Strumigenys strummeri, 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 : 114-117

Strumigenys strummeri sp. nov.

urn:lsid:zoobank.org:act:46D1F149-0813-4993-8925-CC9EA9ACAAAB

Fig. 38 ; Tables 2 , 6

Diagnosis

Strumigenys strummeri sp. nov. can be distinguished from other species in the S. leptothrix -group by a combination of the following characters: clypeal dorsum with small appressed acicular setae; mandibular dorsum with small appressed narrowly elliptic setae; in profile view, long suberect to erect setae densely present on cephalic dorsum and gaster; erect setae present on mesonotal dorsum as three pairs; in dorsal view, pronotum with laterally-projecting setae behind humeral setae; pronotum marginated dorsolaterally; propodeal spines subtended by broad lamellae; femora, tibiae and basitarsi with long erect setae.

Etymology

The species is named in honor of the late musician Joe Strummer, lead singer and co-founder of the punk band The Clash. The name was created by adding the singular Latin genitive case suffix -i to the last name of a male person.

Type material

Holotype worker ( Fig. 38 )

VIETNAM – Đỗng Nai Province • Cat Tien National Park, Site 11; 11.45098° N, 107.36353° E; 160 m a.s.l.; 4 Jun. 2018; IBBL members leg.; Winkler, 4 corners; LKCNHM ANTWEB1010914 (collection code IBBL CT-S11-4m2-sp14).

Paratype workers

VIETNAM – Đỗng Nai Province • 8 workers; same collection data as for holotype; HKBM ANTWEB1010912 , ANTWEB1010913 , ANTWEB1010915 to ANTWEB1010920 (collection code IBBL CT-S11- 4m 2-sp14) .

Additional material examined

VIETNAM – Đỗng Nai Province • 1 worker; Cat Tien National Park , Site 13; 11.45298° N, 107.36467° E; 174 m a.s.l.; 4 Jun. 2018; IBBL members leg.; Winkler, 4 corners; IBBL CT-S13-4m2-sp01 .

Measurements

Holotype worker

TL 2.7, HL 0.64, HW 0.55, MandL 0.13, SL 0.32, EL 0.071, PW 0.30, ML 0.67, PL 0.36, PH 0.16, DPW 0.12, PPL 0.21, GL 0.71, CI 85, MI 21, SI 59, OI 13, LPI 43, DPI 34.

Paratype workers

TL 2.5–2.8, HL 0.61–0.65, HW 0.49–0.55, MandL 0.12–0.14, SL 0.30–0.33, EL 0.066 –0.077, PW 0.26– 0.31, ML 0.62–0.69, PL 0.32–0.37, PH 0.15–0.16, DPW 0.11–0.14, PPL 0.19–0.24, GL 0.65–0.73, CI 81–85, MI 19–21, SI 58–62, OI 12–14, LPI 43–48, DPI 34–39 (n=8).

Worker description

HEAD. In full-face view, occipital margin deeply concave; occipital corners well developed and bluntly angular; occipital carina broad. Clypeus broader than long, around 1.5–1.7 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 four ommatidia in diameter.

DENTITION ( Fig. 38B ). (Only partially visible with all type specimens having their mandibles fully closed and obscured by setae along the inner mandible margins.) Principal dental row with an elongated-triangular tooth, 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, second tooth longest among all teeth, fourth and sixth tooth subequal in size; third, fifth and seventh tooth broad and rounded, subequal in length with first tooth; apex of mandible at down curvature, in anterior view, with small tooth, followed by crowded series of around six minute denticles, terminating in small conical apical tooth. Total dental count of around 15.

MESOSOMA. In profile view, mesosomal dorsum broadly, weakly convex; pronotum marginated dorsolaterally. In dorsal view, lateral margins of the pronotum broadly convex. In profile view, propodeal spines elongated-triangular, subtended on each side by broad lamella with deeply concave posterior margin that broadens basally into rounded convex propodeal lobe. Metapleural gland bulla well developed.

METASOMA. In profile view, petiolar peduncle grade evenly into node, and about as long as (or slightly shorter than) node. In dorsal view, petiolar node longer than broad, around 1.7–1.9 times as long; disc of postpetiole broader than long, around 1.2–1.4 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 extensive flap at posterolateral angle of node, almost reaching level of spiracle on peduncle in profile; 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, clypeal dorsum covered with appressed acicular setae; mandibular dorsum covered with appressed narrowly elliptic setae; masticatory margins each with row of medially-directed fine setae. Surface of scape covered with appressed acicular setae; surface of funiculus covered with progressively finer setae. Lateral margin of occipital lobe and posterior-half of upper scrobe margin with numerous long, overlapping, laterally-projecting setae; anterior-half of upper scrobe margin and leading edge of scape with decumbent setae. In dorsal view, promesonotal dorsum sparsely with appressed setae; posteriorly-directed decumbent setae present along lateral margins; appressed setae present along margins of petiolar node and disc of postpetiole. Pronotal humeral seta long, slightly-curved and stout, followed by 1–2 similar but shorter laterally-projecting setae. In profile view, long suberect to erect setae present densely throughout cephalic dorsum; suberect to erect setae also present on mesonotal dorsum in three pairs, on petiole in two pairs, on disc of postpetiole as one pair and all over gastral tergites; erect setae on cephalic dorsum and gastral tergites distinctly longer than other setae; ventral surface of head with decumbent setae; gastral sternites with suberect to decumbent setae. Hairwheel present at mesopleural excavation. Surfaces of middle and hind femora, tibiae and basitarsi with long stout erect setae.

SCULPTURE. Cephalic dorsum, clypeal dorsum and ventral surface of head sparsely reticulate-rugulose, with spaces between rugulae densely areolate-rugulose; mandibular dorsum mostly smooth and shining; surface of antennal scrobe, antenna and legs densely areolate. Promesonotal dorsum predominantly, relatively weakly areolate, with weak longitudinal rugulae and long, weak, longitudinal median striation; propodeal dorsum densely areolate-rugulose; dorsum of petiolar node transversely rugulose. Side of pronotum mostly smooth and shining, with weak rugulae around margins; pleurae and side of propodeum densely areolate-rugulose. Disc of postpetiole smooth and shining. Basigastral costulae short, around one fifth in length of first gastral tergite; rest of gaster smooth and shining.

Comments

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

Aside from Strumigenys strummeri sp. nov., there are five other SEA species from the same species group ( S. jacobsoni , S. leptothrix , S. medusa , S. stheno and S. yamanei sp. nov.) that share the following character: cephalic dorsum with suberect to erect setae only and without any appressed seta ( Table 6 ). For S. strummeri , its pronotum strongly marginate dorsolaterally (instead of not marginated as in S. yamanei , or only very weakly marginated as in S. leptothrix ); propodeal spines present and subtended by broad lamellae (instead of subtended by narrow carinae as in S. medusa or S. stheno ). In comparison with S. jacobsoni , in profile view, the erect setae on the cephalic dorsum are much longer and denser in S. strummeri ; erect setae on the mesosomal dorsum are also only restricted to the mesonotal dorsum as three pairs (instead of across the mesosomal dorsum). See comments under S. intermedia sp. nov. for a detailed comparison between the newly described species and the existing species from S. leptothrix -group.

Geographic range

Vietnam (Đồng Nai).

Ecology

Collected in secondary forests at an elevation of 160 m.

Figures

Fig. 38. Type specimens of Strumigenys strummeri sp. nov. A, C–D. Holotype worker (ANTWEB 1010914). B. Paratype worker (ANTWEB1010912). A. Full-face view. B. Mandible close-up. C. Profile view. D. Dorsal view.