On the dispersal of males of Cicada orni in Portugal (Hemiptera: Cicadidae)

Males of Cicada orni Linnaeus 1758 communicate through airborne vibrations producing calling songs, sometimes aggregating at high densities and exhibiting chorus activity. Previous work suggested that males were induced to sing when nearby conspecific males were calling, this resulting in male concentrations and also in poor dispersal ability. The present paper is an introductory investigation of the range of dispersal of the adults in this species, following a mark-recapture method, as well as of the length of adult life. Results show that at the site of the experiment - Sousel (Southern Portugal) - the peak of adult emergence occurred before the 23(rd) of June in 2006. Males of this species can survive for about two weeks, but most of them probably live less than a week. Moreover, almost 90% of the males fly less than 100 m and none was found to disperse beyond 150 m. Present results provide evidence that young males are maximizing their chances of mating by a strong singing activity without pre-mating dispersal. Therefore, it is likely that these cicadas do not disperse far to mate and that both sexes probably mate relatively close to the place where they have emerged.