Pheidole pulchella

Gabon specimens were collected in rainforest habitat from sifted leaf-litter.

Identification
A member of the pulchella species group. Minor workers of Pheidole pulchella can be differentiated easily from those of Pheidole christinae and Pheidole heliosa by the relatively wider, more circular, head (CI: 82–90 [P. pulchella] versus CI: 79–84 [P. christinae] and CI: 73–76 [P. heliosa]), less abundant and thicker standing hairs, short, decumbent scape and metatibia pilosity versus suberect to erect hairs, and shorter propodeal spines (PSLI: 25–29 versus PSLI: 26–36 and PSLI: 28–37). Major workers of P. pulchella are separated from those of P. heliosa by presence of frontal carinae and antennal scrobes. They have a less coarsely sculptured face and promesonotum, a mesonotal processes which is separated from the pronotum by an obtuse angle, and curved versus straight propodeal spines. (Fischer, Hita Garcia, & Peters 2012)

Distribution
Known from Congo, Democratic Republic of Congo and Gabon.

This taxon was described from Congo.

Nomenclature

 *  pulchella. Pheidole pulchella Santschi, 1910c: 360 (w.) CONGO. [Misspelled as putchella by Emery, 1921f: 89.] Senior synonym of niapuana: Santschi, 1930a: 59; of achantella: Fischer, et al. 2012: 33.
 * niapuana. Pheidole niapuana Wheeler, W.M. 1922a: 136, fig. 34 (s.w.) DEMOCRATIC REPUBLIC OF CONGO. Junior synonym of pulchella: Santschi, 1930a: 59.
 * achantella. Pheidole pulchella var. achantella Santschi, 1939b: 242 (s.) CONGO. Junior synonym of pulchella: Fischer et al., 2012: 33.

Fischer, Hita Garcia, & Peters (2012) - Color orange (minor) to dark orange with lighter appendages (major). Minor workers: head shape rounded and relatively wide (CI: 82–90), occipital carina narrow. Scape and metafemur relatively long (SI: 147–161, FI: 169–194), pilosity decumbent. Promesonotal outline in lateral view flat, without raised peak at humeri. Mesonotal processes relatively shallow, metanotal groove broad and deep in lateral view. Dorsopropodeum straight, propodeal spines relatively short (PSLI: 25–29). Standing hairs comparatively thick. Major workers: frontal carinae and antennal scrobes present, rugae in face of varying lengths, grading into weak oblique rugulae on posterolateral lobes, ground sculpture weakly to superficially punctate. Dorsal promesonotum transversely rugulose and weakly punctate, posteriorly towards mesonotum partly smooth and shiny. Mesonotal process strongly produced, right-angled. In lateral view dorsopropodeum anterior to propodeal spines longer than horizontal width of base of spines. Standing hairs relatively long and thick, absent from propodeum.

Worker
Fischer, Hita Garcia, & Peters (2012) - minor: Measurements (n=15): HL: 0.856–0.944 (0.895), HW: 0.733–0.800 (0.766), SL: 1.133–1.254 (1.192), MDL: 0.578–0.644 (0.610), EL: 0.167–0.189 (0.173), MFL: 1.317–1.508 (1.414), MTL: 1.056–1.133 (1.092), WL: 1.156–1.317 (1.258), PSL: 0.222–0.267 (0.244), PTH: 0.172–0.211 (0.190), PPH: 0.206–0.244 (0.221), PTL: 0.289–0.389 (0.347), PPL: 0.211–0.256 (0.237), PTW: 0111–0.133 (0.122), PPW: 0.222–0.267 (0.235), PW: 0.478–0.544 (0.506); CI: 82–90 (86), SI:147–161 (156), MDI: 75–83 (80), PSLI: 25–29 (27), PWI: 64–68 (66), FI: 169–194 (185), PpWI: 182–218 (193), PpLI: 117–175 (147).

Head longer than wide (CI: 82–90), with sides posterior of eye-level evenly rounded towards posterior margin. Occipital carina conspicuous, medially and laterally faintly impressed. Mandibles of moderate length (MDI: 75–83), dorsally smooth to superficially rugulose. Clypeus smooth, median and submedian carinae absent, lateral carinae conspicuous, sometimes short. Frons and vertex smooth, hexagonally micropunctate, with superficial punctures on malar area and near eyes. Malar carinae weak and interrupted, disappearing at posterior eye-level. Scape relatively long (SI: 147–161) in full-face view and when laid back surpassing posterior margin by more than one third of its length with decumbent pilosity. Promesonotal outline in lateral view flat, obtusely angulate at posterior declivity. First and second mesonotal process weakly produced, at edges slightly rounded, not marginate dorsally. Humeri with small, weakly marginate angle, not peaked in lateral view. Pronotal and mesonotal declivities shallow and flatly declining towards deeply and broadly impressed metanotal groove. Promesonotum anteriorly on neck weakly punctate, with short to moderately long, irregular rugulae, remainder smooth and shiny to superficially punctate. Mesonotum dorsally smooth to superficially punctate. Mesopleuron and propodeum weakly punctate, with superficially sculptured or almost smooth spots on anepisternum, katepisternum, and posterior dorsopropodeum. Spines relatively short (PSLI: 25–29), in dorsal view, at apices almost parallel. Metafemur relatively long (FI: 169–194), metatibia pilosity decumbent. Petiolar node and postpetiole weakly punctate lateroventrally and ventrally, dorsum with superficially punctate to smooth and shiny area, peduncle also weakly to superficially punctate dorsally, without smooth strip medially. First gastral tergite smooth and shiny, except very narrow, superficially punctate anterior strip. Standing hairs relatively stiff and of varying lengths, longest hairs on pronotum, gaster and head. Mesonotum and propodeum with shorter subdecumbent hairs, also present on head and projecting beyond lateral margin anterior and posterior of eye-level. Color yellow to light orange.

major: Measurements (n=13): HL: 1.940–2.225 (2.140), HW: 2.000–2.275 (2.162), SL: 1.056–1.167 (1.134), MDL: 0.900–1.111 (1.016), EL: 0.233–0.256 (0.243), MFL: 1.667–1.840 (1.738), MTL: 1.286–1.429 (1.353), WL: 1.397–1.740 (1.651), PSL: 0.244–0.378 (0.316), PTH: 0.333–0.389 (0.357), PPH: 0.367–0.500 (0.443), PTL: 0.533–0.644 (0.594), PPL: 0.333–0.411 (0.378), PTW: 0.200–0.267 (0.240), PPW: 0.422–0.611 (0.524), PW: 0.811–1.033 (0.950); CI: 98–103 (101), SI: 51–56 (53), MDI: 43–50 (47), PSLI: 11–17 (15), PWI: 39–47 (44), FI: 76–90 (80), PeI: 22–29 (25), PpI: 47–61 (55), PpWI: 200–239 (218), PpLI: 141–167 (157).

Head about as long as wide (CI: 98–103), frontal carinae and antennal scrobes conspicuous. Frons longitudinally rugose, with irregular pattern of moderately long to shorter rugae, spaces between rugae weakly punctate to almost smooth. Rugae grading weaker posteriorly and curving towards posterolateral lobes, or replaced by oblique, weak, rugulose-punctate sculpture. Scape pilosity appressed. Promesonotal outline in lateral view rounded or very weakly subangulate, dorsally and anterolaterally with transverse and irregular rugulose and weakly punctate sculpture. Posterolaterally with smooth area, posterodorsally towards well-produced, right-angled mesonotal process weakly sculptured and partly smooth, at its edges weakly marginate, steeply declining towards small or inconspicuous second mesonotal process, terminating in narrow and short transverse ridge. Metanotal groove in lateral view narrow and shallow, dorsopropodeum weakly to superficially punctate. In profile, dorsopropodeum anterior to propodeal spines subequal to horizontal width of base of spine. Propodeal spines weakly curved posteriorly, posteropropodeum with weak transverse rugulae overlaying punctures. Punctures on mesopleuron and metapleuron weak and dense, posterobasally around long and conspicuous metapleural carina and gland scrobe superficial to smooth and shiny. Metatibia with short appressed pilosity. Petiole and postpetiole very densely punctate, anterodorsal petiole superficially sculptured, posterodorsal postpetiole with short irregular rugulae. Anterior half of first gastral tergite shagreened, posterior half smooth and hexagonally microsculptured. Long standing hairs acute, relatively slender, abundantly present on dorsal head, promesonotum, waist segments, and gaster, with additional short appressed pubescence. Color orange to darker orange, legs lighter.

Type Material
Fischer, Hita Garcia, & Peters (2012):

Syntype workers: D.R. CONGO, Brazzaville, 1907 (A. Weiss) [2 major workers and 4 minor workers examined].

Pheidole niapuana Syntype workers: CONGO, Niapu, vi.1913 (H.O. Lang) [7 major workers and 5 minor workers examined].

Pheidole pulchella var. achantella Holotype worker: D.R. CONGO, Brazzaville, 1907 (A. Weiss) [examined].

Additional References

 * Fischer, G., Hita Garcia, F., & Peters, M.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, 1-43.