Myrmecina hirsuta 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 hirsuta Gu & Chen sp. nov.

Fig. 39

Material examined.

Holotype. • worker, Qiandaohu , Zhejiang, China, 30.0319°N, 119.4152°E, 550 m, secondary forest, leaf litter, 04. VII. 2018, Yuhao Zhao, GXNU 179961 [ GXNU] . Paratype. • 1 worker, Qiandaohu , Zhejiang, China, 30.0319°N, 119.4152°E, 550 m, secondary forest, leaf litter, 10. VII. 2017, Yuhao Zhao, GXNU 179962 ; • 1 worker, Qiandaohu , Zhejiang, China, 30.0319°N, 119.4152°E, 550 m, secondary forest, leaf litter, 18. VII. 2017, Yuhao Zhao, GXNU 179963 ; • 1 worker, Qiandaohu , Zhejiang, China, 30.0319°N, 119.4152°E, 550 m, secondary forest, leaf litter, 03. VIII. 2017, Yuhao Zhao, GXNU 179964 ; • 1 worker, Qiandaohu , Zhejiang, China, 30.0319°N, 119.4152°E, 550 m, secondary forest, leaf litter, 04. VII. 2018, Yuhao Zhao, GXNU 179965 [ 3 workers, GXNU; 1 worker, IZCAS] .

Diagnostic features.

(1) Eyes exceptionally large, composed of 37–40 ommatidia, exceeding the count in most congeners; (2) body with dense, long erect hairs, particularly elongated on the mesosoma.

Notes.

M. hirsuta Gu & Chen , sp. nov. is characterized by its subquadrate head with weakly convex lateral margins, exceptionally large eyes composed of 37–40 ommatidia, distinctive longitudinal sinuous rugae on the head dorsum, and dense body pilosity with elongated erect hairs on the mesosoma, key diagnostic features distinguishing it from closely related taxa. It most closely resembles M. pierceae but can be readily distinguished by the following combination of characters: (1) the head of M. hirsuta Gu & Chen , sp. nov. is subquadrate (width ≈ length), with weakly convex lateral margins and a medially shallowly concave posterior margin bordered by a faint carina, while the head of M. pierceae is subrectangular ( CI 100), with a weakly concave median occipital portion and rounded occipital corners; (2) the dorsal surface of the head in M. hirsuta Gu & Chen , sp. nov. bears distinctive longitudinal, sinuous rugae, whereas M. pierceae exhibits thin longitudinal rugae that curve toward the occipital corners; (3) the eyes of M. hirsuta Gu & Chen , sp. nov. are exceptionally large (37–40 ommatidia), significantly exceeding the small eyes (10 ommatidia) of M. pierceae ; (4) the antennal scapes of M. hirsuta Gu & Chen , sp. nov. extend just to the posterior corners of the head in full-face view, while those of M. pierceae are shorter and do not reach the posterolateral corners; (5) the mesosoma of M. hirsuta Gu & Chen , sp. nov. features a bluntly denticulate eumetanotal spines and robust, weakly upturned propodeal spines (length subequal to their basal width), whereas M. pierceae has a pair of vestigial eumetanotal spine (visible as a small denticle) and short, triangular propodeal spines directed posteriorly; (6) the postpetiole of M. hirsuta Gu & Chen , sp. nov. is broadly U-shaped in dorsal view and lacks anterolateral corners, while in M. pierceae it is rectangular and with anterolateral corners; (7) the body of M. hirsuta Gu & Chen , sp. nov. displays dense, elongated erect hairs, particularly on the mesosoma, while the body of M. pierceae displays uniformly short erect pilosity. In addition, comparing to other Myrmecina species, M. hirsuta Gu & Chen , sp. nov. is similar to M. macrops from Malaysia. mesosomal dorsum with straight longitudinal striae in M. hirsuta Gu & Chen , sp. nov. (vs. mesosomal dorsum with waved longitudinal rugae in M. macrops ) and postpetiole with longitudinal striae in M. hirsuta Gu & Chen , sp. nov. (vs. postpetiole without longitudinal striae in M. macrops ).

Worker measurements.

(N = 4). HL 0.78–0.83, HW 0.88–0.92, CI 107–111, SL 0.59–0.63, SI 66–68, ED 0.11–0.12, MSL 0.83–0.86 PW 0.60–0.62, PL 0.24–0.26, PH 0.25–0.27, DPW 0.23–0.25, LPI 103–106, DPI 92–96, GL 1.24–1.33, TL 3.70–3.76.

Worker description.

Head. In full-face view, head subquadrate, slightly broader than long, with weakly convex lateral margins and nearly straight (somewhat medially shallowly concave) posterior margin. Mandibles with 6 teeth: apical and subapical teeth robust, teeth 3–5 relatively small, basal tooth broader and blunter than teeth 3 and 4. Clypeus projecting beyond anterior head margin, its anterior margin arcuately emarginate, with stout lateral teeth and a transverse median prominence (non-denticulate). Frontal lobes well-developed, flattened and laterally expanded. Antennae 12 - segmented, scapes extending just to the posterior corners of head in full-face view. In lateral view, eyes well-developed, composed of 37–40 ommatidia. Mesosoma. In lateral view, mesosoma stout and short, dorsal outline convex, eumetanotal spines bluntly denticulate. Propodeal spines robust, length subequal to their basal width, weakly upturned apically. Propodeal spiracle large, positioned close to the propodeal declivity, distance to propodeal declivity equal to spiracle diameter. In dorsal view, pronotum convex anteriorly, humeral corners prominent; lateral margins gradually converging posteriorly toward the eumetanotal spines, which blunt and laterally denticulate. Propodeal spines short, directed posterolaterally, their apices slightly outwardly curved; spine length equal to 1 / 3 the distance between their apices. Inter-spinal distance greater than petiolar width and slightly less than postpetiolar width. Metasoma. In lateral view, petiole as long as high, with a triangular denticulate projection posterodorsally; ventral margin straight, anteroventral corner angulate. Postpetiole dorsally convex, anterior margin sloping, with a distinct anterodorsal corner; ventral margin short, anteroventral corner weakly denticulate; gaster ovoid. In dorsal view, postpetiole U-shaped, lacking anterolateral corners; gaster circular, without humeral corners. Sculpture. Mandibles smooth and shining, except for short longitudinal striae basolaterally. Head in full-face view with longitudinal, sinuous rugae, except for clypeus and medial portion between and frontal lobes smooth and shining. Lateroventral portion of head smooth and shining. Antennal scapes with longitudinal striae ventroapically, otherwise smooth and shining, except for piligerous puncta. Mesosoma laterally with oblique, posteriorly ascending carinae; dorsum with about 12 longitudinal carinae converging posteriorly (sometimes intersecting); 2–3 transverse carinae present between eumetanotal spines. Petiole and postpetiole with weaker, shorter longitudinal carinae than mesosoma. Gaster smooth and shining. Pilosity and pubescence. Body densely covered with erect long hairs, those on mesosoma longer than on head. Pubescence restricted to apical two segments of antennae. Coloration. Mandibles, antennae, and legs reddish-brown, except antennal club dark yellowish-brown. Body predominantly black, with anterior margin of head and gastral apex reddish-brown.

Etymology.

The specific epithet “ hirsuta ” is a Latin adjective meaning “hairy” or “bristly”, referring to the remarkably dense pilosity covering the body of this species, particularly notable on the dorsum of the head, mesosoma, and gaster. The name highlights one of the most distinctive diagnostic traits of this taxon compared to congeners.

Distribution.

Zhejiang.

Figures

Figure 39. Myrmecina hirsuta Gu & Chen, sp. nov. A. Clypeus and mandible in full-face view; B. Head in full-face view; C. Body in dorsal view; D. Body in lateral view.