Pheidole ochracea HNS sp.n.
Figs. 17a-h
Type material examined: Holotype: major (IEBR), S. Cat Tien N.P. (forest along Bird Lake Trail <ca. 160 m alt.), Dong Nai, S. Vietnam (K. Eguchi leg., 14 Oct 2004, colony: Eg04-VN-621) [IEBR]; paratypes: 5 majors & 6 minors, same data as holotype (IEBR, MHNG, MCZC & ACKE).
Other material examined: S. China: Guangxi: Guilin City [Eg00-GNGX-06], Nonggang & Longhu, Longzhou [J. Fellowes]; Guangdong: Yangchun Baiyong N.R. [J. Fellowes]; Hong Kong: Victoria Park, Hong Kong I. [Eg99-HK-19, -24, -32]. Vietnam: Lao Cai: Y Linh Ho, ca. 1100 m alt., Sa Pa [Eg02-VN-212]; Bac Giang: W. Yen Tu N.P. (=Tay Yen Tu N.P.), 21°11'N, 106°43'E, 150 m alt. [as preys of a colony (Eg04-VN- 146) of Aenictus dentatus HNS]; Vinh Phuc: Tam Dao N.P., 800-900 m alt. [Eg99-VN-003, -035, -063]; Ha Tay (mislabeled as Ha Tai): Ba Vi N.P., 21°03'N, 105°22'E, 400-800 m alt. [Eg99-VN-102, -125; Eg01-VN-236; Eg02-VN-016]; Dong Nai: S. Cat Tien N.P., <160 m alt. [Eg04-VN-583, -602, -614, -790]. Part of specimens to which Eguchi's informal species code " Pheidole HNS sp. eg-101" has been applied (Eguchi, Bui et al. 2005: 90) is P. ochracea HNS, and the remainder is P. elongicephala HNS.
Worker measurements & indices: Holotype (major). - HL 1.79 mm; HW 1.61 mm; CI 90; SL 0.98 mm; SI 61; FL 1.31 mm; FI 81.
Nontype major (n=4). - HL 1.74-1.89 mm; HW 1.58-1.65 mm; CI 86-92; SL 0.99-1.03 mm; SI 62-63; FL 1.33-1.39 mm; FI 83-85.
Minor (n=5, including one paratype minor). - HL 0.72-0.83 mm; HW 0.57-0.66 mm; CI 79-80; SL 0.88-1.00 mm; SI 148-154; FL 0.91-1.06 mm; FI 154-162.
Worker description
Major. - Body deep yellowish-brown or sometimes brown or deep reddish-brown, with paler appendages. Head in lateral view at most weakly impressed on vertex; vertexal lobes in full-face view relatively close to each other; frons and anterior part of vertex longitudinally rugose; posterior part of vertex and dorsum of vertexal lobe reticulate or rugoso-reticulate; clypeus without a median longitudinal carina; frontal carina conspicuous; antennal scrobe very shallow; hypostoma with low or inconspicuous median and low or inconspicuous submedian processes in addition to conspicuous lateral processes; antenna with a 3-segmented club; maximal diameter of eye (a little) shorter than antennal segment X. Promesonotal dome smooth and shining, with transverse rugulae; a conspicuous prominence present on its posterior slope; humerus of the dome not or hardly produced laterad; the dome at the humeri much narrower than at the bottom; mesopleuron and metapleuron weakly punctured, overlain by rugoso-reticulation; propodeal spine narrowly based, usually slightly curved apically. Petiole longer than postpetiole (excluding helcium); postpetiole not massive. First gastral tergite smooth and shining entirely, or rarely shagreened only around its articulation with postpetiole.
Minor. - Body yellowish-brown, with paler appendages. Head in full-face view elliptical; frons and vertex smooth and shining, or partly shagreened; median portion of clypeus smooth and shining, without a median longitudinal carina; occipital carina well-developed; antenna with a 3-segmented club; scape extending far beyond posterolateral margin of head; maximal diameter of eye much shorter than antennal segment X; 6-7 ommatidia present on the long axis of eye. Promesonotal dome smooth and shining, in lateral view with a low mound on its gentle posterior slope; humerus in dorso-oblique view not raised/produced; mesopleuron, metapleuron and lateral face of propodeum punctured, often overlain by weak rugulae (sculpure on the lateral face of propodeum often weaker than mesopleuron and metapleuron); propodeal spine elongate-triangular, directing upward. Petiole a little longer than postpetiole (excluding helcium); postpetiole not massive.
Recognition: Pheidole ochracea HNS, Pheidole elongicephala HNS sp.n. and P binghamii HNS are morphologically very similar to each other. Differences between P. ochracea HNS and P. elongicephala HNS are given under the remaks of P. elongicephala HNS. Difference between P. ochracea HNS and P. binghamii HNS are as follows: mound on the posterior slope of the promesonotal dome is less developed in the minor of P. ochracea HNS than in that of P. binghamii HNS; body of minor yellowish-brown in the former, but usually brown to dark-brown in the latter. Pheidole ochracea HNS and P. binghamii HNS are sympatric in S. Vietnam.
Distribution & bionomics: Known from Vietnam and S. China. This species usually occurs in forests and woody habitats, and nests in the soil and sometimes in termite mounds abandoned [e.g., Eg04-VN-621]. This species is prey of Aenictus dentatus Forel HNS [Eg04-VN-146, det. Sk. Yamane, 2005].