Cnodocentron has a disjunct Laurasian distribution, with species in South-East Asia and the New World. It is divided into two subgenera: Cnodocentron and Caenocentron. Here, we infer the evolutionary history of the genus through phylogenetic and biogeographic data combining COI and 46 morphological characters. Phylogenetic relationships and divergence-time estimation were simultaneously inferred through Bayesian inference. The dating analysis was performed through relaxed morphological and molecular clocks. The historical biogeography was investigated using the dispersal–extinction–cladogenesis model. Our results indicate the polyphyly of the genus Cnodocentron, with each subgenus being more related to other genera than to each other. Therefore, the subgenus Caenocentron is elevated to genus status here. The biogeographical analysis showed that the Oriental Cnodocentron diverged in the Indian subcontinent during the Middle Eocene, while the New World Caenocentron stat. nov. originated in the Chortis Block in the Late Eocene. The dispersal of Caenocentron to South America occurred only after the Late Miocene, around 10 Mya. Additionally, we provide a revision of Caenocentron, with an identification key and description of the male and female of two new species from Costa Rica: Caenocentron carlosdelarosai sp. nov. and Caenocentron rafamoralesi sp. nov..
Smicridea is the only genus recorded in the New World for the Gondwanan subfamily Smicrideinae (Hydropsychidae). The genus comprises two subgenera, Smicridea (Smicridea) and Smicridea (Rhyacophylax). In Brazil, Smicridea numbers 55 species, of which 16 are referred to subgenus Smicridea and 39 to subgenus Rhyacophylax. Here, we describe two new species in Smicridea (Rhyacophylax) and one in Smicridea (Smicridea), both from Brazil. Smicridea (Rhyacophylax) scalprum sp. nov. belongs to the Smicridea dispar group and is diagnosed mainly by the truncate apex of segment X that has a concave notch apically. Smicridea (Rhyacophylax) sororis sp. nov. belongs to the Smicridea argentina group and is similar to Smicridea (Rhyacophylax) froehlichi, possibly representing a recent speciation process; Smicridea (Rhyacophylax) sororis sp. nov. is differentiated mainly by the papilla‐like lateral lobes on the phallus. DNA barcode sequences (577 bp of the mitochondrial gene COI) of Smicridea (Rhyacophylax) sororis sp. nov. and Smicridea (Rhyacophylax) froehlichi were integrated to evaluate species delimitations. Smicridea (Smicridea) capao sp. nov. belongs to the Smicridea fasciatella group and appears to be morphologically similar to some Smicridea (Smicridea) from Colombia. Smicridea capao sp. nov. is diagnosed by the strong subapical constriction on the phallus and the rounded apex. Additionally, we provide new distributional records of Smicridea (Rhyacophylax) froehlichi, Smicridea (Rhyacophylax) abrupta, Smicridea (Rhyacophylax) roraimense and Smicridea (Smicridea) franciscana.
The genus Machairocentron is revised and its included species, M. ascanius Schmid 1982, M. echinatum (Flint 1981), M. falciforme Pes & Hamada 2013, M. lucumon Schmid 1982, M. tarpeia Schmid 1982, and M. teucrus Schmid 1982, are redescribed and illustrated based on type specimens. Two new species from Costa Rica, M. chorotegae
sp. nov. and M. eugeniarguedasae
sp. nov., and one from Venezuela, M. kalinae
sp. nov., are described. An identification key for the Machairocentron genus is also provided.
Xiphocentron is the most species-rich genus of the pantropical family Xiphocentronidae. Among its five subgenera, Antillotrichia is the most diverse and the only one to occur in South America and Antilles. In the present study, two new species of Xiphocentron (Antillotrichia) are described from southern Atlantic Forest, Brazil. Xiphocentron gwarakeraba sp. nov. is diagnosed by the very elongate inferior appendage not bearing spines and with a simple mesal sclerite; X. muelleri sp. nov. is diagnosed by the inferior appendage with its ventral margin produced posterad and distinctly truncate. New distributional records are provided for X. acqualume, X. jaguare, X. kamakan, and X. maracanan. Additional non-genital diagnostic characters are presented for X. jaguare, and intraspecific morphological variations of forewing fork II (R3 and R4) and male genitalia are described for X. maracanan.
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