Arthrobrachus flavomarginatus Blanchard 1843, n. comb.

Arthrobrachus flavomarginatus (Blanchard, 1843) n. comb.

(Figure 6).

Dasytes flavomarginatus Blanchard, 1843: 100; Lacordaire1857: 402 (Astylus?); Gemminger and Harold 1869: 1717 (Astylus);

Pic 1929: 9 (Astylus); Blackwelder 1945: 378 (Astylus) (Type locality: Chuquitacos, Bolivia) n. comb.

Dasytes xanthurus Blanchard, 1843: 100; Lacordaire 1857: 402 (Astylus?); Gemminger and Harold 1869: 1718 (Astylus); Pic

1929: 16 (Arthrobrachus); Blackwelder 1945: 379 (Arthrobrachus). (Type locality: Montevideo, Uruguay) n.syn. Arthrobrachus boucardi Pic, 1919: 9; Pic 1929: 15; Blackwelder 1945: 379 (type locality: Uruguay) n.syn.

Arthrobrachus lajoyei Pic, 1919: 11; Pic 1929:16; Blackwelder 1945: 379 (Type locality: Montevideo, Uruguay) n.syn. Types examined:

- flavomarginatus: Two syntypes deposited in MNHN. One male, herein designated as lectotype, and labelled as follows: D. flavomarginatus Blanch. (rectangular, green) // Chuquitacos M. D’Orbigny (white) // 2987 (white) // 46 (white) (all handwritten) // 1986 34 (green, circular) // Type (red, printed). One female, herein designated as paralectotype and labelled as follows: 1986 36 (circular, green) // N°47 (white) (both handwritten) // Type (red, printed). The female is doubtfully assigned as paralectotype.

- xanthurus: Five syntypes deposited in MNHN. One male herein designated as lectotype and labelled as follows: Montevideo M. D’Orbigny (large, green) // 252 (small square, white) // 5250-34 (green top, white bottom) // Dasytes xanthurus Bl. (white) // N°40 (white) (all handwritten) // Museum Paris Maldonado D’Orbigny, 1834 // Type (both printed). Four specimens, herein designated as paralectotypes and labelled as follows: 5250 34 (green, circular) // A. xanthurus (white) // N°41 (white) (all handwritten) // Museum Paris Maldonado D’Orbigny, 1834 (printed) // Type (both printed) (1♂). Dasytes xanthurus Bl. // 5251-34 (green, circular) // N°42 (all handwritten) // Museum Paris Maldonado D’Orbigny // Type (both printed) (1♂). A. xanthurus // 5251/34 // Museum Paris Maldonado D’Orbigny, 1834 // Type (1♀). A. xanthurus // Dasytes xanthurus types Blanchard // 5257 34 // Museum Paris Maldonado D’Orbigny, 1834 // N°44 // Type (1 ♀). The females of the type series by Blanchard are doubtfully assigned as paralectotypes.

- boucardi: One male in poor condition, deposited in MNHN, herein designated as lectotype and labeled as follows: A. boucardi Pic // Type // Uruguay // Museum Paris coll. M. Pic // N°34 // Type.

- lajoyei: One male, deposited in MNHN, herein designated as lectotype and labelled as follows: Arthrobrachus limbatus Sol (gardé a) // Type // lajoyei Pic (all handwritten) // Montevideo // Pic type // Museum Paris coll. M. Pic // Type (all printed).

Diagnosis. Antennae generally with three dilated preapical antennomeres (Fig. 6 i); pronotum with a lateral, oblique carina, at least in the anterior half, and one moderate circular impression near the basal angles; epipleura wide, with convergent edges in the apex; males: ventrite 6 with two flat, transverse, subcontiguous plates (Fig. 6 h); last tergite subsquare, with moderately rounded hind angles (Fig. 6 h); parameres weakly sclerotized basally (Fig. 6 a,b); tegmen without dorsal flange at the base of the parameres, tegminal plate reduced and flat, sometimes projected in the area of the apodeme (Fig. 6 c), tegminal arms moderately curved at the base (Fig. 6 c); median lobe with sclerotized dorsal surface and membranous narrow flection area (Fig. 6 d–f).

Description. Males: Average body length 3.49 mm (range: 3.0–4.0 mm), length: width ratio 2.34:1, sides subparallel; pronotum and elytra with distinct coarse punctures covering their dorsal surface; pubescense fine, short and inclined, dense in dorsal surface; body dark-testaceous, elytra with a light testaceous marginal stripe, also slightly extended by the suture from the apex, antennae and legs orange.

Head: Included the eyes almost as wide as the distal margin of the pronotum (0.925:1); antennae shorter than the length of the pronotum (0.762:1), generally with three mesally dilated preapical antennomeres (Fig. 6 i).

Thorax: Pronotum wider than long (1.4:1), moderately convex transversely and slightly curved longitudinally, the base wider than the apex (1.38:1) and almost as wide as the humeral region (0.927:1), from a dorsal view the anterior margin slightly convex, anterior and posterior margins well marked, lateral margins slightly curved, lateral edges of disc flat; the oblique lateral carina prolonged from the anterior margin, never less than half the length of the pronotum, better marked on the distal part, one moderate circular impression present near the basal angle; elytra 1.75:1 longer than wide; lateral margins subparallel in the two basal thirds and rounded in the distal one; disc moderately convex, with light lateral border; epipleura wide, their margins convergent at the apex, almost flat, generally grainy and hairy, sometimes with blunt apical denticles; legs: median and hind tibiae with scarce spines in the external margin, tarsomeres with few ventral spines.

Abdomen: Ventrite 5 with straight distal margin, slightly convex; ventrite 6 with two flat lateral subcontiguous plates; last tergite subsquare, distal angles moderately rounded, its posterior margin rounded, apodemes moderately long (Fig. 6 h); segment 9 weakly sclerotized, tergum narrow, fine sternal arms and moderately long apodeme (Fig. 6 g). Genitalia: parameres acuminate at apex, sides subparallels, slightly convex, emarginated or weakly sclerotized at the base, lateral edge narrow, sometimes lateral margins communicated on the apex, from a lateral view the lower margin of parameres and tegmen slightly curved; tegmen without dorsal flange at the base of the parameres, tegminal arms thick, sides subparallel, gradually convergent toward the base, from a lateral view strongly curved at base, tegminal plate reduced, distal margin slightly concave, apodeme rounded (Fig. 6 a–c); median lobe subcylindrical, sides subparallel convergent at apex, almost straight in lateral view, forming an obtuse angle with the apodeme, apex acuminate, dorsal surface sclerotized with narrow membranous area, flection area narrow, apodeme enlarged (Fig. 6 d–f, f1).

Distribution. ARGENTINA (Fig. 10): Provinces of Jujuy (IMLA), Formosa (IMLA), Chaco (MACN, IMLA, MLPA), Salta (IMLA, JEBC), Misiones (MLPA), Catamarca (IMLA), La Rioja (IMLA, MACN), Santiago del Estero (IMLA, MLPA), Santa Fé (MACN, MLPA), Entre Ríos (MLPA), San Luis (JEBC, IMLA), Córdoba (IMLA, MLPA), Buenos Aires (MLPA), Mendoza (MLPA). URUGUAY: Montevideo (MNHN). BOLIVIA: Chuquitacos (MNHN).

Comment: Lacordaire (1857) assigned with doubts Dasytes flavomarginatus and D. xanthurus to Astylus, classification followed by Gemminger & Harold (1869). Pic (1929) transferred D. xanthurus to Arthrobrachus, what was followed by Blackwelder (1945). A study of the type material of Blanchard allows to propose the transfer of Astylus flavomarginatus to the genus Arthrobrachus and to recognize the synonymy of this species with xanthurus. As Blanchard (1843) described Dasytes flavomarginatus and D. xanthurus in the same page the first name is selected as the valid name and the second as its synonym. Further, the type locality of A. boucardi (Paraguay in Blackwelder 1945 and Pic 1919) must be changed to Uruguay based on the type label data.