Myrmecina carinolateralis Gu & Chen, 2025

Gu, Zhuojian, Zhang, Chen, Du, Congcong & Chen, Zhilin, 2025, Synopsis of the ant genus Myrmecina Curtis, 1829 from China (Hymenoptera, Formicidae, Myrmicinae), with description of eleven new species, Deutsche Entomologische Zeitschrift 72 (2), pp. 395-448 : 395-448

Myrmecina carinolateralis Gu & Chen sp. nov.

Fig. 30

Material examined.

Holotype. • worker, Motuo , Xizang, China, 29.3201°N, 095.3401°E, 1230 m, secondary forest, soil, 27. VIII. 2016, Zhilin Chen, GXNU 160058 [ GXNU] . Paratype. • 1 worker, with the same collection data as the holotype ; • 2 workers, Motuo , Xizang, China, 29.2501°N, 095.1901°E, 840 m, secondary forest, soil, 28. VIII. 2016, Zhilin Chen, GXNU 160604 [ 2 workers, GXNU; 1 worker, IZCAS] .

Diagnostic features.

(1) Coarse longitudinal carinae on the lateroventral surface of head; (2) gastal tergite I with very fine reticulation (visible at 50 × magnification); (3) propodeal spines needle-like, weakly downcurved, approximately 1.5 times longer than their basal width; (4) eyes medium-sized, composed of 10–12 ommatidia; (5) body uniformly black, with yellowish-brown appendages and gastral apex; (6) mesosomal dorsum with abundant longitudinal carinae, more rugose than in related species.

Notes.

M. carinolateralis Gu & Chen , sp. nov. is characterized by its coarsely carinate lateroventral surface of head and finely reticulated gaster, key diagnostic features distinguishing it from closely related taxa. It most closely resembles M. curvispina but can be separated by the following combination of characters: (1) M. carinolateralis Gu & Chen , sp. nov. possesses coarse longitudinal carinae on the lateroventral portion and rugose dorsal carinae, contrasting with M. curvispina ’ s completely smooth lateroventral surface and uniformly striate dorsum; (2) the gaster of M. carinolateralis Gu & Chen , sp. nov. exhibits very fine reticulations (visible at 50 × magnification), while that of M. curvispina is entirely smooth; (3) Propodeal spines in M. carinolateralis Gu & Chen , sp. nov. are needle-like, weakly downcurved, approximately 1.5 times longer than their basal width, whereas in M. curvispina are broadly triangular, strongly outcurved, and approximately equal length and width; (4) eyes in M. carinolateralis Gu & Chen , sp. nov. are medium-sized (10–12 ommatidia), compared to reduced eyes (<10 ommatidia) of M. curvispina . These consistent morphological differences separate the two species.

Worker measurements.

(N = 4). HL 0.58–0.63, HW 0.56–0.60, CI 95–97, SL 0.44–0.46, SI 77–79, ED 0.06–0.07, MSL 0.66–0.70, PW 0.41–0.44, PL 0.16–0.18, PH 0.17–0.19, DPW 0.17–0.19, LPI 105–106, DPI 100–101, GL 0.71–0.79, TL 2.69–2.75.

Worker description.

Head. In full-face view, head subquadrate, with weakly convex lateral margins and medially a shallow concave posterior margin. Mandibles with 7 teeth: apical two robust, teeth 3–6 small and indistinct, basal tooth smaller than apical tooth but more distinct than intermediate teeth; masticatory margin approximately equal in length to inner margin. Clypeus with nearly straight anterior margin, distinct lateral corners, and a prominent median denticle. Frontal lobes broad and laterally expanded. Antennae 12 - segmented, scapes extending posteriorly to reach posterolateral corners of head. Eyes medium-sized, composed of 10–12 ommatidia. Mesosoma. In lateral view, dorsal outline evenly convex; eumetanotal spines ( sensu Okido et al. 2020) blunt, not interrupting dorsal profile. Propodeal spines robust and elongate, approximately 1.5 times longer than their basal width, weakly downcurved and directed posteriorly. Propodeal spiracle small, diameter about one-third its distance to propodeal declivity. In dorsal view, anterior margin of mesosoma evenly convex, with distinct humeral corners; lateral margins gradually converging posteriorly toward bases of propodeal spines. Propodeal spines needle-like, weakly curved, directed posterolaterally. Metasoma. In lateral view, petiole slightly higher than long, with triangular dorsal projection; ventral margin straight. Postpetiole dorsally weakly concave, with distinct anterodorsal corner; gaster ovoid. In dorsal view, petiole with concave anterior margin and straight lateral and posterior margins; postpetiole with distinct anterodorsal and posterodorsal corners; gaster with rounded anterolateral corners. Sculpture. Mandibles with two basal longitudinal grooves on frontal surface, otherwise smooth and shining. Clypeus smooth and shining. Head in full-face and lateral views with coarse longitudinal carinae, some extending across frontal lobes surfaces. Mesosoma with abundant longitudinal carinae laterally and dorsally. Petiole and postpetiole with short longitudinal carinae laterally, dorsal carinae somewhat rugose; gaster with microreticulations. Pilosity and pubescence. Body with moderately dense erect hairs. Pubescence sparse, restricted to antennal club. Coloration. Mandibles, anterior clypeal margin, antennae, legs, and posterior gastral segments yellowish-brown to reddish-brown; remainder of body black.

Etymology.

The specific epithet “ carinolateralis ” is a compound Latin adjective, derived from “ carina ” (meaning “keel” or “ridge”) and “ lateralis ” (meaning “lateral”), referring to the diagnostic character of coarse longitudinal carinae on the lateroventral portion of the head capsule. The name highlights this distinctive sculptural feature that distinguishes this new species from M. curvispina .

Distribution.

Xizang.

Figures

Figure 30. Myrmecina carinolateralis Gu & Chen, sp. nov. A. Propodeal spines in dorsal view; B. Head in full-face view; C. Body in dorsal view; D. Body in lateral view.