New combinations for the Australian species of Baetis (Ephemeroptera: Baetidae), with a new synonym

摘要

The Australian small minnow mayfly fauna remains poorly known with only 21 described species (Webb & Suter 2010). Four species were described in the genus Baetis Leach: B. baddamsae Harker, 1950; B. confluens Harker, 1950; B.frater Tillyard, 1936; andB. soror Ulmer, 1908. Baetis soror and B. frater were both placed in Offadens Lugo-Ortiz & McCafferty (Lugo-Ortiz & McCafferty 1998, Suter 2000), but the two remaining species are still included in Baetis. Revisionary work of the last few decades has clarified the concept of Baetis and related genera and showed that older concepts of the genus were highly polyphyletic (i.e. Waltz & McCafferty 1987). Examination of larvae and adults of all known baetids occurring in Australia showed that true Baetis does not occur and that the generic placement of B. baddamsae and B. confluens should be changed. Both species have hindwings and double marginal intercalaries in the forewings, indicating they belong to either Offadens or Edmundsiops Lugo-Ortiz & McCafferty, which are equivalent to Genus 1 and Genus 2 sensu Suter (1997), respectively.