Pseudocanthon chaquensis Nazaré-Silva & Silva, 2021

Nazaré-Silva, Everton E. & Silva, Fernando A. B., 2021, A taxonomic revision of the South American species of Pseudocanthon Bates, 1887 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini), Zootaxa 5027 (1), pp. 61-86 : 76-82

publication ID	https://doi.org/ 10.11646/zootaxa.5027.1.3
publication LSID	lsid:zoobank.org:pub:D8FE51C2-C34F-47CE-87FC-80BAB16C54BD
DOI	https://doi.org/10.5281/zenodo.5492698
persistent identifier	https://treatment.plazi.org/id/038A87A7-FFF2-FFBA-71F5-F927BEAE1EAE
treatment provided by	Plazi
scientific name	Pseudocanthon chaquensis Nazaré-Silva & Silva
status	sp. nov.

Treatment

Pseudocanthon chaquensis Nazaré-Silva & Silva View in CoL , new species

( Figs. 1B, 1D View FIGURE 1 , 2H View FIGURE 2 , 3F View FIGURE 3 4E View FIGURE 4 , 5F View FIGURE 5 , 6F View FIGURE 6 , 7B View FIGURE 7 )

urn:lsid:zoobank.org:act:49764003-1A6D-4962-8B57-A968B9C4461B

Etymology. The specific name is a Latinization of the Spanish demonym “chaqueño”, which refers to the inhabitants of the Chaco region, the place where most of the known specimens were collected. It should be treated as a Latin third-declension adjective in the nominative case.

Diagnosis. Pseudocanthon chaquensis is similar to P. pantanensis in having the pronotum with dense, wellimpressed granulate microsculpture centrally ( Fig. 2A View FIGURE 2 ); eighth stria of elytra extending to approximately anterior half of elytra, with shallow carina at anterior portion ( Fig. 2D View FIGURE 2 ); and posterior edge of metafemur lightly angulate at basal third, expanded towards the abdominal ventrites ( Figs 4E View FIGURE 4 ). However, P. chaquensis can be easily distinguished by having pygidium completely orange ( Fig. 2H View FIGURE 2 ); parameres truncate apically, with small obtuse projection at ventral edge ( Fig. 5F View FIGURE 5 ); frontolateral peripheral (FLP) endophallite elongate, bifurcate at inferior portion ( Fig. 6F View FIGURE 6 ); accessory endophallite (AE) small and elongate ( Fig. 6F View FIGURE 6 ). In P. pantanensis , the pygidium is metallic green and has an orange band at posterior edge ( Fig. 2G View FIGURE 2 ); the parameres are curved and pointed apically ( Fig. 5E View FIGURE 5 ); the frontolateral peripheral endophallite is sinuous, with inferior portion rounded ( Fig. 6E View FIGURE 6 ); and the accessory endophallite is absent ( Fig. 6E View FIGURE 6 ).

Description. Holotype. Length. 5.4 mm. Width. 3.3 mm. Colour. Surface of body dark brown with metallic green reflections; legs orange; orange spot on clypeus and on last abdominal ventrite. Surface punctation and sculpturing. In general, surface punctation consists of foveolate punctures. Surface of head, mesoventrite, metaventrite, elytra, abdomen, tibiae, and femora with dense and well-impressed granulate microsculpture; lateral edges and anterior angle of pronotum, hypomera, lateral edges, and anterior portion of metaventrite, mesepimeron, metanepisternum, epipleuron, tibiae, and femora with imbricate microsculpture. Pronotum with dense and wellimpressed granulate microsculpture centrally ( Fig. 2A View FIGURE 2 ). Elytra. Eighth elytral stria extending across the basal half of the elytra, with shallow carina at basal portion ( Fig. 2D View FIGURE 2 ). Legs. Posterior edge of metafemur lightly angulate at basal third, expanded towards at abdominal ventrites ( Fig. 4E View FIGURE 4 ). Abdomen. Pygidium completely orange ( Fig. 2H View FIGURE 2 ) Tegmen. Apex of parameres truncate, with small obtuse projection at ventral edge ( Fig. 5F View FIGURE 5 ). Endophallus. Frontolateral peripheral (FLP) endophallite elongate, bifurcate at inferior portion ( Fig. 6F View FIGURE 6 ); acessory endophallite (AE) small and elongate ( Fig. 6F View FIGURE 6 ).

Type material. 14♀ and 23♂. Holotype. BRAZIL: MATO GROSSO: Poconé, Pousada Araras ,[16°30’43.39’’S; 56°42’41.61’’W], 03.XII.1998, J. Moreno & T. Mestre GoogleMaps — 1♂ ( CEMT). Paratypes. BRAZIL: MATO GROSSO: Poconé, Pousada Araras , [16°30’43.39’’S; 56°42’41.61’’W], 03.XII.1998, J. Moreno & T. Mestre GoogleMaps — 6♀ 17♂ ( CEMT); Pirizal [pantanal region], [16°14’23.94’’S; 56°22’29.67’’W], 13.X.2007, pitfall, A. Tissiani GoogleMaps — 1♀ 1♂ ( CEMT). ARGENTINA: FORMOSA: [26°11’08.8’’S; 58°10’32.04’’W], 66 m, XII.1953, no collector GoogleMaps — 1♂ ( CMNC); Reserva Privada Estancia Guaycolec [woodland], [25°58’16.4’’S; 58°11’07.9’’W], 13.X.2015, rotten meat, A. Guerra GoogleMaps — 1♀ ( CEMT); CHACO: Resistencia , [27°27’06.7’’S; 58°59’08’’W], 58 m, XI.1945, no collector GoogleMaps — 1♀ ( CMNC); Resistencia [woodland], [27°30’26.9’’S; 59°05’03.5’’W], 54 m, 30.III.2016, pitfall, A. Raimundo GoogleMaps — 3♀ 1♂ ( CEMT); Resistencia [chaco region], [26°50’57.4’’S; 59°36’28.6’’W], 10.XI.2016, human feces, A. Guerra GoogleMaps — 1♀ ( CEMT). URUGUAY: CANELONES, San Luis , 18.IV.2000, P. Gonzalez — 1♂ ( CEMT); San Luis , 23.III.2000, P. Gonzalez — 1♂ ( CEMT) .

Distribution. Known from Argentina (Chaco and Formosa) and Brazil (Mato Grosso) ( Fig. 7B View FIGURE 7 ). Areas of endemism [South America]: Brazilian subregion: South Brazilian dominion: Rondônia province. Chacoan subregion: Chacoan dominion: Chaco province (see Morrone 2014: fig. 12).