Martinezidium, 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 : 34

8. Martinezidium new genus

Diagnosis: Clypeus with two, four or six teeth ( Figs. 74, 76). Males without modified proclaws or apicomesal protibial tooth. Elytral interstriae either with one or two rows of setose punctures; pseudoepipleura gradually narrowed to apex and with row of setae. Mesotibiae and metatibiae longer than four times tibial apical width. Parameres conical ( Fig. 75).

Description: Length 2.8–5.0 mm. Body oval, elongated ( Figs. 24–25), dorsally brown or black, sometimes with metallic sheen. Clypeus rounded, with two to six triangular teeth separated by wide U- or V-shaped emargination. Clypeofrontal suture indistinct, clypeogenal suture very weak. Eyes, in dorsal view, as wide as four- to seven-tenths eye length; interocular width about six to eight times eye width ( Figs. 74, 76). Pronotum lacking anterior or posterior beads, both anterior and posterior angles obtuse; separated from hypomeron by strong lateral carina, hypomeron with strong posterior carina parallel to lateral border. Both anterior and posterior pronotal angles obtuse, anterior margin not beaded. Mesoepimera with anterior transverse carina. Protibiae with three strong lateral teeth, middle one broader, all acute; teeth distributed along apical threefifths; laterally denticulate from base to basal tooth; with ventral scale-like setae on teeth. Proclaws small, evenly curved in both sexes. Metatarsi with basal tarsomere equal or shorter than second one. Interstriae flat to feebly convex on disc, with one to two rows of setiferous punctures. Pseudoepipleura gradually narrowed posteriorly, with setiferous punctures all along the mesal margin (poorly preserved or worn specimens lacking in anterior third). Striae much deeper and with larger punctures apically. Aedeagus with each paramere conical ( Fig. 75). Coxites small and symmetrical. Spermatheca C-shaped, with very long and swollen unsclerotized duct.

Sexual dimorphism: Females differ from males by having broader protibiae, lateral teeth slender and less conspicuous than in males, protibial spur shorter and basally broader than in males; abdominal sternite VI longer medially than in males, pygidium wider than in males.

Type species: Pedaridium galileoae Génier & Vaz-de-Mello, 2002 (present designation) = Martinezidium galileoae ( Génier & Vaz-de-Mello, 2002), new combination.

Etymology: Named after Antonio Martínez, from whose collection a great part of the examined material came, and who contributed much to the study of Trichillum and Pedaridium from the 1950’s to just before his death in 1993. Gender neutral.

Distribution: The genus has a very widely disjunct distribution, with one group in Southern Paraguay and Argentina, from Jujuy to Chubut, occupying the Chaco and Pampa provinces of the Chacoan subregion in the Neotropical region, and the Monte province in the South American transition zone; and the other in Mexico (Jalisco, San Luis Potosí, Veracruz, Yucatán, Quintana-Roo, Chiapas, Campeche) and Guatemala (Petén), equivalent to Mexican Gulf and Yucatán Peninsula provinces of the Caribbean subregion of the Neotropical region, and the western part of Transmexican Volcanic Belt province of the Mexican Transition Zone.

Remarks: The relationship of this genus to other genera are unclear. Its disjunct distribution is correlated to morphological differences indicating that the geographic groups likely correspond to species-group clades. Northern species are black, without traces of metallic sheen, and clearly flatter than southern species, and with slightly convex discal elytral striae ( Fig. 25). Southern species are brown, with slight to very strong cupreous to green metallic sheen, and have unique modifications in parameres mesally, making them asymmetrical ( Fig. 75). Apomorphies for this genus are the conical parameres and the lack of sexual differences in tarsi and mesally in protibia.

Composition: Besides the type species, the genus contains also M. martinsi ( Ferreira & Galileo, 1993) , new combination, M. fulgens ( Arrow, 1913) , new combination, M. maya (Vaz-de-Mello, Halffter, & Halffter, 2004), new combination (all described as Pedaridium ) and at least five new species currently being described.

Material examined: