Does agroforestry affect phytoseiid mite communities in vineyards int the South of France?

The abundance and diversity of phytoseiid mites were surveyed from April to September 2003-2005 in several grape crops in the South of France, with Grenache and Syrah cultivars, co-planted with rows of Sorbus domestica or Pinus pinea and in plots with monocultures of grapes. Densities of phytoseiid mites differed on the two tree species. Pinus pinea seemed to be a better host than S. domestica. Typhlodromus exhilaratus was the dominant species in the crops and on co-planted rows of S. domestica and P. pinea, whereas T. phialatus was the most abundant species in plots with monocultures of trees. Agroforestry management does not seem to affect mite diversity in vine plots. The densities of phytoseiid mites in vine crops may well be affected by the co-plantation of trees, especially in 2005. Although the densities observed during 2003 and 2004 were probably low due to very dry and hot climatic conditions, the agroforestry management seems to have had a significant impact on mite densities in 2005. Further experiments should be carried out to confirm this effect