Abstract
The species Americabaetis alphus is recorded for the first time from the Colombian territory based on nymphs collected in Caldas and Huila departments. The species was previously know from several countries in South America and from Nicaragua in Central America.
Introduction
Baetidae is among the most diverse families of the Ephemeroptera order in the Neotropical region (Barber-James et al. 2008), even so, the knowledge on their taxonomy and distribution in the Colombian territory is incipient with only 18 genera and 26 species recorded (Dias et al. 2009). For the genus Americabaetis Kluge the only species so far recorded is Americabaetis robacki (Lugo-Ortiz & McCafferty, 1994) from the Amazon region (Domínguez et al. 2002). The species Americabaetis alphus Lugo-Ortiz & McCafferty, 1996 was first described based on specimens from Argentina, Bolivia, Brazil, Chile and Paraguay (Lugo-Ortiz & McCafferty 1996); subsequently was reported from Nicaragua by Meyer et al. (2008). Although the presence of this species in northern South America is not unexpected, this record is important as it contributes to the understanding of the distribution and biogeography of these insects. In addition, this report aims to encourage the taxonomic accuracy in the identification of aquatic insects for ecological studies, as these organisms are proven bioindicators of water quality (Cummins et al. 2005; Buss & Salles 2007).
Taxonomic keys by Salles et al. (2010) and Domínguez et al. (2006), original descriptions of Lugo-Ortiz & McCafferty (1996) and permanent mounts of important structures following Waltz & McCafferty (1987) methodology were used for the identification of the specimens housed at the CEBUC (Colección Entomológica del programa de Biología de La Universidad de Caldas, Manizales, Colombia).
Comments
This represents the first report of the species A. alphus from Colombia, which can be differentiated from its congeners by the following combination of characters: frontal keel present; lingua apically pointed; labium with glossae 0.8 times the length of paraglossae, segment II of the labial palpi with a strong distomedial projection; and posterior margin of abdominal terga with pointed spines (Domíngues et al. 2006). As this species is sexually dichromatic, the males have a pronounced color pattern as shown in Fig. 1 while females possess a more discrete pattern ranging from brown to pale yellow.
Americabaetis alphus Lugo-Ortiz & McCafferty. Dorsal, lateral and ventral habitus of a male nymph.
The species A. alphus has a wide distribution in South and Central America and can be found in very different types of habitats and altitudes (ranging from the sea level to 1,900 m), possibly due to its tolerance to environmental impacts (Salles et al. 2003, Buss & Salles 2007; Salles et al. 2010; Falcão et al. 2011). The specimens studied were associated with leaves and stony substrates in two Andean habitats.
Material Examined
4 nymphs.
Footnotes
Acknowledgements
To Vladymeer León Cuellar for allowing the access to part of the reviewed material, and José L. Benavides and Lucimar Dias for the support in the fieldwork.