Pheidole pieli Santschi

Eguchi, K., 2008, A revision of Northern Vietnamese species of the ant genus Pheidole (Insecta: Hymenoptera: Formicidae: Myrmicinae)., Zootaxa 1902, pp. 1-118 : 70-73

Pheidole pieli Santschi

Figs. 19a-g

Pheidole pieli Santschi , 1925: 83. Ogata 1982: 195-196 (description of male), Yamane et al. 2003: 57 (checklist), Eguchi et al. 2004 (ecological study), Eguchi, Bui et al. 2005: 90 (checklist), Eguchi, Yamane & Zhou 2007: 265-269 (redescription of major & minor). Syntypes: 2 majors & 9 minors, "Zo-Se 27-7-24" [Zo-Ce, China], NHMB, examined.

Pheidole rinae subsp. incensa Wheeler , 1928: 13. Eguchi, Yamane & Zhou 2007: 265-269 (junior synonym of pieli ). Syntypes: 3 majors & 3 minors, "Peta, Foochow, Silvestri" [Foochow, China], MCZC cotype- 20669, examined.

Other material examined: Mainland Japan: Kagoshima: Eboshi-dake, ca. 100 m alt., Hirakawa, Kagoshima-shi [Eg02-JPN-11, -14, -15, -17]. Ryukyus: Tanega-shima I.: Makikawa, 15 m alt., stream-side [M. Yano's colony: No. Ph84010]; Yaku-shima I.: Hanyama, [Y. Nishizono]; Kuchinoerabu-jima I.: Honmura, [S. Handa's colony: No. P.89-33, P.90-09]; Okinoerabu-jima I. [A. Shimono: Bait #29]; Okinawa-jima I.: Nago, [Sk. Yamane], Naha-shi [Y. Nishizono]; Ishigaki-jima I.: Omoto-dake, 90 m alt.; Iriomote-jima I.: [H. Watanabe's colony: No. P.91-06], Ohtomi [M. Terayama], upper Urauchi-gawa River [Y. Nishizono], Udara-gawa, Amitori [Y. Nishizono]; Yonaguni-jima I.: Tindabana, Sonai [H. Watanabe's colony: No. P.91- 01]. S. China: Guangxi: New campus of Guangxi Normal Univ., Guilin City [Eg00-GNGX-05], Mt. Mao Er Shan, 690 m alt. [Eg00-GNGX-039]; Hong Kong: Victoria Park, Hong Kong I. [Eg99-HK-33], Taipo Kau N.P., New Territory [Eg99-HK-11; Eg00-HK-20, -026; J. Fellowes]. N. Vietnam: Bac Kan: Ba Be N.P., 22°24'N, 105°38'E, 200-220 m alt. [T.V. Bui]; Bac Giang: W. Yen Tu N.P. (= Tay Yen Tu N.P.), 21°10-11'N, 106°43-44'E, 170 m alt. [Eg03-VN-078], W. Yen Tu N.P., 190 m alt. [Eg03-VN-037], W. Yen Tu N.P., 195 m alt. [B&E03-8], W. Yen Tu N.P., 1070 m alt. [Eg03-VN-123]; Quang Ninh: Ky Thuong N.R., 21°09'N, 107°06'E, 570 m alt. [Eg03-VN-212], Chua Yen Tu, 21°09'N, 106°43'E, 720-845 m alt. [Eg04-VN-040, - 041, -046, -068]; Vinh Phuc: Tam Dao N.P., 900 m alt. [Eg99-VN-064, -066; Eg01-VN-107, -113]; Ha Tay (mislabeled as "Ha Tai"): Ba Vi N.P., 21°03'N, 105°22'E, 400-600 m alt. [Eg02-VN-004], Ba Vi N.P., 400- 800 m alt. [Eg99-VN-096], Ba Vi N.P., 670 m alt. [Eg01-VN-226], Ba Vi N.P., 800 m alt. [Eg02-VN-056]; Ninh Binh: Cuc Phuong N.P., 20°14'N, 105°36'E [Eg10vi05-23]; Hoa Binh: Moc Chau [K. Ogata: 15 min.- TUS#3]; Nghe An: Pu Mat N.P. (Pha Lai Area) [Eg26iii06-04]; Pu Mat N.P. (Sang Le Forest Area, 19°11'N, 104°37-38'E, <220 m alt.) [Eg01iv06-12]; Ban Om, 600 m alt., Pu Hoat [T.V. Bui]. Thailand: Chiang Mai: Campus of Chiang Mai Univ. [Eg01-TH-154, -157, -163], Doi Suthep-Pui N.P., 800-900 m alt. [Eg01-TH- 104, -106, -108], Doi Suthep-Pui N.P., 900 m alt. [K. Eguchi]; Chanthaburi: Khao Soi Dao [Eg01-TH-026, - 028]; Nakonratchasima: nr. Sakaerat Environmental Research Centre [Eg99-TH-011, -015, -021]; Kanchanaburi: Srinakarin Dam N.P., 150-200 m alt. [TH02-SKY-40]; Songkhla: Songkhla Univ., Khao Kor Hong [Eg01-TH-600]. Eguchi's informal species code " Pheidole sp. eg-104" has been applied to these specimens.

Worker measurements & indices: Major (data from Eguchi, Yamane & Zhou 2007). - HL 0.79-1.03 mm; HW 0.69-0.97 mm; CI 85-96; SL 0.35-0.48 mm; SI 46-51; FL 0.44-0.60 mm; FI 59-66.

Minor (data from Eguchi, Yamane & Zhou 2007). - HL 0.38-0.47 mm; HW 0.33-0.43 mm; CI 85-92; SL 0.31-0.42 mm; SI 89-108; FL 0.32-0.44 mm; FI 92-111.

Worker description

Major. - Head in lateral view hardly or weakly (rarely strongly) impressed on vertex; frons longitudinally rugose; vertex and dorsal and dorsolateral faces of vertexal lobe reticulate, rugoso-reticulate or obliquely rugose, or rarely sculptured dimly; frontal carina inconspicuous, present just as rugula(e); antennal scrobe absent or inconspicuous; median longitudinal carina on clypeus absent or evanescent, or sometimes present but very weak; median process of hypostoma usually conspicuous, but rarely inconspicuous or almost absent; submedian and lateral processes always conspicuous; antenna with a 3-segmented club; maximal diameter of eye (a little) longer than antennal segment X. Promesonotal dome smooth and shining, sparsely sculptured with transverse or irregular rugulae, in lateral view at most with an inconspicuous mound on its posterior slope; humerus of the dome weakly or sometimes very weakly produced laterad; the dome at the humeri almost as broad as or a little broader than at the bottom (rarely a little narrower than at the bottom). Petiole (much) longer than postpetiole (excluding helcium); postpetiole not massive. First gastral tergite usually smooth, excluding weakly rugoso-punctate area around its articulation with postpetiole, but rarely shagreened entirely.

Minor. - Frons largely smooth and shining, or rarely shagreened with weak rugulae; vertex and dorsolateral face of head almost smooth, or very weakly rugoso-reticulate or rugoso-punctate; preoccipital carina absent or evanescent dorsally; median part of clypeus smooth and shining; the median longitudinal carina absent, or rarely present but very weak; antenna with a 3-segmented club; scape not reaching or exceeding the posterior margin of head by at most the length of second antennal segment; maximal diameter of eye (a little) longer than antennal segment X (rarely as long as antennal segment X). Promesonotal dome smooth and shining, often with weak transverse rugula(e) on its anterior slope, in lateral view without a mound on its relatively steep posterior slope; humerus of the dome in dorso-oblique view not or hardly produced; mesopleuron, metapleuron and lateral face of propodeum usually almost smooth, but sometimes weakly punctured; propodeal spine usually reduced to a tiny dent. Petiole much longer than postpetiole (excluding helcium); postpetiole not massive.

Recognition: This species is characterized among Indo-Chinese species by the combination of the following features: in the major frontal carina inconspicuous, present just as rugula(e); in the major hypostoma in the middle with 3 processes (median process rarely inconspicuous or absent); in the minor preoccipital carina absent or evanescent dorsally; in the minor promesonotal dome smooth and shining, often with weak transverse rugula(e); in the major and minor posterior slope of promesonotal dome without a conspicuous prominence /mound; in the minor propodeal spine usually reduced to a tiny dent.

P. pieli is most similar to P. laevicolor and P. taipoana among Indo-Chinese species, but the minor of the latter two has rather developed propodeal spines and rather gentle posterior slope of promesonotal dome. Head in lateral view is more strongly concave on vertex in the major of P. taipoana than in that of P. pieli .

Distribution & bionomics: Known from N. Vietnam, S. Japan, China and Thailand. Indo-Chinese populations usually occur in forest edges and patches with poorly developed vegetation than in well-developed forests, and nest in the soil. On the other hand, Japanese populations usually occur in relatively developed forests, and nest in wood fragments on the ground as well as in the soil (Eguchi et al. 2004, Eguchi, Yamane & Zhou 2005). According to Eguchi (2004b) workers gather and feed on seeds of sesame and amaranthus put on the ground in S. Japan. Majors serve as repletes (Handa 1992).