Oligostethius capensis ( Schwarz, 1903 )

Rosa, Simone Policena, 2014, Phylogenetic analysis and taxonomic revision of Physodactylinae (Coleoptera, Elateridae), Papéis Avulsos de Zoologia (São Paulo) 54 (18), pp. 217-292 : 235-237

publication ID	https://doi.org/ 10.1590/0031-1049.2014.54.18
persistent identifier	https://treatment.plazi.org/id/7B52527A-2410-FF95-75A6-63BDF436F8EB
treatment provided by	Felipe
scientific name	Oligostethius capensis ( Schwarz, 1903 )
status

Treatment

Oligostethius capensis ( Schwarz, 1903)

( Figs. 5 View FIGURE 5 , 6 View FIGURE 6 , 34E View FIGURE 34 )

Idiotropia capensis Schwarz 1903: 375 .

Oligostethius capensis ; Schwarz, 1906: 315; Schenkling, 1927: 510.

Redescription (male, Fig. 34E View FIGURE 34 ): Body convex. Integument brown or dark brown with antennae and legs light brown, covered with very short, fine, decumbent silvery setae. Total length: 9.6-10.0 mm; elytral base 0.83x as wide as prothorax, elytra 1.91x times longer than pronotum.

Head ( Fig. 5C View FIGURE 5 ) with frons ( Fig. 5A View FIGURE 5 ) concave at median line, frontal carina absent medially; frontoclypeal region gradually declivous to base of labrum; punctures umbilicate, 0.5-1.0 diameter apart; antennal insertion ( Figs. 5A, B View FIGURE 5 ) placed within saucerlike impression. Antenna with antennomere II cylindrical 1.3x longer than wide; antennomeres III-VI convex and serrate; III 1.7x longer than II and 1.6x wider than long; IV-VI subequal 0.92x as long as III and 1.1x wider than long. IEP 0.24; mouthparts directed ventrally. Labrum ( Fig. 5A View FIGURE 5 ) semielliptical, convex. Mandible ( Fig. 5A View FIGURE 5 ) narrow and long, bidentate, apical tooth long and acute, subapical tooth smaller; laterodorsal surface at base coarsely punctate with long setae, lateral edge evenly curved apicad; mesal margin at base with a row of short setae. Maxilla with galea oboval, densely pilose, lacinia elliptical, densely pilose; medistipes trapezoidal longer than wide with several long stiff setae and a few finer and shorter setae. Labial palpigers separate; mentum trapezoidal with a lateroposterior pair of long setae and sparsely short setae.

Pronotum ( Fig. 5D View FIGURE 5 ) dorsally convex, 1.17-1.19x longer than wide, sides rounded, lateral carina complete ( Fig. 5F View FIGURE 5 ), with punctures umbilicate, coalescent forming irregular striae; anterior angle produced anteriorly, wide and rounded covering half eye ( Fig. 5F View FIGURE 5 ); posterior angle acute, short, with tip upturned ( Fig. 3F View FIGURE 3 ), carinate; posterior margin adjacent to posterior angle with a short incision contiguous to a carina. Hypomeron ( Fig. 5G View FIGURE 5 ) with punctures umbilicate, 0.5-1.0 diameter apart; posterior margin straight and contiguous to tip of posterior angle, without notch. Notosternal suture ( Fig. 5E View FIGURE 5 ) margined by a shiny band along hypomeron margin at posterior half, grooved anteriorly. Prosternum ( Fig. 5E View FIGURE 5 ) parallel-sided on posterior half, with divergent sides on anterior half, 2.31x longer than wide, with punctures umbilicate, 0.5-1.0 diameters apart; anterior prosternal lobe rounded and produced, covering mentum. Prosternal process ( Figs. 5E, F View FIGURE 5 ) with ventral surface laterally compressed and ascending at about 45° to apex, 2.8x longer than procoxal diameter. Procoxae open.

Pterothorax: Mesoventrite gradually inclined ventrad posteriorly about 30°, anterior articulating surfaces ( Figs. 5H, I View FIGURE 5 ) concave marginate posteriorly by a prominent carina; borders of mesoventral cavity divergent from base to anterior margin of mesocoxae then curved and convergent. Mesoventral cavity deep, floor with a smooth median band bordered by minuscule punctation ( Fig. 5H View FIGURE 5 ). Mesocoxal cavity ( Fig. 5I View FIGURE 5 ) open to mesepisternum and mesepimeron, mesepimeron long, closing the major part of cavity; mesotrocantin visible; mesepisternum with a carina on the outer angle and a prominent carina on inner anterior angle contiguous to the anterior carina of mesoventrite. Mesoventrite separated from the metaventrite at middle by a weak groove. Metaventrite ( Fig. 5H View FIGURE 5 ) 1.91x wider than long, 0.9x as long as mesoventrite, with punctation 0.5-1.0 diameter apart; metepisternum about 7x longer than wide. Elytra fused to each other along the median suture, sides divergent from humerus to posterior third then rounded to apex; striae with a row of punctures, interstices flat with dense, rasp-like punctation, epipleura abruptly narrowed near metacoxae. Scutellum ( Fig. 5J View FIGURE 5 ) elliptical wider than long, strongly convex, abruptly elevated above the level of mesoscutum. Hind wings absent.

Metacoxa ( Figs. 5H, I View FIGURE 5 ) inclined 25° in relation to transverse axis of body, median region of the dorsal surface about 15x longer than outer region; free margin of metacoxal plate very small. Legs densely pilose, setae moderately long and curved apically. Metatrochanter and metafemur compressed laterally, metafemur 3.5x longer than wide. Tibiae compressed laterally, 2x wider at apex than at base, with two subequal spurs shorter than setae, with a row of 10-13 stiff setae along apical border; tarsomeres simple, densely setose on ventral face, decreasing in length from I-IV, V as long as III and IV together; claws simple.

Abdominal ventrites ( Figs. 5K, L View FIGURE 5 ) with punctures umbilicate, 0.5-1.0 diameter apart, marginal plates absent; lateral part of ventrite 1 2.0x longer than its median part, ventrite 1 narrower than 3, 3-4 subequal, 5 semioval 1.12x wider than long. Sternite VIII ( Fig. 6A View FIGURE 6 ) subrectangular 2.73x wider than long with posterior margin emarginate, predominantly membranous with a pair of dark sclerotizations along the anterior margin and a pair of lateroposterior light scletotizations; tergite VIII ( Fig. 6B View FIGURE 6 ) semioval, pilose, evenly sclerotized except for a membranous triangular region on anteromedian margin; sternite IX ( Fig. 6C View FIGURE 6 ) partly sclerotized, fused to tergite IX at half length of sternite IX, with anterior margin bilobed and produced dorsad; posterior margin rounded, apex with short and long setae; tergite IX ( Fig. 6D View FIGURE 6 ) evenly sclerotized, posterior lobes densely covered with short setae and a few long setae apically; tergite X ( Fig. 6D View FIGURE 6 ) semicircular with apex membranous, sparsely pilose.

Aedeagus ( Figs. 6 View FIGURE 6 E-G): Phallobase semicircular, strongly convex with a median dorsal apodeme, 0.3x total length of aedeagus; length ratio between lateroposterior and median parts 0.3. Parameres convex on anterior 1/3, dorsoventrally flattened on posterior 2/3 ( Fig. 6G View FIGURE 6 ); apex securiform short with outer angle rounded and produced, with a few setae on ventral face. Penis parallel-sided from base of basal struts to apex, basal struts 0.28x length of penis; dorsal articulation of penis with a short and narrow process between the basal struts fused to the parameres; ventral sclerite reduced to a line.

Lectotype: [Coll. Schwarz], [Cap Alte Sammlung], [ Oligostethius capensins Schw. ], [Dtsch. Entomol. Institut Berlin], [Lectotype], [ Oligostethius capensis Schwarz, C. Girard vid. 1979], [coll. DEI, Müncheberg], male, (DEI).

Material examined: SOUTH AFRICA, 1 ex. ( BMNH) .

Distribution: SOUTH AFRICA.

Remarks: The specimen deposited in the MNHN collection has broken legs and antennae. The specimen of the BMNH collection has complete legs, incomplete antennae, broken elytra and its abdomen was lost. Last segment of maxillary and labial palpi was lost in both specimens.

The data analyzed here support a close relationship of Oligostethius capensis and Idiotropia henoni . Oligostethius capensis also shares some noticeable characters with the Dimini Apteroelater : sutura mesometasternal grooved and elytral suture fused to each other. As discussed above, Oligostethius and Idiotropia appear to be related to Dimini species because they share the non-carinate frons, metacoxal plate reduced laterally and loss of hind wings. Oligostethius also shares with species of the genera Neodima Schimmel & Platia, 1992 (Southeast Asia) and Anthracopteryx Horn, 1891 (Cental and North America) the shape of scutellum (convex, wider than long) and the oblongovate elytra. It is distinguishable from those species by its longer prothorax, which is wider than elytra, pronotum with punctation dense and coalescent forming irregular striae and posterior margin with a pair of lateral incisions.