Pheidole glabrella Fischer, Hita Garcia & Peters

Type location Cameroun (Fischer, Hita Garcia & Peters, 2012: 26, Figures 36-41); holotype (major worker) CAMEROON, Ebodije, 4.xi.91 (A. Dejean) (BMNH: CASENT0227950) - images not available on Antweb (November 2014).
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Paratypes: (2 major workers, 6 minor workers) same data as holotype (BMNH: CASENT0227951, CASENT0227952, CASENT0227953).
Diagnosis: Colour reddish brown to dark brown. Minor workers: head shape broadly rounded, with rounded to slightly compressed posterior head margin (CI 88–95). Scapes short to moderately long (SI 123–141) with appressed to decumbent pilosity. Promesonotum and parts of meso- and metapleuron smooth and shiny to superficially punctate, second mesonotal process usually shallow, spines relatively long and massive (PSLI 28–40). Pilosity on metatibia mostly appressed, standing hairs scarce to practically absent from dorsum of entire body, completely absent from alitrunk [mesosoma]. Major workers: head irregularly rugose-punctate, rugae of varying lengths, punctures weak to superficial with smooth areas between rugae. Scapes relatively short (SI 49–53), with appressed pilosity. Pronotum irregularly and transversely rugulose, declivity smooth and shiny. Metanotal groove broad, in profile view, dorsopropodeum anterior to propodeal spines shorter than horizontal width of base of spines. Metatibia pilosity fully appressed, standing hairs rare, absent from alitrunk.

Description of major worker: Some rugae on frons long and others short or interrupted, posterolateral lobes weakly and obliquely rugulose-punctate to smooth on corners or weakly reticulate. Sides of head laterally of antennal scrobe weakly rugose-reticulate or irregularly rugose, punctures weak to superficial and sometimes smooth areas present between sculpture. Scapes relatively short (SI:49–53), with appressed pilosity. Promesonotum in lateral view in some specimens short, dorsally nearly flat and posteriorly slightly compressed, with steep and long declivity, in other specimens longer and rounding into posterior declivity. Anteropronotum dorsally and laterally with irregularly distributed transverse rugulae, in between with weak to superficial punctures, grading to smooth and shiny promesonotal declivity dorsally and posteropronotum laterally. Humeral area laterally weakly processed and angulate, mesonotal process shallow to well-produced, dorsally smooth with oblique angle or right-angled and steeply declining. Second mesonotal process inconspicuous, at most visible as weak ridge, metanotal groove broad and shallow. Dorsopropodeum very short and in profile view anterior to propodeal spines significantly shorter than horizontal width of base of spines, weakly punctate, but with dense punctures lateroventrally. Meso- and metapleuron weakly to super- ficially punctate, smooth and shiny around metapleural carina, metapleural gland scrobe absent or inconspicuous. Transverse rugula(e) present posteriorly between spines, posteropropodeum otherwise weakly punctate. Metatibia with fully appressed pilosity. Petiole (except anterodorsally) and postpetiole punctate to weakly punctate, the latter posterodorsally with weak irregular rugulae. First gastral tergite shagreened, posteriorly hexagonally microsculptured. Long standing hairs very rare on head, postpetiole and dorsal gaster, their apices blunt or truncate, on alitrunk completely absent. Color reddish brown, gaster dark brown.
Measurements (holotype): HL 1.800, HW 1.800, SL 0.956, MDL 0.778, EL 0.222, MFL 1.397, MTL 1.067, WL 1.349, PSL 0.311, PTH 0.300, PPH 0.333, PTL 0.489, PPL 0.300, PTW 0.200, PPW 0.411, PW 0.744
Indices: CI 100, SI 53, MDI 43, PSLI 17, PWI 41, FI 78, PeI 27, PpI 55, PpWI 206, PpLI 163.
Measurements (n=5): HL 1.820–2.125 (1.974), HW 1.840–2.150 (2.015), SL 0.944–1.078 (1.024), MDL 0.778–0.967 (0.878), EL 0.228–0.267 (0.246), MFL 1.429–1.635 (1.537), MTL 1.089–1.270 (1.192), WL 1.381–1.619 (1.524), PSL 0.311–0.367 (0.342), PTH 0.300–0.356 (0.333), PPH 0.344–0.444 (0.392), PTL 0.467–0.567 (0.536), PPL 0.311–0.344 (0.329), PTW 0.200–0.261 (0.232), PPW 0.428–0.544 (0.483), PW 0.800–0.944 (0.880)
Indices: CI 99–105 (102), SI 49–53 (51), MDI 42–45 (44), PSLI 16–18 (17), PWI 42–44 (44), FI 75–79 (76), PeI 24–28 (26), PpI 50–59 (55), PpWI 186–222 (209), PpLI 145–170 (163).

Measurements (n=26): HL 0.722–0.922 (0.851), HW 0.667–0.856 (0.779), SL 0.876–1.133 (1.022), MDL 0.511–0.633 (0.576), EL 0.167–0.194 (0.181), MFL 1.044–1.349 (1.224), MTL 0.789–1.044 (0.951), WL 1.011–1.286 (1.162), PSL 0.200–0.356 (0.282), PTH 0.167–0.206 (0.185), PPH 0.183–0.239 (0.212), PTL 0.267–0.367 (0.336), PPL 0.178–0.233 (0.198), PTW 0.106–0.133 (0.121), PPW 0.183–0.267 (0.225), PW 0.456–0.557 (0.506)
Indices: CI: 88–95 (92), SI 123–141 (131), MDI 71–78 (74), PSLI 28–40 (33), PWI 61–68 (65), FI 143–170 (157), PpWI 165–210 (186), PpLI 142–206 (170).

Discussion: Minor and major workers show a relatively great degree of variability in size and sculpture, especially between the type specimens from Cameroon and the material from the Central African Republic and Gabon. Minors from the Central African Republic differ from the types in a more variable sculpture on the mesonotum, mesopleuron and propodeum. The latter is almost smooth in some specimens versus strongly punctate in others. The minor workers of the type series possess a smooth mesonotum and superficially sculptured mesopleuron and propodeum. Majors from Gabon are differentiated from the type majors by the absence of punctate sculpture between the rugae on the head, and in lateral view a longer, rounded promesonotum. They are also more than 10 percent larger than the majors from the type series, although the indices are not significantly different between the two populations. Other than these differences, all specimens share the same morphometric profile and overall habitus. This, and the fact that intermediate forms are present in the minor subcaste, is in support of a one-species hypothesis. Still, there is a small probability that the different populations could turn out to be heterospecific, if more material from other sites and particularly from the major worker subcaste becomes available.
The species most similar to Pheidole glabrella is P. rebeccae. The minor workers of the latter are separated from those of the former by a slightly less convex posterior head margin, and shorter scapes (SI 114–121 versus SI 123–141), spines (PSLI 25–30 versus PSLI 28–40) and legs (FI 133–139 versus FI 143-170). The major workers of P. rebeccae differ from those of P. glabrella by longer and uninterrupted rugae in the face, a narrow versus broad metanotal groove, and significantly more standing hairs on all dorsal surfaces, except the propodeum. P. glabrella has a West to Central African distribution, from Cameroon to the D.R. Congo, where several minor workers were collected by the American Museum Congo Expedition together with and included in the type series of P. batrachorum. The other material has been collected in rainforests from sifted leaf-litter, rotten logs, and beating of the lower vegetation.
Additional material examined: CAMEROON: (7 minor workers) Prov. Sud, P.N. Campo, 43.3 km 108° ESE Campo, 290 m, 7.iv.2000, 02° 17.0’ N, 10° 12.4' E (B.L. Fisher); (1 minor worker) Mbalmayo, xi.1993 (N. Stork); CENTRAL AFRICAN REPUBLIC: (1 minor worker) Reserve Dzanga-Sangha, 12.7 km 326° NW Bayanga, 03° 00.27' N, 16° 11.55' E, 420 m, 11–17.v.2001 (S. van Noort); (2 minor workers) P.N. Dzanga-Sangha, 38.6 km 173° S Lidjombo, 02° 21.60' N, 16° 03.20' E, 350 m, 21–27.v.2001 (S. van Noort); (1 minor worker) P.N. Dzanga- Ndoki, 21.4 km 53° NE Bayanga, 03° 02.01' N, 16° 24.57' E, 510 m, 3.v.2001 (S. van Noort); (5 minor workers) Reserve Dzanga-Ndoki, Mabea Bai, 21.4 km 53° NE Bayanga, 03° 02' N, 16° 25' E, 510 m, 1–07.v.2001 (B.L. Fisher); (2 minor workers) Reserve Dzanga-Ndoki, 37.9 km 169° S Lidjombo, 02° 22' N, 16° 10' E, 360 m, 21.v.2001 (B.L. Fisher); (1 minor worker) Reserve Dzanga-Sangha, 12.7 km 326° NW Bayanga, 03°00' N, 16° 12' E, 470 m, 10–17.v.2001 (B.L. Fisher); D.R. CONGO: (5 major workers, among syntypes of P. batrachorum) Akenge (H.O. Lang); GABON: (2 minor workers) Prov. Ogooue Maritime, Reserve Moukalaba, 12.2 km 305° NW Doussala, 110 m, 02° 17.0' S, 10°29.8' E, 24.ii.2000 (B.L. Fisher); (5 minor workers) Prov. Woleu-Ntem, 31.3 km 108° ESE Minvoul, 02° 04.8' N, 12° 24.4' E, 600 m, 12.ii.1998 (B.L. Fisher); (2 major workers, 4 minor workers) Prov. Ogooue Maritime, Reserve Monts Doudou Moukalaba, 12.2 km 305° NW Doussala, 110 m, 02° 17.0' S, 10° 29.8' E, 24.ii.–3.iii.2000 (B.L. Fisher); (1 minor worker, 1 major worker) Prov. Ogooue Maritime, Reserve Monts Doudou, 25.2 km, 304° NW Doussala, 02° 13.60' S, 10° 23.70' E, 14.iii.2000, 640 m (B.L. Fisher).

Illustration from Fischer, Hita Garcia & Peters (2012).

Oxford University Museum specimens

Pheidole glabrella B Taylor det.	Liberia E Poirier Liabala PF 8	2.iv.2013 Nimba County 07°31’06" N 08°35’34" E	Pitfall trap Secondary forest 473 m asl minor	2
Pheidole glabrella B Taylor det.	Cameroun G Debout & A Dalecky Cameroon 09	24.iii.2001 TM 2°34.04' N 9°50.64' E	on soil and surface in forest understorey	2
Pheidole glabrella B Taylor det.	Central African Republic P Moretto 1-2.iii.2012	Sangha PN Ndoki 02˚28'39" N 22˚01'20" E	06-05 Camp 1, forêt dense diversifiée, piège iule minor worker	1

The photomontage is of minors collected in Cameroun - south-western tropical coastal forest area between Edéa and Campo (McKey Wolbachia project, Cameroon 09).
My notes as P. pulchella were: the overall morphology appears to match Santschi & Wheeler's descriptions of the pulchella minor, notably the round head and long backward curved propodeal spines. However, the colour, near black, differs, perhaps being equivalent to the colour given for the major of Santschi's (1939b) variety achantella, i.e. more or less dark red-brown, gaster pitch brown, antennae and legs reddish. There is an almost total lack of erect hairs apart from a distinct pair projecting forwards on the clypeus, and the appressed pilosity on the legs and antennae, which differ from the type. Noticeable also is the clypeus which, although convex, is depressed below the general level of the face.

The photomontage is of a minor collected in Liberia, Liabala; collector E Poirier (Liabala PF 8).

The photomontage is of a minor collected in the Central African Republic, Ndoki, Sangha; collector P Moretto.