Pheidole christinae, FISCHER & GARCIA & PETERS, 2012

FISCHER, GEORG., GARCIA, FRANCISCO HITA & PETERS, MARCELL K., 2012, Taxonomy of the ant genus Pheidole Westwood (Hymenoptera: Formicidae) in the Afrotropical zoogeographic region: definition of species groups and systematic revision of the Pheidole pulchella group, Zootaxa 3232 (1), pp. 1-43 : 17-19

Pheidole christinae sp. n.

( Figures 18–20 )

Holotype: (minor worker) UGANDA, 01° 45' N, 31° 34' 59'' E, Budongo Forest Reserve , 900 m, 30.vi.2004 (M. Peters) ( ZFMK: CASENT0227935 ) . Paratypes: (6 minor workers) same data as holotype ( BMNH: CASENT0227938, CASC: CASENT0227939, CASENT0227940, SAMC: CASENT0227941, ZFMK: CASENT0227936, CASENT0227937); (3 minor workers) 01° 43' N, 31° 33' E, Bunyoro District, Budongo Forest, 1000 m, hand collection, 30.vi.2004 (M. Peters) ( ZFMK: CASENT0227942, CASENT0227943, CASENT0227944).

Diagnosis: Pheidole christinae is known from minor workers only. Color orange. Head elliptical, posterior of eye-level slightly elongated (CI: 79–84). Occipital carina very narrow, scape relatively long (SI: 143–164) and with erect to suberect pilosity. Promesonotum at humeri with small dent, in lateral view slightly raised above dorsal outline. Spines and metafemur long (PSLI: 26–36, FI: 175–198), metatibia with pilosity on inner edge subdecumbent, on outer edge subdecumbent to suberect. Standing hairs of variable lengths, mostly blunted or truncated.

Description of minor worker: Measurements (holotype): HL: 0.989, HW: 0.811, SL: 1.302, MDL: 0.633, EL: 0.167, MFL: 1.508, MTL: 1.167, WL: 1.286, PSL: 0.278, PTH: 0.178, PPH: 0.244, PTL: 0.367, PPL: 0.256, PTW: 0.122, PPW: 0.256, PW: 0.533, CI: 82, SI: 160, MDI: 78, PSLI: 28, PWI: 66, FI: 186, PpWI: 209, PpLI: 143.

Measurements (n=21): HW: 0.733–0.833 (0.798), HL: 0.878–1.022 (0.977), SL: 1.100–1.349 (1.244), MDL: 0.578–0.678 (0.643), EL: 0.156–0.178 (0.166), MFL: 1.333–1.635 (1.497), MTL: 1.044–1.333 (1.187), WL: 1.144–1.556 (1.315), PSL: 0.256–0.344 (0.304), PTH: 0.144–0.206 (0.188), PPH: 0.222–0.267 (0.247), PTL: 0.333–0.411 (0.378), PPL: 0.233–0.278 (0.254), PTW: 0.122–0.133 (0.129), PPW: 0.222–0.267 (0.251), PW: 0.489–0.567 (0.538); CI: 79–84 (82), SI: 143–164 (156), MDI: 77–83 (81), PSLI: 26–36 (31), PWI: 64–70 (67), FI: 175–198 (188), PpWI: 182–209 (195), PpLI: 136–168 (149).

Head elongated elliptical, about 1.2 times longer than wide (CI: 79–84), with sides posterior of eye-level elongate, converging evenly towards posterior margin. Occipital carina narrow, clypeus smooth and lateral carinae absent. Face smooth, only malar area weakly punctate and irregularly rugulose near antennal insertion, with some cross-meshes present, rugulae ending at anterior eye-level. Hairs on face relatively slender and of varying lengths, longer and shorter hairs uniformly distributed, often apically truncated or split. Scapes long (SI: 143–164), in full face view and when laid back, surpassing posterior head margin by about one third of its length, with pilosity erect to suberect and almost twice as long as maximum scape diameter. Promesonotum anteriorly punctate towards neck, smooth and shiny to superficially punctate, anteriorly towards neck weakly punctate, posteriorly towards mesonotum superficially punctuate. Humeri with a tiny, prominent peak in profile, representing highest point of pronotum. Pronotal declivity smooth and long, midway between humeral peak and mesonotal process obtusely angular, mesonotal process conspicuously produced, dorsal face often marginate and smooth or weakly and irregularly rugulose-punctate. Second mesonotal process conspicuously produced, similarly shaped and sculptured. Metanotal groove in lateral view shallowly to conspicuously impressed, highest point of dorsopropodeum at about midlength towards base of propodeal spines. Mesopleuron and propodeum weakly punctate, spines long and slender (PSLI: 26–36), strongly curved posteriorly. Metafemur long (FI: 175–198). Pilosity of metatibia on inner edge subdecumbent, outer edge with subdecumbent to suberect hairs and slightly longer hairs. Standing hairs of variable lengths, not very abundant, apices often blunted or split. Color yellow to light orange.

Discussion: Pheidole christinae is a readily recognizable species by its color, head shape and pilosity. In color it is similar to P. pulchella and P. heliosa , and in general appearance it is very close to the latter and with an intermediate head shape (CI: 79–84 [ christinae ], versus CI: 82–90 [ pulchella ] and CI: 73–76 [ heliosa ]). From P. h e l i o s a it can be separated best by its shorter appendages, a significantly narrower occipital carina, less abundant pilosity (especially by its lack of laterally projecting hairs ventrally on meso- and metapleuron), different kinds of metatibial pilosity on inner and outer edges, and asymmetrically shaped postpetiole in lateral view. From P. pulchella it can be distinguished by longer propodeal spines (PSLI (mean): 31 versus 27), erect versus decumbent scape pilosity, the small peaks at the humeri which are raised above the pronotal outline, and the shape of the dorsopropodeum in profile view, which has its highest point at about midlength versus immediately at the metanotal groove in P. pulchella . The population in Gabon differs from the Ugandan P. christinae type specimens in a deeper, conspicuously impressed, metanotal groove, and longer, more spinose, propodeal spines. The minor workers of P. christinae were collected in the Budongo Forest, Uganda, in Gabon and in D.R. Congo from sifted leaf-litter, pitfalls and hand-collections. Majors have not yet been collected.

Etymology: This species is named in honor of the first author’s wife Christina.

Additional material examined: D.R. CONGO: (1 minor worker) Epulu, 01° 23' N, 28° 35' E, 750 m, xi.1995 (S.D. Torti); GABON: (18 minor workers) Prov. Woleu-Ntem, 31.3km, 108° ESE Minvoul, 2°04.8'N, 12°24.4'E, 600m, 7.ii.1998 (B.L. Fisher); UGANDA: (1 minor worker) 01° 43.583' N, 31° 33.142' E, Budongo Forest FS, 1081 m, 08.vii.09 (W. Freund & T. Klug).

Figures

FIGURE 18 – 20 P. christinae sp. n.: full-face, lateral & dorsal view of minor worker (Uganda, CASENT 0227940).