19.9294°N, 41.4417°E, 741 m., 15.v.2011, (M. R. Sharaf Leg.); 1 major worker, SAUDI ARABIA, Al Bahah, Al Mukhwah, Dhi Ain Archaeological Village, 19.928°N, 41.4419°E ±50 m, 735 m., (B. L. Fisher Leg.), 23.ix.2011, Coll. Code BLF27577 [CASC].

Neotype major worker. TL 2.45, HL 0.71, HW 0.52, SL 0.26, ML 0.59, PRW 0.35, PL 0.15, PW 0.17, PPL 0.12, PPW 0.21, SI 50, CI 73.

Major workers. TL 1.77-2.76, HL 0.56-0.72, HW 0.44-0.52, SL 0.22-0.28, ML 0.49-0.63, PRW 0.29-0.35, PL 0.12-0.19, PW 0.12-0.17, PPL 0.11-0.18, PPW 0.14-0.25, SI 48-64, CI 69-80 (N=10).

Holotype major worker: TL 2.53, HL 0.75, HW 0.36, SL 0.63 (Collingwood and van Harten 2001) [Presumably lost]. (In the original description, the HW and SL for major are given wrongly as 0.36 and 0.63 respectively, from the illustration they would be ca. HW 0.55 and SL 0.30).

Major worker. (Figs 1–3) Headrectangular (HL ~ 1.38 × HW) with strongly concave posterior margin and straight parallel sides; mandibles smooth and shining; masticatory margin armed with five teeth; eyes with a single oval ommatidium; anterior clypeal margin shallowly concave; antennae ten segmented with a two segmented club; scapes very short (mean SI = 54); posterior margin of head transversally carinate and posterior corners with a pair of outgrowths, appearing as blunt teeth in lateral view. Promesonotum strongly convex; metanotal area with apparent vestigial wing bases; metanotal groove deep; propodeal spines blunt, short and broadly based; petiole distinctly broader than long in dorsal view. Postpetiole clearly broader than long and broader than petiole in dorsal view. Gaster smooth and shining. Sculpture: cephalic dorsum and area in front of eyes finely densely regularly longitudinally rugulose; the ground-sculpture a fine, dense, conspicuous granulation; lateral cephalic dorsum from the posterior margin of eyes to posterior margin of head faintly and densely granulate; promesonotum smooth and shining; anepisternum smooth and shining; katepisternum and propodeum densely, transversely and conspicuously reticulate-punctate; petiole densely irregularly reticulate; postpetiole dorsum smooth and shining. Pilosity: head hairs long and sparse; petiole with two pairs of long backward directed hairs; postpetiole with three pairs of long hairs; gaster with few scattered long suberect hairs and abundant subdecumbent short hairs. Colour:concolorous brownish.

Minor workers. TL 0.99–1.13, HL 0.35–0.41, HW 0.29–0.32, SL 0.21–0.28, ML 0.31–0.34, PRW 0.17–0.19, PL 0.08–0.12, PW 0.07–0.08, PPL 0.05–0.07, PPW 0.08–09, SI 69–88, CI 74–89 (N=7).

Minor worker. (Figs 4–6) Head distinctly longer than broad (CI 74-89), with clearly convex sides and straight posterior margin; mandibles smooth and shining with relatively long yellow hairs and armed with four teeth; median portion of clypeus flat; in anterolateral view, clypeal lateral carinae strongly narrowed posteriorly between frontal lobes, then continued as a frontal triangle; eyes minute, with a single ommatidium; antennae ten segmented with a two segmented club; scapes broaden evenly from about mid-length and fail to reach head posterior margin by about one-third of the head length. Mesosoma in lateral view feebly convex; metanotal groove shallow but distinct, dorsally and laterally; propodeum obliquely angled; propodeal spiracle relatively large, circular, high and close to propodeal declivity; metapleural gland orifice prominent. Petiole longer than broad in dorsal view with short peduncle. Node of postpetiolelower than petiole and dorsally clearly convex and nearly as long as broad. Sculpture: Anterolateral sides of head very finely longitudinally striated; lower half of mesopleura, metapleura, petiole and postpetiole with areolate-rugose sculpture. Pilosity: appressed, cephalic dorsum with abundant scattered hair pits, few and short on mesosoma, petiole, postpetiole, and rare on first gastral tergite, underside of head with few short straight hairs. Clypeus with two pairs of standing hairs, central pair long and lateral pair shorter. Colour: Overall unicolorous yellow, smooth and shining.

A recent search conducted by the senior author and Tony Hunter (Curator of Entomology, WMLC) failed to locate any original type material of Carebara arabica at the cited depository (Collingwood and van Harten 2001). Identification of this species has been difficult for non-specialists due to the brief original description and illustrations not indicating important diagnostic characters. Due to the apparent loss of all type material and the brief description, a Neotype from southwestern KSA is designated above for Carebara arabica.

Following the definition of Fernández (2004), Carebara arabica belongs to the Carebara concinna species complex that can be recognized by the following combination of characters: the minor workers are very small; the majors with massive heads; antennae nine to eleven-segmented, with a two segmented club; mandibles armed with four or five teeth; eyes present but reduced in both minor and major workers; metanotal groove distinct; propodeum armed with triangular teeth or denticles.

Carebara arabica was found in Fayfa, KSA nesting in leaf litter among Azadirachta indica A. Juss. (Meliaceae), Artocarpus heterophyllus Lam (Moraceae), and Rosadamascena Mill. (Rosaceae) trees and coexisting with an unidentified termite species. The other nest series from Wadi Bagara was found nesting in loose soil under roots of a Poaceae and near Acacia and Giant Milkweed, Calotropis procera (Aiton) (Asclepiadaceae). Other ants’ associates included Paratrechina jaegerskioeldi (Mayr, 1904); Tapinoma melanocephalum F., 1793, and Cardiocondyla sp. An interesting observation concerning a nest series from Zei Ein Archaeological Village included major workers, an uncommon phenomenon as compared to other nests found in Wadi Khat, Wadi Bagara, Wadi Aljora, and Fayfa. Two major workers were collected by digging in soil. Numerous minor workers were observed foraging above ground and exiting and entering tiny nest entrances in compacted humid clay soil. No major workers were observed foraging above ground.

Holotype major worker. SAUDI ARABIA, Al Qatif, El Naft, Eastern Province, 26.51028°N, 49.96889°E, 30 m. 23.iii.2012 (M. R. Sharaf Leg.) (MRS0066); King Saud University Museum of Arthropods (KSMA), College of Food and Agriculture Sciences, King Saud University, Riyadh, KSA.

Paratypes. 28 minor workers (CASENT0280994), 16 major workers (CASENT0280975), 4 queens (CASENT0906362) with same locality and data as the holotype (KSMA); a single paratype specimen of minor and major workers, and queen are deposited in MHNG; NHMB; CASC; MCZC; SEMC; WMLC; BMNH; 2 minor workers, SAUDI ARABIA, Riyadh, Alhaeir, 24.59214°N, 46.74522°E, 24.iii.2009, lemon soil, Berlese funnel (Acarology lab team at Department of Plant Protection, KSU Leg.); 4 minor workers, SAUDI ARABIA, Riyadh, iii.1989, Soil fauna (no collector data); 2 minor workers, SAUDI ARABIA, N. Riyadh, Ammaryia, 5.iii.2010, 24.806402°N, 46.428845°E, 681m, Lettuce soil fauna, Berlese funnel (Acarology lab team at Department of Plant Protection, KSU Leg.) These paratypes are in KSMA; 1 minor worker, SAUDI ARABIA, Riyadh, Mezahmia, Rawdat Kharara, 24.38931°N, 46.24211°E, 712 m. 30.i.2011, (M. R. Sharaf Leg.) (CASC); 1 minor worker, SAUDI ARABIA, Riyadh, Al Rowayda, 25.88016°N, 45.11563°E, 22.ii.2009, (M. R. Sharaf Leg.) (CASC) (All are paratypes).

Holotype major worker. TL 3.62, HL 1.10, HW 0.72, SL 0.37, EL 0.05, ML 0.87, PRW 0.50, PL0.20, PW 0.25, PPL 0.20, PPW 0.27, SI 51, CI 65.

Paratype major workers. TL 3.27–5.00, HL 1.00–1.20, HW 0.72–0.87, SL 0.32–0.42, EL 0.05, ML0.85–1.12, PRW 0.50–0.60, PL 0.20–0.27, PW 0.22–0.30, PPL 0.20–0.27, PPW 0.27–0.40, SI 38–53, CI 65–78 (N=15).

Major worker. (Figs 7–9) Head longer than broad (HL = 1.5 × HW), with feebly concave posterior margin, rounded posterior corners and parallel sides; masticatory margin of mandibles armed with four teeth; antennae nine-segmented; antennal scapes very short; clypeus narrow and with weakly concave anterior margin; eyes very tiny (in some individuals eyes absent); ocelli absent. Mesosoma in profile with distinct promesonotal suture; promesonotum feebly concave; metanotum small and narrow; dorsal face of propodeum continuously sloping and curving into declivity without spine or angle. Petiole in dorsal view little broader than long; petiolar peduncle short; petiolar ventral process distinct. Postpetiole in dorsal view nearly twice as broad as long, with acute lateral angles. Postpetiole in profile with distinct ventral process. Sculpture: Body smooth and glossy, anterior part of head finely, longitudinally rugulose, area between meso- and metapleura finely cross-ribbed. Pilosity: Head dorsum with scattered short hairs, rest of body with longer dense, yellow hairs. Colour:Bicolored species, head and mesosoma brownish, petiole and postpetiole brownish yellow, antennae, legs and gaster clear yellow.

Paratype minor workers. TL 1.66–1.94, HL 0.44–0.51, HW 0.29–0.44, SL 0.25–0.31, EL 0.007, ML0.49–0.53, PRW 0.22–0.31, PL 0.09–0.17, PW 0.09–0.14, PPL 0.07–0.09, PPW 0.09–0.12, SI 59–79, CI 78–100 (N=15).

Minor worker. (Figs 10–12) Head distinctly longer than broad, with straight posterior margin and parallel sides; masticatory margin of mandibles armed with four teeth; antennae nine-segmented; scapes when laid back from their insertions fail to reach posterior margin of head by about one third of head width; anterior clypeal margin nearly straight; eyes with only one ommatidium (absent in some individuals). Mesosoma nearly flat in profile; promesonotal suture indistinct; metanotal groove distinct; propodeal dorsum meeting declivity in a continuous curve; propodeal spiracle in profile high and located above midline of propodeum. Petiole in profile shortly pedunculate, with blunt ventral process and in dorsal view slightly longer than broad. Node of postpetiole in dorsal view clearly broader than long and in profile distinctly lower than petiolar node. Colour:Unicolorous clear yellow, hairy, smooth and moderately shining.

Paratype queens. TL 9.75–10.75, HL 1.10–1.35, HW 1.45–1.50, SL 0.60–0.90, EL 0.35-0.45, ML3.25–3.50, PL 0.50–0.75, PW 0.65–0.70, PPL 0.50–0.60, PPW 0.85–1.00, SI 40–62, CI 107–136 (N=3).

Queen. (Figs 13–15) Body enormous, notably larger than minor and major workers. Head triangular, broader than long (HW = 1.2 × HL), with straight posterior margin and strongly convex lateral margins; masticatory margin of mandibles armed with four teeth; antennae nine-segmented; antennal scapes when laid back from their insertions reach level of posterior margin of eyes; anterior clypeal margin convex, eyes large and multifaceted (about 0.27 × HW); ocelli present. Mesosoma robust, pronotum not exposed above, lying entirely beneath the mesonotum; propodeum unarmed; remaining characters modified as in myrmicine queens. Petiole in dorsal view longer than broad. Postpetiole very broadly attached to gaster and node in dorsal view distinctly broader than long. Sculpture: Anterior half of cephalic dorsum with fine longitudinal striations extend to before posterior level of eyes; median portion of clypeus, posterior half of head, mesosoma and gaster smooth and shining, petiole and postpetiole superficially and finely shagreenate. Pilosity: Whole body covered with abundant, long, yellow hairs. Colour: Uniformly black, funiculi, tibiae and tarsi blackish brown.

Male. Not known.

This new species is the second member of the genus recorded from the Arabian Peninsula. According to Fernández (2004), Carebara fayrouzae belongs to Carebara lignata species complex with nine antennal segments and unarmed propodeum. It does not resemble any of the American species (Fernández, pers. comm.), or Madagascar species (Azorsa, pers. comm.) and majors are easily distinguished from Carebara arabica of the Carebara concinna group, by the nine segmented antennae, the absence of cephalic posterolateral teeth and the smooth and shining cephalic dorsum. Superficially, Carebara fayrouzae resembles Carebara afghana (Pisarski, 1970) from Afghanistan in regard to the smooth and shining habitus and the absence of cephalic posterolateral teeth. Carebara fayrouzae can be easily distinguished by the bicoloured major workers, the nine-segmented antennae and the node of postpetiole which is broader than petiolar node in dorsal view. In Carebara afghana, major workers are concolorous yellow, antennae ten-segmented and node of postpetiole as broad as petiolar node in dorsal view.

This new species was found nesting in leaf litter under a large almond tree, Prunus amygdalus Batsch (Rosaceae) in a fenced area of a farm. The soil was composed of two layers, a thin upper clay layer organically enriched where most specimens were found foraging, and a lower thicker layer of loose sand where few specimens were found. Two beetle species were found coexisting with the ants, Oryzaephilus surinamensis (Silvanidae) and Cryptophagus acutangulus (Cryptophagidae).

This new species is dedicated to Fayrouz Sharaf (the daughter of the senior author).