Nesomyrmex latinodis (Mayr) - revived status

Type location Mozambique (Leptothorax latinodis nov. spec., Mayr, 1895: 130, worker) Delagoa Bay, Dr Brauns - see below
possible junior synonym concolor (Leptothorax angulatus var. concolor nov., Santschi, 1914b: 107, illustrated, worker) from Kenya, Mombasa, 3.x.1912, Alluaud & Jeannel - see below
genus name change by Bolton (2003: 249) .

For reasons set out below, I prefer to revert to the original status determined by Mayr and remove it from synonymy under Nesomyrmex angulatus.

Mayr's (1895) description of latinodis is at . Arnold's (1916: 269) translation of latinodis is at . Santschi's (1914b) description of concolor is at . Bolton's modern description (1982) of angulatus is at

In his 1982 paper and his other revisionary works, Bolton adopted a curious approach to his analyses. There are instances where, when dealing with what he decided to describe as new species, relatively small characteristics were deemed significant. When dealing with the work of the early authors, notably Forel and Santschi, he commonly adopted the obverse tactic and wrote of variations in colour, size and morphology as not justifying separation of forms (subspecies, varieties, strips, etc) and made sometimes substantial synonymization of such forms.

In the instance of N. angulatus he took all specimens he examined from sub-Saharan Africa as meeting the characters of the type form from Egypt (noting that he had examined a lectotype worker from the original collection, Mayr, 1862). It seems curious that Bolton, who had not been able to sight latinodis should have ignored the simple fact that it was Mayr, an obviously very accurate and cautious worker, who described both species.

Nigerian specimen (Leptothorax species 1 in Taylor, 1979: 57). WORKER. TL 3.08 mm, HL 0.78, HW 0.62, SL 0.54, PW 0.50.
Colour golden-yellow, the apical segment of the antenna is dark. Dorsum of head and alitrunk faintly rugo-reticulose, rugae longitudinal; alitrunk laterally is punctate. No visible alitrunk sutures. Propodeum with acute pyramidal teeth.

Rare in Nigeria but collected at the Cocoa Research Institute of Nigeria, Idi Ayunre, foraging on cocoa and on a hedge (my finding was listed by Bolton, 1982). At Ogunmakin, near CRIN, it was found nesting in dead parts of a cocoa tree.

Assuming most if not all the sub-Saharan records are of N. latinodis - from Ghana, Bolton (1982) listed Legon (D. Leston), CRIG (B. Bolton; C.A. Collingwood) and Adeiso (P.M. Room; D. Leston). A single specimen was collected by Belshaw & Bolton (1994b) from leaf litter under cocoa at Bunso. I surmise this was Leptothorax species A, listed as found in five cocoa canopy samples by Room (1971).

East African populations

Here there does seem to be an overlap in forms as Santschi's concolor (1914b) from Kenya seems more like the North African forms. However, the specimens shown below from Tanzania are similar to those I drew in Nigeria. Santschi noted that Forel's ilgii (1894b) was consistently darker than the type form; ilgii seems from Forel's (1894b) description to have the same shape of head, etc., as the type angulatus.

The availability of type images of angulatus, concolor and ilgii from Antweb (June 2014) firm my opinion. Apart from the margination on the petiole in my drawing, there is an exact match between the concolor type and the Nigeria worker in both size and form. The Tanzania workers, however, clearly have the margination on the petiole.

The photomontage of the type worker is collated from http://www.antweb.org/specimen.do?name=casent0914925.

The photomontage of the type of concolor is collated from http://www.antweb.org/specimen.do?name=casent0908991.

Oxford University Museum specimens

Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 5-55	12.i.1997 Mkomazi 3°54.75' S 37°48.58' E	pkd collection from Acacia nilotica; 37M 0375378 UTM 9571003	1
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 5-63	13.i.1997 Mkomazi 3°54.75' S 37°48.58' E	pkd collection from Acacia nilotica; 37M 0375103 UTM 9570896	1
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 5-64	13.i.1997 Mkomazi 3°54.75' S 37°48.58' E	pkd collection from Acacia nilotica; 37M 0375103 UTM 9570896	1
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 3-66	16.i.1996 Mkomazi 3°57.996' S 37°48.128' E	pkd collection from Lannea schweinfurthii	1
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 3-67	16.i.1996 Mkomazi 3°57.996' S 37°48.128' E	pkd collection from Lannea schweinfurthii	1
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 2-18	8.iv.1995 Mkomazi 3°54.75' S 37°48.58' E	pkd collection from Combretum molle	4
Nesomyrmex latinodis B Taylor det.	Tanzania G McGavin tree 3-68	8.iv.1995 Mkomazi 3°54.75' S 37°48.58' E	pkd collection from Terminalia brownii	2
Nesomyrmex latinodis B Taylor det. Queen	Tanzania G McGavin tree 2-31	9.iv.1995 Mkomazi 3°54.75' S 37°48.50' E	pkd collection from Combretum molle	1

The photomontage is of a worker from Tanzania, Mkomazi Game Reserve, 9.iv.1995, by G McGavin (Tree 2/18). 

The photomontage is of a worker from Tanzania, Mkomazi Game Reserve; 9.iv.1995, by G McGavin (Tree 5/55). 

The photomontage is of a queen from Tanzania, Mkomazi Game Reserve, 9.iv.1995, by G McGavin (Tree 2/31).