Trichomyrmex almosayari Sharaf & Aldawood

Mostafa R. Sharaf, Shehzad Salman, Hathal M. Al Dhafer, Shahid A. Akbar, Mahmoud S. Abdel-Dayem & Abdulrahman S. Aldawood, 2016, Taxonomy and distribution of the genus Trichomyrmex Mayr, 1865 (Hymenoptera: Formicidae) in the Arabian Peninsula, with the description of two new species, European Journal of Taxonomy 246, pp. 1-36 : 12-14

Trichomyrmex almosayari Sharaf & Aldawood sp. nov.

urn:lsid:zoobank.org:act:A1AA36BD-D206-46FB-A21D-FF26D7EB4609

Fig. 6 A–C

Etymology

The patronym almosayari has been selected to honor the late Egyptian Islamic writer Dr. Mohammed Sayed Almosayar (1948-2008).

Material examined

Holotype

SAUDI ARABIA: w, Riyadh Province, Rawdhat Khorim , 25.38˚ N, 47.27˚ E, alt. 574 m, 9 Jan. 2015, S. Salman leg. ( KSMA).

Paratypes

SAUDI ARABIA: 4 w, same data as holotype (KSMA); 1 w, same data as holotype (CASC); 3 w, same data as holotype (KSMA, 1 without gaster); 5 workers, Riyadh Province, Rawdhat Khorim, 25.38˚ N, 47.27˚ E, alt. 618 m, 2 Jun. 2013, S. Salman leg. (KSMA); 1 w, Riyadh Province, Al Zulfi, Rawdhat Al Sabalah, 26.36˚ N, 44.98˚ E, alt. 670 m, 25 Oct. 2015, Aldhafer et al. leg. (WMLC).

Description

MEASUREMENTS. Holotype. TL 2.60; HL 0.75; HW 0.67; SL 0.55; EL 0.20; ML 0.77; PW 0.40; PTL 0.22; PTW 0.12; PPL 0.15; PPW 0.17; CI 89; SI 82. Paratypes. TL 2.62–2.92; HL 0.70–0.75; HW 0.67–0.72; SL 0.52–0.60; EL 0.17–0.20; ML 0.75–0.80; PW 0.37–0.42; PTL 0.15–0.22; PTW 0.12; PPL 0.12–0.15; PPW 0.15–0.17; CI 93–96; EI 25–28; SI 74–90 (n = 5).

HEAD. Head short, only slightly longer than broad (CI 93–96), with feebly convex sides and emarginated posterior margin; anterior clypeal margin lacking teeth of any description; masticatory margin of mandibles armed with three teeth; eyes relatively large, with 12 ommatidia in the longest row (EL 0.25–0.27 × HW), reniform with ventral margin weakly but distinctly concave, dorsal margin distinctly broadly convex; scapes short, when laid back from their insertions failing to reach posterior margin of head (SI 74–90).

MESOSOMA. Promesonotum strongly convex, descending evenly to a much lower, shallowly but distinctly impressed metanotal groove; propodeal spiracles circular.

PILOSITY. Underside of head with crowded, long J-shaped ammochaete hairs forming a psammophore; two pairs of hairs on pronotum and mesonotum, propodeum bare, petiole and postpetiole each with one pair of long hairs, gaster with decumbent pubescence; cephalic pilosity shorter than body pilosity.

SCULPTURE. Mandibles longitudinally striolate; cephalic dorsum smooth and shining, except for scattered hair pits; area in front of eyes and behind posterior clypeal margin finely striolate; pronotal dorsum faintly shagreenate; mesosomal dorsum, sides, petiole and postpetiole finely and densely punctulate or shagreenate, general appearance dull; gaster smooth and polished.

COLOR. Dark brown to blackish brown; mandibles, antennae, and legs brownish.

Differential diagnosis

Trichomyrmex almosayari sp. nov. can be immediately separated from all known African and Arabian species of the genus by the reniform eyes, the ventral eye margin feebly concave and the dorsal eye margin distinctly broadly convex.

Ecological and biological notes

The new species was foraging on dry sandy soil ( Fig. 6 D) surrounding shrubs of Rhazya stricta Decnet (Apocynaceae) and coexisting with several other ant species, including Camponotus sericeus (Fabricius, 1798) , Cataglyphis semitonsa (Santschi, 1929) , Messor ebeninus (Santschi, 1927) , M. minor (André, 1883) , Monomorium venustum (Smith, 1858) , M. abeillei (Emery, 1881) , and T. mayri . Several additional attempts to collect more material at the type locality were not successful, indicating that the new species may be an uncommon taxon. The type locality, Rawdhat Khorim, is one of the most important natural protectorates in Saudi Arabia due to its diverse flora ( Al-Farraj et al. 1997, Alfarhan 2001). The region occupies an area of 24 km2, located about 95 km northeast of Riyadh (25.38˚ N, 47.28˚ E, alt. 560 m) ( Vesey-Fizberald 1957). The diversity of the flora in Rawdhat Khorim is relatively high, with about 153 plant species in 32 families recognized ( Alfarhan 2001).

Figures

Fig. 6. Trichomyrmex almosayari sp. nov., paratype, worker (CASENT 0914921). A. Body in profile. B. Body in dorsal view. C. Head in full-face view (photos: Michele Esposito). D. Type locality (photo: Shehzad Salman).