Pheidole ochracea, Eguchi, 2008

Eguchi, Katsuyuki, 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae), Zootaxa 1902 (1), pp. 1-118 : 63-66

Pheidole ochracea 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 ]; 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 sp. eg-101” has been applied (Eguchi, Bui et al. 2005: 90) is P. ochracea , and the remainder is P. elongicephala .

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 , Pheidole elongicephala sp.n. and P. binghamii are morphologically very similar to each other. Differences between P. ochracea and P. elongicephala are given under the remaks of P. elongicephala . Difference between P. ochracea and P. binghamii are as follows: mound on the posterior slope of the promesonotal dome is less developed in the minor of P. ochracea than in that of P. binghamii ; body of minor yellowish-brown in the former, but usually brown to dark-brown in the latter. Pheidole ochracea and P. binghamii 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 [Eg04-VN-146, det. Sk. Yamane, 2005].

Figures

FIGURE 17a–d, Pheidole ochracea, holotype (major) [Eg04-VN-621] — a, head in full-face view; b, head in lateral view; c, mesosoma and waist in dorsal view; d, mesosoma and waist in lateral view.