Leotrichillum, 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 : 32-33

7. Leotrichillum new genus

Diagnosis: Small (2.2–2.8 mm), oval, and elongated body ( Fig. 23); color tan to brown; clypeus with two teeth and evenly rounded laterally ( Fig. 72). Pronotum separated of hypomeron by sharp carina, hypomeron with sharp lateral longitudinal carina posteriorly. Elytral interstriae with uniseriate setose punctures; pseudoepipleura glabrous and gradually narrowed posteriorly. Mesofemora and metafemora oval; mesotibiae and metatibiae apical width of tibia much longer than third of tibial length. Metatarsi with basal tarsomere slightly longer than second. Parameres with an apicolateral invagination ( Fig. 73).

Description: Length 2.2–2.8 mm, body oval, elongated, convex ( Fig. 23); tan to brown, shiny, lacking metallic sheen, dorsal setae slightly claviform. Clypeus with two short triangular teeth, separated by wide Vshaped emargination, evenly curved laterally, continuous with genal margin. Clypeofrontal and clypeogenal sutures indistinct. Eyes, in dorsal view, rounded, each about as wide as seven-tenths of its length; interocular width five to six times eye width ( Fig. 72). Pronotum lacking without anterior or posterior beads; lateral pronotal callosity indicated by indistinct dark spot; disc covered by simple setose punctures, separated from hypomeron by very weak carina. Hypomeron with strong longitudinal lateral carina; mesoepimera with weak anterior transverse carina, stronger mesally; metasternal disc covered by simple punctures. Elytral interstriae with one row of setose punctures, flat. Elytral striae not distinctly widened or deeper on declivity. Pseudoepipleura glabrous, gradually narrowed to apex, with longitudinal fold near metacoxa, causing anterior part to be almost vertical in position, and posterior part almost horizontal. Protibiae with three strong teeth distributed along apical three-fifths of lateral margin, which is denticulate from base to basal tooth, with ventral scale-like setae on teeth. Mesofemora and metafemora oval; mesotibiae and metatibiae apically wider than third of tibial length. Pygidium nearly vertical. Parameres shorter than half length of phallobase, flattened and apically rounded, laterally incised ( Fig. 73). Pseudoflagellum helicoidal and thick, with flat elongated auxiliary lamella. Coxites large, oval and symmetrical. Spermatheca simply C-shaped, gradually narrowed apically, bulbous at base, with duct insertion at ventral part of the base of the spermathecal body.

Sexual dimorphism: Males with proclaws bent in the middle, protarsi with apical tarsomere modified to receive claws; mesotarsi and metatarsi with claws bigger and stronger than in females. All tibiae with apicomesal tooth in males, mesotibial and metatibial teeth smaller than protibial one. Metasternum slightly concave in males, flat in females; pygidium slightly longer in males than females.

Type species: Pedaridium louzadaorum Vaz-de-Mello & Canhedo, 1998 (monotypy) = Leotrichillum louzadaorum ( Vaz-de-Mello & Canhedo, 1998), new combination.

Etymology: After my son, Léo Falqueto Vaz de Mello. Gender neutral.

Distribution: Northern Argentina and southern Paraguay, central and northeastern Brazil, occupying the Chaco, Caatinga and Cerrado provinces of the Chacoan subregion.

Remarks: The pygidial sulcus of L. louzadaorum is, in fact, not divided as described originally (Vaz-de- Mello & Canhedo 1998); it is entire. The relationship of Leotrichillum to other genera is uncertain, as it has several characters relating it both to Genieridium (e.g. oval and elongated body, presence of mesotibial and metatibial mesoapical teeth in males, slightly modified mesotibial and metatibial male claws, weak pronotalhypomeral carina) and to Degallieridium (e.g. very small size, color tan to brown with darkened pronotal callosities, claviform dorsal setae, longitudinally bent pseudoepipleura, large eyes). Unambiguous synapomorphies for Leotrichillum are the laterally incised parameres and the ventral position of spermathecal duct insertion, apart of others that depend on the resolution of its phylogenetic position.

Composition: Besides the type species, the genus contains at least one undescribed species.

Material examined: