Gebrauch biologischer Insektizide im Kampf gegen den Scaphoideus titanus, den Vektor von Flavescence dorée

Summary

Flavescence dorée and the mandatory control of its vector Scaphoideus titanus pose
important problems in organic vineyards. The goal of our field studies conducted in the
Ticino was to develop a pest control strategy conform to the guidelines of organic
production. Insecticides containing pyrethrin were the only organic products showing
an efficacy higher than 90% against the immature stages of S. titanus. However, these
products had no effect on adult leafhoppers. Repeated applications of pyrethrin
proved to be toxic against the predatory mite species Amblyseius andersoni. Despite
this toxicity, the only efficient and recommended control strategy in organic vineyards
is their application. Pyrethrin should be applied three times at an interval of ten days
after the first appearance of individuals of the 3rd nymphal stage. Symptomatic plants
must be eradicated from the vineyard to remove the phytoplasma inoculum.