Vibrational mating disruption against insect pests: five years of experimentation in the vineyard

The use of vibrational signals in agriculture is becoming an important research topic as a new method of behavioural manipulation of insect pests. Semiophysicals include mechanical signals that have the potential to become environmentally friendly alternatives to pesticides. Like pheromones, vibrations endowed with specific spectral and temporal characteristics, can interfere with the mating behaviour of pests, thus preventing population outbreaks and crop damage. This approach is called "vibrational mating disruption" (VMD) and can be applied to control leafhoppers, insects that rely almost exclusively on vibrational signals for mating. Laboratory and semi-field tests have demonstrated that a species-specific mechanical stimulus transmitted to a plant (i.e., grapevine) by means of mini-shakers, can cause the total interruption of mating. In the present contribution, we report the results of a long-term research conducted on two target species, the leafhoppers Scaphoideus titanus and Hebata vitis. Since 2017 a field-scale experiment has been launched by setting up the first world 'vibrational vineyard' in the Trentino region (Italy) to evaluate the VMD efficacy. Every summer, the population density of the two insects has been measured by visual counting of the nymphs on leaves and yellow sticky traps for the adults. The efficiency of the actuator prototypes was monitored using highly sensitive equipment (laser Doppler vibrometer and accelerometers) and the transmission of vibrations in the trellis system was evaluated with a numerical model of the vineyard. Overall, the vibrational mating disruption technique proved to be effective in reducing the population density of both S. titanus and H. vitis as long as the disruptive signal was transmitted on the leaves above an active threshold of ca. 15 µm/s of amplitude. The use of vibrations to control pests in vineyards seems to be a promising innovation. Next step will be the application of the method on large vine surfaces