Intensity of vibrational signals determines mating behaviourin Scaphoideus titanus Ball (Hemiptera: Cicadellidae)

Abstract: Insects use different signal modalities to communicate with their conspecifics.Substrate-borne vibrations are widely used among those communicating with mechanical signals.We studied the role of signal intensity for the mating behaviour in Scaphoideus titanus, avibrational communicating leafhopper that is a vector of the lethal phytoplasma grapevine diseaseFlavescence dorée. As males called for the females and the substrate velocity (intensity)measured at the dominant frequency of the female replies was in the range 0.0005-0.001mm/s,males either walked around randomly and emitted long, irregular identification signals, orperformed call-fly behaviour, by jumping off the plant after a female reply. When malesperceived female signals over 0.001mm/s they started searching while performing a locationduet. Only when male and female were on the same leaf, courtship duets were recorded withintensities over 0.01mm/s. These results show that S. titanus males may adjust their behaviouralstrategies to localize conspecific partners according to signal intensity.