Rediscovery of Brassicogethes salvan (Coleoptera: Nitidulidae, Meligethinae) in the southwestern Alps

Brassicogethes salvan (Audisio et al. Insect Systematics and Evolution, 34, 121) is certainly among the most important and unexpected recent discoveries in the European beetle fauna. The species was initially described from a couple of unidentified specimens collected in 1912 on the Maritime Alps (NW Italy). Despite a long series of attempts to recollect the species at the type locality (Rovina Lake, Mount Argentera Massif, Cuneo Province, Piedmont, NW Italy) and several neighbouring areas of the SW Alps between 2002 and 2016, no specimens of this species were found. We re-discovered B. salvan in a small high valley of the Regional Natural Park of the Maritime Alps, a few dozen kilometers from the type locality. The previously unknown larval host-plant as Descurainia tanacetifolia (L.) Rchb., Brassicaceae was determined. Some unusual life history traits were also observed. In an effort to yield a suitable taxonomic placement for this species, we present a partial preliminary molecular phylogeny for this species and related taxa. A discussion regarding some issues about its actual and potential geographic distribution in southern France and northwestern Italy is also provided. We propose an EN (Endangered) classification for this species following the IUCN criteria, and discuss aspects of its rather problematic conservation biology.