Monomorium exiguum Forel, 1894

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 : 343-345

Monomorium exiguum Forel, 1894

( Figure 14 (a–c))

For full synonymy see Heterick (2006), pp.115–116.

Monomorium exiguum Forel, 1894: 85 . ( Lectotype worker) Ethiopia. Afrotropical. ‘Ethiopia, Sudabessinien. ’ ( MHNG), http://www.antweb.org/specimen/CASENT0101870 [Image of type specimen examined].

Monomorium baushare Collingwood & Agosti, 1996: 342 (w.) Oman. Palaearctic. (WMLC), http://www.antweb.org/specimen/CASENT0906343. Syntype worker [examined], Syn. nov.

Monomorium qarahe Collingwood & Agosti, 1996: 353 (w.) KSA. Afrotropical (WMLC), http://www.antweb.org/specimen/CASENT0906344. Syntype worker [examined], Syn. nov.

Diagnosis

Worker. Eyes small, with six ommatidia in the longest row; promesonotum convex in profile; metanotal groove impressed; pronotum with a single pair of erect hairs at the humeri. Colour uniform yellow to pale yellowish brown; posterior margin of first gastral tergite, lateral sides and remaining tergites, usually darker than disc of first tergite.

Material examined

Yemen, Socotra Island, Deyishil village , 21 April 2014, 180 m, (M. R. Sharaf leg.), 12.52010° N, 54.17438°E (2 w, KSMA); Yemen, Socotra Island, W. Jo’ o, 21 April 2014, 196 m, (M. R. Sharaf leg.), 12.54038°N, 54.17186°E (5 w, KSMA); Yemen, Socotra Island, W. Ayhift , 20 April 2014, 38 m, (M. R. Sharaf leg.), 12.61064°N, 53.97672°E (12 w, 1 q, KSMA); Yemen, Socotra Island, Lehanoh, 22 April 2014, 931 m, (M. R. Sharaf leg.), 12.57583°N, 54.04836°E (1 w, KSMA); Yemen, Socotra Island, W. Jo’ o, 21 April 2014, 196 m, (M. R. Sharaf leg.), 12.54038°N, 54.17186°E (1 w, CASC) .

Note

Collingwood and Agosti (1996) described Monomorium baushare from Oman and Yemen, and Monomorium qarahe from KSA based on the worker castes. Comparison of type material of both species with that of Monomorium exiguum indicates the above synonymy.

Geographic range

This minute species belongs to the Monomorium monomorium -group and has been recorded from numerous countries in the Afrotropical region including Ivory Coast, Nigeria, Cameroun, Gabon, Zaire, Ethiopia, Kenya and Zimbabwe ( Bolton 1987). In the Mediterranean region it has been reported from the Balearic Islands ( Gòmez and Espadaleer 2006) and Egypt ( Sharaf 2006). Monomorium exiguum was recorded from the Asir Mountains, KSA by Aldawood and Sharaf (2009). This species is a new record for Socotra.

Ecological and biological notes

This tiny yellow species was found nesting under a stone next to a large fig tree and inside the galleries of a termite nest. The soil was dry with ample dry seeds. Another nest series was found in leaf litter next to a date palm tree where the soil was rich in decaying organic material.

Figures

Figure 14. Monomorium exiguum. (a) Body in profile. (b) Head in full-face view, CASENT0906390, AntWeb.org, (Estella Ortega), KSA. (c) Distribution map from recent records.