Study of spatial distribution of Empoasca vitis goethe (Homoptera, Typhlocybidae) and contribution for sampling. 1 - Distribution on vinestock

Abstract

The spatial distribution of the grape leafhopper on a vinestock was studied by enumerating larvae on an entire plant in a vineyard and completed by following the hatching of eggs on different leaflevels in the laboratory.

The main results are : (1) The age of the leaf is determinant for egg laying. (2) The eggs are aranged according to a « false contagion » standard dispersion model induced by the environment. (3) The larvae are diluted in the vegetation during the season independently of the vine variety. (4) Leafs occupied which are in the vegetation are more representative during all the season. (5) The distribution of the larvae is similar in summer between the primary and the secondary boughs. This results allow us to recommend to sampling one leaf by the vinestock at the grape level troughout the whole season.