Control of the olive fly (Bactrocera oleae) through the use of copper products in Central Italy

The olive fly fitness is greatly advantaged by the presence of associated bacteria living both on the phylloplane and in specialized parts of the gut . These microrganisms play an important role both as proteinaceous source for the adult and as elicitors of the protein hydrolisis in the blind sac of the young larva midgut. In the past several authors studied this association and some of them demonstrated the importance of this kind of association in order to develop alternative control strategies. Recently, the great developement of the organic olivicolture in Italy, has generated a new interest towards the possible application of copper products against the pest. It is well known that copper could play an important role as oviposition deterrent but, more recently our attention was focused on the possible effectiveness of the copper acting as bactericide. This work refer about some results obtained during two years of applications of copper products in some olive groves areas of the Tuscany. In 2000 Bordeaux mixture was sprayed at two different dosages (1 kg/100 l water or 500 g/100 l water). In 2001 copper hydroxide, oxychloride and Bordeaux mixture have been compared. In the first year results showed a good effectiveness of the Bordeaux mixture; infact the level of infestation in the control plot was, at the harvest time, about 20% whereas in the treated plots was respectively of 9 and 6%. In 2001 no one evident differences among copper products were enhanced, anyway all of them reduced the final level of olive infestation compared to the control plot. Two years data were discussed in order to evaluate the effectiveness of different copper active ingredients tested for future applications of copper products or any other a.i. acting as bactericide, in IPM strategies in olive orchards.