Trichomyrmex chobauti (Emery, 1897)

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 : 14-16

Trichomyrmex chobauti (Emery, 1897)

Fig. 7 A–C

Holcomyrmex chobauti Emery, 1897: 418 , Fig. (worker). Algeria: Palearctic. Syntype worker (MSNG) (CASENT0904606) [examined].

Trichomyrmex faf Emery, 1922: 176 .

Holcomyrmex chobauti – Délye 1961: 69 (q., m.).

Monomorium chobauti – Emery 1908: 672.

Monomorium (Equestrimessor) chobauti – Santschi 1919: 92.

Trichomyrmex chobauti – Ward, Brady, Fisher & Schultz 2015: 16.

Trichomyrmex faf – Bolton 1987: 297.

Material examined

UNITED ARAB EMIRATES: 2 w, Nr. Mahafiz, 25.15˚ N, 55.8˚ E, 24 Mar. – 2 Apr. 2011, M. Hauser et al. leg. (United Arab Emirates 13055) (KSMA).

Previous records

UNITED ARAB EMIRATES: 1 w, Baynounah, 23.64˚ N, 53.62˚ E, Mar. 1995; 1 w, Medinat Zayed, 23.65˚ N, 53.65˚ E, Mar. 1995, Collingwood et al. leg. (WMLC).

Description

MEASUREMENTS. TL 3.27; HL 0.88; HW 0.88; SL 0.72; EL 0.16; ML 1.22; PW 0.45; PTL 0.28; PTW 0.30;

PPL 0.25; CI 100; El 18; SI 82.

HEAD. As long as broad, with feebly concave posterior margin and weakly convex sides; anterior clypeal margin distinctly concave; eyes of moderate size (EL 0.18 × HW) with 11 ommatidia in longest row; scapes when laid back from their insertions reach posterior margin of head.

MESOSOMA. Promesonotum convex in profile, running back to straight mesonotum; metanotal groove impressed; propodeal dorsum nearly twice as long as declivity in profile; propodeal spiracle circular, situated above midline of propodeum in profile.

PETIOLE. Petiolar node rounded in profile.

POSTPETIOLE. Node low and broad in profile.

PILOSITY. Underside of head with long ammochaete J-shaped hairs forming a distinct psammophore; cephalic dorsum with sparse suberect hairs directed inward to midline of head; antennae with dense appressed pubescence; anterior clypeal margin with abundant long curved hairs; pilosity on mesosoma restricted to two or three pairs of hairs on pronotum and promesonotum; sparse decumbent pubescence on mesonotal and propodeal dorsum; petiole and postpetiole bare; gastral tergites with sparse appressed pubescence, few longer pairs of hairs present at gastral apex.

SCULPTURE. Clypeus, mandibles, and cephalic surface between frontal carinae and in front of eyes longitudinally rugulose; promesonotum and mesonotum faintly longitudinally rugulose; propodeum and sides of mesonotum, petiole and postpetiole densely punctulate-reticulate, gaster smooth and shining.

COLOUR. Head, mesosoma, petiole and postpetiole reddish brown, gaster dark brown.

Differential diagnosis

Trichomyrmex chobauti is closest to almosayari sp. nov. and lameerei . All three species share the abundant long ammochaete J-shaped hairs that form a distinct psammophore on the underside of the head. Trichomyrmex chobauti can be readily separated from T. almosayari sp. nov. by the bicoloured body, the oval eyes, and the straight or feebly concave posterior margin of the head. From T. lameerei it can be distinguished by the smaller size, the longer antennal scapes that reach the posterior margin of the head, and the unsculptured posterior half of the head.

Distribution

Trichomyrmex chobauti was originally described from Algeria and recorded from the Middle East and from two countries of the Arabian Peninsula, Saudi Arabia and United Arab Emirates ( Collingwood & Agosti 1996; Collingwood et al. 2011).

Figures

Fig. 7. Trichomyrmex chobauti (Emery, 1897), syntype, worker (CASENT 0904606). A. Body in profile. B. Body in dorsal view. C. Head in full-face view (photos: Will Ericson).