Falcicornis banjinshuaii Xin, Yang & Zhong, 2025

Falcicornis banjinshuaii Xin, Yang & Zhong , sp. nov. IJae小刀Ɓm

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( Figs. 1A, D View FIGURE 1 ; 2A, D, G, J View FIGURE 2 ; 3A–D View FIGURE 3 ; 4A, D View FIGURE 4 ; 5A–H View FIGURE 5 ; 6A–B, E–F, I–J View FIGURE 6 ; 7A–B View FIGURE 7 ; 8A–C View FIGURE 8 ; 10B View FIGURE 10 ; 11A–F View FIGURE 11 )

Type locality. China, Guizhou, Guiyang, Wudang, Xinchang , alt. 1300 m .

Type material. Holotype: ♂ ( NACRC: IOZ (E) 224803; IMS: B1; GBAN: PV656219 ), CHINA, Guizhou, Guiyang, Wudang, Xinchang ( Ĕ场Oi), alt. 1300 m, XI.2024, Xue-Tong Yang & Jin-Shuai Ban leg. Paratypes ( 2 ♂♂, 2 ♀♀): 1 ♂ ( GHC) , 1 ♂ ( GHC; IMS: B2; GBAN: PX218533 ) , 1 ♀ ( GHC) 1 ♀ ( NACRC: IOZ (E) 224804; IMS: B4; GBAN: PX132383 ), same data as holotype .

Differential diagnosis. The new species can be easily identified as a member of the Falcicornis bisignatus group by the following feature of large-sized males: the slender mandibles, with no small protrusions at the base, and distinct protrusions with non-flat margin near the apex. Within the F. bisignatus group, the new specie is the most morphologically similar to F. ruficrus (De Lisle, 1970) and F. moellenkampi (Nagel, 1924) , but the following set of external and genital characters will help to recognize this new species precisely. For large male: 1) whole body dark red with moderate luster in new species (coloration brighter, weakly glossier in F. ruficrus ; coloration darker, obviously glossier in F. moellenkampi ) ( Fig. 1 View FIGURE 1 ); 2) the apical mandibular protrusion of the new species relatively longer, at a shallower angle to the apex, with moderately serrate apical margin (relatively shorter, at a weakly larger angle to the apex, with strongly serrate apical margin in F. ruficrus ; relatively shorter, at a larger angle to the apex, apical margin relatively smooth in F. moellenkampi ) ( Fig. 2A–C View FIGURE 2 ); 3) the clypeolabrum of the new species generally short, with the median protuberance and lateral protuberances exhibiting little difference in the degree of anterior extension (generally longer, with the median protuberance exhibiting a distinctly smaller degree of anterior extension than the lateral protuberances in F. ruficrus ; shorter, the median protuberance curved apically, exhibits a broad arc shape, and the anterior extension roughly comparable to that of the lateral protuberances in F. moellenkampi ) ( Fig. 2D–F View FIGURE 2 ); 4) the pronotum of the new species with elongated anterior angles and straight lateral margin (in same size, anterior angles of pronotum shorter in F. ruficrus and F. moellenkampi ; particularly, the anterolateral outer margin of the pronotum in F. moellenkampi exhibits a distinct outward curvature) ( Fig. 2G–I View FIGURE 2 ); 5) vestiture on metaventrite relatively short and more sparse in new species (obviously longer and more dense in F. ruficrus ; relatively longer and more dense in F. moellenkampi ) ( Fig. 2J–L View FIGURE 2 ); 6) the penis of aedeagus longer than the two related species ( Fig. 6I–L View FIGURE 6 ). For female, the luster of new species is not bright, which could be easily distinguished from F. moellenkampi (clearly glossy in F. moellenkampi ) ( Fig. 4A, C View FIGURE 4 ). However, the female of the new species is hard to distinguish from that of F. ruficrus by external characters. The new species can be identified by its relatively longer spermathecal duct (shorter in F. ruficrus ; Fig. 8C, I View FIGURE 8 ) and a more sclerotized, shorter and rounder spermatheca. In addition, the new species exhibits morphological similarities to F. virginiae (Bomans, 1991) , but can be readily distinguished by its flattened clypeolabrum, the relatively rounded outer margin of the mandible (which is distinctly incurred near the apex in the new species), and a shorter spermathecal duct ( Huang & Chen 2017, 2023).

Description of the holotype, male.

Dimensions. Body length 30.5 mm. Length of particular body parts: head ( 4.6 mm), mandible ( 8.7 mm), pronotum ( 5.9 mm), elytra ( 13.1 mm); width: head ( 8.3 mm), pronotum ( 9.6 mm), elytra (9.0 mm).

Coloration and vestiture ( Fig. 1A, D View FIGURE 1 ). Body red to dark-red in dorsal view with moderate gloss, amber to maroon in ventral view with conspicuous gloss. Each femur primarily amber, each tibia dark-red to black. Dorsal surface of body without visible pubescence; metaventrite and visible abdominal ventrite with short yellow pubescence.

Head. Anterior margin bisinuate. Canthus sub-quadrangular, dividing over 1/2 of the eye. Mandible ( Fig. 2A View FIGURE 2 ) about 2.4 times as long as head, distinctly incurved behind apex, with a small, triangular protuberance on the dorsal surface behind the apex; protrusion at apical 1/3 sub-quadrangular, upturned slightly, inner margin serrated. Clypeolabrum ( Fig. 2D View FIGURE 2 ) transverse, 1/3 width of head, widely and shallowly, protruding at apical margin, lateral angles acute, indistinct defined by a transverse suture. Antennal club with three antennomeres; antennomeres 8–9 sub-quadrilateral; antennomere 10 semi-elliptic.

Pronotum ( Fig. 2G View FIGURE 2 ) transverse, 1.6 times wider than long, distance between two lateral angle widest. Anterior margin obviously bisinuate, clearly extending to the front at midline; anterior angles blunt and directed forwards. lateral angles rounded and distinctly protruded. Posterior margin weakly bisinuate, posterior angles obsolete and blunt.

Scutellum subtriangular, punctate, 1.6 times wider than long.

Legs. Protibia shrink basally, outer margin serrated with nine acute oblique erect protuberances (excluding apex bifurcate), almost ever-larger from base to apex along, a spur at apex; apex bifurcate with sharp branches at tip. The outer margin of mesotibia with a sharp sub-erect spine and metatibia smooth, with terminal spines.

Elytra elongate, 1.4 times longer than wide, the anterior margin of elytra obviously narrower than pronotum.

Abdomen and aedeagus. Abdominal tergite VIII ( Fig. 5A View FIGURE 5 ) without lateral angles, a clearly defined crack in midline almost runs through tergite. Abdominal ventrite VIII ( Fig. 5B View FIGURE 5 ) with a transverse distinct membranous area in the middle of base. Ventral plate of the abdominal segment IX ( Fig. 5D View FIGURE 5 ) without clearly membranous stripe. Aedeagus ( Fig. 6A, E, I View FIGURE 6 ) in dorsal view about 2.9 times longer than wide. Basal piece elongated, distinctly constricted in basal part, nearly 1.8 times longer than parameres in dorsal view, with a pair of triangular sclerotized dorsal plates; ventral plate at apical end of basal piece membranous. Paramere with flat apical margin. Penis clearly shorter than paramere. Outer margin of penis sclerotic, extending at apex basally forming an inverted-U-shape. Flagellum divided into three sections in basal 1/4, the middle one extremely slender, about 2.1 times longer than aedeagus.

Variation of males (n = 2). Body length 19.0– 22.3 mm. Mandible shorter, simply structured, with serrated inner margin.

Females. Body length 19.0–20.0 mm.

Coloration and vestiture ( Fig. 4A, D View FIGURE 4 ). Body dark red, pronotum moderately glossy and smooth; elytra textured. body without pubescence. Dorsal surface of body without visible pubescence; metaventrite and visible abdominal ventrite with relatively long yellow pubescence.

Head covered with deep dense punctures. Canthus thin, covering apical 1/3 of eye. Clypeolabrum tiny, transverse, trapezoidal. Mandibles short, about 0.7 times length of head, with a tooth at apical 2/5 on inner margin. Antennal club with 3 antennomeres; antennomeres 8–9 subquadrilateral; antennomere 10 semi-elliptic.

Pronotum transverse, slightly punctate, 1.6 times wider than long, widest across lateral angles; anterior margin bisinuate, posterior margin slightly bisinuate; anterior angles acute; lateral angles and posterior angles blunt.

Scutellum slightly punctate, about 1.2 times wider than long.

Elytra clearly punctate apically, about 1.6 times as long as wide. Surface relatively smooth, with shallow punctures.

Legs. Outer margin of protibia serrate, with sparse 5 conspicuous sharp protuberances (excluding apical fork) along outer margin, apex bifurcate with branches moderately sharp at tip, extend apically. Mesotibia and metatibia straight, with a oblique spine at outer margin and a terminal spine.

Abdomen and genitalia. Abdominal tergite VIII ( Fig. 8A View FIGURE 8 ) semicircular, with clear, wide, linear membranous area, almost runs from apex to base. Abdominal ventrite VIII ( Fig. 8B View FIGURE 8 ) with membranous area at central part, runs from apex to base. Hemisternite ( Figs. 8C View FIGURE 8 ) with curved at lateral margins, apical margin rounded with setae. Spermathecal duct long and thin. Spermatheca droplet-shaped, sclerotic.

Analysis based on COI fragment ( Fig. 9 View FIGURE 9 ; Table 1). Based on the Bayesian Information Criterion (BIC) evaluation, the TIM2+F+G4 model was selected as the optimal nucleotide substitution model, owing to its lowest score among all candidate models. The inferred phylogenetic topology is as follows: ((( F. ruficrus + F. banjinshuaii ) + ( F. mochizukii + F. moellenkampi )) + ( F. bisignatus + F. himalayae )) + Outgroup. Phylogenetic reconstruction revealed pronounced genetic differentiation between the new species and other sequenced members of the F. bisignatus species group (sensu Huang & Chen 2013), with strong statistical support from nodal metrics (bootstrap values> 0.95). Both maximum likelihood (ML) topology and Kimura-2-parameter (K2P) genetic distance analyses consistently confirmed a close genetic affinity between the new species and F. ruficrus (De Lisle, 1970) . The interspecific K2P genetic divergence between the new species and F. ruficrus ( 0.04566 –0.04866) substantially exceeded the typical intraspecific variation threshold for the F. bisignatus species group ( 0.00275 –0.02524). Notably, this interspecific divergence was also lower than the overall mean genetic distance (0.09) observed among species of the F. bisignatus group—a pattern that further underscores the close genetic affinity between the new species and F. ruficrus . This intermediate genetic distance, combined with distinct morphological differentiation, supports the delineation of the novel lineage as a distinct species within F. bisignatus group, while acknowledging its sisterspecies relationship to F. ruficrus . Furthermore, species delimitation analyses—employing both the distance-based ABGD method and the tree-based bPTP approach—corroborated the new species’ validity. Congruent clustering patterns were consistently identified across these independent analytical frameworks, providing robust evidence for its species status. Incidentally, the three samples of the new species exhibit a COI sequence genetic distance of 0. Additionally, all samples were collected from the same piece of decayed wood. Based on the maternal inheritance characteristic of mitochondrial genes, it can be inferred that these samples are all offspring of a single female individual.

Etymology. The new species is named after Mr. Jin-Shuai Ban ( IJaeĸ) ( Guizhou, China), who provided the type specimens for our research.

Life history. In early November 2024, five third-instar (early stage) larvae were collected by splitting a piece of broad-leaved decayed wood, and then brought back for rearing. Among these larvae, two small males and two females pupated successively in late January 2025; after a pupal period of one month, they eclosed sequentially in late February. The largest male pupated in mid-March, with a pupal period also lasting one month, and eclosed in mid-April ( Figs. 10–11 View FIGURE 10 View FIGURE 11 ).

Distribution. China ( Guizhou) ( Fig. 12 View FIGURE 12 ).