Pheidole parva

This species prefers open lands, tillage and gardens to woody habitats, and nests under the ground. In rural areas of N. Vietnamese this species and Pheidole yeensis are the most dominant Pheidole species. (Eguchi 2008)

Identification
Eguchi (2008) - This species is characterized among Indo-Chinese species by the combination of the following features: in the major frontal carina almost absent; in the major hypostoma in the middle with 3 processes (median process is often low, rarely much reduced); in the minor scape exceeding posterior margin of head by less than half length of antennal segment II, or not reaching the posterior margin; in the minor maximal diameter of eye longer than antennal segment X; in the minor dorsal and lateral faces of head and mesosoma punctured; in the major and minor posterior slope of promesonotal dome lacking a conspicuous prominence/mound.

P. parva is most similar to Pheidole rabo Forel. In the minor of the latter, however, scape usually exceeds posterior margin of head by almost the length of antennal segment II, and maximal diameter of eye is almost as long as or a little shorter than antennal segment X.

Key to Pheidole of North Vietnam

Distribution
Widely distributed in the Oriental region, Austro-Malayan subregion and W. Pacific.

Distribution based on Regional Taxon Lists
Afrotropical Region: Saudi Arabia, United Arab Emirates. Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines. Malagasy Region: Mauritius, Seychelles. Oriental Region: India, Myanmar, Sri Lanka, Taiwan, Thailand, Vietnam. Palaearctic Region: China, Japan.

Nomenclature

 *  parva. Pheidole parva Mayr, 1865: 98, pl. 4, fig. 28 (s.w.) SRI LANKA. Bingham, 1903: 245 (q.). Senior synonym of bugi, decanica, mala, sauteri, tipuna: Eguchi, Yamane & Zhou, 2007: 262; of farquharensis, tarda: Fischer & Fisher, 2013: 340.
 * decanica. Pheidole parva var. decanica Forel, 1902c: 175 (s.), 192 (w.q.m.) INDIA. [Also described as new by Forel, 1902f: 542.] Junior synonym of parva: Eguchi, Yamane & Zhou, 2007: 261.
 * sauteri. Pheidole sauteri Wheeler, W.M. 1909d: 334 (s.w.) TAIWAN. Junior synonym of parva: Eguchi, Yamane & Zhou, 2007: 262.
 * mala. Pheidole rinae var. mala Forel, 1911b: 205 (s.w.) INDONESIA (Java). Junior synonym of parva: Eguchi, Yamane & Zhou, 2007: 262.
 * tipuna. Pheidole rinae r. tipuna Forel, 1912a: 68 (s.w.) TAIWAN. Junior synonym of parva: Eguchi, Yamane & Zhou, 2007: 262.
 * bugi. Pheidole bugi Wheeler, W.M. 1919e: 66 (s.w.) BORNEO. Junior synonym of parva: Eguchi, Yamane & Zhou, 2007: 262. See also: Eguchi, 2001b: 37.
 * farquharensis. Pheidole flavens var. farquharensis Forel, 1907d: 91 (w.) MADAGASCAR. Junior synonym of parva: Fischer & Fisher, 2013: 340. See also: Wilson, 2003: 419.
 * tarda. Pheidole (Pheidole) tardus Donisthorpe, 1947a: 285 (q.) MAURITIUS. Junior synonym of parva: Fischer & Fisher, 2013: 341.

Worker
Eguchi (2008) - Major (data from Eguchi, Yamane & Zhou 2007). — HL 0.96–1.07 mm; HW 0.85–0.92 mm; CI 85–92; SL 0.41–0.45 mm; SI 45–51; FL 0.57–0.62 mm; FI 64–68. Minor (data from Eguchi, Yamane & Zhou 2007). — HL 0.43–0.54 mm; HW 0.39–0.50 mm; CI 88–94; SL 0.38–0.46 mm; SI 84–102; FL 0.39–0.48 mm; FI 93–109.

Major — Head in lateral view not or very weakly impressed on vertex; frons to anterior part of vertex longitudinally rugose; posterior part of vertex rusogo-reticulate; dorsal and dorsolateral faces of vertexal lobe reticulate or rusogo-reticulate; frontal carina absent or inconspicuous (present just as weak rugulae); antennal scrobe absent; median longitudinal carina on clypeus absent, or rarely present but weak; hypostoma with median and submedian processes in addition to conspicuous lateral processes; median process often lower than submedian process, or sometimes almost disappearing; submedian processes usually conspicuous; outer surface of mandible (excluding area around the base) smooth or dimly rugose partly, sparsely with (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 or irregularly rugose with interspaces smooth or dimly to distinctly punctured, or punctured weakly; the dome in lateral view at most with an inconspicuous mound on its posterior slope; humerus weakly produced laterad; the dome at the humeri almost as broad as or broader than at the bottom. Petiole much longer than postpetiole (excluding helcium); petiolar node in lateral view relatively high; postpetiole not massive; first gastral tergite weakly rugoso-punctate in its anterior 1/3 or at least around its articulation with postpetiole.

Minor — Dorsum of head punctured and often overlain by weak rugoso-reticulation; preoccipital carina absent or inconspicuous dorsally; median part of clypeus smooth or weakly punctured; median longitudinal carina absent, or present but weak; antenna with a 3-segmented club; scape exceeding posterior margin of head by less than half length of antennal segment II, or not reaching the posterior margin; maximal diameter of eye longer than antennal segment X. Mesosoma punctured; punctuation on dorsum of promesonotal dome often overlain sparsely by weak rugulae; promesonotal dome in lateral view relatively weakly convex, at most with an inconspicuous mound on its posterior slope; humerus in dorso-oblique view very weakly produced; propodeal spine elongate-triangular. Petiole much longer than postpetiole (excluding helcium); postpetiole not massive.

Type Material
Eguchi (2008):

Syntypes: 1 major & 2 minors, “Ceylon” [= Sri Lanka],, examined.

Pheidole parva var. decanica. Lectotype: major, “Cochin (Inde) (Rothney)” [India], MHNG, examined; paralectotypes: 2 majors, “Cochin (Inde) (Rothney)” [India],, examined; 3 minors, “Kanara XXXI 8 (Aitken)” [India], MHNG, examined; 3 queens, “Belgaum. (Wroughton) XXXII 1c” [India], MHNG, exam- ined; 3 males, “Belgaum (Wroughton) XXXII 1b”, MHNG, examined; specimens from Poona [India] and Ceylon [Sri Lanka] (according to the original description), not examined.

Pheidole bugi. Lectotype: major, “Sarawak, Borneo, R. Thaxter”, cotype-8947, examined.

Pheidole rinae var. mala. Lectotype: major, “Semarang Java (Jacobson)”, MHNG, examined; paralectotypes: 2 majors & 3 minors, “Semarang Java (Jacobson)”, MHNG, examined.

Pheidole rinae r. tipuna. Lectotype: major, “Takao Formose (Sauter) 25” [= Kaoshung, Taiwan], MHNG, examined; paralectotypes: 3 minors, “Takao 25 Formose (Sauter)”, MHNG, examined.

Pheidole sauteri. Syntypes: 3 majors & 19 minors, “Takao, Formosa, H. Sauter” [= Kaoshung, Taiwan], MCZC cotype 20671, examined.