Pheidole Westwood

Eguchi, K., Viet, B. T. & Yamane, S., 2011, Generic synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part I - Myrmicinae and Pseudomyrmicinae., Zootaxa 2878, pp. 1-61 : 23-24

Pheidole Westwood , 1839

Taxonomy. The genus Pheidole is placed in the tribe Pheidolini (for its complete taxonomic history see Bolton (2003) and Bolton et al. (2006)). North Vietnamese species of the genus were recently revised and 31 species were recognized by Eguchi (2008). Workers of Vietnamese species have the following features.

Worker dimorphic; major with head in full-face view subrectangular, subtrapezoidal or cordate, with posterolateral corner developed as preoccipital lobe; minor with head in full-face view oval, elliptical or subrectangular; frontal lobes far apart so that posteromedian portion of clypeus, where it projects between frontal lobes, is usually broader than one of the lobes; midpoint of anterior clypeal margin without an unpaired median seta; mandible of major massive, with 2 large apical and 1 or 2 conspicuous basal teeth, and margin between these groups of teeth edentate or irregularly and bluntly crenulate; mandible of minor triangular; masticatory margin with 7 or more teeth/denticles; 1 or 2 small denticles present between preapical tooth and 3rd large tooth; in major hypostoma always bearing a large or reduced "lateral" process just mesal to each mandibular base, and often bearing a "median" process and/or a pair of "submedian" processes, i.e. middle of hypostoma bearing 0-3 processes; palp formula 2,2; antenna 12-segmented, with 3- or 4-segmented club, or without a conspicuous club (3-segmented club the dominant condition); eye always present but varying in size, rarely consisting of only a few ommatidia; promesonotum forming a dome which is well raised above level of dorsum of propodeum; promesonotal suture absent or indistinct dorsally; posterior slope of promesonotal dome sometimes with a mound or prominence; metanotal groove weakly to strongly impressed dorsally; propodeal spine usually present (rarely vestigial or almost absent), and variable in size and shape; propodeal lobe inconspicuous, or present as a low lamella, or moderately roundly expanded; petiole in lateral view consisting of slender anterior peduncle and raised posterior node, or petiole gradually rising from base to summit of node; postpetiole in lateral view hemispherical, globular or highly domed, sometimes with anteroventral angle or projection.

The minor worker of Pheidole is similar to the worker of Aphaenogaster (for distinguishing characters see under Aphaenogaster ), Kartidris and Lophomyrmex (see under Lophomyrmex ). However, in the worker of Kartidris , the masticatory margin of the mandible bears 5 sharp teeth which decrease in size from the apex to the base, and a broad depressed area is present on the vertex between the eyes.

Vietnamese species. Forty-two species have been recognized by us from Vietnam: aspidata Eguchi & Bui (Nam Cat Tien); binghamii Forel (Binh Chau-Phuoc Buu, Nam Cat Tien, Phu Quoc); capellinii Emery (Ba Vi, Nam Cat Tien); colpigaleata Eguchi (Ba Vi, Sa Pa, Tay Yen Tu); dugasi Forel (Ba Vi, Cuc Phuong, Nam Cat Tien); elongicephala Eguchi (Ba Vi, Cuc Phuong, My Yen, Tay Yen Tu, Van Ban); fervens F. Smith (Ha Noi, My Yen, Nui Chua); fervida F. S m i t h (Sa Pa); fortis Eguchi (Sa Pa, Tam Dao); foveolata Eguchi (Sa Pa); gatesi (Wheeler) (Ba Vi, Cuc Phuong, Tam Dao); hongkongensis Wheeler (Ba Be, My Yen, Pu Mat, Tam Dao, Tay Yen Tu, Van Ban); indosinensis Wheeler (Ba Vi, Tam Dao); laevicolor Eguchi (Ba Be, Ba Vi, Chua Yen Tu, My Yen, Tay Yen Tu, Van Ban); laevithorax Eguchi (Ba Vi, Chua Yen Tu, Tay Yen Tu); magna Eguchi (Ba Vi, Sa Pa); megacephala (Fabricius) (Ha Noi, Quang Ninh, Vinh Long); noda F. Smith (Ba Be, Ba Vi, Chua Yen Tu, Cuc Phuong, Sa Pa, Tam Dao, Van Ban); ochracea Eguchi (Ba Vi, Nam Cat Tien, Sa Pa, Tam Dao, Tay Yen Tu); parva Mayr (Cuc Phuong, Ho Chi Minh City, My Yen); pieli Santschi (Ba Be, Ba Vi, Chua Yen Tu, Cuc Phuong, Hoa Binh, Ky Thuong, Phu Quoc, Pu Hoat, Pu Mat, Tam Dao, Tay Yen Tu, Van Ban); plagiaria F. S m i t h (Ba Vi, My Yen, Tam Dao, Phu Quoc); planidorsum Eguchi (Nam Cat Tien); planifrons Santschi (Nam Cat Tien, Pu Mat, Tam Dao, Tay Yen Tu, Van Ban); rabo Forel (Ba Vi, Chua Yen Tu, Cuc Phuong, Ky Thuong, Nam Cat Tien, Phu Quoc, Pu Mat, Tay Yen Tu, Van Ban); rinae Emery (Nam Cat Tien); rugithorax Eguchi (Pu Mat, Nam Cat Tien, Nui Chua, Phu Quoc); smythiesii Forel (Ba Vi, Pu Hoat, Tam Dao); taipoana Wheeler (Ky Thuong, Pu Mat); tandjongensis Forel (Phu Quoc); tjibodana Forel (Ba Be, Chua Yen Tu, Cuc Phuong, Nam Cat Tien, Ky Thuong, Pu Mat, Tay Yen Tu, V a n B a n); tumida Eguchi (Ba Be, Ba Vi, Chua Yen Tu, Cuc Phuong, Ky Thuong, Nam Cat Tien, Nui Chua, Pu Mat, Tay Yen Tu; Van Ban); vieti Eguchi (Ba Vi, Tam Dao); vulgaris Eguchi (Ba Vi, Chua Yen Tu, Cuc Phuong, Ky Thuong, My Yen, Sa Pa, Tam Dao, Tay Yen Tu); yeensis Forel (Ba Be, Ba Vi, Cuc Phuong, Ky Thuong, My Yen, Nam Cat Tien, Pu Hoat, Pu Mat, Tam Dao, Tay Yen Tu); zoceana Santschi (Pu Hoat, Sa Pa); sp. eg-165 (Lam Dong); sp. eg-170 (Nam Cat Tien); sp. eg-179 (Nam Cat Tien); sp. eg-187 (Nui Chua); sp. eg-188 (Van Ban); sp. eg-189 (Nui Chua).

Bionomics. Pheidole inhabits various habitats such as bare lands, grasslands, forest edges and well-developed forests. Their nests are usually found in rotting logs, twigs, wood fragments, under stones and in soil. The majority of species forage on the ground, but some such as P. v u lg a r is forage both on and under the ground.