Trichomyrmex oscaris (Forel)

Type location Ethiopia (Monomorium Oscaris n. spec., Forel, 1894b: 86, worker; most synonymy by Bolton, 1987: 327) Sudabessinien, Ilg - see below
junior synonyms
despecta (Monomorium destructor Jerdon subsp. kalahariensis Forel var. despecta n. var., Forel, 1910c: 252; Menozzi, 1931a: 154, worker; Forel, 1913b: 331, queen) from Eritrea, Ghinda - see http://www.antweb.org/specimenImages.do?code=casent0908751
dispar (Monomorium dispar n.sp., Emery, 1895h: 24, worker) from South Africa, Makapan - see below.
kalahariense (Monomorium destructor Jerdon subsp. kalahariense n. subsp., Forel, 1910f: 18) from Botswana, Kooa-Sekgoma - see http://www.antweb.org/specimenImages.do?code=casent0908750
prossae (Monomorium amblyops r prossae, Forel, 1916: 418; replacement name for bulawayense, Forel: 1914d: 247) from Zimbabwe - see below; also a male at http://www.antweb.org/specimenImages.do?code=casent0902180
solleri (Rhoptromyrmex Solleri n. sp.,  Forel, 1910e: 430, queen) from Senegal, Bissao, Soller - no images on Antweb (February 2015)
worker & queen known (see Bolton, 1995) .

Forel's (1894b) description is at . Emery's (1895h) description of dispar is at . Forel's (1910c) description of despecta is at . Forel's (1910c) description of solleri is at . Forel's (1910f) description of kalhariense is at . Forel's (1914d) description of prossae (as M. amblyops r bulawayense) is at . Arnold (1916: 235) gave a translation of dispar, this is at . Arnold (1916: 235) gave a translation of kalahariense, this is at . Arnold (1916: 235) gave a translation of prossae, this is at and . Bolton's modern description (1987: 326, illustrated pedicel dorsal view) is at

Note monophasic allometry: Worker TL 1.6-3.8 mm, HL 0.46-0.94, HW 0.36-0.84, SL 0.34-0.54, PW 0.24-0.52 (Bolton, 1987).

The findings listed by Bolton give no indication of arboreal habits and many are from drier locations - Bolton commented that oscaris is a widely distributed and versatile species ranging over most of the Afrotropical region outside the rainforest zone or within that zone in cleared areas; i.e. it is essentially a savannah species.

Bolton described how he found it in termitaria and nesting in the earth, but once finding a nest in an old rotting cocoa pod still attached to the tree and some distance above the ground (Bolton, 1987). Elsewhere from Nigeria, Bolton (1987) listed a finding at Mokwa (C. Longhurst).

From Ghana, Bolton (1987) examined specimens from Legon (D. Leston; G. Benson); Navrongo (P.M. Room) and Dawhwenya (C.A. Collingwood). These are all savannah locations. Separately, in a record not mentioned by Bolton, 6 workers were collected by pkd from the canopy of Amelonado cocoa at CRIG by Bigger (1981a), at a guess these are variant given below.

This leads to the puzzle of specimens collected in Nigeria, at CRIN (B. Bolton), found nesting in an old cocoa pod and also on open ground. In the CRIN collection they were labelled Syllophopsis species 1. Before now (2002), I felt they were clear members of the fossulatum-group, being the former afrotropical Syllophopsis (Bolton, 1987) and only the larger size distinguishes them from the brief description given by Bolton.

The photomontage is of the type (minor) worker collated from http://www.antweb.org/specimen.do?name=casent0908712
The size, TL 1.5 mm (which is as given by Forel, 1894b) and form show it to be a minor worker.

The photomontage is of a type worker of dispar collated from http://www.antweb.org/specimen.do?name=casent0904583.

The photomontage is of a type worker of prossae (bulawayensis) collated from http://www.antweb.org/specimen.do?name=casent0902208
Notes The size and general morphology suggest that this is a media worker (listed by Bolton 1987: 327).

Nigeria specimen (Syllophopsis species 1 in Taylor, 1980a: 45). WORKER. TL 2.74 mm, HL 0.78, HW 0.68, SL 0.50, PW 0.39; colour golden yellow. Sculpturation of very fine striations on the head; spiculation on lateral mesonotum and propodeum; fine transverse striations on dorsal and upper lateral propodeum. Erect hairs long and moderately abundant; pilosity short and sparse. In profile the propodeum has a flat dorsum rounded into a near vertical posterior face.

It seems either that one is dealing with a medium to large oscaris, or possibly, Trichomyrmex epinotale, as described by Santschi (1923e), which has a matching propodeal profile, position of eyes at one-third point of head, anterior striation on head, etc.

Nigeria specimen (Syllophopsis species 2 in Taylor, 1980a: 45). TL 1.68, HL 0.47, HW 0.37, SL 0.31, PW 0.26; colour golden yellow. Sculpturation of fine reticulo-striation on the lateral mesonotum; very faint transverse striations on the dorsal propodeum and similar but longitudinal striations on the posterior of the lateral propodeum. Erect hairs sparse and fairly coarse.

I found it ground nesting and foraging at CRIN (specimen in my voucher collection either missed by Bolton or not identifiable from his lists of findings).

Oxford University Museum specimens

Trichomyrmex oscaris B Taylor det.	Burkina Faso David King King 96	9.ii.2009 Ouagadougou 12.23.07° N 001.29.14° W	elev 293 m; vacant lot in residential area; nest in soil	7
Trichomyrmex oscaris B Taylor det.	Senegal Tambacounda B Ndiaye	9.v.2009 Dindifa 13°09'40" N 12°06'46" W	Dindifa 09-V-09 St 7 sur un arbre 213 m; Soudanian savannah, minor worker	1
Trichomyrmex oscaris B Taylor det.	Senegal Ferlo B Ndiaye	x.2010 Katané 15.48° N 14.08° W	Katané X 2010 T6P14/P10 Sahelian savannah, pitfall traps	3
Trichomyrmex oscaris B Taylor det.	Senegal Tambacounda B Ndiaye	14.v.2009 Kenieba 14°05'54" N 12°03'34" W	Sabodola 14-V-09 Kenieba St 11 P8F [A] 84 m; Soudanian savannah, pitfall traps (1 of 4 mounted)	1
Trichomyrmex oscaris B Taylor det.	Senegal Tambacounda B Ndiaye	5.v.2009 Tandiankunda 13°06'30"N 12°05'18" W	Tandiankunda 05-V-09 St 2 P6F Soudanian savannah, East Senegal, pitfall traps minor worker	1
Trichomyrmex oscaris B Taylor det.	Senegal Tambacounda B Ndiaye	14.viii.2009 Tandiankunda 13°06'30"N 12°05'18" W	Tandiankunda 14-VIII-09 avec termites Soudanian savannah, hand collection, on soil with termites	2
Trichomyrmex oscaris B Taylor det.	Senegal Lamine Diamé 65	08.iv.2012 Thiés 14°45'N 17°03'W	Sigelec (S. saiche) tube 04 two larger workers sp 3	2
Trichomyrmex oscaris B Taylor det.	Benin J-F Vayssieres RVA 2919	1.ix.2012 Korobourou 09°22'13'' N 02°40'16'' E	Mangifera indica orchard Quadrat  1, tube 1, variété: Kent Ground nesting Media worker	1
Trichomyrmex oscaris B Taylor det.	Benin J-F Vayssieres RVA 3013	9.xi.2012 Korobourou 09°22'13'' N 02°40'16'' E	Mangifera indica orchard Quadrat 1, série 1, variété Gouverneur; ground nesting Range of workers	3
Trichomyrmex oscaris B Taylor det.	Sudan J Mathews JM 093	25.x.2000 Kordofan 11°21' N 34°27' E	El Ain near El Obeid pyrethrum fogging of Acacia senegal	1
Trichomyrmex oscaris B Taylor det.	Sudan J Mathews JM 040	18.x.2000 Kordofan 11°21' N 34°27' E	El Ain near El Obeid pyrethrum fogging of Acacia senegal	3
Trichomyrmex oscaris B Taylor det.	Sudan J Mathews JM 394	20.x.2001 Blue Nile 11°21' N 34°27' E	Abu Gmein Canopy fogging of Acacia senegal	2

Photomontage of a major worker from Burkina Faso, Ouagadougou, collector David King (King 96).

Photomontage of a media 1 worker from Burkina Faso (as above).

Photomontage of a media 2 worker from Burkina Faso (as above).

Photomontage of a minima worker from Burkina Faso (as above).

The photomontage is of a worker from Sudan, Kordofan, El Ain, near El Obeid; collector J Mathews (JM 093)

The photomontage is of a minor worker from Sudan, collector J Mathews

The photomontage of a worker (media 2?) from South Africa is collated from http://www.antweb.org/specimen.do?name=casent0235926