Plagiolepis abyssinica

Nests in partially rotting wood.

Identification
Collingwood’s (1985) decision to elevate this taxon to species rank is confirmed here. P. abyssinica was originally described as a subspecies of Plagiolepis exigua but differs on a number of points. For P. abyssinica, the body color is brownish and the antennal scapes surpass the posterior margin of the head, whereas in P. exigua the color is yellowish and the antennal scapes do not reach posterior margin. Moreover, the eyes in P. abyssinica are consistently larger (EL 0.24 X HW) with 9 ommatidia in the longest row and exigua is smaller (EL 0.19 X HW), with only 6 ommatidia in the longest row. P. exigua as described by Forel (1894) had a smooth, shiny appearance but with sparse punctations on the head and gaster, P. abyssinica has no obvious punctuation.

Distribution based on Regional Taxon Lists
Afrotropical Region: Eritrea, Saudi Arabia. Palaearctic Region: Ethiopia.

Biology
Taken in a roadside tree, nesting in partially rotting wood.

Castes
Queens and males are unknown.

Nomenclature

 *  abyssinica. Plagiolepis exigua r. abyssinica Forel, 1894b: 73 (w.) ETHIOPIA. Raised to species: Collingwood, 1985: 297. See also: Sharaf, Aldawood & Taylor, 2011: 204.

Description
Redescription of worker.— TL 1.20, HL 0.30, HW 0.30, SL 0.29, EL 0.07, PRW 0.18, ML 0.30, CI 97, SI 100.

Collingwood (1985) gave a typical worker from Fayfa, Saudi Arabia, as: TL 1.25, HL 0.35, HW 0.28, CI 80, SI 100, EL 0.05 (0.18 X HW) Body blackish brown, femora yellowish brown, antennae, clypeus and mandibles yellowish, smooth and shining. Head nearly as long as broad with clearly convex sides. Occiput distinctly concave with rounded corners. Head dorsum with scattered short yellow pubescence. Eyes relatively large, 0.24 X HW, with 9 ommatidia in the longest row and occupying less than one quarter of head sides. Antennal scape just surpassing the posterior margin of head. Clypeus and mandibles with relatively abundant long yellow hairs. Area in front of eyes with several pairs of long hairs. Mesosoma and gaster with relatively abundant pubescence. Erect pilosity of gastral tergites long and situated on the posterior margins.

Additional References

 * [[Media:Collingwood 1985.pdf|Collingwood, C. A. 1985. Hymenoptera: Fam. Formicidae of Saudi Arabia. Fauna Saudi Arab. 7: 230-302]]


 * [[Media:Forel 1894b.pdf|Forel, A. 1894b. Abessinische und andere afrikanische Ameisen, gesammelt von Herrn Ingenieur Alfred Ilg, von Herrn Dr. Liengme, von Herrn Pfarrer Missionar P. Berthoud, Herrn Dr. Arth. Müller etc. Mitt. Schweiz. Entomol. Ges. 9: 64-100]]


 * [[Media:Sharaf 2011.pdf| Sharaf, M., Aldawood, A. and Taylor, B. 2011 The formicine ant genus Plagiolepis Mayr (Hymenoptera: Formicidae) in the Arabian Peninsula, with description of two new species. Transactions of the American Entomological Society, Vol 137:(1+2) 203-215.]]