Morphohaptoderus Tschitschérine, 1898

Fedorenko, D. N., 2023, New taxa of Pterostichus (Coleoptera: Carabidae) from Vietnam, Russian Entomological Journal 32 (1), pp. 16-39 : 17

Subgenus Morphohaptoderus Tschitschérine, 1898

Tschitschérine, 1898a: 190 ( Feronia subg.); Sciaky, 1994: 1; Shi et al., 2013: 105.

Type species: Haptoderus maximus Tschitschérine, 1889 , subsequently designated by Jeannel [1937].

DIAGNOSIS. A polytypic subgenus of Pterostichus from southern China to northern Vietnam, defined chiefly by cx 3 trisetose, tr 3 setose and the body apterous, with metepisterna short.

REDESCRIPTION (For recognition only). Body smallto medium-sized, BL 4.8– 13 mm. Dorsum shiny black, often iridescent, sometimes dull in female. Head rather small, eyes convex to flat, neck constriction indistinct. Antennae filiform, moderately long, scape with preapical seta, pedicel with ventral seta and often with a few short setae toward apex; antennomeres 4–11 and often extreme apex of antennomere 3 pubescent. Submentum bi- or quadrisetose.

Pronotum flattened, each side mostly finely beaded, with basal angle distinct and two basolateral sulci on each side.

Elytra rather wide at bases, with striae 1–7 inside humeral angle; humeri and humeral tooth mostly distinct, parascutellar seta present and parascutellar striole short or missing. Interval 3 with discal setae varying from species to species in number as well as in position, sometimes multiple or missing. USS consisting of 16–17 (mostly 16) or 14–15 US in larger or smaller species, respectively; US arranged into a row 6–1–1– … ( US 1–6 — US 7 — US 8–…), i.e., sparser at middle, and adjoining stria 8 while US 3 adjoining striae 8 and 9.

Body setation otherwise complete, including clypeus bisetose, two supraocular setae, two elytral apical setae in stria 7, fe 1 with three posterior setae, fe 2 with two anteroventral setae in basal three fifths and 2–4 anterodorsal setae in apical two fifths, fe 3 bisetose; ti 3 mostly without lateral setae. Tarsomere 5 glabrous or setose ventrally.

Prosternal process flat or with indistinct median groove, apex truncate and indistinctly bifid in anteroventral view due to the median groove more impressed at extreme apex, angles rounded or blunt; inclination flat, with lateral beads converging ventrad to enclose triangular dorsal part or nearly so. Abdominal sternite VII bi- (♂) or quadrisetose (♀) at apex, not modified in male.

Legs rather slender; ti 1 anterior face smooth and glabrous; ta 2 and ta 3 mostly with tarsomeres 1–3 carinate laterally and bisulcate dorsolaterally; posterior (inner) sulcus being more shallow than anterior (outer) one and varying from distinct to totally obliterate between species.

Aedeagus rather typical for the genus, median lobe in lateral view strongly curved to geniculate, with apical orifice left dorsolateral to nearly dorsal; left paramere quadrate, with a deep dorsobasal fissure; right paramere short. Everted and inflated internal sac curved first leftward and then ventrad and slightly basad, sometimes apicad only.

Female tergite VIII moderate in length (moderately wide), with basolateral apodemes slightly less sclerotized toward tips; sternite VIII mostly well sclerotized laterobasally, densely setulose along apical margin to glabrous or nearly so. Tergite IX: laterotergite with apical margin rounded and densely setose, setae varying between species in length; gonosubcoxite with a short row of fairly short and dense setae along latero-apical margin; gonocoxite triangular, more or less crescent, with preapical nematiform seta, 2–3 outer (ventral) and one, sometimes two, inner (dorsal) ensiform setae. Reproductive tract rather characteristic of the genus: bursa copulatrix trapezoidal, with apex invaginated and sclerotized; spermatheca long, subdivided into long and narrow seminal canal and shorter subclavate receptacle; spermathecal gland duct long.

COMMENTS. This subgenus includes over 30 described and a number of undescribed species from China. Three species described below are very similar to one another in body size and appearance and share similar male and female genitalia, but their some, derived, characters are unusual for the subgenus. These polythetic characters include some elytral setae missing, parascutellar or discal, or both, and the inclination of the prosternal process not apically beaded. Furthermore, the cx 3 setae tend to be reduced from three to two in number. The posterior two setae are short or vestigial yet constantly present in P. glabellus sp.n. while the inner seta is absent from one ( P. unisetosus sp.n., one of two specimens examined) or both ( P. primitivus sp.n.) sides.