Pheidole tjibodana Forel, 2001

Eguchi, Katsuyuki, 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae), Zootaxa 1902 (1), pp. 1-118 : 93-96

Pheidole tjibodana Forel

Figs. 26a–g

Pheidole nodgii var. tjibodana Forel, 1905 c: 16 . Lectotype: major, “Tjibodas, Java K. Kraepelin leg. 25-28/ III/1904 ” [ Cibodas , Java, Indonesia], MHNG, examined; paralectotypes: 1 minor & 1 queen, same data as lectotype, MHNG, examined.

Pheidole tjibodana Forel. Eguchi 2001a: 29–30 (raised to species, lectotype designation, redescription of major & minor).

Pheidole sp. eg-161. Yamane et al. 2003: 58.

Other material examined: Vietnam: Bac Kan: Ba Be N.P., 22°24–25N’, 105°37–38’, <260 m alt. [Eg04-VN-194, -204, -207, -215]; Quang Ninh: Chua Yen Tu , 21°09’N, 106°43’E, 720–845 m alt. [Eg04- VN-024]; Ky Thuong N.R., 21°09–11’N, 107°06–07’E, 160–570 m alt. [Eg03-VN-175, -215]; Ninh Binh: Cuc Phuong N.P., 20°14’N, 105°36’E [Eg 14vi05-05]; Dong Nai: S. Cat Tien N.P., <160 m alt. [Eg 04-VN- 584, -644, -651] . Thailand: Nakhonratchasima: Khao Yai N.P., 900–1000 m alt. [TH00-SKY-15]; Chacheong- sao: Lumchangwat Station , Khao Ang Rew Nai W.S. [TH03-SKY-86]; Trang: Khao Chong Waterfall [Eg 01- TH-713]. W . Malaysia: Johor: Kota Tingii Fall , 100 m alt. [P.S. Ward #9586-15]. E . Malaysia: Sabah: Tawau Hills Park [Eg96-BOR-031, -039], Guong Rara [Eg97-BOR-565], Poring , 600 m alt. [T. Kikuta’s colony: 6XI0106-16-1], Sayap Kinabalu [K. Eguchi’s soil sample: S-27] . Indonesia: W. Java: G. Sarak, nr. Bogor [JA97-SKY-12], Halimun [FI98-382], Cibodas [K. Ohkawara’s colony: 10/1a (1999)] .

Worker measurements & indices: Major (n=5). — HL 0.97–1.14 mm, HW 0.95–1.05 mm, CI 89–100, SL 0.49–0.53 mm, SI 48–52, FL 0.54–0.63 mm, FI 56–61.

Minor (n=5). — HL 0.51–0.55 mm, HW 0.49–0.55 mm, CI 92–100, SL 0.42–0.47 mm, SI 84–96, FL 0.45–0.51 mm, FI 90–100.

Worker description

Major. — Head in lateral view not or hardly impressed on vertex, sometimes highly raised on the posterior part of frons; anterior part of frons longitudinally rugose; posterior part of frons, vertex and dorsal and dorsolateral faces of vertexal lobe reticulate; frontal carina well developed horizontally, partly overhanging antennal scrobe; median longitudinal carina of clypeus absent, or sometimes present but very weak; hypostoma with a very large median process in addition to well-developed lateral processes; submedian processes nearly or completely absent; outer surface of mandible (excluding area around the base) smooth, with sparse and very short appressed hairs; antenna with a 3-segmented club; maximal diameter of eye longer or much longer than antennal segment X. Promesonotal dome in dorsal view reticulate, in lateral view at most with an inconspicuous or low mound/process on its posterior slope; humerus moderately produced laterad; the dome at the humeri as broad as or broader than at the bottom; propodeal spine usually well developed as a long horn. Petiole much longer than postpetiole (excluding helcium); postpetiole not massive. First gastral tergite smooth to shagreened largely, or weakly punctured anteriorly and shagreened posteriorly.

Minor. — Dorsum of head well punctured and overlain by weak rugoso-reticulation, or well reticulate with enclosure weakly or dimly punctured; preoccipital carina inconspicuous or very weak dorsally; median part of clypeus rugoso-reticulate, or punctured and overlain by very weak rugoso-reticulation; median longitudinal carina absent, or present as rugula(e); antenna with a 3-segmented club; scape usually exceeding posterior margin of head by less than the length of antennal segment II, but sometimes not exceeding posterior margin; maximal diameter of eye almost as long as or a little longer than antennal segment X (but rarely a little shorther than antennal segment X). Dorsum of promesonotal dome well punctured and overlain by weak rugoso-reticulation, or well reticulate with enclosure weakly or dimly punctured; lateral face of promesonotal dome, mesopleuron, metapleuron and lateral face of propodeum well punctured; promesonotal dome in lateral view lacking a conspicuous mound on its posterior slope; humerus of the dome in dorso-oblique view produced weakly or forming a small tubercle; propodeal spine variable in size and shape. Petiole much longer than postpetiole (excluding helcium); postpetiole not massive.

Recognition: Based on his examination of the type material Eguchi (2001a) distinguished Pheidole tjibodana from P. nodgii Forel (lectotype (major) & paralectotype minor, “Depok, Java K. Kraepelin leg. 9. III. 1904 ” [Jakarta, Java, Indonesia], MHNG; 1 paralectotype queen, “Buitenzorg, Java K. Kraepelin leg. 24. II. - 12. III. 1904 ” [Bogor, Java], MHNG) based on the following differences: posterior part of frons of the major higher in P. tjibodana than in P. nodgii ; posterior slope of promesonotal dome of the minor steeper in P. tjibodana than in P. nodgii . Intermediate conditions in each of the two “diagnostic characters” were, however, observed in the present examination of nontype material. On the other hand, postpetiole of the minor of P. nodgii were always highly raised and somewhat globular in lateral view. I at present treat them as different species, although only two colonies (FI96-253 & FI97-551 from Bogor, W. Java) referable to P. nodgii have been found.

This species is well characterized among Indo-Chinese species by the combination of the following features: in the major frontal carina well developed horizontally, partly overhanging antennal scrobe; in the major median process well developed but submedian processes absent; in the minor dorsum of head and mesosoma punctured or reticulate with enclosures punctured weakly or dimly; in the major and minor promesonotal dome in lateral view at most with a low or inconspicuous mound on its posterior slope.

Distribution & bionomics: Known from the Indo-Chinese and Indo-Malayan subregions. This species is wide spread through the Indo-Chinese and Indo-Malayan subregions, and inhabits forest from lowland to hilly areas. Bornean populations usually nest in litter, but Vietnamese populations usually nest in rotting twigs and small wood fragments. Small seeds are sometimes stored inside the nest [Eg96-BOR-031, Eg04-VN-215]. The number of adults per colony is: 8 majors, 71 minors, 1 dealate queen & 3 alate queens [Eg04-VN-204]; 5 majors, 52 minors & 1 dealate queen (with queen pupae) [Eg04-VN-207]; 24 majors, 259 minors, 1 dealate queen & 31 alate queens [Eg04-VN-215].

Figures

FIGURE 26a–d, Pheidole tjibodana, major [Eg03-VN-175] — 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.