Besourenga, Vaz-De-Mello, 2008

Vaz-De-Mello, Fernando Z., 2008, Synopsis of the new subtribe Scatimina (Coleoptera: Scarabaeidae: Scarabaeinae: Ateuchini), with descriptions of twelve new genera and review of Genieridium, new genus, Zootaxa 1955, pp. 1-75 : 16-17

1. Besourenga new genus

Diagnosis: Size small (2.0– 3.5 mm); clypeus with two teeth separated by narrow U- or V-shaped emargination; clypeogenal edge straight or sinuate, with lateral border of clypeus angled or strongly curved lateral to clypeal teeth ( Figs. 39, 41); elytra with only one row of setose punctures on each discal interstria; pseudoepipleuron strongly narrowed near metacoxa, extending to apex ( Fig. 10).

Description: Size small, body oval ( Figs. 15–16), color grey or brown to black, always lacking metallic sheen. Clypeus anteriorly bearing two strong teeth, separated by narrow U- or V-shaped emargination. Clypeogenal and frontoclypeal sutures indistinct. Clypeal margin externally to clypeal teeth strongly curved or angled, becoming straight anteriorly to clypeogenal border, which is straight or slightly sinuate. Genal margin straight or slightly curved between clypeus and lateral angle ( Figs. 39, 41). Pronotum lacking anterior or posterior beads. Pronotal disc laterally with glabrous indistinct callosity, centrally covered by large setose punctures. Hypomeron posteriorly with longitudinal carina. Mesoepimeron with transverse anterior carina. Metasternum with setiferous punctures on the disc. Elytra with discal interstriae with single row of setiferous punctures, mesal striae slightly to strongly widened and deepened at apical declivity. Pseudoepipleura strongly narrowed near metacoxa extending to apex; with setiferous punctures present only at base. Protibiae with three strong lateral teeth distributed along apical four fifths of tibial length; ventrally with scale-like setae on teeth. Parameres shorter than one half of the length of the phallobase, simply elongated and flattened ( Fig. 40). Coxites symmetrical well separated. Spermatheca spiral shaped.

Sexual dimorphism: Males bear a digitiform projection of mesal apical angle of protibia, and apical tarsomere of protarsi excavated dorsally to receive proclaws that are strongly angulated at mid-length ( Fig. 42). Metasternal disc is somewhat concave in males, but very flat in females.

Type species: Trichillum minutum Saylor, 1935 (present designation) = Besourenga minutus ( Saylor, 1935) , new combination.

Etymology: Combination of besouro (Brazilian Portuguese word for “beetle”), and Alvarenga , proper name, in honor to Moacyr Alvarenga , good friend and amateur coleopterist responsible for collecting much of the material studied here and specialist in the taxonomy of the family Erotylidae . Besourenga was his nickname in the Brazilian Air Force, where his passion for collecting beetles was widely celebrated. Masculine in gender.

Distribution: Bolivia east of the Andes, southern Amazonia in Bolivia, Peru and Brazil, eastern Paraguay and central Brazil including western parts of São Paulo , Minas Gerais, and Bahia states. This distribution comprises the Pantanal and Tapajós-Xingu provinces of the Amazonian subregion, and the Cerrado and Chaco provinces of the Chacoan subregion ( Morrone 2006).

Remarks: A clade comprising Trichillum , Besourenga , Degallieridium , Feeridium and Eutrichillum is putatively supported by the absence of the transvese carina on mesoepimeral disc, while the sister-genus relationship of Besourenga and Trichillum is supported by the spiral spermathecal shape and the form of clypeal border sides. The monophyly of the genus is supported by: (1) slight expansion of the lateral genal angle in relation to other groups closely related; (2) smaller size; and (3) absence of a lateral pronotal callosity. The optimizations of the presence of setiferous punctures on the pronotal disc (also present in one species of Trichillum ) and modification of proclaws in males are ambiguous and could be merely symplesiomorphies. Except for B. horacioi from forests in southern Amazonia, all species of Besourenga are from open habitats in the Chaco and Cerrado biomes. Specimens of this genus are usually collected with flight intercept traps, at light, or more rarely with dung-baited pitfall traps.

Composition: Besides the type species, the new genus includes Besourenga vejdovskyi (Balthasar, 1939) , new combination (described as Trichillum ), Besourenga amarillai ( Aguilar-Julio, 2001) , new combination (described as Pedaridium ), Besourenga horacioi ( Martínez, 1969) , new combination, and several new species currently under study.

Material examined: