Pheidole batrachorum Wheeler, 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 : 14-17

Pheidole batrachorum Wheeler

( Figures 12–17 )

Pheidole batrachorum Wheeler, W.M. 1922: 128 . Lectotype (minor worker) [designated here]: D.R. CONGO, Akenge, stomach Bufo polycerus (H. O. Lang) ; paralectotypes (1 major worker, 3 minor workers): Akenge, stomach Arthroleptis variabilis (H. O. Lang) (USNM) [examined]. [Previously synonymized with Pheidole dea by Santschi, 1930: 59.] Stat. rev.

Diagnosis: Both subcastes reddish brown to dark brown. Minor workers: head shape elliptical and relatively narrow (CI: 79–86), antennal scapes long (SI: 153–172), head margin posterior of eye-level with laterally projecting hairs. Frons, vertex and most of mesosoma uniformly punctate, except smooth spots medially between eyes and on posterior lateropronotum. Head and body with long standing and shorter decumbent to subdecumbent hairs, scape and metatibia pilosity mostly decumbent. Major workers: head sculpture rugose-punctate with relatively long rugae, scape relatively long. Sculpture on anterior portion of dorsopropodeum transversely rugulose-punctate, posteriorly with obliquely curved or longitudinal rugulae and superficial punctures to partly smooth. Long standing hairs present on promesonotum, pilosity on scape and metatibia appressed to decumbent.

Description of minor worker: Measurements (lectotype): HW: 0.744, HL: 0.867, SL: 1.133, MDL: 0.556, EL: 0.183, MFL: 1.381, MTL: 1.078, WL: 1.206, PSL: 0.244, PTH: 0.178, PPH: 0.233, PTL: 0.322, PPL: 0.256, PTW: 0.133, PPW: 0.244, PW: 0.478; CI: 86, SI: 152, MDI: 75, PSLI: 28, PWI: 64, FI: 186, PpWI: 183, PpLI: 126

Measurements (n=15): HW: 0.589–0.722 (0.675), HL: 0.683–0.867 (0.816), SL: 0.900–1.122 (1.085), MDL: 0.456–0.567 (0.540), EL: 0.156–0.189 (0.177), MFL: 1.011–1.317 (1.267), MTL: 0.789–1.033 (0.970), WL: 0.956–1.167 (1.119), PSL: 0.144–0.244 (0.213), PTH: 0.144–0.189 (0.174), PPH: 0.172–0.233 (0.214), PTL: 0.256–0.367 (0.329), PPL: 0.178–0.267 (0.233), PTW: 0.100–0.133 (0.119), PPW: 0.189–0.244 (0.226), PW: 0.400–0.511 (0.471); CI: 79–86 (83), SI: 153–172 (161), MDI: 77–83 (80), PSLI: 21–29 (26), PWI: 67–72 (70), FI: 172–196 (188), PpWI: 181–200 (189), PpLI: 125–160 (141)

Head shape in full-face view elliptical (CI: 79–86), head margin posterior of eye-level rounded towards welldeveloped occipital carina, with weak to absent medial impression. Mandible dorsally unsculptured and smooth. Clypeus smooth or superficially punctate, median carina absent to inconspicuous, lateral carinae weak and irregular. Most of face uniformly punctate, except smooth to superficially sculptured central spot at eye-level. Malar area punctate, overlain by some irregular rugulae, ending at posterior eye-level. Scapes long (SI: 152–172) with decumbent to subdecumbent pilosity. Promesonotal outline in lateral view subangular, dorsopronotum flat. First and second mesonotal process conspicuously produced and subangular. Mesosoma mostly punctate, save for smooth central area on lateropronotum. Punctures on anteropronotum partly overlain with weak irregular transverse to diagonal rugulae, posteriorly sometimes with weak longitudinal rugulae. Propodeal spines relatively short (PSLI: 21–29). Metafemur long (FI: 172–196), metatibia with decumbent pilosity. Petiole and postpetiole densely punctate, weaker dorsally than ventrally. Anterior margin on gaster weakly shagreened, rest smooth and shiny. Standing hairs on head, pronotum and waist segments moderately long and acute, longer on gaster. Face with four to five pairs of long standing hairs, in addition with shorter subdecumbent hairs, in full-face view projecting laterally over head margin posterior of eye-level. One hair immediately above eye curved in weak S-shape. Mesonotum, propodeum and waist segments with short subdecumbent hairs. Color dark brown, mandibles and appendages lighter colored.

Description of major worker: Measurements (paralectotype): HL: 2.000, HW: 2.040, SL: 1.133, MDL: 0.944, EL: 0.278, MFL: 1.700, MTL: 1.302, WL: 1.700, PSL: 0.322, PTH: 0.378, PPH: 0.456, PTL: 0.511, PPL: 0.389, PTW:0.278, PPW: 0.511, PW: 0.889; CI: 98, SI: 57, MDI: 47, PSLI: 16, PWI: 44, FI: 85, PeI: 31, PpI: 58, PpWI: 184, PpLI: 131

Measurements (n=5): HL: 1.860–1.920 (1.888), HW: 1.800–1.880 (1.860), SL: 1.011–1.089 (1.053), MDL: 0.889–1.000 (0.951), EL: 0.233–0.267 (0.247), MFL: 1.476–1.603 (1.546), MTL: 1.111–1.254 (1.181), WL: 1.444–1.587 (1.508), PSL: 0.278–0.322 (0.304), PTH: 0.300–0.344 (0.324), PPH: 0.367–0.422 (0.394), PTL: 0.511–0.567 (0.542), PPL: 0.333–0.378 (0.358), PTW: 0.222–0.244 (0.233), PPW: 0.483–0.556 (0.514), PW: 0.800–0.844 (0.820); CI: 97–100 (99), SI: 55–58 (57), MDI: 49–53 (51), PSLI: 14–17 (16), PWI: 44–45 (44), FI: 79–85 (83), PeI: 27–30 (28), PpI: 60–66 (63), PpWI: 212–235 (221), PpLI: 144–160 (152)

Frons longitudinally rugose-punctate, some rugae moderately long, others shorter and irregular, posterolateral lobes weakly rugulose-punctate. Sides lateral of antennal scrobe and posterior of eye-level irregularly rugose-reticulate, with punctate ground sculpture. Scape pilosity appressed-decumbent and shorter than maximum scape diameter. Pronotal outline in profile relatively rounded to subangular, in dorsal view laterally angulate and weakly produced. Promesonotal and mesonotal declivity steep, mesonotal process right-angled. Second mesonotal process small and dorsally narrow, sometimes only a short median ridge ( Fig. 1 C–5), but usually raised above level of dorsal propodeum. Anteropronotum transversely rugulose-punctate, posteropronotum with irregular oblique to longitudinal rugulae and superficial to smooth ground-sculpture, and posterior lateropronotum with smooth central area. Meso- and metapleuron punctate, except smooth areas around metapleural carinae and metapleural gland scrobe. Dorsopropodeum anteriorly punctate, grading from weak to superficial punctures posteriorly, transverse rugulae in dorsal view visible between spines and on posteropropodeum. Metatibia pilosity appressed to decumbent. Petiole and postpetiole densely punctate, sides of postpetiole in dorsal view angulate, posteriorly with a conspicuous flange. Punctures on posterodorsal face partly overlain by short oblique to longitudinal rugulae. Anterior half of first gastral tergite weakly punctate, posterior half shagreened or microsculptured. Standing hairs of moderate length, relatively stiff and truncated, on mesonotum and propodeum short, subdecumbent to decumbent. Color reddish brown to brown, gaster darker.

Discussion: Santschi (1930) synonymized Pheidole batrachorum with P. d e a, yet the similarities are superficial (see below), which is the reason why species status is revived in this revision. Another strongly punctate species is P. n i m b a. Both P. dea and P. ni m b a were described only from minor workers. These two species are best separated from P. batrachorum by their wider heads and more rounded posterior head margins (CI: 86–93 [ dea ] and CI: 90 [ nimba ] versus CI: 79–86 [ batrachorum ]), at most one or two laterally projecting hairs at eye-level or posterior margin versus several, and significantly shorter antennal scapes (SI: 134–147 and SI: 129 versus SI: 153– 172). A unique character for P. nimba is the uniformity and strength of its punctate sculpture without any superficially punctate or smooth dorsal surfaces on the head, mesosoma and metasoma. In the Central African Republic P. batrachorum co-occurs with P. d a r w i n i, from which minors are separated by shorter spines (PSLI: 29–35 versus PSLI: 21–29), slightly longer scapes (SI: 153–172 versus SI: 139–160) and narrower head (CI: 79–86 versus CI: 84–89); majors are separated by slightly shorter scapes (SI: 49–53 versus SI: 55–58), mandibles (MDI: 42–51 versus MDI: 47–53) and metafemur (FI: 75–80 versus FI: 79–85); both worker castes have significantly more sculpture in the face and dorsopronotum.

Wheeler described Pheidole batrachorum from four major and twenty-one minor workers, found in stomachs of toads and frogs in the rainforest of Akenge in the D.R. Congo. Of the eight minor and two major workers loaned from the NMNH, the two majors are concordant with Wheeler’s description, but only three of the minors are; the rest belong to P. glabrella and are treated as such. Additional non-type material listed below was collected in Gabon and the Central African Republic, from within rotten logs and sifted leaf-litter in rainforest habitat.

Additional material examined: 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) ; (1 minor worker) P.N. Dzanga-Ndoki, 21.4 km 53° NE Bayanga 03° 02.01' N, 16° 24.57' E, 510 m, 1–7.v.2001 (S. van Noort) ; (1 minor worker) 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) ; (4 major workers, 13 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) ; (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) ; (2 major workers, 6 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) ; GABON: (4 minor workers) Prov. Woleu-Ntem, 31.3 km 108° ESE Minvoul, 02° 04.8' N, 12° 24.4' E, 600 m, 11.ii.1998 (B.L. Fisher) ; (1 major worker) Prov. Woleu-Ntem, 31.3 km 108° ESE Minvoul, 02° 04.8' N, 12° 24.4' E, 600 m, 7.ii.1998 (B.L. Fisher)

Figures

FIGURE 12 – 17 P. batrachorum Wheeler: full-face, lateral & dorsal view of minor (Fig. 12 – 14) (Central African Republic, CASENT 0401882) and major worker (Fig. 15 – 17) (Central African Republic, CASENT 0415367).

FIGURE 1 A) Pheidole pulchella, full-face view of minor worker: the two lines show the lateral clypeal carinae on the sides of the clypeus (1). B) P. pulchella, lateral view of minor worker: illustrating posterior head margin with a weakly developed occipital carina (2), promesonotum with inconspicuous humeri (3), and second mesonotal process not reduced (4). C) P. pulchella, lateral view of major worker: illustrating second mesonotal process reduced to a small ridge anterior of the metanotal groove (5) and well-developed metapleural carina (6) situated above the metapleural gland scrobe (7). D) P. pulchella, in oblique fronto-dorsal (dorsocaudad) view (Will Ericson 2011): measurement of propodeal spine length (PSL), the bold line representing the measurement, bordered by the perpendicular line across the base of the spine.