Dysanellus Bernhauer, 1911

Chatzimanolis, Stylianos, 2018, A Review of the Genera Dysanellus Bernhauer and Torobus Herman (Coleoptera: Staphylinidae: Staphylininae: Staphylinini), The Coleopterists Bulletin 72 (2), pp. 279-291 : 280-282

Dysanellus Bernhauer, 1911

( Figs. 1–2 , 5–6 , 9 , 11–13 , 16–18 , 25 )

Type Species. Dysanellus bruchi , fixed by monotypy ( Bernhauer 1911).

Diagnosis. The following character statess in combination can distinguish Dysanellus from all other genera in Xanthopygina : head transverse; antennomeres 1–7, 11 longer than wide; antennomeres 8–10 not transverse; mandibles long; labial palpomere 3 securiform; pronotum with several rows of punctures; and postcoxal process present. Species in Ocyolinus Sharp might be confused with Dysanellus , but the two genera can be easily distinguished by the shape of labial palpomere 3 (securiform in Dysanellus , dilated but not securiform in Ocyolinus ) and presence of a postcoxal process in Dysanellus (absent in Ocyolinus ).

Description. Habitus as in Figs. 1–2 , body medium to large size, 13.6–17.6 mm in total length. Color of head and pronotum dark metallic brown with purple overtones or metallic green-blue; elytra metallic golden brown or metallic green-blue; mouthparts, mesoscutellum, ventral surface of body, and legs brown; proximal antennomeres brown, distal antennomeres dark orange; abdomen brown with segment VII orange-brown or brown and segment VIII orange-brown.

Head transverse, with medium-sized to large, setose punctures and microsculpture around margin of head; with various punctures and sculpture on epicranium. Clypeus slightly emarginate; anteclypeus not expanded. Eyes small to medium size, occupying 1/2 to 1/3 of lateral margins of head. Ventral surface of head with transverse microsculpture and scattered medium-sized to large punctures; postoccipital suture and ventral basal ridge present; infraorbital ridge short but well delineated; postmandibular ridge present, prominent, extending from near mandible to lateral side of head; gular sutures separated anteriorly, converging medially; nuchal depression prominent, forming well-defined neck; neck with microsculpture and micropunctures.

Antennomeres 1–3 with multiple rows of macrosetae; antennomeres 4 (distally) and 5–11 with macrosetae but also with microtrichiae; antennomeres 1–7 and 11 longer than wide; antennomeres 8–10 longer than wide or subquadrate; antennomere 1 twice as long as antennomere 2; antennomere 3 longer than 2; antennomeres 4–7 subequal in size; antennomeres 8–10 becoming gradually shorter in length, shorter than antennomeres 4–7.

Mouthparts with labrum medially emarginate to its base. Mandibles large, curved, blunt; with or without long medial tooth; mandibles with dorsolateral groove extending from condyle to just above tooth; prostheca setose. Maxilla with galea and lacinia densely setose; maxillary palpi 4-segmented; P 1 small, about 1/3 as long as P 2; P 2 curved, elongate, longer than P 3; P 2 –P 3 with large setae apically; P 4 elongate, longer than P 3. Submentum with 1 long and 1 shorter anterolateral seta in each end; labial palpi 3-segmented; P 1 subequal in length to P 2; both P 1 and P 2 with several long setae; P 3 with distal end securiform.

Pronotum quadrate; lateral margins of pronotum concave in dorsal aspect; pronotum broadest in apical 1/3 and narrower at basal angles. Hypomeron expanded, with transverse microsculpture and few micropunctures; superior and inferior marginal lines of hypomeron separate throughout their lengths; superior line fully visible from above, extending around anterolateral margin of pronotum and contacting inferior line at neck fossa; no portion of dorsum of pronotum visible from below. Pronotum with multiple rows of punctures. Postcoxal process present,elongate.Mesoscutellum prominent, long, with dense polygonal microsculpture and micropunctures; with multiple rows of small punctures. Basisternum with dense polygonal microsculpture and carina; anterior marginal depression present; furcasternum with medial carina pointed vertically; furcasternum without polygonal microsculpture.

Elytral width subequal to pronotal width; with multiple rows of punctures and large setae and sparse microsculpture; elytra shiny due to lack of extensive microsculpture. Hind wings fully developed. Mesoventrite with anterior margin forming “lip”; with dense polygonal microsculpture and few punctures along edges; without median carina. Metaventrite with dense, uniform, medium-sized punctures; metaventral process small, rounded, with v-shaped emargination.

Tarsal segmentation 5-5-5; meso- and metatibiae with multiple rows of spurs. Protarsus enlarged in both sexes, with spatulate setae ventrally; meso- and metatarsi not enlarged. Empodium with 2 small setae.

Abdomen with paired protergal glands; abdomen expanding from segment III to segment V (widest) and then becoming narrower towards segment VIII. Abdominal terga III–V with basal carina; D. bruchi with faint subbasal (arch-like) carina on III–V; D. transverserugosus Bernhauer without subbasal (arch-like) carina on III–V. Segments with dense, uniform, small punctures and microsculpture. Males with secondary sexual structures of sterna VIII–IX (only known for D. transverserugosus ); presence of porose structure on abdominal sternum VII unclear (see Remarks on the description of D. transverserugosus for more details). Lateral tergal sclerites of abdominal segment IX long and straight, covered with long macrosetae.

Male genitalia with aedeagus typical of Xanthopygina ( Figs. 16–18 ); with median lobe longer and wider than paramere; median lobe with single dorsal tooth; paramere wide and long, not divided into lobes. Paramere with peg setae and short apical setae. Spermatheca not sclerotized.

Synoptic Catalogue. The catalogue presented below follows the format of the catalogue presented in Herman (2001b), and its purpose here is to clarify the status of all taxa assigned to Dysanellus in the past. For the complete catalogue entry details, see Herman (2001b).

Dysanellus Bernhauer 1911: 419 (species included: D. bruchi ).

Leptodiastemus Bernhauer 1934: 214 , originally proposed as a subgenus of Dysanellus (species included: D. excellens ), currently in synonymy with Xenopygus Bernhauer ( Chatzimanolis and Caron 2016).

brevipennis Cameron 1933: 347 (Dysanellus) , in Algon Sharp as Algon dysanelloides Schillhammer, 1999 (a replacement name for Algon brevipennis ( Cameron, 1933) that was preoccupied).

bruchi Bernhauer 1911: 419 (Dysanellus) .

elegans Bernhauer 1915: 145 ( Dysanellus , cited as Disanellus), in Algon ( Hammond 1984) .

excellens Bernhauer 1934 :(215 Dysanellus , subgenus Leptodiastemus ), in Xenopygus ( Chatzimanolis and Caron 2016 ).

transverserugosus Bernhauer 1921: 175 .

Figures

Figs. 1–2. Dysanellus species, habitus. 1) D. bruchi, total length = 15.2 mm; 2) D. transverserugosus, total length = 17.4 mm.

Figs. 5–6. Heads and pronota of Dysanellus species. 5) D. bruchi; 6) D. transverserugosus. Not to scale.

Figs. 9–10. Head, ventral view. 9. Dysanellus transverserugosus; 10) Torobus laetipes. Not to scale.

Figs. 11–12. Distal end of labial palpomere 3 in Dysanellus species. 11) D. bruchi; 12) D. transverserugosus. Scale bar = 50 µm.

Figs. 13–15. Abdominal sterna VII and VIII. Arrows indicate the position of porose structure. 13) Dysanellus transverserugosus (While there is a broad area with no setae on VII, it is not clear if there is a porose structure. See text for more details); 14) Torobus laetipes; 15) Torobus purpurascens. Not to scale.

Figs. 16–18. Aedeagus of Dysanellus transverserugosus. 16) Dorsal view; 17) Lateral view; 18) Paramere, ventral view.

Fig. 25. Distribution map of Dysanellus bruchi and Dysanellus transverserugosus.