Pheidole laevicolor

Eguchi, K., 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae)., Zootaxa 1902, pp. 1-118 : 46-47

Pheidole laevicolor Eguchi

Figs. 12a-g

Pheidole laevicolor Eguchi, 2006: 123-125. Holotype: major, "Tam Dao N.P., 21°27'N, 105°38'E, ca. 1000 m alt., Vinh Phuc, Vietnam, Eg01-VN-130", IEBR, examined; paratypes: 14 majors & 15 minors, same data as holotype, (IEBR, MHNG, MCZC, BMNH, FSKU & ACEG, examined.

Pheidole sp. eg-114. Eguchi et al. 2004 (ecological study), Eguchi, Bui et al. 2005: 91 (checklist).

Other material examined: Vietnam: Bac Kan: Ba Be N.P., 22°24-25'N, 105°37-38'E, <260 m alt. [Eg04-VN-153, -155, -161, -173, -179, -202, -212, -214]; Thai Nguyen: My Yen Commune Forest (21°35'N, 105°36'E), Na Hau Village [Eg01-VN-160]; Bac Giang: W. Yen Tu N.P. (=Tay Yen Tu N.P.), 21°10-11'N, 106°43-44'E, 170 m alt. [B&E03-30], W. Yen Tu N.P., 190 m alt. [Eg03-VN-023], W. Yen Tu N.P., 195 m alt. [B&E03-01, -03], W. Yen Tu N.P., 330-400 m alt. [Eg04-VN-094], W. Yen Tu N.P., 415 m alt. [B&E03-35, - 36, -40; Eg03-VN-093], W. Yen Tu N.P., 435 m alt. [Eg04-VN-123, -124]; Quang Ninh: Chua Yen Tu, 21°09'N, 106°43'E, 520-725 m alt. [Eg04-VN-015, -016]; Ha Tay (mislabeled as "Ha Tai"): Ba Vi N.P., 21°03'N, 105°22'E, 1100-1200 m alt. [Eg99-VN-129; Eg02-VN-033]. Eguchi's informal species code " Pheidole sp. eg-114" has been applied to these specimens.

Worker measurements & indices: Major (data from the original description, but FL was erroneously given as "0.86-0.76" in the original description). - HL 1.06-1.20 mm; HW 0.98-1.08 mm; CI 90-92; SL 0.49-0.55 mm; SI 50-52; FL 0.68-0.76 mm; FI 67-72.

Minor (data from the original description). - HL 0.50-0.58 mm; HW 0.42-0.50 mm; CI 84-88; SL 0.47- 0.58 mm; SI 108-116; FL 0.49-0.62 mm; FI 117-124.

Worker description

Major. - Head in lateral view weakly or hardly impressed on vertex; frons longitudinally rugose; vertex and dorsal and lateral facecs of vertexal lobe reticulate, with enclosures weakly punctured; frontal carina very weak or inconspicuous (present just as rugulae); antennal scrobe inconspicuous; clypeus at most with an inconspicuous median longitudinal carina; median, submedian and lateral processes of hypostoma conspicuous; antenna with a 3-segmented club; maximal diameter of eye a little longer than antennal segment X. Promesonotal dome at most with an inconspicuous mound on its posterior slope; humerus weakly produced laterad; the dome at the humeri usually as broad as or a little broader than at the bottom (but sometime a little narrower than at the bottom). Petiole much longer than postpetiole (excluding helcium); postpetiole not massive. First gastral tergite weakly punctured around its articulation with postpetiole, and shagreened to smooth in the remainder.

Minor. - Dorsum of head smooth and shining; preoccipital carina complete, but usually very weak dorsally; median part of clypeus smooth and shining, without a median longitudinal carina; antenna with a 3-segmented club; scape exceeding posterior margin of head at least by the half length of antennal segment II; maximal diameter of eye almost as long as or a little longer than antennal segment X. Promesonotal dome largely smooth and shining, with one or several weak or inconspicuous transverse rugulae anterodorsally, in lateral view at most with an inconspicuous mound on its posterior slope; humerus in dorso-oblique view not or hardly produced laterad; mesopleuron, metapleuron and lateral face of propodeum weakly or dimly punctured; propodeal spine elongate-triangular. Petiole (much) longer than postpetiole (excluding helcium); postpetiole not massive.

Recognition: This species is characterized among Indo-Chinese species by the combination of the following characteristics: in the major dorsal and lateral faces of head and promesonotal dome smooth and shining; in the major vertex and dorsal and lateral faces of vertexal lobe reticulate, with enclosures weakly punctured; in the major hypostoma in the middle with a conspicuous median process and a pair of conspicuous submedian processes; in the major and minor promesonotal dome at most with an inconspicuous mound on its posterior slope.

It is very similar to Pheidole taipoana Wheeler , but distinguished from the latter which has the following characteristics in the major: impression on vertex in lateral view deep; area in front of a transverse impression on vertex sparsely sculptured with weak longitudinal rugulae, with interspaces smooth and shining (see also Eguchi 2006).

Distribution & bionomics: Known from N. Vietnam. This species occurs from forest edges to well-developed forests and nests in the soil (Eguchi et al. 2004, Eguchi 2006). Majors serve as repletes (e.g., the type series, B&E03-03, Eg02-VN-033, Eg04-VN-161).