Pheidole colpigaleata Eguchi, 2006

Eguchi, Katsuyuki, 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae), Zootaxa 1902 (1), pp. 1-118 : 14-17

Pheidole colpigaleata Eguchi

Figs. 2a–g

Pheidole colpigaleata Eguchi, 2006: 116–118 . Holotype: major, Ba Vi N.P., Ha Tay, Vietnam, Eg01-VN-222, IEBR, examined; paratypes: 11 majors, 13 minors & 1 dealate queen, same data as holotype, IEBR, MHNG, MCZC, BMNH, FSKU & ACEG, examined.

Pheidole sp. eg-113. Bui & Eguchi 2003: 9 (checklist), Eguchi et al., 2004 (ecological study), Eguchi, Bui et al. 2005: 91 (checklist).

Other material examined: N. Vietnam: Lao Cai: Y Linh Ho (a small fragment of forest), ca. 1100 m alt., Sa Pa [Eg02-VN-219] ; Bac Giang: W. Yen Tu N.P. (= Tay Yen Tu N.P.), 21°11’N, 106°44’E, 195 m alt. [B&E03-04], W. Yen Tu, 21°10’N, 106°43’E, 435 m alt. [Eg04-VN-127], W. Yen Tu, 21°11’N, 106°43’E, 1070 m alt. [Eg03-VN-127, -128]; Ha Tay (mislabeled as Ha Tai): Ba Vi N.P., 21°03’N, 105°22’E, 1100–1200 m alt. [Eg99-VN-130; Eg01-VN-213; Eg02-VN-038, -039]. Eguchi’s informal species code “ Pheidole sp. eg- 113” has been applied to these specimens .

Worker measurements & indices: Major (data from the original description). — HL 1.21–1.29 mm, HW 1.16–1.24 mm, CI 92–96, SL 0.60–0.63 mm, SI 48–53, FL 0.74–0.78 mm, FI 61–66.

Minor (data from the original description). — HL 0.53–0.58 mm, HW 0.50–0.54 mm, CI 91–95, SL 0.51– 0.56 mm, SI 98–106, FL 0.53–0.58 mm, FI 106–110.

Worker description

Major. — Head in lateral view hardly or weakly impressed on vertex; anterior part of frons longitudinally rugose; posterior part of frons, vertex and dorsal and dorsolateral faces of vertexal lobe reticulate; frontal carina well developed, partly overhanging antennal scrobe; median longitudinal carina of clypeus absent, or present but inconspicuous; median, submedian and lateral processes of hypostoma conspicuous; outer surface of mandible (excluding basal area) smooth, bearing sparse, very short appressed hairs; antenna with a 3-segmented club; maximal diameter of eye longer than antennal segment X. Promesonotal dome in dorsal view rugoso-reticulate transversely or reticulate irregularly, in lateral view lacking a conspicuous prominence or mound on its posterior slope; humerus moderately produced laterad; the dome broader at the humeri than at the bottom. Petiole (much) longer than postpetiole (excluding helcium); postpetiole not massive, in lateral view with its anteroventral part acutely produced. First gastral tergite largely smooth, but usually with a weakly sculptured area around its articulation with postpetiole.

Minor. — Dorsal and lateral faces of head largely punctured, often overlain by weak rugoso-reticulation; anteromedian part of frons (just behind frontal triangle) dimly punctured; preoccipital carina inconspicuous or very weak dorsally; median part of clypeus smooth and shining; median longitudinal carina of clypeus absent, or present but inconspicuous; antenna with a 3-segmented club; scape usually exceeding posterior margin of head by the length of antennal segment II or more; maximal diameter of eye as long as or a little longer than antennal segment X. Dorsum of promesonotal dome well punctured and often overlain by weak rugoso-reticulation, or well reticulate with enclosure weakly punctured; lateral face of the dome, mesopleuron, metapleuron and lateral face of propodeum punctured well; the dome in lateral view lacking a prominence/mound on its posterior slope; humerus of the dome in dorsal-oblique view very weakly produced laterad; propodeal spine small, elongate-triangular. Petiole longer than postpetiole (excluding helcium); postpetiole not massive, in lateral view somewhat globular.

Recognition: This species is characterized among Indo-Chinese species by the following characteristics: in the minor dorsal and lateral faces of head and mesosoma punctured; in the major hypostoma in the middle with a conspicuous median and a pair of conspicuous submedian processes; in the major frontal carina well developed horizontally; in the major and minor promesonotal dome lacking a conspicuous prominence/mound on its posterior slope. The major of P. colpigaleata is very similar to that of Pheidole nodgii Forel and its relatives, e.g., P. tjibodana Forel , P. magrettii Emery and P. retivertex Eguchi , but is well distinguished from the latter three which have hypostoma in the middle with a well-developed median process only. The major of P. colpigaleata is also similar to those of Pheidole rabo Forel , P. zoceana Santschi and P.parva Mayr , but is well distinguished from the latter three which have frontal carinae almost absent or vestigial.

Distribution & bionomics: Known from N. Vietnam. This species inhabits forest from lowland to hilly areas (ca. 1200 m alt.), and nests in rotting twigs and small wood fragments. Majors serve as repletes (e.g., Eg02-VN-038, -039). Colony Eg01-VN-222 (the type series) stored many small seeds inside the nest.

Figures

FIGURE 2a–d, Pheidole colpigaleata, paratype major [Eg01-VN-222] — 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.