Protanilla beijingensis

By means of a subterranean pitfall trap sampling ants between 30 and 55 cm below ground, we collected three workers and one queen of Protanilla beijingensis in Xiaolongmen Forest Park, west of Beijing in 2015. The habitat was monsoon deciduous forest.

Identification
Man et al (2017) - Close to Protanilla lini but its petiolar node is relatively low, with rounded anterodorsal corner; dorsum of postpetiolar node almost straight, subpostpetiolar process longer with anteroventral corner rounded; body size larger with TL 3.9 to 4.0 and HL 0.65 to 0.70; body color reddish brown, posterior half of mesothorax and anterior half of metathorax black.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  beijingensis. Protanilla beijingensis Man, Ran, Chen & Xu, 2017: 6, figs. 4-9 (w.q.) CHINA.

Worker
Holotype worker (Figs. 4-6): TL 4.0, HL 0.70, HW 0.68, CI 97, SL 0.61, SI 90, ML 0.51, PW 0.44, AL 1.21, PNL 0.25, PNH 0.44, PNW 0.29, PI 116, PPNL 0.28, PPNH 0.40, PPNW 0.29, PPI 104.

In full face view, head roughly trapezoidal and slightly longer than broad, anterior 1/3 of the head distinctly narrowed anteriorly and strongly constricted at antennal socket position, lateral margins evenly convex. Posterior margin weakly concave, posterior corners rounded. Mandibles elongate and curving downwards apically, lateral surface with a longitudinal groove, basal corners prominently round, masticatory margin with 19 peg-like teeth. Clypeus nearly trapezoidal, with a depressed longitudinal central furrow, anterior margin weakly concave. Apex of labrum moderately convex, with a peglike tooth and a pair of stout long hairs. Antennae 12-segmented, apex of scape surpassed posterior head corner by about 1/6 of its length, flagella segments 4-9 about as broad as long.

In profile view, dorsum of mandible strongly convex. Mesosoma strongly constricted at middle position. Dorsum of pronotum weakly convex. Promesonotal suture complete and weakly depressed. Dorsum of mesonotum straight, weakly sloping down posteriorly. Metanotal groove moderately impressed. Dorsum of propodeum weakly convex, posterodorsal corner rounded; declivity slightly convex, about 1/2 length of the dorsum. Petiolar node nearly trapezoidal and narrowed dorsally, anterior face weakly convex, posterior face nearly straight, dorsal face roundly convex; anterodorsal corner rounded, posterodorsal corner relatively prominent. Subpetiolar process large and triangular, with an elliptical semitransparent fenestra, anteroventral corner blunt, anterior and posteroventral margins weakly convex. Postpetiolar node roughly rectangular and weakly widened dorsaly, dorsal face weakly convex, anterior face strongly convex, anterodorsal corner rounded, posterodorsal corner blunt. Subpostpetiolar process large and lobe-like, anteroventrally pointed and rounded at apex. Gaster roughly elliptical, first gastral segment occupies about 1/2 length of gaster. Sting well-developed and extruding.

In dorsal view, pronotum wide with strongly convex sides. Mesonotum strongly constricted and nearly square. Propodeum relatively narrow and rectangular, with weakly convex sides. Petiolar node nearly rectangular, slightly broader than long, sides evenly convex, anterior face almost straight, posterior face slightly concave. Postpetiolar node trapezoidal and widened posteriorly, as broad as long; anterior face, sides and posterior face weakly convex. Anterior margin of gaster weakly concave.

Mandibles finely retirugose. Head and body smooth and shining. Body dorsum with sparse subdecumbent hairs and abundant decumbent pubescence. Scapes with sparse subdecumbent hairs and abundant decumbent pubescence. Tibiae with abundant decumbent pubescence. Mandibles and clypeus with relatively abundant stouter and longer hairs, apex of each mandible with a very long stout hair on ventral portion. Body color reddish brown with the exception of the black parts of the posterior half of mesothorax and anterior half of the metathorax Mandibles, antennae, pronotum, legs, and posterior 2/3 of gaster brownish yellow.

Paratype workers: TL 3.9-4.0, HL 0.65-0.70, HW 0.63-0.68, CI 96-97, SL 0.61-0.63, SI 90-98, ML 0.47-0.51, PW 0.43-0.44, AL 1.21-1.23, PNL 0.31-0.35, PNH 0.42-0.44, PNW 0.28-0.30, PI 86-90, PPNL 0.25-0.28, PPNH 0.38-0.40, PPNW 0.28-0.30, PPI 107-112 (2 individuals measured). As holotype, but slightly vary in total length and body color darker.

Queen
Paratype queen (Figs. 7-9): TL 4.6, HL 0.78, HW 0.73, CI 94, SL 0.66, SI 90, ML 0.50, PW 0.55, AL 1.46, PNL 0.28, PNH 0.49, PNW 0.35, PI 125, PPNL 0.30, PPNH 0.48, PPNW 0.36, PPI 120 (1 individual measured).

In full face view, head similar to the holotype worker, but posterior margin almost straight. Masticatory margin of mandible with approximately 34 peg-like teeth. Anterior margin of clypeus concavity more pronounced than in worker caste. Antennae relatively shorter, apex of scape surpasses posterior head corners by about 1/8 of its length. Compound eyes present and moderately large, located slightly behind midlength of head side, with 14 ommatidia in the longest diameter and 11 ommatidia in the shortest diameter, weakly convex with sparse interommatidial pilosity. Vertex with 3 distinct ocelli.

In profile view, body basically similar to holotype worker, but dorsal outline of mesosoma moderately arched. Promesonotal suture and metanotal groove weakly impressed, mesometanotal suture narrowly notched. Mesopleuron with a distinct oblique furrow. Posterodorsal corner of propodeum very bluntly angled, dorsum short and as of similar length to declivity, the latter straight. Petiolar node weakly narrowed dorsally, anterior and posterior faces almost straight, dorsal face weakly convex; anterodorsal and posterodorsal corners bluntly angled; subpetiolar process similar to worker caste. Dorsum of postpetiolar node strongly convex, subpostpetiolar process similar to worker caste.

In dorsal view, body basically similar to holotype worker, but mesonotum massive and complex, scutum with a pair of posteriorly convergent longitudinal furrows, transverse furrow posteriorly arched, scutellum rounded posteriorly. Metanotum transverse and very short, posteriorly arched. Propodeum short, posterior corners rounded. Both petiolar node and postpetiolar node broader than long.

Sculpture and pilosity similar to holotype worker. Body color yellowish brown. Ocellar area, mesothorax, metathorax, propodeum, petiole and postpetiole brownish black. Antennae, legs and gastral apex brownish yellow. Eyes grey.

Type Material
Holotype. Worker. China: Beijing, Mentougou District, Xiaolongmen National Forest Park, N39 o 58’25’’, E115 o 25’30’’, 1247m, collected by subterranean pitfall trap in monsoon deciduous forest, 2015.X.15, Pei Man leg., No. IOZ(E) 227911. The holotype worker is deposited in the Institute of Zoology, Chinese Academy Of Sciences, Beijing, China. Paratypes: 2 workers and 1 queen; the paratypes were collected by the same method and with the same data. One queen (No. IOZ(E) 227912) is deposited in the Institute of Zoology, Chinese Academy Of Sciences, Beijing, China. One worker (No. IOZ(E) 227913) is deposited in the Insect Collection, Guangxi Normal University, Guilin, Guangxi Region, China. The other worker (No. IOZ(E) 227914) is deposited in the Insect Collection, Southwest Forestry University, Kunming, Yunnan Province, China.

Etymology
Named after the type locality “Beijing”.

References based on Global Ant Biodiversity Informatics

 * Man P., H. Ran, Z. Chen, and Z. Xu. 2017. The northern-most record of Leptanillinae in China with description of Protanilla beijingensis sp. nov. (Hymenoptera: Formicidae). Asian Myrmecology 9 DOI: 10.20362/am.009008