Segesta riograndensis, Ephemeroptera, Leptophlebiidae, Atalophlebiinae: first record from state of Mato Grosso do Sul, western Brazil

The mayfly Segesta riograndensis (Ephemeroptera: Leptophlebiidae) was recently described by Siegloch et al. (2006) based on larvae from southern Brazil, municipality of Independencia, northwest from state of Rio Grande do Sul. The larvae can be distinguished from other genera of Atalophlebiinae by the following combination of characters: clypeus slightly divergent with sinuous margin; labrum with shallow emargination and three nonprominent denticles; maxillary palpi very large and curved with setae in varied combinations; labial palpi very long and curved, with long setae (Figure 1A-B); paraglossae wider than long; abdominal posterolateral spines gradually longer posteriorly. Here we are extending the range distribution of S. riograndensis in 850 kilometers to the northwest Rio Grande do Sul to state of Mato Grosso do Sul (Figure 2).