Nesomyrmex latinodis (Mayr) - revived status

Type location Mozambique (Leptothoax latinodis, Mayr, 1895: 130, worker); possible junior synonym concolor (Leptothorax angulatus var. concolor nov., Santschi, 1914b: 107, illustrated, worker) from Kenya; 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 sshape of head, etc., as the type angulatus.

The photomontage is of a specimen from Tanzania, Mkomazi Game Reserve, 3°54.75' S 37°48.50' E, pkd collection from Combretum molle, 9.iv.1995, by G McGavin. Other images can be seen in the folder at -