Ubiquitous but Ignored? A Case of Water Beetle in Southeastern Europe

Abstract

Although freshwater habitats, especially springs, are widely recognized as top-priority habitats for monitoring and conservation procedures, their fauna, especially water beetles, are still poorly studied in the southeastern part of Europe. Thus, the dominant water beetle in these habitats, E. bosnica (Zaitzev, 1908) (Insecta: Coleoptera: Elmidae), has been completely ignored and misidentified. This study represents the first review of its taxonomy and its population and ecological traits. Both published and unpublished data are presented and discussed, as well as the results of field sampling in 46 springs and other waterbodies conducted in this region from 2004 to 2019. The identification characters of the male genitalia and the first DNA barcode of the species are presented. The results confirm the close phylogenetic relationship of E. bosnica with E. aenea (Müller, 1806) and E. rioloides (Kuwert, 1890). The species proved to be a useful environmental descriptor and can easily be used as a biological indicator due to its easy identification. The species shows remarkable sensitivity to environmental conditions and inhabits sites that are potentially under increased anthropogenic pressure and could disappear at an alarming rate. Thus, karstic habitats should be included in future conservation and monitoring procedures in this part of Europe.

The Emergence of the Family Scirtidae (Insecta: Coleoptera) in Lotic Karst Habitats: A Case Study over 15 Years

“…The sex ratio of water beetles is generally poorly known and studied [69]. The low number of Elodes representatives could have been caused by an inadequate sampling method.…”

Elmis syriaca (Kuwert, 1890) and E. zoufali (Reitter, 1910) (Coleoptera: Elmidae) confirmed as distinct species based on molecular data, morphology and geographical distribution

“…In the family Elmidae, recent molecular investigations enabled the clarification of various taxonomic and phylogenetic questions in certain genera [5][6][7][8][9]. DNA barcoding was used in population studies [10][11][12] and contributed to revisions of species distribution and in descriptions of newly discovered or previously overlooked taxa [7,8,[13][14][15][16][17][18][19][20]. Besides the cytochrome C oxidase subunit I (COI) gene (the standard mitochondrial barcoding marker), various nuclear markers have been proposed as alternative or supplementary barcodes for species delineation in Coleoptera (e.g., [21][22][23][24]); however, the sole use of molecular data may be misleading, and a combined evidence approach is warranted whenever possible in order to gain insight into taxonomic and systematic relationships (e.g., [3,6,8]).…”