Biological control of Frankliniella occidentalis on table grapevine using predation and plant association

Summary

Since 1989-90, Frankliniella occidentalis (Pergande) has been classified as the most harmful insect for table grapes after Lobesia botrana ( Den et Schiff.)Cultivar “Italia”, the most economically-relevant table grapes variety in Apulia, is susceptible to Frankliniella occidentalis which induces typical halo spots symptoms. Many conventional and IPM control methods have been developed to limit the attacks of this pest. In contrast little has been made for the biological control in the vineyard. This present work aims on one hand to verify the damage of Frankliniella in the presence of attractive blue flowers of Phacelia tanacetifolia, and on the other to evaluate the predation efficiency of the predator Orius. In that context, Phacelia tanacetifolia, intercropped between rows in the vineyard, blooms at the same time as the vine and can limit a possible increase of F. occidentalis population up to 50-70% as the experiment has shown by trapping or attracting the plant pest. If the population is not numerous during the season, Phacelia could be alone a reliable practical way to control this pest and can decrease the population below the threshold level. Orius has succeeded in decreasing F. occidentalis population by limiting the damage up to 7 berries per cluster while Orius reared in the Biofactory laboratories has shown a lower predation efficiency leading to a higher damage up to 14 berries per cluster.In a general way, Orius endogenous population could decrease F. occidentalis damage to a certain level, but it is not so efficient as Phacelia tanacetifolia in our conditions.