Pterostichus ( Morphohaptoderus ) rongyu, Wu & Chen & Shi, 2025

[13] Pterostichus ( Morphohaptoderus) rongyu sp. nov.

Figs 4 H View Figure 4 , 5 N View Figure 5 , 25 View Figure 25

Type material.

Holotype: Hubei • ♂, labeled “ Hubei Province, Shennongjia, Guanmenshan , N 31.4362, E 110.3824, pitfall trap, 1361 m, 2022. VII. 29, Hongliang Shi & Ganyan Yang leg. ” [in Chinese] ( IZAS) GoogleMaps . Paratype: Chongqing • 1 ♀, labeled “ Chongqing, Wuxi, Yintiaoling, Luomadian, Huanglianchanggou , 1467 m, N 31.5414224, E 109.850047 // hardwoods & bamboo mixed forest, under stone, 2024. VIII. 11; Jiaheng Chen lgt. ” ( CBFU) GoogleMaps .

Diagnosis.

Small-sized species for the subgenus ( BL = 5.7–6.1 mm); elytra with linear microsculpture in both sexes; antennomere 3 without accessory on apical half; pronotum rounded quadrate; basal foveae coarsely punctate, outer sulcus indistinct; elytral oval, lateral margins distinctly expanded near middle; interval 3 with two setigerous pores, all adjacent to stria 2; fifth tarsomeres without seta ventrally; median lobe of aedeagus without ridge on ventral surface, apical lamella without denticle or tooth.

Comparisons.

The present new species, P. rongyu sp. nov., is highly distinctive within the subgenus Morphohaptoderus . It is characterized by the absence of ventral setae on the fifth tarsomeres and the presence of two setigerous pores on elytral interval 3, both of which are adjacent to stria 2. In this regard, the present new species resembles only P. yaotiao sp. nov. However, the two species differ substantially in terms of body size, overall habitus, and male genitalia. Specifically, P. yaotiao sp. nov. has a significantly larger body ( BL = 7.9–10.0 mm), a more elongate body form with nearly parallel lateral margins, and the median lobe of aedeagus features a ventral ridge and lamellar denticles.

Actually, among all other Chinese species within the subgenus Morphohaptoderus that possess two setigerous pores on elytral interval 3 adjacent to stria 2, the male genitalia exhibit a particular form. Specifically, the ventral surface of the median lobe has a ridge, and the apical lamella has lamellar denticle on its left surface. In this regard, P. rongyu sp. nov. is very special within the subgenus.

Although they have similar elytral chaetotaxy, we do not consider P. rongyu sp. nov. to be related to P. yaotiao sp. nov. due to their markedly different male genitalia. Instead, we suspect a relationship between P. rongyu sp. nov. and P. zhizheng sp. nov. as well as P. lianquan sp. nov., even though the latter two species have only one setigerous pore on elytral interval 3. All three of these mentioned species share a relatively simple form of the median lobe of aedeagus, lacking a ventral ridge or apical lamellar denticle. However, P. zhizheng sp. nov. and P. lianquan sp. nov. can be easily distinguished from P. rongyu sp. nov. by their much larger body size, more elongated body form, the presence of only one setigerous pore on interval 3, and the longer apical lamella of the aedeagus.

Description.

BL = 5.7–6.1 mm, BW = 2.4–2.7 mm; dorsal surface dark brown to black, appendages brown; elytra with linear microsculpture in both sexes (Fig. 25 D, E View Figure 25 ).

Head slightly thickened, HW / PW = 0.56–0.59; frons without puncture; frontal sulci deep and straight, extended near to the anterior supraorbital seta; antennae filiform, reaching elytral basal sixth, antennomere 3 without accessory seta; eyes large and hemispherical, tempora very shortly swollen behind eyes; submentum with one seta on each side.

Pronotum rounded-rectangular, distinctly wider than length, PW / PL = 1.34–1.35, widest a little before middle, posterior margin much narrower than greatest width, PBW / PW = 0.82–0.84. Anterior margin shallowly concaved at middle, slightly narrower than posterior margin, PAW / PBW = 0.71–0.74; anterior broadly rounded, weakly projecting; lateral margins evenly arched before middle, distinctly narrowed and nearly straight along posterior half, not sinuate before posterior angles, posterior angles nearly right-angled, with a small denticle slightly projecting out. Basal foveae (Fig. 4 H View Figure 4 ) with coarse and sparse punctures along inner and outer sulcus, as well as on base of intersulcate area; inner sulcus shallow with distinct boundary, slightly oblique to pronotum basal margin, base ending before pronotum basal margin; outer sulcus very faintly indicated, only represented by a few gathered punctures; a short and shallow basal sulcus usually present, medially not extending to the base of inner sulcus; intersulcate area flat; area between lateral margin and outer sulcus flat; lateral channels narrow, with very faint punctures. Pronotal disc without wrinkles aside median line; median line shallow.

Elytra oval and slightly convex, lateral sides distinctly expanded behind middle, BW / EL = 0.74–0.75. Elytral basal border slightly curved, forming an obtuse angle with lateral margin, humeral tooth small, apex faintly pointed; striae punctate on basal third; parascutellar striole joined to apical portion of stria 1, angular base of stria 1 absent (Fig. 4 H View Figure 4 ). Parascutellar pore present; interval 3 with two setigerous pores, both adjacent to stria 2, first setigerous pore positioned near middle, the rest one near apical third; umbilical pore series on ninth interval sparse in middle, composed of 13–14 pores (5–6, 1–2, 6–7).

Fifth tarsomeres without seta ventrally.

Male sternite without secondary sexual modification, apex of sternite VII evenly rounded.

Median lobe of aedeagus (Fig. 25 A View Figure 25 ) relatively slender in lateral view, ventral margin evenly curved along all the full length, apex weakly bent to the ventral side; apical orifice wide and short, weakly turned to left side, opened to the dorsal left surface of median lobe. Ventral surface without ridge. Apical lamella thin in lateral view; short and wide in dorsal view ( AL / AW = 0.69–0.71), faintly turned to left side, gradually narrowed to apex, shaped a wide triangle, apex widely rounded, without denticle or tooth (Fig. 25 B View Figure 25 ). Right paramere short, apex rounded (Fig. 25 C View Figure 25 ).

Endophallus of male genitalia not studied due to restricted materials.

Gonocoxite 2 of female ovipositor small, widely crescent-shaped (Fig. 5 N View Figure 5 ), sharp apically; outer margin with two ensiform setae in large size, length of the largest ensiform seta ca. 0.04 mm; dorsal margin with one ensiform seta near apical third, ridged between the ensiform seta and apex of gonocoxite 2, one nematiform seta located on the apical seventh of outer surface.

Distribution.

The new species is known by two specimens collected from Shennongjia in Hubei Province and Wuxi County in Chongqing Municipality. These two collection sites are adjacent to each other, with a linear distance of about 50 km between them. The altitude of this species is relatively low, ranging from 1361 m to 1467 m.

Etymology.

The scientific name of the new species is derived from Qu Yuan’s work “ Xiang Fu Ren ”: 时不可兮骤得 [Shi Bu Ke Xi Zhou De], 聊逍遥兮容与 [Liao Xiao Yao Xi Rong Yu]. This couplet can be translated as: The wonderful moments have passed, never to return. Let me roam at ease, with a leisurely air. Rongyu (容与) is a term used to depict a carefree scene in the poem. The name rongyu is proper for a Pterostichus species because these beetles are often seen running freely in the forest. The name is treated as a noun in apposition.