Stomis vignai ssp. vignai Sciaky, 1998

Sciaky, Riccardo, 2024, Review of the Chinese Stomis, with description of nine new taxa and a new key (Carabidae: Pterostichini), Zootaxa 5523 (1), pp. 1-34 : 2-3

Stomis vignai ssp. vignai Sciaky, 1998

Loc. typ.: China, Western Sichuan, Wolong, Wujipeg .

= Stomis cavazzutii Lassalle, 2003 syn. nov.

Loc. typ.: Gansu merid., 2400 m, Tochiji, sud Wudu .

= Stomis morvani Deuve, 2022

Loc. typ.: Sichuan, Maoxian syn. nov.

Described in 1998 upon a single male specimen collected by the late Vigna Taglianti in the area around Wolong , it has never been collected again in the type locality, although I have been able to examine a certain number of specimens from other localities of northern Sichuan and southern Gansu not far from Wolong. The illustrations of the habitus and of the aedeagus of the holotype are found in Sciaky (1998).

A few years after the description of S. vignai, Lassalle (2003) described two new species, Stomis cavazzutii from Gansu and Sichuan, and S. taibashanensis from Shaanxi, both characterized (in the specimens examined by him) by a multiplication of the pronotal anterolateral setae. In spite of this character, that proved to be highly variable, I have interpreted the former as a population belonging to S. vignai , only slightly different, while the latter as a slightly differentiated subspecies of S. vignai . I know directly the populations from Gansu and northern Sichuan upon further material, thus becoming persuaded that they belong to the same form described from Wolong. The other species described by Lassalle (2003) can be maintained as a subspecies of S. vignai , and two more subspecies will be added in the next pages. The peculiar features of this species (only species of this group) are the very convex shape, the short mandibles and the broadly rounded basal angles of pronotum. The character of the multiple pronotal setae, very stable in other groups of Carabidae , here is very unstable, being present occasionally in specimens of at least three out of four known subspecies, more frequently in some populations than in others, but without any stability allowing to use it as a diagnostic character between species or subspecies. Also the size is extremely variable in two of the known subspecies, presenting small specimens and very large specimens with few intermediate forms and without visible differences in the aedeagus structure.

In a recent paper, Deuve (2022) described S. morvani , a new species related to S. vignai , but different in the pronotal shape and few other morphological details. I have examined some specimens from a locality almost coincident with the type locality of this form, verifying that, as in the case of S. cavazzutii , these differences do not allow even a subspecific differentiation, since this species shows a very strong variability and the type localities of all these three forms are really very close to each other, all in the area comprised between southern Gansu and northern Sichuan.

I can therefore state the two new synonymies:

Stomis cavazzutii Lassalle, 2003 = S. vignai ssp. vignai Sciaky, 1998 syn. nov.

Stomis morvani Deuve, 2022 = S. vignai ssp. vignai Sciaky, 1998 syn. nov.

Description. Habitus as in Fig. 1 . The combination of characters allowing to distinguish this subspecies are: length 7.2–10.3 mm; with the characters of the species group. Body length usually short (7.3–8.5 mm), only in few cases above 9 mm. Pronotum not sinuate towards base and less constricted than in the other subspecies, only seldom with multiple anterolateral setae; elytra oval, with shoulders more distinct than in other subspecies; aedeagus long and slender, in lateral view with apical portion almost as long as basal one, subsinuate before apex ( Fig. 29 ). Ratios: El/Pl = 2.08; Ew/Pw = 1.11; El/Ew = 1.68.

Distribution. Northern Sichuan, Southern Gansu. In one locality in Gansu it was found in syntopy with S. exilis ssp. brivioi .

Material examined: Gansu, 3000 m, 20 km N Wenxian : 6 ♂ ♀ ( CS) ; NW Sichuan, 20 km NW Maowen, Jiuding Shan , coniferous wood, 2150 m, 7–28. VI.2004, leg. R. Fabbri : 4 ♂ 1 ♀ ( CM) .

Figures

FIGURES 1–4. Habitus of: (1) S. vignai ssp. vignai from 20 km NW Maowen (9.5 mm); (2) S. vignai ssp. taibashanensis from Shaanxi, Houzhenzhi (9.3 mm); (3) S. vignai ssp. maior HT (11.3 mm); (4) S. vignai ssp. megacephalus HT (11.2 mm).

FIGURES 29–31. Aedeagus in lateral and dorsal view of: (29) S. vignai ssp. vignai from from 20 km NW Maowen; (30) S. vignai ssp. taibashanensis from Shaanxi, Houzhenzhi; (31) S. vignai ssp. maior HT.