Zoological Studies

Vol. 44 No. 1, 2005

Calling Song Structure and Geographic Variation in Cicada orni Linnaeus (Hemiptera: Cicadidae)

Gabriela Pinto-Juma1, Paula C. Simões1,2, Sofia G. Seabra1, and José A. Quartau1,2,*

1Centro de Biologia Ambiental C2-3°Piso, Faculdade de Ciências de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
2Departamento de Biologia Animal, C2-3°Piso, Faculdade de Ciências de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal

Gabriela Pinto-Juma, Paula C. Simões, Sofia G. Seabra, and José A. Quartau (2005) An analysis of the structure of the calling song of Cicada orni Linnaeus, 1758 over a selected part of its distribution range in the Mediterranean area was carried out in order to better understand the pattern of its geographic variation and population history. Calling songs of males from several localities in western and southeastern Europe were recorded from 1995 to 2003, and were analysed in time and frequency domains. The calling songs analyzed constituted a relatively homogeneous group. However, there was some tendency of songs from southeastern Europe (Greece) to group apart from those of western Europe (Iberian Peninsula and France). The inter-echeme interval duration was the variable that contributed most to this separation, but males from Greece showed significant differences in almost every acoustic variable in relation to the remaining studied regions. This acoustic differentiation is in agreement with introductory genetic results still under investigation. Echeme duration proved to be quite constant across the geographic range of this cicada and, as such, is probably one of the most important parameters encoding species-specific information for species recognition. Conversely, the inter-echeme interval was quite variable, and so it is expected that this variable is not an important parameter for species recognition and isolation in C. orni. The observed distinctiveness of the populations of the Aegean area may be the result of repeated cycles of isolation in southern refugia through the mountain ranges of the Balkans during the ice ages. Furthermore, it is hypothesized that the Aegean area and West Asia Minor might constitute the main area of origin of C. orni.

Key words: Cicada orni, Calling song, Acoustic signals, Acoustic divergence, Geographic variation.

*Correspondence: Tel: 351-21-7500000. Fax: 351-21-7500028. E-mail: jaquartau@fc.ul.pt