Scotaena Klug, 1810

Carnimeo, Fernando Henrique & Noll, Fernando Barbosa, 2018, On the dumping ground genus Scotaena Klug, 1810 (Hymenoptera: Tiphiidae: Thynninae): Phylogeny, taxonomy and geographic distribution, Zootaxa 4399 (4), pp. 451-490 : 456-458

Scotaena Klug

Type species: Scotaena trifasciata Klug, 1810

Male description. Head: Antennal sockets under supra-antennal projections, with well-developed supra-antennal plate on the medial apex, the margins strongly carinate (except in S. reversa sp. nov.). A short longitudinal line between the anterior ocelli and the supra-antennal projection, reaching the middle of the supra-antennal plates in S. trifasciata ; clypeus apical margin with central notch with depth of about 1/2 to 1/4 of clypeus length, the notch is deeper in S. horni and S. vetusta . Two acute teeth are formed towards down by the notch, longer in S. horni and S. vetusta . A longitudinal line is present, more or less raised, on the medial region of the clypeus (except in S. trifasciata ). Basal region of the clypeus convex, depressed on the basolateral margins. Laterals of the apical margins concave. Mandible bidentate, the apical tooth long and acute, the subapical short and rounded. Basal region of the mandible triangular shaped. Maxillary palpi with palpomeres about the same size, the III rd often shorter and broader (unknown in S. trifasciata ); antennae filiform, with 11 flagelomeres, the apical ones slightly arcuate (unknown in S. trifasciata ).

Mesosoma: Pronotum constricted in the middle, forming elevations anterior and posteriorly in lateral view. Anterior margin carinate and narrower than the posterior; forewing with nervure 2m-cu received by beyond about 1/5 of the base of the submarginal cell; mesoscutum subquadrate in dorsal view, with dorsal surface convex. A pair of longitudinal submedial sutures and a pair of longitudinal carina laterally, culminating in a transverse posterior carina; scutellum surface rounded, medially raised dorsally in S. reversa Delimited anteriorly by a deep transverse suture and the posterior margin rounded. Latero-posterior margins with borders enlarged towards the axilla; metanotum short with two sublateral fossae; mesopleural transverse sulcus wide and diffuse; metapleuron triangular in lateral view; propodeum with convex dorsal surface. Apex of the propodeum with two longitudinal petiolar grooves reaching less than half its extension. Dorsal surface of the propodeum with dense and coalescent punctures (except in S. trifasciata ); mesepisternal lamellae triangular, narrow and acute, with the apex slightly rounded. Except in S. trifasciata , where the lamellae are short and subquadrate; mesepisternal suture slightly raised at the apex, more strongly raised in S. reversa ; a pair of longitudinal sutures on the ventral surface of the mesepistenum; forecoxae with ventral surface slightly convex, the inner margin straighter and the outer more sinuous curved. Hindcoxae with longitudinal carina on the dorsal surface; posterior margins of the mid and hindtibiae with row of projections or serrations, more conspicuous on hindtibiae. With short carina on the external base of the tibia. Hindfemoral-hindtibial joint lobes asymmetrical with inner lobe longest and both thickened posteriorly;

Metasoma: Metasoma with constrictions between the segments, mainly in lateral view; first metasomal tergite with length longer than its apical breadth in S. vetusta and S. reversa , and with length as long as its breadth in S. trifasciata and S. horni . The longitudinal sulcus reaching more than half the segment extension; apical margins of tergites I–VI with transverse smooth fasciae, preceded by a transverse row of setae horizontally arranged; epipygium oval, tapering towards the apex and feebly constricted before the apical margin. With lateral carinas raised by the epipygium rugosities; hypopygium subquadrate, with longitudinal line feebly raised in the middle of the hypopygium surface, touching the apical margin (unknown in S. trifasciata );

Coloration: Body predominantly black or variegated with yellow markings.

Included species. Scotaena trifasciata , S. horni , S. reversa , S. vetusta .

Distribution. The genus is recorded from southeast Paraguay, northeast Argentina and mainly in the Brazilian Atlantic Forest: Bahia state, southeast of Minas Gerais, west of Santa Catarina and on the Atlantic coast of São Paulo and Rio de Janeiro.

Discussion. The diagnostic features presented by Klug in the original description of Scotaena rely completely on coloration, while the morphologic characters utilized in the identification keys for the South American genera are not exclusive to Scotaena . Therefore, one of the main results of this work was to redescribe the genus and provide synapomorphic features to define it. The species S. brunnea and S. pallida were originally described by Fox (1989) for female individuals only. Their holotypes are deposited at the Hymenoptera collection of the Carnegie Museum of Natural History (Pittsburgh, USA). None of them are associated with males and it is possible that these may actually be females for already described species of Scotaena or the new genera described here. Therefore, due to their uncertain position, leaving these two specimens as incertae sedis is the safest approach.