Vibrational signals associated to the mating behaviour of Hyalesthes obsoletus Signoret (Hemiptera Fulgoromorpha)

Hyalesthes obsoletus Signoret is a vector of the stolbur phytoplasma (group 16SrXII-A), causal agent of the grapevine disease ‘Bois Noir’. In planthoppers the intraspecific communication is based on substrate-borne vibrational signals. The aim of this study was to investigate the mating behaviour of H. obsoletus. Vibrational signals were detected from nettle cuttings by laser vibrometer. Both male and female can start the mating process by the emission of calling signals. The male calling signal is a single short syllable (Male Syllable 1) whereas the female’s is a train of pulses of variable length. Initially, the male/female duet is based on the alternating emission of calling signals (recognition phase). In a second step, the male starts emitting long syllable trains (male courtship signal) in which the female occasionally inserts single pulses (courtship phase). The male courtship signal is made of two different types of syllables (Male Syllable 2 and 3), the switch from one to another often triggered by the emission of a female pulse. When partners are in close vicinity the male emits a specific pre-copula signal that precedes the copula (pre-copula phase). Rivalry tests, either pairs of males or trios, showed a strong competition between males, expressed in the form of chorusing, rivalry signals and aggressiveness