Monomorium exiguum Forel, 1894

Sharaf, Mostafa R., Wetterer, James K., Mohamed, Amr A. & Aldawood, Abdulrahman S., 2022, Faunal composition, diversity, and distribution of ants (Hymenoptera: Formicidae) of Dhofar Governorate, Oman, with updated list of the Omani species and remarks on zoogeography, European Journal of Taxonomy 838 (1), pp. 1-106 : 61-64

Monomorium exiguum Forel, 1894

Fig. 39

Monomorium exiguum Forel, 1894: 85 (w) Ethiopia. Afrotropic.

Diagnosis

Color varies from clear yellow to uniform dark brown, usually with a pair of brown patches on first gastral tergite; metanotal groove sharply impressed; propodeal dorsum and declivity meeting in a rounded convexity; body smooth and shining, except for metanotal cross-ribs on sides of metanotal groove.

Material examined

Lectotype ETHIOPIA • Shoa , 3; CASENT0101870; MHNG.

Paralectotype ETHIOPIA • same collection data as for lectotype; CASENT0101853; MHNG .

OMAN – Dhofar • 1 w; Ayn Dirbat ; 17.106° N, 54.453° E; alt. 207 m; 17 Nov. 2017; SF; M.R. Sharaf leg.; KSMA .

Ecological and biological notes

Monomorium exiguum is the most widely distributed species of the M. monomorium species group of the Arabian Peninsula. It has a remarkable ability to inhabit most types of environments including natural and urban sites, native and established agricultural areas, and nests in leaf litter, in sandy and clay soils, or under rocks and bark ( Sharaf et al. 2018a, 2018b). This diversity of habitats could reflect the occurrence of several cryptic species currently listed under one name.

Geographic range

This species was originally described from Ethiopia and is widely distributed in several zoogeographical regions including the Palearctic ( Sharaf et al. 2018b), the Afrotropical ( Bolton 1987; Sharaf et al. 2017c), the Malagasy Region ( Heterick 2006), and the Mediterranean Basin ( Gòmez & Espadaler 2006; Sharaf 2006). For details of geographical distribution see Sharaf et al. (2018b). Bolton (1987) commented on the variability in color, “from clear yellow to dark brown”, and felt the name as then understood concealed more than one valid species. Heterick (2006) sought to clarify the situation by defining forms of varying color by defining lectotypes of earlier varietal names and synonymizing those names under M. exiguum . Our collection represents a new record for Dhofar.

Figures

Fig. 39. Monomorium exiguum Forel, 1894, worker (CASENT0922878, AntWeb.org (Michele Esposito)). A. Body in profile. B. Head in full-face view. C. Distribution map.