Stenaptinus javanus
Creators: name: Fedorenko, D. N.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Stenaptinus
Stenaptinus javanus

description: The javanus species group.
DIAGNOSIS. Body variegated (Figs 71–111), nearly glabrous dorsally, with very short individual setae scattered over elytral disc, without or with similar setae at pronotal base and/or at apex, and near supra-ocular seta. Head mostly pale, with a contrastingly darker V- or U-, or Y-shaped, patch between eyes; this patch mostly extended onto neck and often reaching pronotum.
Pronotum impunctate or with very few large punctures; when present, dark median stripe not or barely wider in apical than in basal half. Prosternum and propleura glabrous except 2–6 strong paramedian setae between procoxae.
Elytra subparallel-sided, with humeri distinct to trapezoidal, in the latter case much broader apically than basally due to humeri imperceptible; ridges wide and slightly convex. Elytral pale pattern generally consisting of large to missing humeral spot, transverse median band, rather narrow lateral margin, and apical margin. Transverse median band more or less strongly dentate at even ridges anteriorly and at odd ridges posteriorly, inwardly reaching ridge 2; apical margin mostly narrow or missing, in the latter case only including apices of elytral ridges.
Body mostly macropterous, sometimes (S. stenoderus and S. marginicollis) apterous. In some populations of S. javanus, brachypterous adults have also been observed.
Profemora laterally tumid in male.
Abdominal apical urites (Figs 1–20): In female, tergite VII with 9–17 rather strong setae; tergite VIII with median sclerotization (psm) transvere subrectangular, apical depigmented region (adr) long, densely tuberculate and setulose; sternite VIII densely pubescent, without medioapical sclerite, with a membranous area just in front of 14–20 strong apical setae and inner internal carina running close to re-entrant angle between base and laterobasal apophysis. Sternite VII bisetose to quadrisetose in male.
Median lobe of aedeagus with apex round in crosssection to flattened dorsoventrally, mostly finely carinate ventro-apically.
Urite IX evenly membranous ventrally (Figs 56–64) in female; gonocoxite moderately long, glabrous at dorsal edges. Spermathecal receptacle from Y-shaped, with horns unequal in length, to bulbous, with one horn tumid and the other totally absorbed (Figs 56–70).
GEOGRAPHIC DISTRIBUTION. Throughout the Paleotropical realm and southern Palearctic subregion in southern Europe and East Asia. The group is much more diverse in the Oriental than in Afrotropical region. All the Oriental species are widespread.
HABITATS AND HABITS. The adults are nocturnal carnivores generally found in open habitats in lowlands and piedmonts. Many species are frequent on bogs and by pools in floodlands or along rivers and larger streams, including in plant debris on riverbanks. Some of them occur also along forest edges, wood trails and even roads.Macropterous species often flight to light at night. Sympatric species of the group often live syntopically.
COMMENTS. This group includes ten species in the Oriental region north to the East Asian Palearctic subregion, with some others occurring in the Afrotropical and Madagascan regions; S. hispanicus (Dejean, 1824) from southwestern Paleactic is most likely to belong to the group, too.
Most of these species are very similar in appearance, including body shape, proportions and colour pattern.Because the pattern varies greatly between individuals as well as between local populations of a species, particular color morphs being often observed in different species. As a result, the species of the group are hard to determine, and examination of the male genitalia is very advisable for the purpose.
The group is here divided into the javanus -subgroup and the fimbriatus- subgroup, based chiefly on a particular groundplan of the internal sac of aedeagus.
The javanus -subgroup includes six Oriental species (S. javanus, S. fumigatus, S. lissoderus, S. consularis, S. stenoderus, and S. marginicollis) and a few Afrotropical and Madagascan ones, including S. humeralis Chaudoir, 1843 and S. madagascariensis Dejean, 1825. The internal sac is asymmetrical in all of them because a well-developed left distal basal bulb is present (Figs 21–42). The internal sac is more or less straight (Figs 23, 25, 30, 32, 34, 37, 41) or geniculate (S. javanus), with membranous apex starting from below the apex of, and perpendicular to, the body of the internal sac. A well defined apex of the body of the internal sac (Figs 21, 23, 27) makes S. javanus, S. marginicollis and S. madagascariensis similar.Four species with straight internal sac have an additional preapical frontal bulb which is either distinct (S. fumigatus, S. stenoderus, S. lissoderus) or vague to missing (S. consularis). Spermathecal receptacle is asymmetric Y-shaped. Aedeagus apex is either pointed (S. javanus, S. lissoderus) or blunt and mostly slightly S-shaped in dorsal view, with ventro-apical carina either missing (S. lissoderus, S. marginicollis) or distinct.
The fimbriatus -subgroup includes four species: S. fimbriatus, S. dongnaiensis sp.n., S. sumatrensis sp.n., and S. agnatus. The former three are closely related, as they have the internal sac of aedeagus symmetrical, with distal basal bulbs missing (Figs 48–55), and spermathecal receptacle peculiar, bulbous (Figs 66–70). Stenaptinus agnatus is somewhat intermediate between the two subgroups. It has the apex of aedeagus median lobe and spermathecal receptacle similar to those in the javanus -subgroup (Figs 43, 44, 47, 69), and a vestigial left distal bulb is sometimes traceable (Figs 43, 47).
KEY TO SPECIES OF THE JAVANUS-GROUP (species not recorded in Vietnam are in square brackets).
1(2) Pronotum uniform red to black, without or with brown lateral margins, rarely with vague traces of pale spots (Figs 98–102). Head red or at least entire frons and vertex infuscated .............. [2. S. lissoderus (Chaudoir, 1850)]
2(1) Pronotum bicoloured, dark, with two paramedian yellow spots, to yellow, with margins or at least base and apex infuscated.Frons pale anterior to black patch between eyes.
3(4) Elytra subtriangular, much broader apically than basally, with humeri indistinct or almost so (Figs 96–97, 103– 105). Head with dark patch Y-shaped to pentagonal. Elytral median fascia not reaching lateral margin, mostly wide and only slightly dentate before and behind. Body apterous ....................... 4. S. stenoderus Chaudoir, 1850
4(3) Elytra subrectangular and more or less parallel-sided, with humeri rounded yet distinct; if notably broader apically than basally, then head with dark patch small Vshaped to missing. Body mostly macropterous or wings polymorphic.
5(6) Elytra uniform dark brown to black or with a minute pale humeral spot only; pronotum with rather small paramedian pale spots; black patch between eyes parallel-sided and extended to pronotum. — The Philippines ............. ....................................... [S. fumigatus (Dejean, 1825)]
6(5) Elytra bicoloured, black, with pale median spot or transverse band, smaller humeral spot and often also narrow to wide apical margin.
7(10) Head without or with a small black patch between eyes.
8(9) Black patch V-shaped to missing (Figs 90–94). Median lobe of aedeagus with apex blunt and strongly bent ventrad ............ 3. S. consularis (Schmidt-Göbel, 1846)
a(b) Elytra short (EL/EW 1.44–1.53) and wider relative to rather narrow pronotum, pronotal base narrower. Head with black V-shaped patch distinct to vague; pronotum and elytra with black colour prevailing due to pronotal pale spots narrow and separate, elytral transvere band narrow and isolated from lateral margin, and apices of elytral ridges only pale (Figs 90–92) ............................. .................. 3a. S. c. consularis (Schmidt-Göbel, 1846)
b(a) Elytra longer and narrower (EL/EW 1.52–1.66), pronotum and its base slightly wider. Head entirely pale, pronotum yellow, with base, apex and lateral beads black only; elytron with pale transverse band and apical margin both wide and confluent along lateral margin or along interval 8 (Figs 93–94) ......................... 3b. S. c. flaviceps ssp.n.
9(8) Head with a small subtransverse spot (Figs 106–107). Median lobe of aedeagus (Fig. 55) and abdominal sternites as in couplet 11 ................ 7. S. dongnaiensis sp.n.
10(7) Black patch large, sometimes V-shaped to missing (in some specimens of S. agnatus).
11(14) Head with black patch reaching pronotum, parallel-sided to occupying entire neck (Figs 77–81, 108–109).
12(13) Pronotal paramedian spots large, mostly reaching lateral margins. Elytron with transverse median band mostly wide or very wide. Aedeagus apex large, tapered in lateral view, with a minute and very pointed apical beak in dorsal view (Fig. 48). Female tergite VII with apical setae very strong and apically unciform or almost so; tergite VII withapicaltuberculateareaabruptlyseparatedfromsmooth region in front. Sternite VII quadrisetose in male ......... .................................. 6. S. fimbriatus (Chaudoir, 1876)
13(12) Colour pattern as in melanistic specimens of S. fimbriatus (Figs 108–109). Aedeagus, including internal sac, as in S. dongnaiensis sp.n., except for proximal basal bulbs invisible in dorsal view .............. 8. S. sumatrensis sp.n.
14(11) Head with black patch subtransverse to Y-shaped, reaching pronotum or not (Figs 74–76, 82–89, 95). Tergite VII with apical setae rather short and straight in female; sternite VII mostly bisetose in male.
15(16) Head with black patch rather small, transverse, parallel-sided, V-shaped at anterior and posterior margins. Pronotum pale, with black margins, and more or less rugulose. Body apterous ................................................. .................... [9. S. marginicollis (Motschulsky, 1854)]
16(15) Head with black patch well-developed, generally Yshaped. Body macropterous or brachypterous.
17(18) Apex of aedeagus median lobe wide in dorsal view; internal sac asymmetric, with left distal basal bulb conspicuous (Figs 27–28). Elytral transverse band mostly narrow. Body macropterous or brachypterous ............... .......................................... 1. S. javanus (Dejean, 1825)
18(17) Apex of aedeagus median lobe narrow in dorsal view; internal sac nearly symmetric, with left distal basal bulb missing or rudimentary (Figs 43–47). Elytral transverse band mostly wide. Body macropterous .......................... ...................................... 5. S. agnatus (Chaudoir, 1876)
description: Published as part of Fedorenko, D. N., 2021, Stenaptinus (Coleoptera: Carabidae: Brachininae) of Vietnam. Note 2, pp. 25-42 in Russian Entomological Journal 30 (1) on pages 26-28, DOI: 10.15298/rusentj.30.1.05, http://zenodo.org/record/10920063