Pareuryaptus Dubault, Lassalle et Roux 2008
Creators: name: Fedorenko, D. N.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Pareuryaptus

description: Pareuryaptus Dubault, Lassalle et Roux, 2008
Dubault et al., 2008a: 241; 2008b: 197; Roux et al., 2016: 22, 47; Li et al., 2022: 1. – Trigonotoma (part.): Tschitschérine, 1900: 161; Kirschenhofer, 2007: 11.
Type species: Trigonotoma curtula Chaudoir, 1868.
DIAGNOSIS. As for Trigonotoma except as follows. Antennal scape from barely longer than antennomeres 2 and 3 to almost as long as those 2 to 5 combined; pedicel without seta; clypeus subsinuate so that labral membrane is not or narrowly exposed; inner four labral setae proximate; mentum with lateral lobes angulate and much in front of median tooth. Elytra without setigerous pores, stria 7 with two preapical setae, basal ridge inwardly reaching stria 1. Mesoventrite without precoxal tooth, metepisterna long. Metacoxa with single, anterolateral, seta. Meso- and metatatarsomere 1 with anterolateral (outer) carina, tarsi without lateral setae. Terminal labial palpomere securiform in male. Median lobe of aedeagus nearly symmetrical in dorsal view, with apex very short and rounded.
REDESCRIPTION. Body macropterous, rather small to medium-sized, BL 11–16 mm, sometimes up to 22 mm; dorsum shiny black or brown black, without or with slight metallic green or violaceus luster; lateral bead of pronotum slightly to indistinctly brownish. Eyes medium-sized, convex, gena and neck constriction indistinct. Mandibles moderate in length, with apex very pointed and strongly incurved. Frontal sulci deep s-shaped, reaching the level of anterior supra-ocular seta. Shape of maxillary palpomeres 3 and 4 dependent on particular species or species group.
Pronotum (Figs 81–92) cordiform to nearly circular, except for base and apex truncate, broadest two fifths or little more from apex. Lateral bead rather thick, broadened and flattened toward base. Basal foveae very deep and narrow, densely to confluently punctate, often reduced to outer basal sulcus only, combined with inner one shallow or vague; outer basal sulcus directly extended into lateral groove inside lateral bead. Basal bead missing, apical bead distinct just inside angles. Base and lateral groove often distinctly punctate. Median line well impressed, obliterate apically, either fine and obliterate basally or deepened in basal half and reaching basal margin.
Elytra short and wide, with sides slightly rounded or parallel, humeri rather widely rounded yet distinct, and apices rounded combined. Striae deep, punctate; parascutellar striole (= base of stria 1) very short to missing. Intervals flat to convex, more convex before apex.
Venter coarsely and more or less densely punctate along sides of meso- and metathorax; punctation of propleura and metepisterna varying much between specimens of a species from sparse to missing; and abdominal sternites II–IV (sometimes II–VI) very unevenly, sparsely to moderately, punctate and often with 1–2 large and deep sublateral puncture. Prosternal process not beaded, its posterior inclination wide and flat to sharply carinate.
Protibiae with four apical (preapical-to-apical) spinules at outer edge (vs. three in Trigonotoma and Trigonaptus or two apical in Lesticus). Metatibia with 1–4 setae at outer margin.
Secondary sexual characters. Protarsomeres 1–3 dilated and biserially squamose on ventral side in male. Labial palpomere 3 securiform in male, subtriangular in female. Elytra not or barely shorter in female than in male. Mesotibia slightly longitudinally rugulose in about apical third of anterolateral face, with a small latero-apical tooth just above longer movable apical spur, in male, nearly smooth and without tooth in female.
Internal sac of aedeagus (Figs 11–30, 138–147) with additional, separate, hooked to bifid dorsobasal bulb.
Female pregenital segments, genitalia and reproductive tract (Figs 32–35) as for Trigonotoma, except for stigmata of tergite VIII exposed dorsally (vs. cryptic due to incurved latero-apical portions of the tergite) and spermathecal receptacle small and capitate. Bursa copulatrix short.
GEOGRAPHIC DISTRIBUTION. Indochina from Myanmar to Vietnam, southern China, including Taiwan; single species is known from Sumatra.
HABITATS AND HABITS. Protibiae with apical spinules increased from 2–3 to four in number suggest an adaptation to burrowing in rather solid soils. These are characteristic of forests edges, larger forest trails, some agrocenoses rather than forests proper, and the fact that some species (e.g., P. chalceolus) have been collected in very large numbers in cornfields makes me suppose similar habitats for other member-species of the genus. Many specimens were taken at light at night.
COMMENTS. This genus was at first considered and keyed as a group compact of five species similar to Trigonotoma chalceola [Tschitschérine, 1900]. Then it was enlarged to ten species [Kirschenhofer, 2007], and afterwards erected to a separate genus and extensively revised [Dubault et al., 2008a: 241, 2008b; Roux et al., 2016], with a few new species described, to include altogether 18 species currently. Most of these species are very similar to one another in appearance as well as in shape of aedeagus so that only lengths ratio of the apical two maxillary palpomeres and particular shape of the terminal palpomere often serve for the purpose of species identification. Besides, some of the species included were described by comparing them with voluntarily chosen rather than similar congeners. For instance, P. loeffleri was diagnosed from P. aethiops instead of P. adoxus or P. morosus, thus leaving differences between the former and the latter two species unclear.
The shape and length/width ratio of the terminal maxilary palpomere as diagnostic features of the species are worthy of special note. These characteristics, especially the first, depend much on the behavior of the palpomere in course of drying a dead specimen. During this performance the palpomere either retains its membranous apex subconvex or becomes increasingly truncated at apex as the latter invaginates. For the reason many species defined by particular shape of the palpomere in their descriptions are in fact very similar in this character. These species are, e.g., P. aethiops, P. glastenvalum, P. curtulus, P. cambodgiensis and P. luangphabangensis on one hand and P. adoxus, P. loeffleri, P. morosus and P. namtap, on the other.
The median line of the pronotum is another feature of little individual variation in a species. Pareuryaptus curtulus, P. chalceolus, P. adoxus, P. loeffleri, P. morosus, P. namtap and P. parvus have the pronotum with median line reaching the base, which is densely punctate in addition in most of them, while the other congeners have the median line obliterate from behind and the base impunctate.
KEY (PRELIMINARY) TO SPECIES OF PAREURYAPTUS FROM
VIETNAM:
1(22) Pronotal base impunctate between basal foveae (Figs 81–89).
2(3) Antennae long, with scape indistinctly longer than antennomeres 2 and 3 combined. Mandibles slender, left one straight at outer margin except apex. Elytral microsculpture isodiametric. Pronotum (Fig. 81) quadrate, with sides straight in front of obtuse and blunt basal angles, median line obliterate basally. Lateral bead very slightly dilated in basal half; lateral groove almost straight toward base, crenulate in apical two thirds. Basal foveae moderately deep, moderately wide and rather sparsely punctate, with outer sulcus short and separated from lateral groove. — Northern Vietnam and southern China. ........................... ..................................... 1. P. exiguus Dubault et al., 2008
3(2) Antennae shorter, scape long, barely shorter than antennomeres 2–4 or 2–5 combined. Mandibles triangular, with outer margin rounded. Elytral microsculpture consisting of transverse meshes or dense transverse lines except one species. Pronotum transverse, sides rounded to sinuate in front of base. Pronotal bead conspicuously dilated outside basal foveae due to inner basal sulcus directly extended into lateral groove.
4(21) Maxillary palpomere 3 only slightly shorter than palpomere 4. Scape barely shorter than antennomeres 2–4 combined.
5(18) Median line of pronotum obliterate basally (Figs 81–88), not or very slightly deeper in basal than in apical half.
6(7) Body small, BL 11–13 mm. Sides of pronotum straight to subsinuate in front of obtuse and blunt basal angles. Maxillary palpomere 4 subfusiform and slender, 4.3 times as long as wide, mp3L/mp4L 0.6. — Central Laos. .......... [P. laosensis (Kirschenhofer, 2007)]
7(6) Body larger, BL> 13 mm. Sides of pronotum straight to sinuate in front of base, basal angles obtuse and rounded to rectangular and sharp. Maxillary palpomere 3 longer in general, mp3L/mp4L 0.74–0.92.
8(9) Body large, BL 18–22 mm, dorsum bronzed green. Sides of pronotum deeply concave in front of base; basal angles right and sharp; basal foveae impunctate or almost so. Terminal maxillary palpomere subfusiform, long and narrow. Elytral microsculpture consisting of dense transverse lines. — Vietnam, Laos. .......... P. chalcodes (Andrewes, 1923)
9(8) Body smaller, BL 13–17 mm.
10(11) Sides of pronotum deeply concave in front of base; basal angles right and sharp; basal foveae moderately punctate. Elytral microsculpture isodiametric. Terminal maxillary palpomere subfusiform, long and narrow. Dorsum black. — Laos, Myanmar. ............................................... ....................................... [P. gilletti Dubault et al., 2008]
11(10) Sides of pronotum straight to distinctly sinuate in front of base; basal angles subrectangular to obtuse, sharp to rounded. Terminal maxillary palpomere nearly parallel-sided or very slightly dilated apicad. Elytral microsculpture consisting of transverse meshes. Dorsum often with more or less distinct metallic, green or bronzed green, luster.
12(15) Inclination of prosternal process sharply carinate (Fig. 94).
13(14) Sides of pronotum straight or indistinctly sinuate in front of very obtuse basal angles. Body larger, BL 15 mm. — Southern Vietnam. ...................................................... ................... 6a. P. c. cambodgiensis Dubault et al., 2008
14(13) Sides of pronotum sinuate in front of base, basal angles subrectangular and sharp. Body smaller, BL 13–14.5 mm. — Laos, Central Vietnam, S. China. ............................... .... 6b. P. c. luangphabangensis Kirschenhofer, 2011, stat.n.
15(12) Inclination of prosternal process wide, flat to convex (Fig. 93).
16(17) Pronotum with lateral groove indistinctly punctate in apical half only; sides straight or indistinctly sinuate in front of base, basal angles very obtuse to rounded, lateral bead increasingly broadened basad, wide medially and basally (Figs 82–83). BL 13– 16 mm. — Myanmar to Vietnam. .................................... ............................... 2. P. aethiops (Tschitschérine, 1897)
17(16) Lateral groove of pronotum finely yet distinctly punctate, with punctate area reaching or interrupted just in front of basal fovea; sides distinctly sinuate in front of slightly obtuse and sharp basal angles; lateral bead slightly broadenead toward base (Figs 84–86). BL 13–14.5 mm. — Thailand, N-Vietnam. ...... 3. P. glastenvalum (Morvan, 1992)
18(5) Median line of pronotum reaching base and mostly distinctly deeper in basal than in apical half (Figs 89–92). Sides of pronotum subconvex to indistinctly sinuate in front of very obtuse and just traceable basal angles. Maxillary palpomere 4 subparallel-sided, broadest about a third from base and barely narrowed apicad.
19(20) Body large, BL 15 mm. Maxillary palpomere 4 barely longer, almost five times as long as wide, mp3L/mp4L 0.8. — Southern Vietnam. ... 5. P. curtulus (Chaudoir, 1868)
20(19) Body small, BL 11–13 mm. Sides of pronotum mostly subconvex or straight in front of basal angles (Fig. 89). Maxillary palpomere 4 sligtly shorter, 3.2– 4.25 times as long as wide, mp3L/mp4L 0.7–0.8. — Central and southern Vietnam. ........................................ ...................................... 4. P. parvus Dubault et al., 2008
21(4) Maxillary palpomeres 3 about half as long as subfusiform palpomere 4. Scape barely shorter than antennomeres 2–5 combined. Sides of pronotum straight in front of obtuse and blunt basal angles. BL 14 mm. — Laos. ........... .............................. [P. laolumorum Dubault et al., 2008]
22(1) Pronotum densely punctate along base, as well as along lateral grooves (Figs 90–92). Maxillary palpomere 3 about half as long as subfusiform palpomere 4. Scape barely shorter than antennomeres 2–5 combined. Sides of pronotum straight or indistinctly sinuate in front of obtuse and blunt to rounded basal angles.
23(24) Terminal maxillary palpomere somewhat oval, short and wide, 2–2.5 times as long as wide. Body small, BL 10.7–12.4 mm. — S-China to S-Vietnam. ....................... .......................................... 6. P. chalceolus (Bates, 1873)
24(23) Terminal maxillary palpomere subfusiform, long and narrow, 3.3–5.0 times as long as wide. Body larger, BL 11.7–15.9 mm. — Thailand, Laos, Cambodia, Vietnam, S-China (Yunnan). .... 7. P. morosus (Tschitschérine, 1900)
description: Published as part of Fedorenko, D. N., 2024, Notes on Trigonotoma and Pareuryaptus (Coleoptera: Carabidae: Pterostichini) from Vietnam, pp. 43-71 in Russian Entomological Journal 33 (1) on pages 52-57, DOI: 10.15298/rusentj.33.1.05, http://zenodo.org/record/14162968