Carebara arabica

Carebara arabica was found in Fayfa, KSA nesting in leaf litter among Azadirachta indica A. Juss. (Meliaceae), Artocarpus heterophyllus Lam (Moraceae), and Rosa damascena 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. It seems likely that C. arabica is a species of mountainous ecosystems of southwestern KSA and Republic of Yemen. (Sharaf and Aldwood 2013)

Identification
Sharaf and Aldwood (2013) - Following the definition of Fernández (2004), C. arabica belongs to the C. 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.

At present, two species of Carebara are now known from the Arabian Peninsula, C. arabica of the concinna species complex from the Republic of Yemen and KSA and C. fayrouzae sp. n. of the lignata species complex from KSA.

Major worker
 * Smaller species (TL 1.77–2.76); antennae 10-segmented; concolorous brownish, antennae and legs yellowish; posterior margin of head strongly concave and posterior corners with a pair of teeth or horns, appearing blunt in profile; cephalic dorsum dull, with fine, dense, regular and longitudinal rugulae; lateral margins of postpetiole in dorsal view rounded . . . . . Carebara arabica


 * Larger species (TL 3.27–5.00); antennae 9-segmented; bicolored, head and mesosoma brownish, petiole and postpetiole brownish yellow, antennae, legs and gaster clear yellowish; posterior margin of head feebly concave and posterior corners rounded, without teeth or horns; cephalic dorsum smooth and shining except anterior part of head finely, longitudinally rugulose; lateral margins of postpetiole distinctly angular in dorsal view . . . . . Carebara fayrouzae

Minor worker
 * Antennae 10-segmented; eyes minute, with a single ommatidium (present in all individuals); body pilosity subdecumbent or appressed and much scarce; anterolateral sides of head very finely longitudinally striated; lower halves of mesopleuron, metapleuron, petiole and postpetiole areolate-rugose; propodeal dorsum nearly half as long as propodeal declivity in profile. . . . . . Carebara arabica


 * Antennae 9-segmented; eyes as rudimentary ommatidium (absent in some individuals); body pilosity erect to suberect and dense; entire body smooth without any type of surface sculpture; propodeal dorsum as long as declivity, appearing as a continuous curve in profile . . . . . Carebara fayrouzae

Distribution based on Regional Taxon Lists
Afrotropical Region: Saudi Arabia, Yemen.

Nomenclature

 *  arabica. Oligomyrmex arabicus Collingwood & van Harten, 2001: 564, figs. 2-4 (s.w.) YEMEN. Combination in Carebara: new combination (unpublished). Senior synonym of arabica: Sharaf & Aldawood, 2013: 70.
 * abuhurayri. Carebara abuhurayri Sharaf & Aldawood, 2011: 63, figs. 1-12 (w.) SAUDI ARABIA. Junior synonym of arabica: Sharaf & Aldawood, 2013: 70.

Worker
Sharaf and Aldwood (2013) - Neotype major. 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. 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 Head rectangular (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.

Minors. 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 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 postpetiole lower 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.

Type Material


Sharaf and Aldwood (2013) - A recent search conducted by the senior author and Tony Hunter (Curator of Entomology, WMLC) failed to locate any original type material of C. 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 was designated for C. arabica.