Comparative morphology of larvae of Elathous agilis Németh, 2019 and Elathous brucki (Candèze, 1878) (Coleoptera: Elateridae: Dendrometrinae), with notes on their biology and ecology

The click-beetle genus Elathous Reitter, 1890 (Elateridae: Dendrometrinae) contains almost 50 species distributed in the Palaearctic and Nearctic realms. Specimens of this genus are rare in collections, partly due to their largely unknown biology and ecology. Until now, larvae were known only for three species, all of them described decades ago. Due to the intensive fieldwork research by the first author, who found larvae of Elathous agilis Németh, 2019 in Lebanon and Elathous brucki (Candèze, 1878) in Greece, we have an opportunity to describe their morphology for the first time. We compare them with each other and the remaining known larvae of Elathous and related genera. Although we are able to differentiate larvae of all known Elathous species, our limited knowledge on dendrometrine immature stages as well as the genus-level systematics is insufficient to propose a reliable generic diagnosis for Elathous based on the larval morphology. Additionally, we provide updated information on biology and ecology of Elathous species.