Strumigenys crinigera, 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 : 27-32

Strumigenys crinigera sp. nov.

urn:lsid:zoobank.org:act:FF495B78-D44E-4C97-BC06-D36C67297AAF

Figs 8–9 ; Tables 2 , 5

Diagnosis

Strumigenys crinigera sp. nov. can be distinguished from other species in the S. caniophanes -group by a combination of the following characters: preapical tooth present, elongated-triangular; dorsolateral margin of head with five laterally-projecting flagellate setae, including apicoscrobal seta; cephalic dorsum and mesosoma with dense decumbent simple ground pilosity; pronotal humeral seta flagellate; mesosoma, including pleurae and side of propodeum, fully sculptured; propodeal teeth not subtended by lamella; petiolar node with differentiated anterior face, not claviform; gastral tergites with numerous long erect setae; dorsal and ventral surfaces of femur with erect setae; hind tibiae and basitarsi with long projecting flagellate setae.

Etymology

The species is named after its long and convoluted pilosity present across the body. The epithet ‘ crinigera ’ is the nominative feminine singular of the Latin adjective ‘ criniger ’ (meaning ‘having long hair’).

Type material

Holotype worker ( Fig. 8 )

VIETNAM • Đồng Nai Province , Cat Tien National Park, Site 13 (CT-S13-06); 11.45298° N, 107.36467° E; 174 m a.s.l.; 4 Jun. 2018; IBBL members leg.; Winkler, 4 corners; mature forest; LKCNHM ANTWEB1011848 (collection code IBBL CT-S13-4m2-sp06).

Paratype worker

VIETNAM • 1 worker; same collection data as for holotype; HKBM ANTWEB1011849 (collection code IBBL CT-S13- 4m 2-sp06) .

Paratype queens ( Fig. 9 )

VIETNAM • 2 alate queens; same collection data as for holotype; LKCNHM ANTWEB1011847 , ANTWEB1011850 (collection code IBBL CT-S13- 4m 2-sp06) .

Additional material examined

VIETNAM – Đắk Nông Province • 1 worker; Nam Nung Reserve , Site 48; 12.19245° N, 107.75954° E; 892 m a.s.l.; 9 Jun. 2018; IBBL members legs.; Winkler; IBBL ANTWEB1011853 . – Đỗng Nai Province • 2 workers, 1 queen; Cat Tien National Park , Site 18; 11.45688° N, 107.36958° E; 175 m a.s.l.; 4 Jun. 2018; IBBL members legs.; Winkler, 4 corners; IBBL ANTWEB1011852 • 1 worker; same collection data as for preceding; IBBL ANTWEB1011851 • 1 worker; same collection data as for preceding; IBBL ANTWEB1011913 • 1 queen; Cat Tien National Park , Site 21; 11.48437° N, 107.38658° E; 165 m a.s.l.; 5 Jun. 2018; IBBL members legs.; Winkler, 4 corners; IBBL ANTWEB1011960 .

Measurements

Holotype worker

TL 2.7, HL 0.64, HW 0.50, MandL 0.24, SL 0.33, EL 0.059, PW 0.30, ML 0.68, PL 0.29, PH 0.14, DPW 0.15, PPL 0.16, GL 0.64, CI 77, MI 38, SI 66, OI 12, LPI 47, DPI 52.

Paratype worker

TL 2.7, HL 0.65, HW 0.50, MandL 0.24, SL 0.32, EL 0.057, PW 0.29, ML 0.69, PL 0.27, PH 0.13, DPW 0.14, PPL 0.19, GL 0.64, CI 77, MI 37, SI 63, OI 11, LPI 47, DPI 51 (n=1).

Paratype queens

TL 2.7–2.9, HL 0.62–0.66, HW 0.48–0.53, MandL 0.24–0.25, SL 0.32, EL 0.103 –0.109, PW 0.34–0.36, ML 0.72–0.74, PL 0.31–0.34, PH 0.15, DPW 0.16, PPL 0.18–0.19, GL 0.66–0.70, CI 78–80, MI 37–38, SI 61–66, OI 21, LPI 44–47, DPI 48–50 (n = 2).

Worker description

HEAD. In full-face view, occipital margin evenly concave; occipital corners well developed; preocular lamina wide; anterior clypeal margin broadly, shallowly concave. Scapes subcylindrical, marginated but not converging anteriorly to form thin lamella at leading edge; apical antennomere weakly constricted basally. Mandible curvilinear and long, with elongated-triangular preapical tooth located close to apicodorsal tooth; width of mandible fairly constant from basal portion to where preapical tooth first arose; preapical tooth subequal to slightly shorter than width of mandible at point where tooth arises. In profile view, eye with three ommatidia in diameter.

MESOSOMA. In profile view, promesonotal dorsum broadly convex, propodeum more or less flat transversely; pronotum at most very weakly marginated dorsolaterally. In dorsal view, lateral margins of pronotum evenly convex. Propodeal teeth elongated-triangular and acute, not subtended by lamella. Metapleural gland bulla well developed. Femoral glands small but visible on all legs, around 0.030 – 0.040 mm in length.

METASOMA. In profile view, petiole not claviform; petiolar node with anterior face differentiated from peduncle, petiolar peduncle about as long as node. In dorsal view, petiolar node about as broad as long; disc of postpetiole broader than long, around 1.4–1.6 times as long. Areolate processes (spongiform tissues) present on both petiole and postpetiole; ventral lobes of petiole and postpetiole extensive; lateral lobe of petiole merely a flap at posterolateral angle of node in profile; in dorsal view, processes present along posterior margin of petiolar node, and surrounding disc of postpetiole, thicker along lateral and posterior margins than on anterior margin.

PILOSITY. In full-face view, dorsolateral margin of head with five pairs of long, laterally-projecting flagellate setae: two on upper scrobe margin, of which one posterior to level of eye and one directly above eye; one in apicoscrobal position, two posterior to this on lateral margin of occipital lobe. Antennae and mandibles covered with short appressed simple setae. Pronotal humeral seta long and flagellate. In profile view, cephalic dorsum, against ground pilosity of decumbent simple setae, sometimes with several suberect to erect setae between occipital margin and highest point of vertex but without erect setae anterior to this; ventral surface of head with shorter decumbent setae; mesosoma, petiolar node and postpetiole covered with numerous erect to suberect flagellate setae against shorter decumbent ground pilosity; gastral tergites with numerous filiform to flagellate erect setae; gastral sternites covered with much shorter, suberect curved simple setae. Hairwheel present at mesopleural excavation. Dorsal and ventral surfaces of femur each with row of long fine erect setae against ground pilosity of appressed setae; surfaces of middle and hind tibiae and basitarsi with long projecting flagellate setae.

SCULPTURE. Surface of head (including antennal scrobe) densely reticulate-rugulose; antennae and legs reticulate-punctate; mandibles with sparse weak punctate, but otherwise mostly smooth. Promesonotal dorsum, side of pronotum, petiolar node and disc of postpetiole densely reticulate-rugose; pleurae, dorsum and side of propodeum reticulate-punctate with sparse rugulae. Basigastral costulae short, 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: center of anepisternum and katepisternum each with patch of surface smooth and shining; femoral glands much larger than in worker caste, around 0.070 –0.080 mm in length.

Comments

Strumigenys crinigera sp. nov. is a member of the cygarix -complex in the S. caniophanes -group and shares all its characters ( Bolton 2000). It does not belong to the caniophanes -complex for having petiole with a differentiated anterior face in profile instead of subclaviform or claviform in shape. It also does not belong to the rhadina -complex for not having cuticular lamella along the inner margin of mandible.

Strumigenys crinigera sp. nov. can be distinguished from other members of the species group ( S. benulia Bolton, 2000 , S. cygarix Bolton, 2000 , S. dromica Bolton, 2000 , S. lopotyle Brown, 1969 , S. nothomopyx Bolton, 2000 and S. tadynastes Bolton, 2000 ) by the following characters ( Table 5 ): preapical tooth present, elongated-triangular (instead of completely absent as in S. cygarix or S. dromica , or reduced to merely denticle as in S. nothomopyx ); pleurae and side of propodeum are fully-sculptured in workers (unlike S. benulia ); row of erect setae present on both dorsal and ventral surfaces of femur (unlike S. lopotyle , S. nothomopyx or S. tadynastes ); hind tibiae and basitarsi have long projecting flagellate setae (unlike S. tadynastes ). Strumigenys crinigera also lacks the characteristic overgrowths of the areolate processes on the petiole and postpetiole of S. lopotyle . Strumigenys crinigera (HL 0.64–0.65, ML 0.68–0.69) is a smaller species than S. lopotyle (HL 0.74–0.86, ML 0.76–0.90), S. nothomopyx (HL 0.73–0.75, ML 0.70–0.72) or S. tadynastes (HL 0.70–0.76, ML 0.73–0.76).

Geographic range

Vietnam (Đắk Nông, Đồng Nai).

Ecology

Collected in secondary and mature forest at elevations from 174 to 892 m.

Figures

Fig. 8. Holotype worker (ANTWEB1011848) of Strumigenys crinigera sp. nov. A. Full-face view. B. Profile view. C. Dorsal view.

Fig. 9. Paratype queen (ANTWEB1011847) of Strumigenys crinigera sp. nov. A. Full-face view. B. Profile view. C. Dorsal view.