Triochara Bernhauer 1901
Creators: name: Yamamoto, Shûhei
name: Maruyama, Munetoshi
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Triochara

description: Subgenus Triochara Bernhauer, 1901
(Figs. 53–92, 98–100, 104–105)
Triochara Bernhauer, 1901b: 373 (original description; type species: Aleochara trisulcata Weise, 1877); Eichelbaum, 1909: 246 (as subgenus; generic catalogue of world Staphylinidae); Fenyes, 1920: 398 (as subgenus; key to world subgenera of Aleochara), 414 (as subgenus; catalogue of world species; diagnosis; addition of 5 species to genus); Scheerpeltz, 1925: 447 (as subgenus; catalogue of Palaearctic species of Aleocharinae); Bernhauer & Scheerpeltz, 1926: 795 (as subgenus; catalogue of world species of Aleocharinae; exclusion of these 5 species and only one species, A. trisulcata, left as subgenus); Blackwelder, 1952: 397 (as subgenus; catalogue entry; generic catalogue of world Staphylinidae); Assing, 1995: 219 (as genus; diagnostic key to genera), 229 (notes on genus), 230 (key to all species of genus), 230 (descriptions of each species); Maus & Ashe, 1998c (online) (world checklist of subgenus; diagnosis; bionomics; phylogenetic relationships); Smetana, 2004: 358 (as subgenus; catalogue of Palaearctic species of Aleocharinae).
Redescription. Body (Figs. 53, 57, 61): narrowly elongated extremely, and almost subparallel sided; whole length varying from 2.8 to 5.0 mm, normally around 3.3-3.9 mm; dorsal surface shining to less shining, covered with coarse and distinct punctures. Surface of head and pronotum partly covered with coarse and short but thick setae. Colour (Figs. 53, 57, 61): uniformly blackish gray to black sometimes with somewhat lighter colour in elytra. Head: rounded subquadrangular (HW/HL ≈1.18), moderately convex above, widest around base; dorsal surface of head with two longitudinal and subparallel deep furrows and connected by a transverse deep furrow or by a somewhat shallow impression. Eyes very small, not clearly protruding laterally. Antennae (Fig. 65): moniliform (similar to filiform); robust, thick and extremely short, clearly shorter than combined length of head and pronotum. Mouth Parts: mandibles asymmetric, left mandible with small tooth near apex. Clypeus truncate at apex. Labrum (Fig. 69) transverse, about 1.7 times wider than long; anterior margin slightly emarginated medially; basal half semi-transparent. Mentum (Fig. 68) trapezoidal and strongly emarginated transversely along anterior margin, about 3.2 times as wide as long. Labial palpus (Fig. 66) with segment I prominently thick and longer than segment II; segment III prominently narrower and shorter than II, with minute pseudosegment. Segments of maxillary palpus (Fig. 67) robust, especially, segment II and III; pseudosegment prominent; segment II same length as III; pseudosegment prominent; lacinia with numerous hairs and with about 13 very thick spines pectinately. Thorax: pronotum (Figs. 54, 58, 62) largely octagonal to oblong (PW/PL ≈1.18) with prominent furrows (usually three longitudinal sulci) along midline; slightly longer than head length (PL/HL ≈1.29), slightly broader than head (PW/ HW ≈1.29). Hypomera visible in lateral view. Mesocoxae narrowly separated (Figs. 55, 59, 63). Mesoventrite not carinate at all (Figs. 55–56, 59–60, 63–64). Elytra: widened toward posterior margin, much broader than long (EW/EL ≈1.44), and slightly wider than pronotum (EW/PW ≈1.16); posterior margin of each elytra nearly truncate but gently rounded toward posterior margins; surface rugosely punctured both hexagonal microsculptures and prominent distinct punctures in the species (A. nubis); entire surface densely covered with brown setae; anterior margin with a relatively long blackish bristle. Legs (e. g., Fig. 70): short, thick, robust and with numerous thick spines on surface, especially on fore and mid tibia; tarsi quite short, hindtarsi extremely short (hind tarsal length/ mid tarsal length ≈1.25). Hind wing: entire; veins weakly sclerotized and very obscure; posterior margin with a row of numerous white hairs. Abdomen (Figs. 53, 57, 61): narrowly elongated and almost pararell sided; tergite III-VI impressed weakly and transversely at base. Posterior margin of tergite VIII (Figs. 71–72), with a row of thick and short several sensory setae or a row of thin and long setae (Figs. 79–80, 86–87).
[Male]: posterior margin of sternite VIII (Figs. 73, 81, 88) not pointing strongly, and its shape not greatly varies among species. Median lobe (Figs. 75, 83, 90) compactly elongated. Median lobe of aedeagus with a pair of subapico-ventral projections (Figs. 75, 83, 90) as well as Emplenota species; shape of these projections varying greatly among species. Median lobe of aedeagus (Figs. 75–76, 83–84, 90–91) with rather short but prominent flagellum, as long as median lobe of aedeagus. Apical lobe of paramerite (Fig. 77) narrowly elongated with four setae.
[Female]: tergite VIII (Figs. 72, 80, 87) similar to that of male. Sternite VIII (Figs. 74, 82, 86) having less pointed apex than male, but sometimes very similar to that of male. Spermatheca (Figs. 78, 85, 92) with shallow apical invagination of spermatheca (ai); head (sh) large, moderately swollen, less or longer than twice length of apical portion of stem (sa); spermathecal neck (sn) very short and united with (sh); without a distinct collar in spermatheca (different from Emplenota: Fig. 22); basal portion of stem (sb) narrow and distorted, and with short and erect sclerotized portion of spermathecal stem (ss); membraneous portion of spermathecal duct (sm) moderate in length; inner wall of (sh) and (sa) moderately striate; each part of spermatheca except for (sm) entirely and moderately sclerotized.
Diagnosis. The distinct subgenus Triochara Bernhauer is somewhat similar to the members of the subfamily Oxytelinae (Staphylinidae) rather than the members of Aleocharinae by having furrows on head and pronotum, and by heavily sclerotized, subparallel-sided body. This subgenus is therefore easily discriminated from other littoral staphylinids by following character states: antennae (e. g., Fig. 65) very short, almost moniliform, and quite robust; dorsal surface of head (Figs. 53, 57, 61) with two deep furrows along midline; pronotum (Figs. 54, 58, 62) with longitudinal sulci and three-dimensional pattern on dorsal surface; tarsal fomula: 5-5-5; mesoventrite without carina at all (Figs. 55–56, 59–60, 63–64); legs (e. g., Fig. 70) short but thick, covered with numerous thick spines, especially on tibia. [Male]: sternite VIII (Figs. 73, 81, 88) similar shape that of female, and not greatly discriminated from female (Figs. 74, 82, 89; Emplenota species differes between both sexes); median lobe of aedeagus (Figs. 75–76, 83–84, 90–91) with short but projecting flagellum, and subapico-ventral projections varying in shape among species. [Female]: spermatheca (Figs. 78, 85, 92) simple; head (sh) large; neck (sn) short and fused with (sh); lacking distinct collar, but with erect duct (ss).
Comments. All of the three known species of the subgenus are similar to each other in habitus, but pronotal patterns, the median lobe of the aedeagus, and tergite VIII of both sexes can be easily differentiated. However, the shape of sternite VIII, which usually act as important character state, do not provide precise identification method in Triochara.
The life history of Triochara is thought to be similar to that of Emplenota and Polystomota (Assing, 1995). For information on the dipteran host of A. (T.) trisulcata Weise, 1877, see Yamazaki (2008, 2012). A larval description has never been published.
description: Published as part of Yamamoto, Shûhei & Maruyama, Munetoshi, 2012, Revision of the Seashore-dwelling Subgenera Emplenota Casey and Triochara Bernhauer (Coleoptera: Staphylinidae: genus Aleochara) from Japan, pp. 1-52 in Zootaxa 3517 on pages 29-31, DOI: 10.5281/zenodo.282595