Margogastrius schneideri ( Schwarz, 1902 )

Rosa, Simone Policena, 2014, Phylogenetic analysis and taxonomic revision of Physodactylinae (Coleoptera, Elateridae), Papéis Avulsos de Zoologia (São Paulo) 54 (18), pp. 217-292 : 224-227

publication ID	https://doi.org/ 10.1590/0031-1049.2014.54.18
persistent identifier	https://treatment.plazi.org/id/7B52527A-2405-FF8B-77B4-61D2F4EDFB6B
treatment provided by	Felipe
scientific name	Margogastrius schneideri ( Schwarz, 1902 )
status

Treatment

Margogastrius schneideri ( Schwarz, 1902)

( Figs. 1 View FIGURE 1 , 34A View FIGURE 34 )

Margogastrius schneideri Schwarz, 1903: 80 ; Schwarz,

1906: 312; Schenkling, 1927: 509. Gastrimargus schneideri Schwarz, 1902: 310 .

Redescription (female, Fig. 34A View FIGURE 34 ): Integument light brown with antennae, elytral base, ventral pterothorax and ventrites lighter; covered with short, fine and decumbent yellow setae, denser on ventral surface. Length 13.0 mm; elytral base as wide as prothorax; elytra 2.5 times longer than pronotum.

Head ( Figs. 1 View FIGURE 1 B-C) with frons concave, frontal carina complete medially; frontoclypeal region steeply declivous to base of labrum, rectangular, about 3.0x wider than long; punctation fine and umbilicate, sparse at middle, dense on lateral and anterior margins. Antenna ( Fig. 1A View FIGURE 1 ) with 11 antennomeres, serrate from antennomere III, nearly reaching the posterior half of the pronotum; antennomere III 2.0x longer than the II; IV as long as III. IEP 0.10. Mouthparts directed ventrally; labrum ( Fig. 1B View FIGURE 1 ) semicircular, convex. Mandible ( Fig. 1B View FIGURE 1 ) falcate, unidentate with laterodorsal surface with long setae; mesal margin at base with a row of short setae. Maxilla with galea trapezoidal, widened apicad, densely pilose; lacinia narrow, tongue-like, densely pilose; medistipes fused to the basistipes, corresponding area of the medistipes with one long stiff seta and several shorter and finer setae. Labium with mentum covered with fine and short setae. Maxillary and labial apical palpomeres elliptical.

Prothorax ( Figs. 1 View FIGURE 1 D-F) dorsally and ventrally convex, 1.1x wider than long, sides rounded convergent anteriad from midlength in dorsal view, lateral carina absent; punctures umbilicate, 1-2 diameters apart on disc, denser on lateral margins; anterior angles not produced, posterior angles acute, short. Hypomeron ( Fig. 1G View FIGURE 1 ) with punctures 0.5-1.0 diameter apart, umbilicate; posterior margin with a V-shaped notch near the hind angle. Notosternal sutures ( Fig. 1E View FIGURE 1 ) straight sided, margined by a shiny band along hypomera. Prosternum ( Fig. 1E View FIGURE 1 ) 1.25x longer than wide, with umbilicate punctures larger than those of hypomera, 0.5-1 diameters apart near midline, smaller and denser on lateral margins; prosternal anterior lobe covering mouthparts to mentum when head retracted. Prosternal process ( Figs. 1E, F View FIGURE 1 ) with dorsal surface curved dorsad to apex, 1.0-1.8x longer than diameter of procoxae. Procoxal cavities open externally.

Pterothorax ( Figs. 1H, I View FIGURE 1 ): Mesoventrite with posterior region abruptly inclined ventrad about 43° in relation to anterior region, with anterior articulating surfaces weakly concave; borders of mesoventral cavity curved. Mesocoxal cavity open to mesepisternum ( Fig. 1I View FIGURE 1 ) (closed in the right side of the lectotype); mesotrochantin not visible externally; mesocoxae separated by 0.7x their diameters; mesepisternum with a carina on inner anterior angle ( Fig. 1I View FIGURE 1 ); mesometaventral suture distinct. Scutellum ( Fig. 1J View FIGURE 1 ) cordiform, notched medially on anterior margin, abruptly elevated above the level of mesoscutum. Metaventrite ( Fig. 1H View FIGURE 1 ) 1.7x wider than long, 1.6x longer than mesoventrite, finely and densely punctate; metepisternum about 5.0x longer than wide. Elytral sides parallel-sided to apical third then gradually tapering to apices; striae with a row of punctures, interstices convex, glabrous and non-punctate; epipleura abruptly narrowed near metacoxae. Hind wings ( Fig. 1M View FIGURE 1 ) 1/4 shorter than elytra, unfolded; cross-vein r 3 very short, radial cell 3.5x longer than wide, CuA 1 absent; MP 4 linked to CuA 2 (it is linked to MP 3 in the other wing of the same specimen); wedge cell absent; apex with anterior and posterior field sclerotizations; anal notch present .

Metacoxa ( Fig. 1H View FIGURE 1 ) inclined 17° in relation to transverse axis of body; free margin of metacoxal plate short, absent on outer third. Metatrochanter and metafemur laterally convex, metafemur 2.2x longer than wide ( Fig. 1L View FIGURE 1 ). Tibia ( Figs. 1K, L View FIGURE 1 ) compressed laterally, 2.1x wider at apex than at base, with two spurs, a row of 10-13 spiniform setae along each outer and inner apical border and several spiniform setae on dorsal and ventral margins; tarsomeres simple, with fine and spiniform setae, decreasing in length from I-IV, V as long as III and IV together; claws simple.

Abdominal ventrites with punctures umbilicate, 0.5-1 diameters apart; posterior angles of ventrites 2-4 with acute and prominent marginal plates; ventrite 5 pentagonal 1.5x wider than long. Tergite VIII ( Fig. 1O View FIGURE 1 ) sparsely setose on anterior margin, anterior sclerotized margin rounded with a V-shaped notch medially. Sternite VIII ( Fig. 1N View FIGURE 1 ) with base triangular with anterolateral angles acute directed laterad, apex shortly emarginate, partly membranous with a pair of longitudinal sclerotizations; spiculum 4.75 times longer than base. Sternite X (proctiger) as long as paraprocts; paraprocts 2.24x as long as coxites.

Ovipositor ( Figs. 1P, Q View FIGURE 1 ): baculi 4.6 times longer than coxites, strongly sclerotized; coxites evenly strongly sclerotized, without setae, with apices acute and divergent, without styli. Reproductive tract ( Figs. 1P, R View FIGURE 1 ): bursa copulatrix with a pair of narrow sclerotizations; pedunculate anterior sac spherical and weakly sclerotized; duct of spermathecal gland opening at base of the pedunculate anterior sac.

Lectotype: [Coll. Schwarz], [Africa or., Micindani, ex coll. F. Schneider], [ Margogastrius schneideri Schw., Schneideri schneideri Schw ], [Dtsch. Entomol. Institut Berlin], [coll. DEI, Müncheberg], [ Margogastrius schneideri Schwarz, C. Girard vid. 1974], [S/F ?? Cardiophorinae, C. Girard det. 1974], [Lectotype], [Lectotype Margogastrius schneideri Schwarz , design. Douglas 2006], female (DEI).

Paralectotype: [Coll. Schwarz], [Africa or., Micindani, ex coll. F. Schneider], [ Margogastrius schneideri Schw. ], [Dtsch. Entomol. Institut Berlin], [coll. DEI, Müncheberg], [ Margogastrius schneideri Schwarz, C. Girard vid. 1974], [S/F ?? Cardiophorinae, C. Girard det. 1974], [Paralectotype], [Paralectotype Margogastrius schneideri Schwarz , design. Douglas 2006] 1 female (DEI).

Distribution: TANZANIA.

Remarks: Margogastrius present several characters attributed as synapomorfies to Cardiophorinae , such as cordiform scutellum, hind-wing without CuA 1 and wedge cell, wing anal area notched, female genitalia with a “glandular reservoir” (pedunculate anterior sac) entering the bursa copulatrix ( Calder, 1996) and parallel-sided prosternum ( Douglas, 2011). The phylogenetic analysis carried out by Douglas (2011) found a close phylogenetic relationship between Margogastrius and Cardiophorinae species.

It presents most of the diagnostic characters attributed to the genus Cardiophorus Eschscholtz, 1829 based on species from Nearctic ( Douglas, 2003) and Palearctic regions ( Akhter et al., 2011): head wider than long, frons carinate, labrum large, procoxal cavities open, scutellum notched anteriorly, tarsomeres cylindrical and claws simple. Margogastrius is most similar to Coptostethus Wollaton, 1854 , with which it shares the absence of lateral carina on pronotum and the hind wing reduction. Coptostethus was erected as a subgenus of Cardiophorus and includes various shortwinged Cardiophorinae ( Douglas, 2011) . I have compared Margogastrius species with a female of Coptostethus globulicollis Wollaton, 1862 from Tenerife (Canary island). Those species share the strongly dorsally and ventrally convex body, the prothorax with sides rounded and lateral carina absent, the absence of median occipital carina, the shape of metacoxal plate and the mesoventrite with posterior region abruptly inclined ventrad about 43° in relation to anterior region. Magogastrius differs from Coptostethus globulicollis in (the latter in parenthesis): its mandible unidentate (bidentate), tapered prosternal prosternum (truncate at apex), elytra 2.5 longer than pronotum (about1.5 longer) and fossorial legs (slender). The fossorial legs and the prosternal process tapered in lateral view seem to be the unique character that separate Margogastrius from most Cardiophorus species and Coptostethus globulicollis . Margogastrius also differs from those species in the mesocoxal cavity open to mesepisternum, neverthelles this is probably a labile character, since one specimen present one closed and one open mesocoxal cavity.

Margogastrius is similar to the fossorial genus Patriciella Van Zwaluwenburg, 1953 from Australia ( Calder, 1996) in its pronotum with lateral pronotal carina absent, prosternal process tapered in lateral view, procoxal cavities open, scutellum cordate, metatrochanter strongly convex and tibiae widened apically. It differs from this Australian cardiophorine in (the later in parentheses): median occipital carina absent (present), free margin in metacoxal plate present (absent), the pronotum more convex, tibiae with dorso-apical angle straight (acute and produced) and metafemur slender. Margogastrius is also distinguishable by its short antenna, elytral interstices convex and body ventrally and dorsally strongly convex.

Margogastrius is also similar to the fossorial cardiophorine Blaiseus in the tibiae expanded apicad, the unidentate mandibles and the prosternal process curved dorsad ( Douglas, 2009). It differs from this genus in (the later in parentheses): lateral pronotal carina absent (present), scutellum notched anteromedially (concave), elytral interstices convex (costate). Blaiseus species occurred in Oriental Region, Central America and South Africa and the only known female belonged to B. zamoranoensis Douglas, 2009 from Honduras. This female shares with Margogastrius the small eyes and the short hind wing.