The Cicadetta montana (Scopoli, 1772) species complex contains six cicada species from France including Corsica. Some prospecting carried out at the end of June 2016 in the Tende area (Alpes-Maritimes department) revealed the presence of a seventh species in this complex: C. sibillae Hertach & Trilar, 2015, a cicada newly described from Italy and Switzerland (Hertach et al. 2015). Its ecology is discussed and a first distribution map is drawn up. Morphologically very close to C. cerdaniensis Puissant & Boulard, 2000, the study of the genitalia of C. sibillae shows some new morphological characters notably in the shape of the pseudoparameres. In addition, the forewings base of C. sibillae populations from France tends to be clearer than those from Italy and Switzerland. However, the study of the specific acoustic parameters defined by Hertach et al. (2015) do not reveal significant differences for males recorded in France: their calling songs are very close to those emitted by the males of the western alpine populations from Italy. Advanced analysis of the frequencies reveals an unexpected and particular functioning mechanism of the cymbals. These produce some complex sounds characterized by a different frequency band. Each band is associated with the way each cymbal produces sounds. This complex functioning of the cymbals is for the first time recognized in a natural environment. It was previously only explored in another species, Tympanistalna gastrica (Stål, 1854), in laboratory under controlled experimental conditions. A new acoustic identification key of the seven taxa of the genus Cicadetta Kolenati, 1857 present in France is proposed.
Cryptic species, Hemiptera, France, Maritime Alps, morphology, bioacoustics, distribution, new record.