Temnothorax arabicus Sharaf & Akbar & Al Dhafer & Aldawood 2017, sp. nov.

Temnothorax arabicus Sharaf & Akbar sp. nov.

urn:lsid:zoobank.org:act: CB6D46D1-BBFB-436A-B806-D5423765F053

Figs 1–3

The new species Temnothorax arabicus sp. nov. is named after the Arabian Peninsula.

Holotype worker

SAUDI ARABIA: Asir, Abha, Raydah, 18°12.315' N, 42°24.607' E, alt. 2761 m, 26 Jul. 2014, M.R. Sharaf leg. CASENT0746640 (KSMA).

Paratypes

SAUDI ARABIA: 1 w, same data as the holotype, 5 Mar. 2015, Al Dhafer et al. leg. (PT) (KSMA); 3 w, Al Bahah, Sahda Al Ala, 19°50.411' N, 41°18.686' E, alt. 1611 m, 29 Jul. 2015, Al Dhafer et al. leg. (PT) (KSMA, 1 in CASC); 1 w, Al Bahah, Shohba Forest, 20°2.723' N, 41°28.565' E, 14 May 2010, M.R. Sharaf leg. (KSMA); 1 w, Al Bahah, Sahda Al Ala, 19°50.329' N, 41°18.604' E, alt. 1563 m, 29 Jul. 2015, Al Dhafer et al. leg. (PT) (KSMA); 1 w, Al Bahah, Sahda Al Ala, 19°50.710' N, 41°18.267' E, alt. 1474 m, 29 Jul. 2015, Al Dhafer et al. leg. (PT), (KSMA); 2 w, Al Bahah, Sahda Al Ala, 19°50.411' N, 41°18.686' E, alt. 1611 m, 2 Mar. 2015, Al Dhafer et al. leg. (PT) (KSMA); 1 w, Wadi Shahdan, Jizan, 17°45.222' N, 42°71.516' E, alt. 200 m, 13 Nov. 2012, M.R. Sharaf leg. (CASENT0906493) (KSMA).

MEASUREMENTS. (Holotype in brackets) EL 0.17-(0.20); FRS 0.20-0.21; HFL 0.61-(0.62); HFW 0.11- (0.12); HL 0.63-(0.67); HW 0.50-(0.53); IOD 0.39-(0.42); OMD 0.14-(0.15); PPTL (0.14)-0.15; PPTH (0.15)-0.16; PPTW 0.21-(0.23); PTL (0.14)-0.15; PTH (0.20)-0.21; PTW 0.12-(0.13); SPST 0.21-(0.24); PW 0.35-(0.36); SL 0.49-(0.50); WL 0.74-(0.75); CI (79)-79; OI 34-(38); FI 122-(117); PI 34-(36); PSLI 33-(35); SI (75)-78 (n= 6).

HEAD. Longer than broad in frontal view (CI 79), lateral margins converge anteriorly and posteriorly; posterior margin weakly concave in middle; antenna 12-segmented; scapes large, clavate, when laid back from their insertions fail to reach posterior margin of head (SI 75–78); eyes prominent, situated about at midline on head sides (EL 0.17–0.20, IOD 0.39–0.42); median lobe of clypeus protruding forwards, with a weak submedian carinae; mandibles triangular, with masticatory margin armed with 4–5 prominent teeth. Mesosoma slender (WL 0.74–0.75); in profile, mesosoma forming almost a continuous arch; metanotal groove weakly impressed; humeri in dorsal view rounded; propodeal spines long and sharp with acute tips (PSLI 33–35), slightly longer than distance between their bases; metafemur much longer than wide in dorsal view (HFL 0.61–0.62, HFW 0.11–0.12). Petiole node highest anteriorly, with a slightly concave anterior face and flat dorsum, sloping downwards to the posterior face; subpetiolar process reduced. Postpetiole node rounded in profile and trapezoidal in dorsal view. Gaster ovate, smooth and shiny; basal half of first tergite slightly roughened, becoming increasingly shiny and weakly sculptured.

HEAD AND BODY. Uniformly pale brownish yellow to light brown, head and gaster slightly darker. Head, median lobe of clypeus and supraclypeal area, smooth and shiny; longitudinal rugae distinct over cephalic surface in full-face view; mesosoma weakly reticulate-rugolose. Petiole and postpetiole nodes dull and finely reticulate, without much rugae. Vertex, frons and frontal lobes with few erect hairs; clypeus with a single erect hair on each side of median lobe in addition to usual long curled hairs along anterior margin. Erect hairs also present throughout mesosoma; petiole and postpetiole with several erect hairs which are longer than mesosomal pilosity; all gastral tergites with scattered short, erect or suberect hairs.

The holotype and a single paratype specimen were collected in a pitfall trap set in the Asir Mountains. Other paratype specimens were collected by sifting soil from litter samples taken under a palm tree Hyphaene thebaica (L.) Mart. (Arecaceae) in the provinces of Jizan and Al Bahah in Saudi Arabia.

The new species is a member of the T. laurae (Prebus, 2015) species group of the Afrotropical Region. Among the poorly known species from the region, T. arabicus sp. nov. seems to have affinities with T. mpala Prebus, 2015 from Kenya. The two species can be easily differentiated through a combination of characteristics. T. arabicus sp. nov. = head longer than broad (CI 79), lateral margins strongly converge anteriorly and posteriorly, smaller propodeal Spine Index (PSLI 33–35), clypeus smooth and shiny without any prominent median or longitudinal rugae, cephalic dorsum with feeble longitudinal rugae and pilosity prominent; whereas T. mpala = head subrectangular, longer than broad (CI 72–76), lateral sides parallel, slightly converging towards the mandibular insertions, higher propodeal Spine Index (PSLI 25–27), clypeus with strongly developed median ruga and much more prominent longitudinal rugae, cephalic dorsum reticulate, and pilosity sparse.

The two species differ considerably in morphometrics as well (in T. arabicus sp. nov., PTL 0.14–0.15; PTH 0.20–0.21; PTW 0.12–0.13 compared with PTL 0.20–0.23; PTH 0.19–0.22; PTW 0.16–0.17 in T. mpala) and postpetiole (in T. arabicus sp. nov., PPTH 0.15–0.16; PPTL 0.14–0.15; PPTW 0.21–0.23 compared with PPTH 0.17–0.18; PPTL 0.12–0.15; PPTW 0.22–0.24 in T. mpala).