Platythyrea clypeata Forel, 1911

Jaitrong, Weeyawat, Xu, Zhenghui & Khachonpisitsak, Salinee, 2022, A new species of the ant Platythyrea clypeata species group (Hymenoptera, Formicidae, Ponerinae) from continental Asia, ZooKeys 1115, pp. 151-168 : 151

Platythyrea clypeata Forel, 1911

Figs 2 , 5A1-A3

Platythyrea clypeata Forel, 1911: 378; Brown 1975: 50; Bolton 1995: 336; Schmidt and Shattuck 2014: 51; Khachonpisitsak et al. 2020: 153. Senior synonym of P. thwaitesi : Brown 1975: 8.

Platythyrea thwaitesi Donisthorpe, 1931: 496. Junior synonym of P. clypeata : Brown 1975: 8.

Type.

Holotype of P. clypeata : alate queen from " Pays des Mois" , Cochinchinne française (Indochina), deposited in MHNG (AntWeb image examined, CASENT0907112). Holotype of P. thwaitesi : alate queen from Sri Lanka, deposited in BMNH (AntWeb image examined, CASENT0900568) .

Non-type material examined.

Laos • 10 workers (THNHM-I-24983) and 1 dealate queen (THNHM-I-24982), Laos, Vientiane, Pak Ngum District, Ban Phang Dang, ca 300 m alt., 14.VI.2010, W. Jaitrong leg., Colony no. WJT-LAO-143 (THNHM-I-24981) • 1 worker (THNHM-I-24984), Laos, Vientiane, Pak Ngum District, Ban Phang Dang, 14.VI.2010, Sk. Yamane leg., Colony no. LA10-SKY-128 • 1 worker (THNHM-I-24981) Laos, Vientiane, Pak Ngum District, Ban Phang Dang, ca 300 m alt., 12.VI.2010, W. Jaitrong leg. - Thailand • 9 workers (THNHM-I-02423 to THNHM-I-02431), eastern Thailand, Chachoengsao Province, Tha Takiab District, Khao Ang Reu Nai Wildlife Sanctuary, 27.IX.2002, W. Jaitrong leg., Colony no. WJT270902-01 • 3 workers (THNHM-I-02432 to THNHM-I-02434), same locality, date and collector, Colony no. WJT270902-1 • 6 workers (THNHM-I-02435 to THNHM-I-02440), eastern Thailand, Sa Kaeo Province, Khao Ang Reu Nei Wildlife Sanctuary, 26.VI.2003, W. Jaitrong leg., Colony no. WJT03-TH-228; 22 workers (THNHM-I-02441 to THNHM-I-02452) and 1 male (THNHM-I-02453), eastern Thailand, Chanthaburi Province, Soi Dao District, 14.V.2008, W. Jaitrong leg., Colony no. WJT08-E065 • 14 workers (THNHM-I-24980, THNHM) and 1 dealate queen, central Thailand, Nakhon Nayok Prov., Muang Dist., Nang Rong Temple, in rotting wood, 29.VIII.2018, W. Jaitrong leg., Colony no. WJT290819-09.

Measurements and indices

(n = 10). TL 5.74-6.20, HL 1.29-1.39, HW 0.86-0.89, SL 1.12-1.18, EL 0.10, PW 0.76-0.83, ML 1.85-2.05, PL 0.66-0.73, PH 0.46-0.53, DPW 0.40-0.43, CI 61-69, EI 11, SI 125-138.

Description of workers.

Head in full-face view rectangular, clearly longer than broad, with sides weakly convex or almost parallel, posterior corners narrowly rounded, posterior margin feebly concave. Antennae relatively short, scapes extending beyond posterior corners of head by about 1/5 of their length. Clypeus roughly triangular, median portion distinctly convex, anterior margin bluntly angled. Mandibles triangular, masticatory margin with a large apical tooth, followed by about ten smaller teeth, large and small teeth alternating, basal margin without denticle. Eye very small and flat, located laterally at anterior to mid-length of head, with five ommatidia along longest axis. Frontal lobes close to each other and rounded. Space between frontal carinae distinctly narrowed posteriad.

Mesosoma elongate, in profile pronotum weakly convex, promesonotal suture distinct, dorsal outline of mesonotum and propodeum straight, metanotal groove absent, propodeal junction broadly rounded, declivity of propodeum obviously concave, propodeal spiracle opening elliptical. Legs long.

Petiole cylindrical in profile view and sessile; in profile view clearly longer than high, dorsal outline almost straight, anterodorsal corner broadly rounded, posterodorsal corner forming an acute angle, posterior margin weakly concave, ventral margin weakly concave with narrowly rounded anteroventral corner; in dorsal view the node roughly rectangular, longer than broad, slightly narrower posteriorly, posterior margin convex and with shallow median concavity.

Sculpture. Dorsum of head finely punctate, lateral face of head above eyes punctate, with dense foveae. Dorsum of mesosoma finely punctate similar to dorsum of head, lateral faces of pronotum, metapleuron and propodeum punctate, with sparse shallow foveae. Petiole finely micropunctate. Gastral tergites I and II finely reticulate. Antennal scapes finely micropunctate.

Pilosity. Pubescence very short and fine all over the body surface; standing hairs present on tip of gaster.

Coloration. Body color reddish brown to darkish brown; antennae, legs, and tip of gaster yellowish brown to reddish brown. Eyes grey. Pilosity white.

Description of dealate queen.

See Phengsi et al. (2018).

Habitat.

Platythyrea clypeata occurs in the lowlands (200-300 m alt.) and inhabits primary dry evergreen forest and disturbed forests. All colonies of this species were collected from dead wood on the forest floor in an advanced stage of decomposition.

Distribution.

Sri Lanka, Vietnam, Laos (Vientiane), and Thailand (Chachoengsao, Sa Kaeo, Chanthaburi, and Nakhon Nayok provinces) (Fig. 6).

Comparative notes.

Platythyrea clypeata is similar to P. gracillima , P. janyai , and P. prizo . However, P. clypeata can be easily separated from P. gracillima by the following characteristics (characters of P. gracillima in parentheses unless otherwise stated): 1) body size smaller (TL = 5.74-6.20 in P. clypeata ; TL = 9 mm in P. gracillima ); 2) eye smaller and flat (0.1 mm long in P. clypeata ; 0.3 mm long and convex in P. gracillima ); 3) clypeus narrow and rather convex (clypeus broad and rather flat); 4) declivity of propodeum concave (propodeal declivity flat); 5) seen from back propodeal declivity rounded above (propodeal declivity concave above); 6) petiole laterally swollen (petiole laterally compressed); 7) head finely punctate (head rather smooth).

Platythyrea clypeata can be distinguished from P. prizo by the following characteristics (characters of P. prizo in parentheses unless otherwise stated): 1) head shorter (CI = 61-69 in P. clypeata ; CI = 70-72 in P. prizo ); 2) eye flat and small (0.1 long mm in P. clypeata ; eye very large, 0.31 long mm P. prizo ); 3) eye without erect pubescence (eye covered with extremely fine short erect pubescence); 4) propodeum junction obtusely angulated (propodeum junction armed with a pair of short teeth or tubercles); 5) in profile, posterodorsal corner of petiole forming an acute angle (roundly convex).

Lastly, this species is separated from P. janyai (characters of P. janyai in parentheses unless otherwise stated) by 1) head relatively longer (CI 61-69 in P. clypeata ; CI 72-74 in P. janyai ); 2) eye clearly smaller (EL 0.10 mm long with 5 ommatidia on longest axis in P. clypeata ; EL 0.20 mm long with 11 ommatidia on longest axis in P. janyai ); 3) eye flat (eye convex); 4) head finely punctate with dense shallow foveae (dorsum and lateral face of head finely micropunctate without foveae); 5) in profile petiole slightly longer than high and in dorsal view its node slightly narrower posteriorly (clearly longer than high and in dorsal view node anteriorly as broad as posteriorly); 6) ventral outline of petiole feebly concave (weakly convex) (see Fig. 5 for comparison).

Figures

Figure 2. Platythyrea clypeata (non-type worker, WJT 290819 - 09). A body in profile view B head in full-face view C body in dorsal view.

Figure 5. SEM images of Platythyrea clypeata (A 1 - A 3) P. homasawini sp. nov. (B 1 - B 3) and P. janyai (C 1 - C 3). A 1, B 1, C 1 sculpture on lateral face of head A 2, B 2, C 2 ommatidia of eye A 3, B 3, C 3 petiole in profile view.