The Ants of Africa
Genus Tetraponera
Tetraponera ambigua (Emery)

Tetraponera ambigua (Emery)

return to keyreturn to listIran list {link to the Hymenoptera Name Server} Type location South Africa (Sima ambigua n. sp., Emery, 1895h: 23, worker & queen; Forel, 1910f: 5, male; in Tetraponera, Wheeler, 1922: 796) collected at Hamman's Kraal - see below
subspecies rhodesiana (Sima ambigua em. r. Rhodesiana n. stirps, Forel, 1913a: 112, worker; Arnold, 1916: 187, queen) from Zimbabwe, Palm tree, collector G Arnold - see below
worker and queen described (see Bolton, 1995) .


Emery's (1895h) description is at {original description} - the comparison is with Tetraponera natalensis. Forel's (1910f) description of the male is at {original description}. Forel's (1913a) description of rhodesiana is at {original description}. Arnold (1916) gave translations of ambigua and rhodesiana, these are at {original description}. Ward's (2006: 123) re-interpretation of ambigua is at {original description}.


Notes

{Tetraponera ambigua}Ward states "mesonotum weakly convex and not separated from anterior margin of propodeum by prominently raised metanotal spiracles". Both Stitz (1917) in his drawing of occidentalis, and Santschi (1930b), in his description of angolensis have these spiracles as prominent.

Unfortunately, Ward did not indicate the source of the specimen shown in his drawing and his map shows many records that bear no relation to his list of material examined nor anything else in his report.

Tentatively, I have separated occidentalis (ambigua race erythraea var. occidentalis Stitz 1917: 336; Menozzi, 1934: 154, worker) from Algeria to subspecies of Tetraponera erythraea, as having a wider, oval postpetiole. Moreover, if occidentalis is a genuine subspecies of ambigua, the distribution in North Africa is strange; Menozzi (1934) wrote of the finding in southwest Algeria, plus his record of its collection in Libya (Cirenaica, by Professor L di Caporiacco) as being of the form typical of southern Africa.

Ward's drawing shows roughened patches on the lateral occipitum and prominent erect hairs on the sides of the head; these are not shown or mentioned by Santschi (1930) of angolensis. Santschi's description of angolensis has no roughened patches on the occipitum, no lateral erect hairs on the head, indeed very few erect hairs at all, a more rounded propodeum amd a lower petiole. It is distinctly smaller than the specimen in Ward's illustration, for which he gave no origin, and has the darkened posterior to the gaster mentioned by Santschi, plus the narrow frontal area shown by Santschi. There appear to be five distinct teeth on the mandible as opposed to four for Ward's ambigua (also in Arnold's note on rhodesiana). I feel justified in elevating angolensis to full species status - Tetraponera angolensis (Santschi).

As Ward states he examined syntype workers of angolensis and erythraea (but not occidentalis) I surmise that he followed the style of Bolton, in "lumping" the ancient "varieties, subspecies and stirps", mostly attributable to Forel and Santschi. The converse, however, is that, at least by Bolton, other species have been erected on quite small characteristics. My experience with a wide range of fresh material is that Santschi was remarkably accurate in separating his "stirps" but was influenced by his mentor, Forel, and so was reluctant to designate new species. Ward's text has the drawing labelled (South Africa) but it does not match the type worker shown below.  Comparision shows that it matches the type worker of T. erythraea, including the abundance of erect hairs on head and alitrunk dorsum.

April 2015 - the availability of type images shows neither ambigua nor rhodesiana to have more than sparse quite short erect hairs on the alitrunk dorsum or head; also quite distinct is the angularity of the transition form the propodeum dorsum to the declivity. Although I am leaving the Ward drawing here it is to show how it does not match the types below. Specimens from Mkomazi, Tanzania, that I have now are placed under erythraea.


Tetraponera ambiguaThe photomontage of the type worker is collated from http://www.antweb.org/specimen.do?name=casent0904033.


Tetraponera ambigua rhodesianaThe photomontage of the type worker of rhodesiana is collated from http://www.antweb.org/specimen.do?name=casent0907469.


Tetraponera ambigua maleThe photomontage of a possible male is collated from http://www.antweb.org/specimen.do?name=casent07703059. Seemingly not collected with workers.

Contents
2007, 2010, 2013, 2015, 2017, 2018 - Brian Taylor CBiol FRSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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