Just like the mythical and elusive sprites of the woods, called Salvan by the inhabitants of the Maritime Alps,one of the most isolated small green beetles of the Nitidulidi family had escaped the intense research of Italian and French entomologists for more than a century.

When it was stated as extinct, last year a team of researchers from Sapienza, coordinated by Paolo Audisio of the Department of Biology and Biotechnology Charles Darwin, found few examples of the elusive insect Brassicogethes Salvan. The discovery was made during a short expedition to a place in the Maritime Alps, above the village of Palanfré. Here the researchers have finally identified  the host plant of the insect, too, the rare and subendemic Brassicacea Descurainia tanacetifolia.

The finding allowed researchers to study the insect at molecular level and to investigate important aspects of itsecology, biogeography and conservation biology.The results of the research were recently published in early views on the international Insect Conservation and Diversity journal.

Dark metallic green color and less than 3 millimeters long, the species moves very slowly in the yellow inflorescences of Descurainia and appears to be present only in a particular type of environment, such as the wet edges of small lakes at altitude of the Maritime Alps with high environmental quality, whereit was found for the first time by a German entomologist in 1912. 

Quite different, due to many characteristics, from the other European species of its genus all similarly associated for their larval development with flowers of Brassicaceae, the beetle was attributed a surprisingly new species for science, following the random discovery of two specimens a fortnight ago in an old collection of the Frankfurt Natural History Museum.

 “The use of the term Salva in its classification– explains Paolo Audisio – vanted to enlight the surprising morphological peculiarities, and the great elusiveness of this beetle”. The particularly adventurous story of the Salvan made this name even more suitable since even a dozen dedicated scientific expeditions, carried outbetween 2002 and 2016 in many sites in the Maritime Alps, had not given any results.

Besides being an element of great biogeographical importance, the species is also a marker of considerable importance in terms of the biological quality of the colonized mountain ecosystems and taxon of considerable conservation value level of the entire cross-border protected area of the Maritime Alps National Park / Park National of Mercantour. 

 "The discovery of this surprising and beautiful species - concludes Audisio - demonstrates how much remains to be discovered of the small invertebrates of our Alps. The Salvan beetle also represents further evidence of ancient wildlife links with distant areas, perhaps of Central and Eastern Asia, during the Middle-Late Tertiary period; in fact, its mysterious affinities are probably to be found with other rare mountain species present in the Balkans, the Caucasus and western China ". 

References:

Rediscovery of Brassicogethes salvan (Coleoptera: Nitidulidae, Meligethinae) in the southwestern Alps - Liu M., Sabatelli S., Mancini E., Trizzino M., Huang M., Cline A.R., Audisio P. Insect Conservation and Diversity, 2018, doi: 10.1111/icad.12317

For further information

Paolo Audisio
Department of Biology and Biotechnology Charles Darwin, Sapienza University in Rome
paolo.audisio@uniroma1.it