Triochara Bernhauer, 1901

Yamamoto, Shûhei & Maruyama, Munetoshi, 2012, Revision of the Seashore-dwelling Subgenera Emplenota Casey and Triochara Bernhauer (Coleoptera: Staphylinidae: genus Aleochara) from Japan, Zootaxa 3517, pp. 1-52 : 29-31

publication ID	https://doi.org/ 10.5281/zenodo.282595
publication LSID	lsid:zoobank.org:pub:F832C768-A8CA-4FEE-8C3B-BD933247FA6E
DOI	https://doi.org/10.5281/zenodo.6175378
persistent identifier	https://treatment.plazi.org/id/03DE87D8-0830-FFEF-FF28-FE1129BC3F24
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scientific name	Triochara Bernhauer, 1901
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Subgenus Triochara Bernhauer, 1901

( Figs. 53–92 View FIGURES 53 – 64 View FIGURES 65 – 70 View FIGURES 71 – 78 View FIGURES 79 – 85 View FIGURES 86 – 92 , 98–100 View FIGURES 93 – 100 , 104–105 View FIGURES 104 – 105 )

Triochara Bernhauer, 1901b: 373 (original description; type species: Aleochara trisulcata Weise, 1877 View in CoL ); Eichelbaum, 1909: 246 (as subgenus; generic catalogue of world Staphylinidae View in CoL ); Fenyes, 1920: 398 (as subgenus; key to world subgenera of Aleochara View in CoL ), 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 View in CoL ); Bernhauer & Scheerpeltz, 1926: 795 (as subgenus; catalogue of world species of Aleocharinae View in CoL ; exclusion of these 5 species and only one species, A. trisulcata View in CoL , left as subgenus); Blackwelder, 1952: 397 (as subgenus; catalogue entry; generic catalogue of world Staphylinidae View in CoL ); 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 View in CoL ).

Redescription. Body ( Figs. 53, 57, 61 View FIGURES 53 – 64 ): 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 View FIGURES 53 – 64 ): 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 View FIGURES 65 – 70 ): 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 View FIGURES 65 – 70 ) transverse, about 1.7 times wider than long; anterior margin slightly emarginated medially; basal half semi-transparent. Mentum ( Fig. 68 View FIGURES 65 – 70 ) trapezoidal and strongly emarginated transversely along anterior margin, about 3.2 times as wide as long. Labial palpus ( Fig. 66 View FIGURES 65 – 70 ) 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 View FIGURES 65 – 70 ) 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 View FIGURES 53 – 64 ) 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 View FIGURES 53 – 64 ). Mesoventrite not carinate at all ( Figs. 55–56, 59–60, 63–64 View FIGURES 53 – 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 View FIGURES 65 – 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 View FIGURES 53 – 64 ): narrowly elongated and almost pararell sided; tergite III-VI impressed weakly and transversely at base. Posterior margin of tergite VIII ( Figs. 71–72 View FIGURES 71 – 78 ), with a row of thick and short several sensory setae or a row of thin and long setae ( Figs. 79–80 View FIGURES 79 – 85 , 86–87 View FIGURES 86 – 92 ).

[Male]: posterior margin of sternite VIII ( Figs. 73 View FIGURES 71 – 78 , 81 View FIGURES 79 – 85 , 88 View FIGURES 86 – 92 ) not pointing strongly, and its shape not greatly varies among species. Median lobe ( Figs. 75 View FIGURES 71 – 78 , 83 View FIGURES 79 – 85 , 90 View FIGURES 86 – 92 ) compactly elongated. Median lobe of aedeagus with a pair of subapico-ventral projections ( Figs. 75 View FIGURES 71 – 78 , 83 View FIGURES 79 – 85 , 90 View FIGURES 86 – 92 ) as well as Emplenota species; shape of these projections varying greatly among species. Median lobe of aedeagus ( Figs. 75–76 View FIGURES 71 – 78 , 83–84 View FIGURES 79 – 85 , 90–91 View FIGURES 86 – 92 ) with rather short but prominent flagellum, as long as median lobe of aedeagus. Apical lobe of paramerite ( Fig. 77 View FIGURES 71 – 78 ) narrowly elongated with four setae.

[Female]: tergite VIII ( Figs. 72 View FIGURES 71 – 78 , 80 View FIGURES 79 – 85 , 87 View FIGURES 86 – 92 ) similar to that of male. Sternite VIII ( Figs. 74 View FIGURES 71 – 78 , 82 View FIGURES 79 – 85 , 86 View FIGURES 86 – 92 ) having less pointed apex than male, but sometimes very similar to that of male. Spermatheca ( Figs. 78 View FIGURES 71 – 78 , 85 View FIGURES 79 – 85 , 92 View FIGURES 86 – 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 View FIGURES 14 – 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 View FIGURES 65 – 70 ) very short, almost moniliform, and quite robust; dorsal surface of head ( Figs. 53, 57, 61 View FIGURES 53 – 64 ) with two deep furrows along midline; pronotum ( Figs. 54, 58, 62 View FIGURES 53 – 64 ) 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 View FIGURES 53 – 64 ); legs (e. g., Fig. 70 View FIGURES 65 – 70 ) short but thick, covered with numerous thick spines, especially on tibia. [Male]: sternite VIII ( Figs. 73 View FIGURES 71 – 78 , 81 View FIGURES 79 – 85 , 88 View FIGURES 86 – 92 ) similar shape that of female, and not greatly discriminated from female ( Figs. 74 View FIGURES 71 – 78 , 82 View FIGURES 79 – 85 , 89 View FIGURES 86 – 92 ; Emplenota species differes between both sexes); median lobe of aedeagus ( Figs. 75–76 View FIGURES 71 – 78 , 83–84 View FIGURES 79 – 85 , 90–91 View FIGURES 86 – 92 ) with short but projecting flagellum, and subapico-ventral projections varying in shape among species. [Female]: spermatheca ( Figs. 78 View FIGURES 71 – 78 , 85 View FIGURES 79 – 85 , 92 View FIGURES 86 – 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.