Monomorium elghazalyi Sharaf & Aldawood, 2017

Sharaf, Mostafa R., Fisher, Brian L., Collingwood, Cedric A. & Aldawood, Abdulrahman S., 2017, Ant fauna (Hymenoptera: Formicidae) of the Socotra Archipelago (Yemen): zoogeography, distribution and description of a new species, Journal of Natural History (J. Nat. Hist.) 51 (5 - 6), pp. 317-378 : 339-343

Monomorium elghazalyi Sharaf & Aldawood , sp. nov.

( Figure 13 (a–c))

Holotype worker

Yemen, Socotra Island, Haydibo , Erheno, 12.65023°N, 54.04016°E, 33 m, 19 April 2014, (M.R. Sharaf leg.) (CASENT0822346) ( KSMA).

Paratype workers

Yemen, Socotra Island, W. Sakhalof, 12.63311°N, 54.05632°E, 48 m, 27 April 2014, (M.R. Sharaf leg.), (3 w, KSMA); Yemen, Socotra Island, W. Ayhift, 12.61155°N, 53.97755°E, 198 m, 20 April 2014, (M.R. Sharaf leg.), (CASENT 0746626) (1 w, CASC); Yemen, Socotra Island, Haydibo, Erheno, 12.65023°N, 54.04016°E, 33 m, 19 April 2014, (M.R. Sharaf leg.) (14 w, KSMA) .

Description

Head. Head in full-face view longer than broad (CI 73–86) with shallowly convex sides and feebly concave posterior margin; anterior clypeal margin shallowly concave between a pair of low, broad, blunt teeth; clypeal carinae feebly developed, widely separated and subparallel; maximum diameter of eyes 0.19 × HW and with six ommatidia in the longest row; with head in full-face view the posterior margins of eyes at midlength of lateral sides; antennae 12-segmented; scapes, when laid back from their insertions, just reach posterior margin of head; masticatory margin of mandibles armed with four teeth. Mesosoma. Mesosoma in profile with promesonotum evenly convex and sloping abruptly posteriorly to the strongly and broadly impressed metanotal groove; propodeal dorsum in profile high and followed by long, shallow, convex curve which slopes posteriorly to propodeal declivity; propodeal spiracle small and pinhole-like, located at midline of the upper half of propodeum. Petiole. Petiolar node high and narrow in profile, cuneate, very narrowly rounded above; subpetiolar process absent. Postpetiole. Postpetiolar node lower than postpetiolar node in profile and nearly hexagonal in shape in dorsal view; postpetiolar dorsum in profile distinctly more broadly rounded than petiole. Pilosity. Cephalic dorsum with short scattered hair-pits; underside of head with two or three short hairs; anterior clypeal margin and mandibles with long hairs; antennae and legs with appressed pubescence; mesosoma without hairs (with no indication of abrasion in all specimens), only sparse appressed pubescence; petiole and postpetiole each with a single pair of hairs; gaster with several pairs of hairs. Sculpture. Overall smooth and glossy. Mesopleura, propodeum, petiole and postpetiole finely punctate. Colour. yellow, mesosomal dorsum, petiole, postpetiole and first gastral tergite whitish yellow.

Measurements of holotype worker

EL 0.08; HL 0.48; HW 0.41; ML 0.53; PH 0.14; PL 0.09; PPH 0.11; PPL 0.09; PPW 0.12; PRW 0.24; PW 0.09; SL 0.42; TL 1.88; CI 85; SI 102.

Measurements of paratype workers

EL 0.07–0.08; HL 0.48–0.53; HW 0.36–0.42; ML 0.46–0.59; PH 0.12–0.14; PL 0.08–0.14; PPH 0.09–0.12; PPL 0.07–0.11; PPW 0.09–0.12; PRW 0.21–0.26; PW 0.08–0.11; SL 0.38–0.44; TL 1.76–2.20; CI 73–86; SI 97–117 (n = 17).

Geographic range

Type locality: Socotra Island.

Differential diagnosis

This new species is a member of the Monomorium salomonis -group as defined by Bolton (1987), but will not key in Bolton’ s (1987) study of the Afrotropical Monomorium . It appears similar to Monomorium rotundatum Santschi, 1920 described from South Africa in colour and body size. Monomorium elghazalyi can be readily separated by the concave anterior clypeal margin, the longer antennal scapes (SI 97–117), the absence of erect hairs on mesosoma, the clearly convex promesonotum, the deeply and broadly impressed metanotal groove, the reticulate-punctate mesopleuron and propodeal dorsum. Whereas Monomorium rotundatum has a transverse, or shallowly convex anterior clypeal margin, a shorter antennal scape (SI 79–83), four or five pairs of hairs on the promesonotum, and a single pair on propodeum, a shallowly convex promesonotum profile, a weakly impressed metanotal groove, and a smooth unsculptured body.

Superficially, Monomorium elghazalyi also appears closest to Monomorium tumaire Collingwood & Agosti, 1996 from KSA but Monomorium elghazalyi can be recognized by the smaller eyes composed of six ommatidia in the longest row, the uniform yellow colour, and the lack of the ammochaeta psammophore. Monomorium elghazalyi is a distinctive member of the Arabian Monomorium fauna as it is the first unicolorous yellow species of the Monomorium salomonis -group known from the Arabian Peninsula.

Etymology

A patronymic ( Monomorium elghazalyi ) was chosen to honour the late Egyptian Islamic writer Mohammed Elghazaly (1917–1996).

Ecological and biological notes

The type series of the new species was found nesting in moist soil under a rock next to a date palm tree. The other nest series was collected from Wadi Sakhalof, where it was found foraging in very dry soil rich in decaying goat faeces under a date palm tree. It seems likely that the species may be endemic to Socotra.

Figures

Figure 13. Monomorium elghazalyi sp. nov., Paratype worker. (a) body in profile. (b) Head in full-face view, CASENT0746626, AntWeb.org, (Michele Esposito). (c) Distribution map.