Two new species of Macrelmis Motschulsky (Coleoptera: Elmidae) and a new record of Macrelmis isis (Hinton) from Southeastern Brazil

Abstract

Macrelmis is a genus distributed in the Palearctic, Nearctic and Neotropical regions. Currently there are 40 species, 20being recorded from Brazil but only two from Rio de Janeiro State. Herein two new species of Macrelmis are describedand figured: Macrelmis fluminensis sp. nov. and Macrelmis friburguensis sp. nov. A new record of Macrelmis isis from Rio de Janeiro State is given.

Three new species of Macrelmis Motschulsky (Coleoptera: Elmidae: Elminae) from Southeastern Brazil with new definition of species groups to the genus

“…Macrelmis terea, M. thropei and M. tityra were considered as part of the aristae group by Hinton (1946) based on presence of pronotal sublateral carinae, but this character is also present in other species outside the group that do not have same male genitalia characters. aristaea species group Sampaio et al (2012) Diagnostic character: parameres subequal or smaller than aedeagus; with or without setae concentrated near the apex, positioned internally or externallly; aedeagus always tapering from the base to the apex (Figs. 3D-F); pronotum with poorly developed sublateral carinae; pronotum and elytra surface clothed with erect microscopic setae; entire metasternal disk surface tomentose; and hind tibiae with two apical tomentose fringes.…”

“…History of the group: This group was first cited in Sampaio et al (2012), but not formally described. The species Macrelmis amana and M. aristaea were already cited as closely related by Hinton (1946).…”

“…In the same paper, Hinton stated that M. plaumanni is similar to M. zama, and that M. saleia is close to M. aristea using mouth part characters to relate them, supporting the association of these species with similar genitalia based on other characters. M. fluminensis was considered as similar to M. tijucana by Sampaio et al (2012). M. friburguensis was considered similar to M. tijucana and to the aristaea group since its description, based on the absence of impressions on pronotum (Sampaio et al 2012).…”

“…M. fluminensis was considered as similar to M. tijucana by Sampaio et al (2012). M. friburguensis was considered similar to M. tijucana and to the aristaea group since its description, based on the absence of impressions on pronotum (Sampaio et al 2012). M. salti was never associated with any species since its description (Hinton 1936) and is included for the first time here.…”

“…Spangler (1997) added a new one, the milleri-group, based on two species from Venezuela. Besides these, two other species groups were recognized, aristaea-group (Sampaio et al 2012) and celsa-group (Sampaio et al 2012,), but just half of all these had a formal definition published (granigera, isus and milleri; Hinton 1945and Spangler 1997, i.e., had a diagnosis which stated the delimiting characters.…”