A revision of the genus Contacyphon Gozis in Argentina (Coleoptera: Scirtidae)

RUTA, RAFAL; LIBONATTI, MARÍA LAURA

Luján de Cuyo

Congreso; X Congreso Argentino de Entomología; 2018

Instituto Argentino de Investigaciones de Zonas Aridas

Contacyphon is one of the most speciose genera of marsh beetles, currently containing over 350 species worldwide and 45 in Neotropical region. Almost 90 years have passed since the last description in Argentina, where the genus is represented by only two very poorly known species. In this contribution we revise the Argentine members of Contacyphon, providing detailed descriptions, illustrations of diagnostic characters, updated distribution data for each taxon, and a key to species. We studied almost 200 specimens collected in several trips to the provinces of Buenos Aires, Chubut, Corrientes, Misiones, Neuquén, and Río Negro, during 2000-2012. Types of all species described from Argentina, Chile and selected species from other regions of South America as well as specimens identified as Contacyphon sensu stricto were examined for comparison purposes. Collecting techniques comprised light and Malaise traps, and beating. The following species were recognized: C. cadornai (Pic), C. maculatus (Solier), C. pallicolor (Fairmaire), C. robusticorne (Pic), and five new species. C. cadornai and C. maculatus are recorded from Argentina for the first time. Contacyphon maculatus and C. pallicolor share an arched basal part of tegmen, triangular parameres, hairy stylus, simple trigonium and presence of dictyon. Three of the new species are characterized by the presence of wide, deep setal sockets distributed over ventral surface of thorax, rod-shaped hemisternites of male sternite 8, Y-shaped sternite 9, penis elongate and firmly attached to tegmen, and sexual pilosity in ventrite 5. Contacyphon cadornai resembles members of the Australian genus Notocyphon Zwick in the presence of forked gular sutures and a semicircular sclerite attached to each paramere. None of the species exhibits all the characters proposed for Contacyphon sensu stricto, but C. maculatus and C. pallicolor have buttonhole configuration of subgenal ridge and lack male sternite 8, three of the new species exhibit buttonhole configuration of subgenal ridge and presence of brush organ in female genital tract, and one of the new species has paired appendages on apical part of penis. The number of species of Contacyphon from Argentina increased from two to nine. Additional research analyzing the phylogenetic relationships of the species is suggested to test the monophyly of the genus.