Ichthyurus simplus Y. Yang, Lin & Liu, 2025

Ichthyurus simplus Y. Yang, Lin & Liu sp. nov.

Figs 8 H View Figure 8 , 20 A, B View Figure 20 , 21 View Figure 21 , 22 A ‒ D View Figure 22

Type material.

Holotype. China. Guangxi • ♂ ( MHBU), Guanyang, Taizishan, Zhupoling , 6. V. 2021, Junbo Tong leg.

Paratype. China. Guangxi • 1 ♀ ( MHBU), same data as holotype .

Differential diagnosis.

This species could be distinguished from all others of Ichthyurus by combination of the following characters in the shape of terminal abdominal ventrite in male (Fig. 21 C View Figure 21 ) and female (Fig. 21 D View Figure 21 ), as well as the structure of aedeagus (Fig. 21 A ‒ D View Figure 21 ), particularly in the characteristic proctiger and paraproct (Fig. 21 E, F View Figure 21 ).

Description.

Body length (both sexes): 10.7‒11.2 mm ( 11.2 mm in holotype); body width (both sexes): 1.7‒1.9 mm ( 1.9 mm in holotype).

Male (Fig. 20 A View Figure 20 ). Colouration. Body black, prosternum yellow, pronotum yellow at posterior angles, scutellum yellow, elytra narrowly yellow along basal part of suture, legs yellow at basal 2 / 3 parts of femora, abdomen yellow posteriorly and laterally.

Eyes moderately protruding, interocular distance ca. 0.6 times of the diameter of an eye. Antennomere II ca. 1 / 3 length of I, III ‒ VI subequal in length and ca. 3.0 times longer than II.

Pronotum 1.1 times wider than long, anterior margin arcuate, lateral margins nearly feebly diverging posteriorly, posterior margin slightly bisinuate, anterior angles confluent with anterior margin, posterior angles nearly rectangular.

Elytra 1.4 times longer than wide, ca. 2.1 times longer than pronotum, with lateral margins slightly sinuate, sutural margins sinuate and moderately dehiscent from the basal 1 / 3 part, distance between sutural margins twice as wide as apical width of an elytron, apices rounded.

Pro- and metathoracic legs slender and simple (Fig. 20 A View Figure 20 ); mesotrochanter (Fig. 20 A View Figure 20 ) with an inconspicuous apical tooth, mesofemora weakly swollen.

Terminal abdominal tergite (Fig. 21 A View Figure 21 ) ca. 1.5 times longer than wide, with postero-lateral projections ca. 1 / 3 length of the tergite, moderately arcuate at inner margins and slightly arcuate at outer margins. Proctiger (Fig. 21 E, F View Figure 21 ) bilobed and strongly sclerotised, with outer apical angles rounded and inner apical angles protruding and acute, completely surrounded by paraproct; paraproct (Fig. 21 E, F View Figure 21 ) strongly developed, hexagonal, with lateral margins bordered and extending dorsally into a longitudinal ridge in middle, with a short and conical protrusion in middle of posterior margin, tergal flange weakly sclerotised, expanded at base and narrowly protruding apically.

Terminal abdominal ventrite (Fig. 21 C View Figure 21 ) trilobed, approximately twice as wide as long, fissured in middle of apical half part, with lateral lobes generally axe-like, nearly straight at both inner and outer margins, inner apical angles moderately projecting and rounded at apices, outer apical strongly projecting and acute at apices.

Abdominal sternite IX (Fig. 8 H View Figure 8 ) moderately sclerotised and subparallel-sided, ca. 1.8 times longer than wide, with posterior margin shallowly emarginate, posterior right and left angles nearly rectangular, anterior left angle small beak-shaped and right angle strongly protruding anteriorly.

Aedeagus (Fig. 22 A ‒ D View Figure 22 ): right paramere spine-like, ca. 3.0 times as long as wide (Fig. 22 A, D View Figure 22 ); left paramere nearly straight and cylindrical, rounded at apex, 3.0 times longer than right paramere (Fig. 22 A ‒ D View Figure 22 ); setifore extension reduced and almost invisible (Fig. 22 B View Figure 22 ); median lobe ca. 1.5 times as long as tegmen, even in width along whole length (Fig. 22 A, D View Figure 22 ).

Female (Fig. 20 B View Figure 20 ). Similar to males, but body larger, eyes less protruding, elytra uniformly black, legs yellow at basal 1 / 3 parts of femora; terminal abdominal tergite (Fig. 21 B View Figure 21 ) ca. 1.1 times longer than wide, with postero-lateral projections ca. 1 / 3 length of the tergite; terminal abdominal ventrite (Fig. 21 D View Figure 21 ) nearly as long as wide, widest near middle, triangular at latero-apical angles, arcuate at lateral margins, widely and roundly emarginate in middle of posterior margin.

Etymology.

The specific name is derived from the Latin word “ simplus ” (simple), referring to its simple aedeagus.

Distribution.

China ( Guangxi).

Remarks.

Antennomeres VII ‒ XI of the holotype and V ‒ XI of the paratype are missing.