Massartella hirsuta sp. nov. (Ephemeroptera: Leptophlebiidae: Atalophlebiinae) and new data on mayflies of Guyana Highlands

Abstract

Description and figures of the larva and egg of Massartella hirsuta sp. nov. (Ephemeroptera: Leptophlebiidae) from the south-eastern part of Grand Sabana region (Venezuela) are presented. Diagnostic characters distinguishing the larvae of this species from other known Massartella species include a heavy row of setae along the entire outer margin of the mandibles. This character, among others, will also distinguish the new species from undescribed species of Massartella from the sandstone table mountains. Two well-defined species groups of the genus Massartella can be distinguished in the Guyana Highlands: (1) M. venezuelensis group including M. venezuelensis and M. hirsuta sp. nov., and (2) M. devani group containing M. devani and undescribed taxa from Mt. Roraima and Mt. Chimantá plateaus. The first group seems to be distributed in uplands (∼1000 m a.s.l.), while the second group appeared to be restricted to the thermal refugia above 2000 m a.s.l. The origin of Massartella species in Guyana Highlands is discussed.

Keywords:

• mayfly larva
• egg
• table mountains
• vertical displacement
• Neotropical zoogeography
• South America

Acknowledgements

We are grateful to the referee, Janice Peters, whose comments and suggestions greatly improved the manuscript. The present study was supported by projects APVV-0251-07, VEGA 1/3273/06 and Foundation Ecology (Faculty of Ecology and Environmental Sciences, Technical University in Zvolen).