Pheidole hongkongensis Wheeler

Eguchi, K., 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae)., Zootaxa 1902, pp. 1-118 : 40-43

Pheidole hongkongensis Wheeler

Figs. 10a-g

Pheidole rinae subsp. hongkongensis Wheeler , 1928: 11. Eguchi 2001a: 23 (lectotype designation). Lectotype: major, "Hong Kong, Silvestri", MCZC cotype-20668, examined; paralectotypes: 2 majors, 2 minors & 2 queens, same data as lectotype, MCZC cotype-20668, examined.

Pheidole hongkongensis Wheeler . Zhou & Zheng, 1999: 87 (raised to species), Eguchi, Bui et al. 2005: 89 (checklist), Eguchi, Yamane & Zhou 2007: 259-261 (redescription of the major and minor are given, but two majors and three minors of Pheidole sp. eg-179 were erroneously combined).

Other material examined: China: Hong Kong: Victoria Park, Hong Kong I. [Eg99-HK-34], nr. Taipo Kau N.P., New Territory [Eg00-HK-31]; Macau: Taipa Grande Trail, Taipa I. [Eg99-MAC-09, -10], Taipa I. [Eg99-MAC-03], Hac-Sa, Coloane I. [Eg99-MAC-11]; Hainan: Qingpilin N.R., Warning [J. Fellowes]. Vietnam: Bac Kan: Ba Be N.P., 22°24' N, 105°38'E, ca. 215 m alt. [10-min TUS sample: Eg-6-5, BTV-6-5]; Thai Nguyen: My Yen Commune Forest (edge of secondary forest), 21°35'N, 105°36'E, Na Hau Village [Eg01- VN-159]; Bac Giang: W. Yen Tu N.P., 21°10-11'N, 106°43-44'E, 170 m alt. [Eg03-VN-081]; Vinh Phuc: Tam Dao N.P., 900 m alt., [SKY], Tam Dao N.P., 21°27'N, 105°38'E [VN01-SKY-05]. Thailand: Nakonratchasima: Sakaerat lowland forest, dried dipterocorp forest [TH99-SKY-04]. Eguchi's informal species code " Pheidole sp. eg-103" has been applied to these specimens.

Worker measurements & indices: Major (n=7). - HL 0.96-1.11 mm; HW 0.82-0.93 mm; CI 84-87; SL 0.42-0.46 mm; SI 47-53; FL 0.57-0.65 mm; FI 68-71.

Minor (n=9 for HL, HW, SL, CI and SI, but n=8 for FL and FI). - HL 0.48-0.53 mm; HW 0.44-0.50 mm; CI 88-96; SL 0.41-0.45 mm; SI 89-96; FL 0.43-0.50 mm; FI 99-107. Worker description

Major. - Head in full-face view deeply concave posteromedially, in lateral view strongly impressed on vertex; frons and anterior part of vertex longitudinally rugose; posterior part of vertex rugose to reticulate; dorsum of vertexal lobe reticulate, or obliquely or transversely rugoso-reticulate; frontal carina weak but conspicuous, extending beyond midlength of head; antennal scrobe inconspicuous; clypeus without a median longitudinal carina; hypostoma with a conspicuous (or sometimes reduced) median process and conspicuous submedian processes in addition to conspicuous lateral processes; antenna with a 3-segmented club; maximal diameter of eye much longer than antennal segment X. Promesonotal dome in dorsal view rugose transversely or rugoso-reticulate, in lateral view at most having an inconspicuous mound on its posterior slope; humerus of the dome relatively well produced laterad; the dome at the humeri broader than at the bottom (but sometimes only a little broader 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 smooth or shagreened in the remainder.

Minor. - Frons and vertex smooth to weakly punctured, overlain sparsely by weak londigudinal rugulae; median part of clypeus smooth and shining; the median longitudinal carina absent, or sometimes present but weak; preoccipital carina absent dorsally on head; antenna with a 3-segmented club; scape reaching or exceeding posterior margin of head at most by 1.5* length of antennal segment II; maximal diameter of eye as long as or longer than antennal segment X. Promesonotal dome with sparse standing hairs, in lateral view relatively poorly convex or almost flat dorsally, often with an inconspicuous mound on its posterior slope; the mediodorsal part of the dome almost smooth to shagreened, usually overlain by several weak rugulae, or coarsely rugoso-reticulate; humerus in dorso-oblique view very weakly to weakly produced laterad; mesopleuron, metapleuron and lateral face of propodeum punctured; propodeal spine elongate-triangular. Petiole much longer than postpetiole (excluding helcium); postpetiole not massive.

Recognition: This species is similar to Pheidole taipoana Wheeler , but well separated from the latter which has the following characteristics: head smooth entirely in the minor; longitudinal rugulae on frons weak in the major.

The minor of P. hongkongensis is similar to that of P. planidorsum Eguchi . But in the major both impression on vertex in lateral view and concavity of posterior margin of head in full-face view are shallower in P. planidorsum than in P. hongkongensis . There is a certain possibility that P. planidorsum is just a variant of P. hongkongensis (see also Eguchi, Yamane & Zhou 2007).

Distribution & bionomics: Known from N. Vietnam, S. China and Thailand. This species usually inhabit woody gardens, forest edges and sometimes open habitats, and nests in the soil (but rarely in rotting wood as in colony VN01-SKY-05).