The existence of cryptic, sibling species, distinguished principally by vibrational courtship songs, has been confirmed for the carnea ‐group of Chrysoperla green lacewings in Europe and western Asia. One member of this species‐group, C.lucasina (Lacroix), is characterized by several morphological traits as well, but its taxonomic validity has been considered uncertain due to the subtle and variable nature of those traits. Here, we describe the calling and courtship songs of C.lucasina , which uniquely distinguish that taxon from all other members of the carnea ‐group in Europe. The male of C.lucasina produces two slightly but consistently different types of songs, one while calling and the other while dueting with a female. The female produces just one type of song, identical to the male’s calling song, which is used for both calling and dueting. Measured features of the songs of C.lucasina are nearly invariant over a broad geographical area, from the Canary Islands to Cyprus and from northern Africa to the U.K. Similarly, at least one morphological feature, the presence of a dark stripe on the pleuron of the second abdominal segment, characterizes all adult individuals identified acoustically as C.lucasina . Furthermore, larval head markings vary little among different populations of the song species. We conclude that C.lucasina is a valid biological species, which can also be recognized in museum collections by a suite of morphological attributes. We also briefly compare the songs and adult morphology of C.lucasina with five other currently unnamed song species of the carnea ‐group whose geographic ranges overlap extensively with it.