Macrolycus acutiapex Y. Yang, Liu & X. Yang, 2025

Du, Ruolan, Yang, Yuxia, Yang, Xingke & Liu, Haoyu, 2025, Taxonomic study of the Macrolycus gracilis group (Coleoptera: Lycidae), with descriptions of four new species from China, European Journal of Taxonomy 981, pp. 265-279 : 274-277

publication ID	https://doi.org/10.5852/ejt.2025.981.2825
publication LSID	lsid:zoobank.org:pub:B777C9F1-2913-4810-B6F6-5A654AF7C26A
persistent identifier	https://treatment.plazi.org/id/556987F9-FF94-FFD3-59B3-0896FAE37074
treatment provided by	Plazi
scientific name	Macrolycus acutiapex Y. Yang, Liu & X. Yang
status	sp. nov.

Treatment

Macrolycus acutiapex Y. Yang, Liu & X. Yang sp. nov.

urn:lsid:zoobank.org:act:

Figs 1 View Fig , 3J–L View Fig , 4F View Fig

Diagnosis

This species can be distinguished from the remaining species of the M. gracilis group by the antennomere III with slender and short lamella, 0.7 × as long as joint itself. It is more similar to M. mucronatus Li, Bocak & Pang, 2012 , but can be differentiated by the antennomere III with slender lamella, 0.7 × as long as joint itself; apical part of the phallus gradually narrowed distad in ventral view ( Fig. 3K View Fig ), and subapical part inflated ventrally in lateral view ( Fig. 3L View Fig ). Unlikely, in M. mucronatus , the antennomere III is stouter, with lamella about half length of joint itself; apical part of the phallus is abruptly narrowed distad in ventral view ( Li et al., 2012: fig. 38), and subapical part flat in lateral view ( Li et al., 2012: fig. 37).

Etymology

The specific epithet is derived from the Latin ‘ acutus ’ (‘sharp’) and ‘apex ’ (‘tip’), referring to its lamella of antennomere III with pointed apex.

Type material

Holotype

CHINA • ♂; Hubei, Xingshan, Longmenhe ; 2200 m a.s.l.; 13 Jun. 1995; S.Y. Wang leg.; IOZ(E)1119901; IZAS.

Description

Male ( Fig. 4F View Fig )

MEASUREMENTS. Length 7.3 mm, width at humeri 1.6 mm.

HABITUS AND COLORATION. Body black brown. Pronotum, elytra and scutellum dark red. Elytral costae IV orange-red. Surface covered with decumbent red pubescence.

HEAD. Eyes small, interocular distance about 1.7 × as long as eye diameter. Antennae flabellate, overlapping basal ⅔ length of elytra when inclined. Antennomeres III‒XI lamellate, lamellae pointed at apices, lamella of III extremely slender, about 0.7 × as long as joint itself, lamella of IX longest, 4.2× as long as joint itself ( Fig. 4F View Fig ).

PRONOTUM. Trapezoidal, 1.3 × as wide as long. Anterior margin widely rounded, lateral margins obviously sinuate and posterior margin nearly straight; anterior angles confluent with anterior margin, posterior angles sharp and moderately projected. Scutellum trapezoidal, nearly straight at apex ( Fig. 4F View Fig ).

ELYTRA. Slender and subparallel-sided, 3.9 × as long as humeral width. Costae I and III weak but visible at whole length, costa IV weaker than II and both separated at apical part of elytra ( Fig. 4F View Fig ).

AEDEAGUS. Phallus slender, with basal part narrowed to middle in dorsal and ventral views ( Fig. 3J–K View Fig ), subapical part strongly and almost symmetrically inflated laterally, about 1.67× as wide as basal part, with an oval ventral-cavity, apical part gradually narrowed distad, apex about 0.25× as wide as subapical part; curved ventrally at basal 5 /16 portion, and bent dorsally at apical 7 /16 portion in lateral view ( Fig. 3L View Fig ), subapical part feebly inflated ventrally, apical part nearly straight and flat ventrally.

Female

Unknown.

Distribution

China ( Hubei).

Key to the species of the Macrolycus gracilis group

1. Antennomere III lamellate in male, lamella at least 0.7 × as long as joint itself (e.g., Fig. 4D, F View Fig ; Li 2015: fig. 3e) ..................................................................................................................................... 2

– Antennomere III triangular or cylindrical in male, without any lamella (e.g., Fig. 4A, C View Fig ; Kazantsev 2001: fig. 8; 2002: fig. 9; Li et al. 2012: figs 50–51; 2015: figs 2–6) ............................................... 4

2. Pronotum black ( Fig. 4D View Fig ); phallus with apical part slightly bent dorsally in lateral view ( Fig. 3F View Fig ) .. ..................................................................................................................... M. graciliramus sp. nov.

– Pronotum dark red or orange (e.g., Fig. 4F View Fig ; Li 2015: fig. 3e); phallus with apical part straight in lateral view (e.g., Fig. 4L View Fig ; Li 2015: fig. 10e) .................................................................................... 3

3. Lamella of antennomere III as long as joint itself (Li 2015: fig. 7u); apical part of phallus parallel-sided in ventral view (Li 2015: fig. 10f) ............................................................ M. gracilis Pic, 1923

– Lamella of antennomere III 0.7× as long as joint itself ( Fig. 4F View Fig ); apical part of phallus narrowed distad in ventral view ( Fig. 4K View Fig ) ........................................................................ M. acutiapex sp. nov.

4. Antennomere III cylindrical in male ( Fig. 4C View Fig ); basal part of phallus obviously asymmetrical, expanded to one side in ventral view ( Fig. 3H View Fig ) ............................................. M. breviramus sp. nov.

– Antennomere III triangular in male (e.g., Fig. 4A View Fig ; Kazantsev 2001: fig. 8; 2002: fig. 9; Li et al. 2012: figs 50–51; 2015: figs 2–6); basal part of phallus nearly symmetrical (e.g., Fig. 3B View Fig ; Kazantsev 2001: fig. 9; 2002: fig. 10; Li et al. 2012: figs 38, 40; 2015: figs 15, 17, 19, 21, 23) ................................. 5

5. Apical part of phallus moderately inflated distad in ventral view ( Li et al. 2015: fig. 15) ................ ...................................................................................... M. baihualingensis Li, Bocak & Pang, 2015

– Apical part of phallus narrowed distad in ventral view (e.g., Fig. 3B View Fig ; Kazantsev 2001: fig. 9; 2002: fig. 10; Li et al. 2012: figs 38, 40; 2015: figs 17, 19, 21, 23) ........................................................... 6

6. Pronotum black ( Fig. 4A View Fig ); subapical part of phallus moderately inflated ventrally in lateral view ( Fig. 3C View Fig ) ........................................................................................................... M. nigricollis sp. nov.

– Pronotum dark red or orange; subapical part of phallus flat ventrally in lateral view (e.g., Kazantsev 2001: fig. 10; 2002: fig. 11; Li et al. 2012: figs 37, 39; 2015: figs 16, 18, 20, 22) ........................... 7

7. Phallus with apical part curved dorsally in lateral view (e.g., Li et al. 2015: figs 20, 22) ............... 8

– Phallus with apical part straight in lateral view (e.g., Kazantsev 2001: fig. 10; 2002: fig. 11; Li et al. 2012: figs 37, 39; 2015: figs 16, 18) ................................................................................................. 9

8. Elytral costa II orange-red; phallus with basal part narrowed to middle in ventral view ( Li et al. 2015: fig. 21), and apical part moderately curved dorsally in lateral view ( Li et al. 2015: fig. 20) ............................................................................... M. rhodoneurus Li, Bocak & Pang, 2015

– Elytral costa II dark red; phallus with basal part parallel-sided in ventral view ( Li et al. 2015: fig. 23), and apical part strongly curved dorsally in lateral view ( Li et al. 2015: fig. 22) ............................... .................................................................................................. M. rosaceus Li, Bocak & Pang, 2015

9. Phallus with apical part gradually narrowed distad (e.g., Kazantsev 2001: fig. 9; 2002: fig. 10; Li et al. 2015: fig. 19) .......................................................................................................................... 10

– Phallus with apical part abruptly narrowed distad (e.g., Li et al. 2012: figs 38, 40; Li et al. 2015: fig. 17) ............................................................................................................................................. 12

10. Pronotum and elytra orange; apex of phallus about ¼ as wide as subapical part ( Kazantsev 2001: fig. 9) ............................................................................................... M. aurantiacus Kazantsev, 2001

– Pronotum and elytra dark red (e.g., Li et al. 2015: fig. 4); apex of phallus at most 1 /5 as wide as subapical part (e.g., Kazantsev 2002: fig. 10; Li et al. 2015: fig. 19) ..............................................11

11. Pronotum and elytra orange red ( Li et al. 2015: fig. 4); basal part of phallus uneven in width in ventral view ( Li et al. 2015: fig. 19); apical part moderately inflated ventrally near apex in lateral view ( Li et al. 2015: fig. 18) ............................................... M. phoeniceus Li, Bocak & Pang, 2015

– Pronotum and elytra dark red; basal part of phallus parallel-sided in ventral view ( Kazantsev 2002: fig. 10), apical part flat ventrally in lateral view ( Kazantsev 2002: fig. 11) ....................................... ....................................................................................................... M. multicostatus Kazantsev, 2002

12. Phallus with apical part abruptly narrowed distad in lateral view ( Li et al. 2015: fig. 16) ................ ............................................................................................ M. lizipingensis Li, Bocak & Pang, 2015

– Phallus with apical part nearly parallel-sided in lateral view (e.g., Li et al. 2012: figs 37, 39) ..... 13

13. Antennae relatively long, overlapping basal 4 /5 length of elytra when inclined ( Li et al. 2012: fig. 50); phallus bent dorsally at basal ⅓ portion in lateral view ( Li et al. 2012: fig. 37) ................................ ............................................................................................ M. mucronatus Li, Bocak & Pang, 2012

– Antennae relatively short, overlapping basal ½ length of elytra when inclined ( Li et al. 2012: fig. 51); phallus bent dorsally at basal 1 /6 portion in lateral view ( Li et al. 2012: fig. 39) ............................... .............................................................................................. M. muyuensis Li, Bocak & Pang, 2012