Biological control of the grape berry moths Eupoecilia ambiguella Hb and Lobesia botrana Schiff with Trichogramma cacoeciae Marchal

From 1994 to 1996 field experiments with releases of Trichogramma cacoeciae (strain D 90 O) against the grape berry moths (Eupoecilia ambiguella HE, and Lobesia botrana SCHIFF.) have been conducted in the Rheingau, Germany. In two vineyards the distance of the Trichogramma egg cards and the interval were varied. A distance of 6,0 m and two mass releases two times against each berry moth generation reached the best reduction. The reduction rate was higher in the vineyard with ecological pest management. In some cases within the integrated cultivation it is still not sufficient to control the berry moths. The effects of climate, host density and pesticides are factors that influence the results. Further experiments should refer to these factors and the search for new strains and their selection in the laboratory. The release of Trichogramma could be combined with other biological and biotechnological methods such as the pheromone confusion. In cage experiments three T. cacoeciae strains 'D 90 O', 'Wiese' and 'Weinberg' have been compared. Strain 'D 90 O' has a tendency to a better parasitation.