The genusRivudivaLugo-Ortiz and McCafferty (Ephemeroptera: Baetidae): First generic description of adults, new combinations, and notes on the nymphs

Abstract

-In the present paper, based on the rearing of nymphs in the field, we present for the first time the description of the adult stage of Rivudiva Lugo-Ortiz and McCafferty and of its type species, R. minnatena Lugo-Ortiz and McCafferty. Adults of Rivudiva can be distinguished from the other genera of Baetidae by the following combination of characters: (1) hindwings present or absent, when present with two longitudinal veins and with costal projection pointed, placed in the basal fourth of anterior margin; (2) forceps threesegmented, segment III long, about 2r as long as wide; (3) distal margin of subgenital plate with small pointed projection. Besides that, R. coveloae (Traver, 1971 [Proc. Entomol. Soc. Washington, 73, 58-63]), new combination, and R. venezuelensis (Traver, 1943 [Bol. Entomol. Venezolana, 2, 79-98]), new combination, are proposed based on the characteristics listed above, specially the distal margin of subgenital plate with a small pointed projection. Comments on the biology of the nymphs are also provided.

A cladistic approach for generic delimitation of Paracloeodes Day, Rivudiva Lugo-Ortiz & McCafferty, and Varipes Lugo-Ortiz & McCafferty (Ephemeroptera: Baetidae)

“…In contrast to the group mentioned above, the genus Rivudiva is widespread in South America, with the exception of high altitudes. In Brazil, the species in this genus (some yet to be described) were collected in almost all biomes (see Boldrini & Cruz 2014, Boldrini et al 2012, Cruz et al 2011, Salles & Nascimento 2009. It is likely that future biogeographic investigation will recover these apparent evolutionary patterns, which may corroborate the paraphyletic relationship between each lineage studied here.…”

“…Even though the adult males of the genera mentioned above are poorly known, discussions about generic delimitation include characters for this life stage. Salles & Nascimento (2009) reported that the adult male of Rivudiva minantenna Lugo-Ortiz & McCafferty has a small pointed projection on the posterior margin of the subgenital plate and, mainly because of this character, transferred two species only known by adults to Rivudiva: R. coveloae (Traver) and R. venezuelensis (Traver). Recently, Lima et al (2013) described the same singular projection on the subgenital plate of the adult male of P. charrua Emmerich & Nieto.…”

It is a mess! How many species are in Rivudiva trichobasis Lugo-Ortiz & McCafferty, 1998 (Ephemeroptera: Baetidae)?

“…Domínguez et al (2006) examined the type material, adding some important characteristics to the original description of both described species. The genus was treated as rare until Salles & Nascimento (2009), during a mayfly survey in the Southeastern Region of Brazil, found a good series of nymphs of R. minantenna and reared a few of them in the field. This study brought to light that species of the genus are psammophilous, allowing subsequent fieldwork sampling to be directed so that a series of discoveries could be made.…”

Review of the genusCamelobaetidiusDemoulin (Ephemeroptera: Baetidae) with reduced terminal filament

“…The genus Camelobaetidius Demoulin, 1966 (Ephemeroptera: Baetidae) is represented by 38 species (Lugo-Ortiz and McCafferty 1999;Jacobus and McCafferty 2005;Salles and Serrão 2005;Domínguez et al 2006;Boldrini and Salles 2009;Salles and Nascimento 2009), distributed from Argentina (Traver and Edmunds 1968) to Canada (Lehmkuhl 1976).…”