Chrysapace sauteri ( Forel, 1913 )

Yamada, Aiki, Lin, Chung-Chi & Eguchi, Katsuyuki, 2019, Taxonomic notes on the rare ant genus Chrysapace with description of a new species from Brunei (Hymenoptera: Formicidae: Dorylinae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (2), pp. 467-480 : 473-478

Chrysapace sauteri ( Forel, 1913)

( Figs 20–41 )

Cerapachys sauteri Forel, 1913: 187 , ♀.

Type locality: “Taihorin [= Dalin]” (Chiayi, Taiwan); TERAYAMA et al. (1998: 35, ♀, ♀, ♂).

Chrysapace sauteri: BOROWIEC (2016) : 106 (new combination).

Type material examined. SYNTYPE: ♀, Dalin , Chiayi, Taiwan, H. Sauter leg. [not shown in label, implied in FOREL (1913)], 1.vii.1911 ( DEIC) [images in AntWeb were examined (https://www.antweb.org/specimen/ FOCOL0376)].

Other material examined. TAIWAN: 1 ♂, Nanfen Cun, Nantou, M. Terayama leg., 14.viii.1985 ( MTC); 2 ♀♀, 3 ♂♂, Wushe, Nantou,M. Terayama leg., 22.viii.1987 ( MTC); 2 ♀♀, 1 ♀ (dealate), 24.08982° N, 121.03208° E, 694 m alt., Huisun Forest, Nantou, K. Eguchi leg., 12.v.2017, colony: Eg12v17-1214 ( TARI, ACEG); 3 ♀♀, 1 ♀ (dealate), 21.97° N, 120.80° E, 250–300 m alt., Kenting Forest recreation area, Kenting National Park, Pingtung, 26.vii.2016, A. Yamada leg., colony: AKY26vii16-17 ( TARI, AKYC).

Materialused for DNA barcoding. Colony AKY26vii16-17 (individual no.AKY20170502-21, accession no. LC457502 ); colony Eg12v17-1214 (AIK20170806-1, LC457501 ).Pairwisedistance (proportion of different sites) between the two COI sequences is 0.012 (based on 658 bp).

Diagnosis. In the worker, craniumsubrectangular in fullface view, with costae on vertex just weakly distorted; eye and ocelli relatively small (EI + OI, 23–25); dorsum of mesosoma longitudinally costate; abdominal tergite and sternite III longitudinally costate; abdominal tergite and sternites IV smooth with relatively dense hair-bearing foveae.

Redescription. Worker ( Figs 20–27 , 41 ). Body black; antennae, anterior part of cranium, mandibles, and legs dark reddish brown. Body pilosity relatively dense.

Cranium in full-face view subrectangular with subparallel lateral margins, longer than wide (CI, 83–88); posterior part of craniumabove eyes relatively long (EPI, 21–25), with PEHL distinctly longer than EL. Eye and ocelli relatively small (EI, 18–20; OI, 4–6; EI + OI, 23–25). Median ocellus located a little posteriorly to midlength of posterior part of cranium above eyes in full-face view. Torulo-posttorular complex in full-face view relatively narrow and never concealing antennal socket; width, when measured at level of antennal socket, about as long as length of major axis of antennal socket; lateral margin subparallel and weakly broadly concave; anterior protrusion of anterolateral lobe encircling antennal socket strong, exceeding anterior margin of lateral portion of clypeus in full-face view. Median portion of anterior clypeal margin weakly convex in full-face view, not protruding beyond anterior margin of lateral portion of clypeus. Antenna 12-segmented. Maxillary palp 5-segmented. Labial palp 3-segmented. Mandible relatively short with blunt apex; masticatory margin feebly dentate, in dorsal view distinctly shorter than twice as long as basal margin; ventral face of mandible with a series of modified setae along masticatory margin. Mesosoma in dorsal view relatively slender (DMI, 64–69), with rough lateral margins. Posterodorsal margin of propodeum in dorsal view weakly arched anteriad and margined by weak edge. Petiole in dorsal view barrel-shaped with weakly convex lateral margins. Anterodorsal corner of abdominal tergite III forming weak blunt edge in lateral view. Anteroventral corner of abdominal sternite III (prora) in lateral view weakly angulate with blunt apex. Posterior margin of pygidium in dorsal view straight.

Costae on body relatively roughly running without overlaying microsculpture. Frons transversely costate ( Fig. 20 ). Costae on vertex coarsely obliquely running with just weak distortion. Posterolateral face of cranium and posterior face above preoccipital carina longitudinally costate ( Figs 21–22 ). Torulo-posttorular complex and clypeus largely smooth. Gena largely smooth on face inside parafrontal ridge, whereas coarsely longitudinally costate on face outside the ridge. Outer face of antennal scape coarsely shagreened on about basal half, whereas smooth on remaining face. Outer face of mandible largely imbricate ( Fig. 23 ). Promesonotum, mesopleuron, and dorsal and lateral faces of propodeum longitudinally costate ( Figs 21–22 ); costae on pronotal dorsum overlaid with some coarse fovea. Posterior declivity of propodeum smooth. Legs largely smooth, with each coxa partly shagreened. Dorsal and lateral faces of petiolar tergite longitudinally costate; anterior face of petiole smooth. Posterodorsal face of helcium coarsely longitudinally costate. Abdominal tergite and sternite III longitudinally costate ( Figs 21, 24). Pretergite and presternite of abdominal segment IV imbricate ( Fig. 25 ). Cinctus of abdominal segment IV longitudinally costate. Abdominal segments IV smooth with relatively dense hair-bearing foveae. Abdominal tergites and sternites V–VI, andhypopygium imbricate on anterior marginal areas, whereas smooth with dense conspicuous hair-bearing foveae on remaining face ( Fig. 27 ). Pygidiumimbricate on anterior marginal area whereas, with dense hair-bearing foveae on remaining face (but foveae somewhat sparse in median part, Fig. 26 ).

Syntype worker (FOCOL0376). HL 1.14 mm; HW 0.98 mm; EL 0.22 mm; EW 0.15 mm; ES 0.19 mm; OL 0.05 mm; SL 0.70 mm; WL 1.88 mm; DML 1.50 mm; MW 0.99 mm; MFL 1.05 mm; PH 0.81 mm; PTL 0.73 mm; PTW 0.70 mm; A3L 0.82 mm; A3 W 1.03 mm; CI 86; SI 72; EI 19; OI 5; DMI 66; DMI2 80; LMI 54; MFI 107; PTI 97; A3I 125 (PEHL could not be measured).

Nontype workers (n = 7). HL 1.01–1.23 mm; HW 0.87–1.08 mm; EL 0.19–0.24 mm; EW 0.12–0.18 mm; ES 0.16–0.21 mm; PEHL 0.24–0.31 mm; OL 0.04–0.06 mm; SL 0.64–0.82 mm; WL 1.52–1.97 mm; DML 1.23–1.57 mm; MW 0.81–1.01 mm; MFL 0.92–1.23 mm; PH 0.64– 0.87 mm; PTL 0.67–0.87 mm; PTW 0.59–0.78 mm; A3L 0.70–0.96 mm; A3 W 0.84 –1.08 mm; CI 83–88; SI 73–78; EI 18–20; EPI21–25; OI 4–6; DMI 64–69; DMI2 79–82; LMI 51–57; MFI 105–117; PTI 87–91; A3I 112–124.

Queen ( Figs 28–31 ). Body color and pilosity similar to that of worker. Body structure and sculpture similar to those of worker except for the following features: mesosoma with distinct flight-associated sclerites; dorsal outline of mesosoma almost straight; pronotum coarsely foveolate-reticulate on dorsum, whereas weakly longitudinally costate on ventrolateral face; mesoscutum without notaulus and parapsidal line; mesoscutum and mesoscutellum coarsely longitudinally costate; mesopleuron weakly coarsely longitudinally costate.

Nontype queens (n = 2). HL 1.09–1.30 mm; HW 0.93–1.17 mm; EL 0.23–0.29 mm; EW 0.17–0.21 mm; ES 0.20–0.25 mm; PEHL 0.28–0.32 mm; OL 0.07–0.11 mm; SL 0.68–0.82 mm; WL 1.80–2.36 mm; DML 1.49–2.01 mm; MW 0.96–1.30 mm; MSL 0.55–0.83 mm; MSW 0.75–1.04 mm; MFL 0.99–1.22 mm; PTL 0.70–0.90 mm; PTW 0.63–0.81 mm; A3L 0.75–1.02 mm; A3 W 0.92 –1.22 mm; CI 86–90; SI 70–73; EI 21–22; EPI 24–26; OI 8–9; DMI 64–65; DMI2 83–86; MSI 126–135;MFI 104–107; PTI 90; A3I 120–123.

Male ( Figs 32–40 ). Body black; antennae, anterior part of cranium, mandibles, and legs dark reddish brown.

Cranium in full-face view bulb-shaped, just faintly longer than wide (CI, 94–95); posterolateral corner not angulate; vertex strongly raised, with rounded convex posterior margin that completely conceals preoccipital collar in full-face view. Eye and ocelli relatively large (EI, 35–37; OI,12–13; EI + OI, 48–49). Median ocellus located a little posteriorly to midlength of posterior part of cranium above eyes in full-face view. Torulo-posttorular complex in full-face view relatively broad but without concealing antennal socket; width, when measured at level of antennal socket, distinctly longer than length of major axis of antennal socket; lateral margin almost straightand entirely slightly converging posteriorly; anterior protrusion of anterolateral lobe encircling antennal socket strong. Antenna 13-segmented. Maxillary palp 5-segmented. Labial palp 3-segmented. Mandible relatively short, with blunt apex; masticatory margin feebly dentate, in dorsal view distinctly less than twice as long as basal margin; ventralface of mandible with a series of modified setae along masticatory margin. Mesoscutum subpentagonal, slightlywider than long (MSI, 108–110), with faintly concave anterolateral margin; notaulus distinct as scrobiculate groove; parapsidal line present as very weak and thin furrow. Scuto-scutellar suture fairly deep and broad, strongly scrobiculate. Posterior margin of mesoscutellum in dorsal view strongly convex. Dorsal margin of propodeal declivity in dorsal view narrowly and shallowly arched anteriad, and forming strong edge. Petiole in dorsal view subrectangular, with slightly convex lateral margin. Wing venation as generic description in BOROWIEC (2016). Dorsal outline of abdominal tergite III in lateral view just weakly convex, with angulate anterodorsal corner. Anteroventral corner of abdominal sternite III (prora) in lateral view weakly produced, with acute apex directed ventrad.

Frons weakly obliquely costate. Vertex and lateral and posterior faces of cranium coarsely reticulate. Posterior face above preoccipital carina longitudinally costate. Outer face of mandible imbricate. Outer face of antennal scape coarselyshagreened. Pronotum coarsely foveolate-reticulate on dorsal face, whereas weakly and coarsely longitudinally costate on lateral face. Mesopleuron largely smooth on anterodorsal face whereas coarsely and irregularly rugoso- -reticulate on remaining face. Metapleuron and lateral face of propodeum coarsely and irregularly rugoso-reticulate. Mesoscutum smooth with sparse hair-bearing foveae. Mesoscutellum coarsely foveolate-reticulate, with somewhat smooth median part. Dorsum of propodeum longitudinally costate. Posterior declivity of propodeum smooth. Legs largely smooth, with each coxa partly coarsely shagreened. Anterior face of petiole smooth; dorsal and lateral faces of petiolar tergite coarsely foveolate-reticulate. Posterodorsal face of helcium coarsely longitudinally costate.Abdominal tergite and sternites III largely coarsely foveolate-reticulate. Pretergite and presternite of abdominal segment IV imbricate. Cinctus of abdominal segment IV (the boundary between pre- and postsclerites) longitudinally costate. Abdominal posttergite and poststernite IV smooth with dense hair-bearing foveae. Abdominal tergites and sternites V–VII imbricate on anterior marginal areas, whereas smooth with dense hair-bearing foveae on remaining face. Pygidium with dense hair-bearing foveae.

Spiculum (anterior apophysis) of abdominal sternite IX ( Fig. 36 ) 0.24–0.27 times as long as entire length of sternite IX when spiculum length measured from transverse line spanning posteromost points of each anterolateral margin; lateral margin of sternite continuously straight, with posterior spine not necked basally in ventral view; posteromedian flange between bases of posterior spines broad without conspicuous foveae along anteroventral margin of flange. Posterodorsal part of basimere in lateral view stronglynarrowlyproduced (arrow in Fig. 37 ); articulation of basimere to teromere without thickened margin followed by membranous articulation ( Figs 37–38 ). Telomere in lateral view subrectangular, 1.0–1.1 times as long as wide. Cuspis absent. Digitus in lateral view subrectangular, without tapering apicad ( Fig. 39 ). Posterior apex of valviceps in lateral view not hooked, with rounded apex; about posterior one fifth of ventral margin having 15–16 broad denticles ( Fig. 40 ); anteroventral part of valviceps strongly produced, in lateral view not concealed by lateral apodeme.

Nontype males (n = 3). HL 1.10–1.16 mm; HW 1.05–1.09 mm; EL 0.41–0.46 mm; EW 0.32–0.34 mm; ES 0.37–0.40 mm; PEHL 0.33–0.34 mm; OL 0.13–0.14 mm; SL 0.43–0.44 mm; WL 2.30–2.37 mm; DML 2.03–2.13 mm; MW 1.40–1.48 mm; MSL 1.04–1.07 mm; MSW 1.11–1.15 mm; MFL 1.21–1.27 mm; PTL 0.79–0.84 mm; PTW 0.71–0.78 mm; A3L 0.83–0.87 mm; A3 W 1.04 –1.11 mm; CI 94–95; SI 39–41; EI 35–37; EPI 29–30; OI 12–13; DMI 69–70; DMI2 86–92; MSI 108–110; MFI 115–118; PTI 87–93; A3I 125–131.

Distribution. Taiwan: Nantou; Chiayi; Kaohsiung (TERAYAMA et al. 1998); Pingtung (new record).

Remarks. The worker of C. sauteri is differentiated from its allopatric sibling species C. costatus by having weak distortion of costae on vertex of cranium, and distinctly smaller eye and ocelli (see also remarks for C. costatus below).

Figures

Figs 20–27.Chrysapace sauteri (Forel, 1913), nontype worker from Taiwan, colony: Eg12v17-1214. 20 – head in full-face view; 21 – body in lateral view; 22 – head and mesosoma in dorsal view; 23 – left mandible in dorsal view; 24 – metasoma in dorsal view; 25 – pretergite and cinctus of abdominal segment IV in dorsal view; 26 – pygidium in dorsal view; 27 – hypopygium in ventral view.

Figs 28–31. Chrysapace sauteri (Forel, 1913), nontype dealate queen from Taiwan, colony: Eg12v17-1214. 28 – head in full-face view; 29 – body in lateral view; 30 – head and mesosoma in dorsal view; 31 – metasoma in dorsal view.

Figs 32–35.Chrysapace sauteri (Forel, 1913), nontype male from Taiwan.32 – head in full-face view; 33 – body in lateral view; 34 – head and mesosoma in dorsal view; 35 – metasoma in dorsal view.

Figs 36–40. Male genitalia of Chrysapace sauteri (Forel, 1913), nontypes from Taiwan. 36 – abdominal sternite IX in ventral view; 37 – right paramere and volsella in mesal view; 38 – left paramere in mesal view, volsella removed; 39 – right volsella in mesal view; 40 –left penisvalva in lateral view. Scale bars = 0.2 mm.

Figs 41–43. Difference of worker’s head sculpture between Chrysapace sauteri (Forel, 1913) and Chrysapace costatus (Bharti & Wachkoo, 2013). 41 – C. sauteri nontype from Taiwan, colony: Eg12v17-1214; 42 – C. costatus nontype from Yunnan; 43 – C. costatus holotype from India.