Pterostichus (Wraseiellus) strumatus, Chen & Yin & Shi, 2024

Chen, Jia-Heng, Yin, Wen-Qi & Shi, Hong-Liang, 2024, On the Pterostichus subgenus Wraseiellus from China: descriptions of five new species and supplementary notes on taxonomy (Coleoptera: Carabidae), Zootaxa 5447 (4), pp. 451-472 : 459-461

Pterostichus (Wraseiellus) strumatus sp. nov.

Chinese vernacular name: OiẸaeữfflm

Figures 4 , 9C , 10C

Type materials. Holotype ( IZAS), male, body length = 13.8 mm, “ Emeishan Mt. , Jiulinggang, 2012.8.17. pitfall trap, 1900m, Hao Huang leg.” [in Chinese] // “HOLOTYPE Pterostichus (Wraseiellus) strumatus sp. nov., det. Chen & Shi. 2024” [red label].

Diagnosis. Frontal furrows shallow and short, extending a little behind level of anterior margin of eyes; vertex finely punctate; temporae short (TL/EYL 0.27–0.30). Maximum width of pronotum a little before middle; lateral margins strongly sinuate before posterior angles; posterior angles distinct, nearly rectangular, not forming prominent denticle; pronotal base finely and sparsely punctate; area between inner and outer basal foveal grooves depressed, ridge between outer groove and lateral margin distinct. Median lobe of aedeagus with a tubercle near base of ventral margin, apical lamella apically thickened and turned dorsally ( Fig. 4B ); in dorsal view, apical lamella elongate, apex capitate and rounded, slightly bent to left ( Fig 4C ); right paramere slender and long, apical portion acinaciform ( Fig 4D ).

Comparisons. The new species is most similar to P. crassiapex . These two species can be distinguished from other andrewesi -group species by the combination of following characters: (1) pronotum cordiform, posterior margin narrower than or subequal to anterior margin; (2) pronotum with one mid-lateral seta on each side; (3) pronotal basal fovea not convex between inner and outer grooves; (4) median lobe of aedeagus with apical lamella elongate (AL/AW> 1.40), apex capitate and rounded; (5) right paramere acinaciform.

Comparing to P. crassiapex , P. strumatus sp. nov. is different in: (1) pronotal posterior angles not prominent (versus forming a prominent denticle in P. crassiapex ); (2) basal foveae and pronotal mid-basal area finely and sparsely punctate (versus strongly and densely punctate in P. crassiapex ); (3) proepisterna finely and sparsely punctate (versus densely and coarsely punctate in P. crassiapex ); (4) median lobe of aedeagus with a tubercle on ventral margin; (5) in dorsal view, apical lamella less bent to left, less constricted at base, AL about one and a half times as AW (versus more strongly bent to left, more constricted at base, AL about twice as AW in P. crassiapex ); (6) ventral surface of apical lamella strongly concaved, forming ridged margin (versus weakly concaved, without ridge in P. crassiapex ).

Description. BL 13.8 mm; dorsal surface dark brown, without metallic luster ( Fig. 4A ). Head. Frons finely and sparsely punctate, relatively densely in frontal furrows, frontal furrows short and shallow, extending a little behind level of anterior margin of eyes; vertex finely punctate, with faint longitudinal wrinkles; temporae short (TL/EYL 0.28–0.31), not swollen behind eyes; paraocular grooves deep, impunctate and nearly straight, reaching posterior margin of eyes; antennomere 3 without accessory setae. Pronotum cordiform (PW/PL 1.32); anterior and posterior margins almost straight, lateral margins evenly curved from anterior angles to posterior third, abruptly sinuate before posterior angles; anterior margin slightly wider than posterior margin; anterior angles obtusely rounded, not projecting; posterior angles nearly rectangular, apex sharp, not forming prominent denticle; discal area glabrous; basal foveae relatively short and narrow, deep and areal punctate, area between inner and outer basal foveal grooves rugose and depressed, mid-basal area between two basal foveae sparsely punctate, ridge between outer groove and lateral margin distinct; a few very fine and sparse punctures present in lateral channels and, sometimes, on lateral sides of disc; one mid-lateral seta present on each side. Elytra oblong (EL/EW 1.42), lateral margins subparallel before middle, slightly expanded behind middle; humeral teeth small; intervals slightly convex; striae moderately deep, without punctures; parascutellar striae joined to stria 1, angular base of stria 1 short, apex free; umbilicate series on interval 9 composed of approximately 14–17 pores, sparse in middle and dense in anterior and posterior areas; male with microsculpture typically transverse on basal half, gradually turned to isodiametric towards apex. Ventral side. Proepisterna and metaepisterna sparsely punctate, punctures on metaepisterna relatively coarser; sternite VII of males with a lunate transverse ridge at about anterior third, median region of sternite VII shallowly depressed posterior to the ridge. Legs. Tarsomere 5 with three or four pairs of setae beneath. Male genitalia ( Figs 4B , 10C ). Median lobe of aedeagus relatively stout, tapered to apex; in lateral view, ventral margin with a distinct tubercle close to the basal bend ( Fig. 4B ), ventral margin weakly bent to the ventral side before apex, apical orifice large, slightly turned to left, apical lamella apically thickened and turned dorsally; in dorsal view, apical lamella long (AL/AW 1.47), base slightly constricted, apex rounded and capitate, slightly bent to left; ventral surface of apical lamella strongly concaved on left side, marginal ridge present on the apical and right border of the concavity ( Fig. 10C ). Right paramere acinaciform, narrow and long, apex somewhat blunt. Endophallus of male genitalia not studied. Female genitalia unknown.

Etymology. The scientific name of the new species is derived from the Latin root “ strum -” [tumor], referring to the median lobe of aedeagus with a peculiar swelling.

Distribution. Only known by the holotype collected on Emei Mountain, Sichuan Province.

Figures

FIGURE 4. Holotype of Pterostichus strumatus sp. nov. (A) habitus; (B) median lobe of aedeagus, left lateral view; (C) median lobe of aedeagus, dorsal view; (D) right paramere. Scale bars = 5.0 mm for A; = 1.0 mm for B–D. Abbreviations: t tubercle on ventral margin of aedeagus.

FIGURE 9. Pronotum posterior angle and basal area of Pterostichus (Wraseiellus) spp. (A) P. pseudandrewesi sp. nov.; (B) P. leishanensis sp. nov.; (C) P. strumatus sp. nov.; (D) P. idiopterus sp. nov.; (E) P. hemichlorus sp. nov..

FIGURE 10. Apical portion of aedeagus of Pterostichus (Wraseiellus) spp., left lateral view and ventral view. (A) P. pseudandrewesi sp. nov.; (B) P. leishanensis sp. nov.; (C) P. strumatus sp. nov.; (D) P. andrewesi Jedlička.