A new species of Thraulodes (Ephemeroptera: Leptophlebiidae, Atalophlebiinae) from a highly altered river in western Ecuador

摘要

Thraulodes quevedoensis new species (type locality: Quevedo, Ecuador) is described from adults and nymphs. This species was found in a moderately polluted river running through a highly altered agricultural and urban landscape of western Ecuador. In 2007 during a visit to the downtown area of the city of Quevedo in western Ecuador, male and female images of a species of Thraulodes Ulmer were collected in the evening at light at the city's 'Malecón' (river walk) (Fig. 1). Additional adults were collected the following year at the same location, and associated nymphs were collected in a riffle in the Rio Quevedo 0.5 km upstream from where the adults were found. Additional nymphs were collected at Holandesa, a river crossing north of Quevedo. On comparing the Quevedo species with descriptions of all other known Thraulodes in Dominguez et al. (2006), it became apparent that this species was undescribed. Thraulodes is one of the most ubiquitous Neotropical mayfly genera in low- and mid-elevation streams. However, of the 27 known South American species only eight are known from the nymphal stage (Domínguez et al. 2006, Giordano & Domíngue 2005). In this paper I describe the adults and nymphs of this new species and provide some ecological notes.