The behaviour of alate aphids inside a Prunus orchard : an element to take into account in Plum Pox Virus spread ?

Abstract

National audienceAphid-borne viruses are depending on flight behaviour of their vectors for spreading. When spread takes place in orchards as it is the case for plum pox virus, the flight behaviour of aphids can be modified by the effect of the orchard on the wind. The aim of this experiment was to document both the effect of the orchard on wind speed and its consequence on aphid flight behaviour. Data on the wind speeds inside an apricot orchard demonstrated that the wind speed at the foliage level and at the bottom of the trees is decreased under the value of 1 m/s (speed limit for actively oriented aphid flight). As a consequence, aphids have the possibility to make actively oriented flights inside the orchard most of the time. This was confirmed by a capture-recapture experiment with marked aphids. It can be deduced from the results that the geometry of orchards should be taken into account for analysing spatial pattern of virus spread