Tetragonoderus parviculus Kavanaugh and Cueva-Dabkoski 2023, sp. nov.
Creators: name: Kavanaugh, David H.
name: Cueva-Dabkoski, Mollie
name: Liang, Hongbin
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Tetragonoderus
Tetragonoderus parviculus

description: Tetragonoderus parviculus Kavanaugh and Cueva-Dabkoski, sp. nov.
Figures 11, 13D, 14D, 15D, 16D, 17D, 18 C-D, 21, and 23.
Type material. HOLOTYPE, a male, deposited in IOZ, labeled: “ CASENT1039396 ”/ “ CHINA, Yunnan, Tengchong County, Wuhe Township, Longchuan Jiang just below bridge at Menglian village, 24.89176°/98.67551°,”/ “ 1230 m, 3 June 2006, Stop # DHK-2006-054A, D.H. Kavanaugh, R.L. Brett & D.Z. Dong collectors”/ “HOLOTYPE Tetragonoderus parviculus sp. nov. D.H. Kavanaugh & M. Cueva-Dabkoski 2022” [red label]. A total of four paratypes: three males, in CAS and IOZ, same label data as holotype, except first label [unique identifier label] different, “ CASENT1039394 ”, “ CASENT1039395 ” and “ CASENT1039397 ”, respectively; one female, in NMPC, labeled: “ CHINA: YUNNAN Prov. 5.9 km W Tongbiguan, 24°36.78’N, 97°45.38’E, J. Hájek, J. Růžička, & C.-B. Wang leg.”/ “(CH12) 25.-27.vi.2016; 1290 m, baited pitfall trap #06 (fish meat, ripening cheese), secondary broadleaved forest, valley near stream”. Each paratype also bears the following label: “PARATYPE Tetragonoderus parviculus sp. nov. D.H. Kavanaugh & M. Cueva-Dabkoski 2022” [yellow label].
Type locality. China, Yunnan, Tengchong County, Wuhe Township, Longchuan River just below bridge at Menglian village.
Etymology. The species epithet, parviculus, is a combination of the Latin adjective, parvus, meaning small, and the Latin qualifier, -ic ulus, meaning somewhat, here used as an adjective in the masculine form. It refers to the relatively small size of members of this species.
Diagnosis. Adults of T. parviculus can be distinguished from those of other cyclosomine species in the study area by the following combination of character states: Body size slightly small for genus, BL males = 3.7 to 4.2 mm, female = 4.4 mm; elytra dark without pale markings in basal half, with distinct transverse subapical band of pale spots extended from interval 4 to 8 (Fig. 11A), faintly present also on interval 2 and/or 3 in some individuals, femora dark black or piceous; dorsal surfaces shiny, with distinct aeneous-greenish metallic reflection, of similar sheen throughout; elytral microsculpture comprised of more or less regularly transverse meshes, except their orientation slightly distorted in or near discal setal pore punctures; pronotum widest anterior to middle; elytra slightly to distinctly and obliquely truncate apically; posterior discal setiferous puncture on interval 3 inserted more posteriad, at level of pale transverse subapical band; front tarsomeres 1 to 3 without lateral expansions (Figs. 14D, 15D).
In the study area, specimens of T. parviculus (Fig. 12A) might be confused only with those of T. arcuatus (Figs. 9A). Refer to the key and Diagnosis section for T. arcuatus for features distinguishing these taxa.
Description. Size. Small for genus, BL males = 3.7 to 4.2 mm, female = 4.4 mm.
Color. (Fig 11A). Head, including venter, piceous to black except mandibles paler subapically and antennae with antennomeres 1, 1 to 2, or 1 to 3 paler. Pronotum piceous to black. Elytra piceous to black but with transverse subapical band of pale spots at about five-sixths elytral length, extended from interval 2, 3, or 4 to interval 8, with spots on intervals 2 and 3 less distinct in most specimens, those on intervals 2 to 4 shorter, and spots on intervals 5 to 8 longer, extended more anteriad, and more distinct. Venter piceous laterally, rufo-piceous medially, elytral epipleurae paler rufopiceous. Legs, piceous to rufopiceous, with femora darker than tibiae or tarsi or tibiae paler than femora and tarsi.
Reflection, luster, and microsculpture. Dorsum of head, pronotum and elytra with distinct aeneous-greenish metallic reflection. Head and pronotum slightly duller than elytra, with microsculpture moderately impressed and comprised of isodiametric meshes; elytra shiny, with microscuplture slightly less deeply impressed and comprised of moderately to markedly transverse meshes, meshes slightly distorted only in immediate vicinity of discal setae; abdominal venter dull laterally and shiny and slightly iridescent medially, with microsculpture moderately impressed and comprised of isodiametric to slightly transverse meshes laterally, more shallowly impressed and formed of transverse microlines and markedly transverse meshes medially.
Head. Eyes large, hemispheric; antennae slightly short, extended only to basal one-fifth of elytra; clypeus bisetose; labrum with three pairs of setae; mentum asetose, with a broadly rounded medial tooth; submentum anteriorly with a single pair of setae.
Prothorax. Pronotum (Fig. 13D) slightly narrow (ratio PWM/EW = 0.61 to 0.65), distinctly narrowed basally (ratio PWB/PWA = 1.04 to 1.09), widest distinctly anterior to mid-length, with anterior angles very short and broadly rounded; posterior angles slightly obtuse and slightly projected laterally; apical margin straight or very slightly concave between anterior angles; lateral margins arcuate and with a short and shallow sinuation just anterior to posterior angles; basal margin faintly bisinuate, not or only slightly lobate medially; anterior margination distinct laterally, more or less effaced medially; lateral margination distinct and complete, joined with apical and basal margination at anterior and posterior angles, respectively; basal margination distinct laterally, less distinct medially; midlateral setae inserted on lateral margination (“lateral bead”) at about one-fourth pronotal length; basolateral setae inserted on margination at posterior angles. Prosternal intercoxal process short, rounded, with complete but faint margination apically.
Elytra. Broadly ovate, longer than wide (ratio EL/EW = 1.27 to 1.37), widest slightly posterior to mid-length, obliquely truncate apically, humeri obtusely rounded; elytral striae deeply impressed throughout, elytral intervals flat or slightly convex, smooth; parascutellar setiferous pore present at base of interval 1 at junction of striae 1 and 2; two discal setiferous pores present on interval three, the anterior seta inserted adjacent to stria 3 near elytral midlength, the other inserted adjacent to stria 2 near apical one-fourth at level of subapical pale band; apical seta present, inserted near apex of interval 3; umbilicate series comprised of 11 or 12 setae.
Legs. Tarsal claws finely denticulate medially. Males (Figs. 14D, 16D) with front and middle tarsi with tarsomeres 1 to 4 distinctly broader than in females; male front tarsomeres 1 to 3 with two rows of adhesive squamosetae ventrally (Fig. 15D), females without such setae; middle tarsi with tarsomeres 1 to 4 (Fig. 17D) with pads of adhesive setae ventrally, absent from females.
Male genitalia. Median lobe (Fig. 18C,D) long and slender, shaft smoothly arcuate dorsally and ventrally, gradually tapered toward apex, with apical lamella slightly sinuate and tapered to a rounded point apically in lateral view, shaft symmetrically tapered and with apical lamella slightly expanded and apically rounded in dorsal view. Internal sac without evident spines.
Geographical variation. The female specimen from Tongbiquan Township differs from the male specimens from Wuhe Township in having antennae with only antennomere 1 pale (antennomeres 1 to 2 or 3 pale in the other specimens), the tarsi darker than the tibiae (both tibiae and tarsi paler than the femur in the other specimens), and the elytral subapical pale band evident from interval 2 to interval 8 (pale band visible mainly from interval 4 to interval 8 and only very faintly evident on interval 3 in the other specimens). All of these specimens otherwise are similar.
Habitat distribution. Members of this species were found under small stones on the open sandy shore of the Longchuan River, a medium-sized stream, at an elevation of 1230 m and together with adults of T. elegans and T. punctatus. The specimen from the Tombiguan area was collected in a baited pitfall trap near a stream through secondary (disturbed) broadleaf forest at an elevation of 1290 m.
Geographical distribution within the Gaoligong Shan. Fig. 11B. We examined a total of five specimens (four males and one female) from the following localities: Tengchong County: Tongbiguan Township (5.9 km W of Tongbiguan, 24.61276°/97.59121°, 1290 m, 25-27 June 2016, J. Hájek, J. Růžička, & C.B. Wang collectors [1 female; NMPC]; Wuhe Township (Longchuan Jiang just below bridge at Menglian village, 24.89176°/98.67551°, 1230 m, 3 June 2006, D.H. Kavanaugh, R. L. Brett, H.B. Liang & D.Z. Dong collectors [4 males; CAS, IOZ]).
At present, this species is known only from the southwestern part of the study area (Core Area 6).
Overall geographical distribution. (Fig. 23). Known only from Tengchong County, western Yunnan Province, China.
Geographical relationships with other Tetragonoderus species. Members of this species have been found synotopic with those of T. elegans and T. punctatus in the study area. The range of this species also overlaps that of T. arcuatus in the study area, but these two species have not yet been found syntopic. Also, the range of T. microthorax overlaps that of T. parviculus, but the former species has not yet been recorded from the study area.
description: Published as part of Kavanaugh, David H., Cueva-Dabkoski, Mollie & Liang, Hongbin, 2023, Inventory of the Carabid Beetle Fauna of the Gaoligong Mountains, western Yunnan Province, China: Species of the Tribe Cyclosomini Laporte, 1934 (Coleoptera: Carabidae), with Descriptions of Two New Species., pp. 451-491 in Proceedings of the California Academy of Sciences 67 (20) on pages 468-471, DOI: 10.5281/zenodo.11067293