Strumigenys zanderi, Tang & Guénard, 2023

Tang, Kit Lam & Guénard, Benoit, 2023, Further additions to the knowledge of Strumigenys (Formicidae: Myrmicinae) within South East Asia, with the descriptions of 20 new species, European Journal of Taxonomy 907, pp. 1-144 : 125-129

Strumigenys zanderi sp. nov.

urn:lsid:zoobank.org:act:4BE92DF4-C0B7-4588-AAAA-A6E8E51FC158

Figs 42–43 ; Tables 2 , 6

Diagnosis

Strumigenys zanderi sp. nov. can be distinguished from other species in the S. leptothrix -group by a combination of the following characters: cephalic dorsum, surface of scape, promesonotal dorsum with short appressed setae; without any laterally-projecting seta in full-face view; mandibles with appressed obovate setae; pronotum marginated dorsolaterally; pronotal humeral seta absent; side of mesosoma mostly smooth and shining; propodeal spines subtended by broad lamellae; petiolar node with conspicuous anterior face.

Etymology

The species is named after a young boy named Zander who loves all things in nature and insects in particular. The name was created by adding the singular Latin genitive case suffix -i to the given name of a male person.

Type material

Holotype worker ( Fig. 42 )

MAINLAND CHINA • Hainan Province, Bawangling , BWLS6; 19.10423° N, 109.17608° E; 7 Jul. 2016; L. Wang leg.; Winkler, 4 corners; secondary forest; LKCNHM ANTWEB1011885 (collection code IBBL HNA-00851).

Paratype workers

MAINLAND CHINA • 8 workers; same collection data as for holotype; HKBM ANTWEB1011931 to ANTWEB1011938 (collection code IBBL HNA-00851) .

Paratype queen ( Fig. 43 )

MAINLAND CHINA • 1 dealate queen; Hainan Province, Jianfengling , JFLFW1; 19.117° N, 109.152° E; 24 Dec. 2015; L. Wang leg.; Winkler, 12 random; primary forest; LKCNHM ANTWEB1011891 (collection code IBBL HNA-01611) .

Additional material examined

MAINLAND CHINA – Hainan Province • 2 workers; Jiaxi; 940 m a.s.l.; 14 Jun. 1999; J. Fellowes leg.; HKBM ANTWEB1011902 to ANTWEB1011903 • 1 queen; Wuzhishan; 850 m a.s.l.; 9 Jun. 1999; J. Fellowes leg.; HKBM ANTWEB1011907 • 1 worker; Bawangling, BWLP10; 19.094° N, 109.20246° E; 4 Jul. 2016; L. Wang leg.; Winkler, 4 corners; IBBL ANTWEB1011886 • 12 workers; same collection data as for preceding; Winkler, 12 random; IBBL ANTWEB1011887 , ANTWEB1011961 to ANTWEB1011971 • 1 worker; Bawangling, BWLP7; 19.09134° N, 109.19848° E; 3 Jul. 2016; L. Wang leg.; Winkler, 12 random; IBBL ANTWEB1011889 • 1 worker; Bawangling, BWLS6; 19.10423° N, 109.17608° E; 7 Jul. 2016; L. Wang leg.; Winkler, 12 random; IBBL ANTWEB1011890 • 1 worker; Jianfengling, JFLFW2; 19.115° N, 109.159° E; 26 Dec. 2015; L. Wang leg.; Winkler, 4 corners; IBBL ANTWEB1011888 • 1 worker; Jianfengling, JFLFW3; 19.121° N, 109.118° E; 26 Dec. 2015; L. Wang leg.; Winkler, 4 corners; IBBL ANTWEB1011892 .

Measurements

Holotype worker

TL 3.0, HL 0.71, HW 0.58, MandL 0.15, SL 0.31, EL 0.074, PW 0.29, ML 0.77, PL 0.34, PH 0.15, DPW 0.13, PPL 0.21, GL 0.80, CI 82, MI 21, SI 52, OI 13, LPI 43, DPI 37.

Paratype workers

TL 2.6–3.0, HL 0.66–0.80, HW 0.55–0.68, MandL 0.14–0.16, SL 0.29–0.34, EL 0.066 –0.080, PW 0.27– 0.30, ML 0.67–0.77, PL 0.25–0.33, PH 0.12–0.15, DPW 0.11–0.13, PPL 0.17–0.21, GL 0.70–0.80, CI 81–85, MI 20–23, SI 49–55, OI 10–14, LPI 42–49, DPI 38–45 (n=8).

Paratype queen

TL 3.5, HL 0.77, HW 0.62, MandL 0.16, SL 0.31, EL 0.151, PW 0.40, ML 0.94, PL 0.40, PH 0.17, DPW 0.19, PPL 0.23, GL 0.98, CI 81, MI 21, SI 50, OI 24, LPI 41, DPI 47 (n= 1).

Worker description

HEAD. In full-face view, occipital margin deeply concave; occipital corners well developed and bluntly angular; occipital carina present; dorsolateral margin of head broadly convex, lateral margin of the occipital lobe and upper scrobe margin not forming blunt angle. Clypeus broader than long, around 1.3–1.4 times as long, roughly resembling inverted diamond. Scapes subcylindrical, marginated but not converging anteriorly to form thin lamella at leading edge. Mandibles in full-face view triangular; masticatory margins engaged across entire length, without diastema or gap between mandibles; basal lamellae low and broadly triangular, not fully visible at full closure. In profile view, eye with 3–4 ommatidia in diameter.

DENTITION ( Fig. 43B ). Principal dental row with elongated-triangular tooth at oblique orientation towards proximal end of mandibles, followed by six alternating elongated-triangular teeth and rounded teeth; second, fourth and sixth tooth elongated-triangular, longer than first tooth and neighboring rounded teeth; third, fifth and seventh tooth broad and rounded; apex of mandible at down curvature, in anterior view, with elongated-triangular small tooth, followed by crowded series of six minute denticles, terminating in small conical apical tooth. Total dental count of 15.

MESOSOMA. In profile view, dorsum of mesosoma more or less flat transversely, except for small raise between pronotum and mesonotum, as well as two slight depressions immediately anterior and posterior to mesonotum; pronotum marginated dorsolaterally. In dorsal view, lateral margins of pronotum evenly convex. Propodeal spines elongated-triangular, subtended on each side by broad lamella with concave posterior margin that broadens basally into rounded convex propodeal lobe. Metapleural gland bulla well developed.

METASOMA. In profile view, petiolar peduncle not grading evenly into node, and about as long as (or slightly shorter than) node; petiolar node low, with short, conspicuous anterior face and much longer, broadly convex posterior face. In dorsal view, petiolar node longer than broad, around 1.4–1.6 times as long; disc of postpetiole slightly broader than long, around 1.1–1.2 times as long. Areolate processes (spongiform tissues) present on both petiole and postpetiole; ventral lobes of petiole and postpetiole extensive; lateral lobe of petiole forming moderately extensive flap at posterolateral angle of node, almost reaching level of anterior margin of node in profile and in dorsal view; in dorsal view, processes present along lateral and posterior margins of petiolar node, and surrounding disc of postpetiole, thicker along lateral and posterior margins than on anterior margin.

PILOSITY. In full-face view, cephalic dorsum covered with short appressed plank-like to subspatulate setae, clypeal dorsum with appressed oblong to narrowly elliptic setae, all partially embedded within surface sculpture; mandibular dorsum with appressed obovate setae; masticatory margins each with row of medially-directed elliptic setae. Surface of scape with appressed acicular setae; funiculus covered with plank-like setae. Head without any laterally-projecting seta; dorsolateral margin of head with row of decumbent setae; lateral and anterior clypeal margins with small spoon-shaped setae. In dorsal view, surface of pronotal neck, promesonotal dorsum, margins of petiolar node, disc of postpetiole and gastral tergites sparsely with appressed subspatulate setae; posteriorly-directed decumbent setae present along lateral margins of mesosoma. Pronotal humeral seta absent. In profile view, erect absent on dorsal surface of head, mesosoma, petiole or postpetiole; second and third gastral tergites with erect stout setae; gastral sternites with erect to suberect setae; ventral surface of head, anterior to level of the eye, with decumbent setae. Hairwheel present at mesopleural excavation. Appressed to decumbent elliptic to plank-like setae cover femora, tibiae and basitarsi. Surfaces of legs without any laterally-projecting setae; femora and tibiae with appressed to decumbent subspatulate setae.

SCULPTURE. Cephalic dorsum densely areolate-rugulose; clypeal dorsum, except for sculpture encompassing appressed setae, mostly smooth and shining, with sparse vestiges of sculpture; surface of antennal scrobe, antenna and legs densely areolate; ventral surface of head sparsely reticulate-rugulose, with spaces between rugulae densely areolate-rugulose. Promesonotal dorsum areolate, with weak longitudinal striation; propodeal dorsum areolate-rugulose; petiolar node transversely areolate-rugulose; side of mesosoma mostly smooth and shining, with vestiges of sculpture around margins. Disc of postpetiole smooth and shining. Basigastral costulae short, sometimes inconspicuous, around one fifth in length of first gastral tergite; rest of gaster smooth and shining.

Queen description

Similar in all points to worker caste except for reproductive caste morphological characters (presence of 3 ocelli, enlarged eyes and thorax), and following: pronotal dorsum predominantly transversely rugulose; mesosomal dorsum with strong directional rugulae towards midline.

Comments

Strumigenys zanderi sp. nov. is a member of the zanderi -complex in the S. leptothrix -group and shares all its characters ( Bolton 2000).

Aside from Strumigenys zanderi sp. nov., there are three other SEA species from the same species group ( S. assamensis , S. decumbens sp. nov. and S. doydeei sp. nov.) that share the following characters: appressed setae only on the cephalic dorsum, pronotum marginated dorsolaterally, propodeal declivity with broad lamellae ( Table 6 ). Unlike S. assamensis , its propodeal spines are well developed (instead of absent); the lateral lobe of the petiole is moderate in size (instead of extensive and blister-like). Unlike S. decumbens or S. doydeei , an erect seta is absent from the mesosomal dorsum (instead of present as a few pairs on the mesonotum); the side of the mesosoma is mostly smooth and shining (instead of having mostly sculptured pleurae and side of propodeum). Unlike all of the above three species, the petiolar node has an anterior face differentiated from the petiolar peduncle (instead of the petiolar peduncle grading evenly into the node). See comments under S. intermedia sp. nov. for detailed comparison between the newly described species and the existing species S. leptothrix -group.

Geographic range

Mainland China (Hainan).

Ecology

Collected in primary and secondary forest, and relatively rarely in rubber plantations, at elevations from 850 to 940 m.

Figures

Fig. 42. Holotype worker (ANTWEB1011885) of Strumigenys zanderi sp. nov. A. Full-face view. B. Profile view. C. Dorsal view.

Fig. 43. Paratype queen (ANTWEB1011891) of Strumigenys zanderi sp. nov. A. Full-face view. B. Mandible close-up. C. Profile view. D. Dorsal view.