Pheidole tumida, Eguchi, K., 2008

Eguchi, K., 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae)., Zootaxa 1902, pp. 1-118 : 97-100

Pheidole tumida sp.n.

Figs. 27a-g

Pheidole nodifera F. Smith . Eguchi, Bui et al. 2005: 90 (checklist).

Pheidole sp. (cf. nodifera ). Eguchi, Bui & Janssen 2005 (ecological study).

Type material examined: Holotype: major, Cuc Phuong N.P., Ninh Binh, Vietnam (20°14'N, 105°36'E, 370 m alt.) [K. Eguchi leg., colony: Eg01-VN-176] (IEBR); paratypes: 18 majors, 20 minors & 1 queen from the same colony as holotype (IEBR, MCZC, MHNG & ACEG).

Other material examined: S. China: Guangxi: Gao Zhai (300 m alt.), Xing An County [Eg00-GNGX- 012]; Hong Kong: Victoria Park, Hong Kong I. [Eg99-HK-22], Taipo Kau, New Territory [Eg99-HK-07]. Vietnam: Bac Kan: Ba Be N.P., 22°24-25'N, 105°37-38'E, <260 m alt. [Eg04-VN-158, -164, -175, -177, - 180, -200, -206]; Quang Ninh: Ky Thuong N.R., 21°09-11'N, 107°06-07'E, 105-550 m alt. [Eg03-VN-165, - 191, -247; B&E03-77], Chua Yen Tu, 21°09'N, 106°43'E, 520-845 m alt. [Eg04-VN-006, -010, -025]; Bac Giang: W. Yen Tu N.P. (=Tay Yen Tu N.P.), 21°10-11'N, 106°43-44'N, 170-415 m alt. [Eg03-VN-028, -039, -042, -056, -057, -073, -075, -099; Eg04-VN-086, -095; B&E03-13, -14, -19, -24]; Ha Tay (misspelled as "Ha Tai"): Ba Vi N.P., 21°03'N, 105°22'E, 400-600 m alt. [Eg99-VN-081, -108; Eg02-VN-012]; Ninh Binh: Cuc Phuong N.P., 20°14'N, 105°36'E, 370 m alt. [Eg01-VN-162, -163, -170]; Nghe An: Pu Mat N.P. (Sang Le Forest Area, 19°11'N, 104°37-38'E, <220 m alt.) [Eg01iv06-09]; Dong Nai: S. Cat Tien N.P., <160 m alt. [Eg04-VN-553]. Thailand: Chanthaburi: Khao Soi Dao [Eg01-TH-024]; Trang: Khao Chong Waterfall [Eg01- TH-750]; Narathiwat: Bala-Hala W.S. (Bala Area) [Eg01-TH-686]. Malaysia: Selangor: Ulu Gombak [FI98- 84]. Indonesia: Sungai Wain, E. Kalimantan [G. Fredriksson]; W. Java: Halimun [FI98-328]; E. Java: Purwodai[FI98-277]; Bali: Dusun PK Jelati, Mendaya [Eg98-BALI-727, -748], Mt. Kelatakan [Eg98-BALL-1111, - 1114; IKT. Ginarsa's colony: KT-163]. Eguchi's informal species code " Pheidole sp. eg-100" applies to this species.

Worker measurements & indices: Holotype (major). - HL 1.98 mm; HW 1.99 mm; CI 101; SL 1.11 mm; SI 56; FL 1.58 mm; FI 79.

Nontype major (n=4). - HL 1.63-1.90 mm; HW 1.63-1.98 mm; CI 100-105; SL 0.93-1.07 mm; SI 52- 60; FL 1.38-1.54 mm; FI 78-85.

Minor (n=5, including one paratype minor). - HL 0.71-0.78 mm; HW 0.57-0.66 mm; CI 79-87; SL 0.91-1.04 mm; SI 147-166; FL 1.03-1.18 mm; FI 166-192.

Worker description

Major. - Head in lateral view not or very weakly impressed on vertex; frons and anterior part of vertex rugose longitudinally; posterior part of vertex and dorsal and dorsolateral faces of vertexal lobe rugoso-reticulate obliquely, or reticulate; frontal carina weak, or present just as rugula(e); antennal scrobe inconspicuous or absent; median longitudinal carina of clypeus usually conspicuous, but sometimes weak or just present as weak rugula(e); median and submedian processes of hypostoma absent, or sometimes present but inconspicuous; lateral processes conspicuous but often small; antenna with a 3-segmented club; maximal diameter of eye longer than or almost as long as antennal segment X. Promesonotal dome in dorsal view rugoso-reticulate transversely or irregularly, in lateral view with a conspicuous prominence or at least low mound on its posterior slope; humerus (very) weakly produced laterad; the dome at the humeri narrower than at the bottom (or sometimes almost as broad as or a little broader than at the bottom); propodeal spine usually finger-shaped or spatulate. Petiole shorter than postpetiole (excluding helcium), in dorsal view with a well-developed flange laterally; subpetiolar process extremely developed, lobate; postpetiole massive. First gastral tergite rugosopunctate or at least shagreened over the surface.

Minor. - Frons and vertex largely smooth; area between antennal insertion and eye often rugose or rugoso-punctate; preoccipital carina conspicuous dorsally and laterally; median part of clypeus smooth and shining; median longitudinal carina often present; antenna with a 3-segmented club; scape extending far beyond posterolateral margin of head; maximal diameter of eye shorter than antennal segment X. Promesonotal dome largely smooth, but sometimes shagreened dorsolaterally and/or with several short rugulae on humerus, in lateral view with a conspicuous mound on its posterior slope; humerus of the dome in dorso-oblique view not or hardly produced (rarely produced weakly as a mound); mesopleuron, metapleuron and lateral face of propodeum dimly to weakly punctured at least partly; propodeal spine usually reduced to a short and thin spine or a small dent, or sometimes almost absent. Petiole shorter than postpetiole (excluding helcium); subpetiolar process absent, or present as a longitudinal carina; postpetiole massive.

Recognition: This species has the following combination of diagnostic characteristics: in the minor head and promesonotal dome largely smooth and shining; in the major hypostoma without median and submedian processes; in the major and minor promesonotal dome in lateral view with a conspicuous prominence or mound on its posterior slope; in the major subpetiolar process lobate; in the major and minor postpetiole massive.

Pheidole tumida , Pheidole noda and Pheidole nodifera are not distinguished from each other in minor's morphology. Thus, there is a certain possibility that P. tumida is conspecific with P. nodifera which was described by F. Smith (1874) based on the minor alone from N. China. Pheidole tumida , characterised by a lobate subpetiolar process in the major, is easily distinguished from Pheidole noda and other Indo-Chinese species.

Distribution & bionomics: Known from the Indo-Chinese and Indo-Malayan subregions. Ranging from forests edges to well-develop forests. Nesting in the soil and rotting logs.