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

Abstract

Molecular data for 19 specimens of Elmis syriaca syriaca and E. s. zoufali from eight countries have been analysed in order to investigate the taxonomic status and the geographical distribution of these two subspecies. The nominative subspecies was previously thought to be endemic to the Levant (Israel, Lebanon, Syria), while E. s. zoufali was regarded as being widespread from the Balkans to eastern Anatolia and Afghanistan. The results of our molecular studies using DNA barcoding and nuclear DNA data reveal that the two taxa are in fact distinct species, which separated around 2 Mya. A distinction based on the external morphological characters of 354 specimens was found to be impossible due to the pronounced variability, especially of the pronotal microsculpture, which had hitherto been used as the main distinguishing feature. The two species can only be distinguished by the aedeagal parameres and by the geographical distribution, which deviates considerably from the concept of previous authors. Elmis zoufali is distributed in Romania, the Balkan Peninsula, some Aegean Islands and in western Anatolia, while E. syriaca occurs from the Caucasus region southwards to eastern Turkey, Iran (probably also Afghanistan) and the Levant. Geographically, both species are widely separated by the so-called Anatolian Diagonal. Elmis zoufali resp. E. syriaca are recorded for the first time from Croatia, Romania, Azerbaijan, Georgia, Iran and Turkey. In addition, we examined 13 specimens tentatively identified as Elmis quadricollis (Reitter, 1887), a closely related species from Central Asia; we sequenced one specimen from China, which was revealed to be a sister to E. zoufali and E. syriaca.