Ambulatory dispersal of phytoseiidae mites along vine stocks in an agroecological vineyard: unexpected patterns revealed.

Vegetation cover in vineyard inter-rows is known to enhance the abundance and richness of Phytoseiidae predatory mites on the vine canopy. However, the extent to which these mites disperse ambulatory along vine stocks from one compartment to another remains poorly understood. This study investigates the ambulatory dispersal of Phytoseiidae mites in a Mediterranean vineyard in southern France. Specifically, we evaluated (i) whether Phytoseiidae disperse bi-directionally along the vine stock, (ii) whether the presence of inter-row vegetation enhances dispersal toward vine, and (iii) whether mowing affects dispersal by altering shelter and food availability. Samplings were conducted on inter-row vegetation and vine canopies across three systems (bare soil, sown, and spontaneous vegetation). Traps were placed along vine stocks during two sampling periods to assess the effect of mowing. An average of 4.59 Phytoseiidae were captured per trap, belonging to five species. The dominant species, Typhlodromus (Anthoseius) cryptus Athias-Henriot was only found in traps, suggesting habitat specialization. Two other species, Typhlodromus (Anthoseius) recki Wainstein and Typhlodromus exhilaratus Ragusa, were present in both vegetation compartments and in traps, indicating potential ambulatory dispersal. Contrary to expectations, the presence of inter-row vegetation had limited influence on overall Phytoseiidae abundance and richness in traps. However, increased numbers of T. (A.) recki and T. exhilaratus on traps following mowing suggest that disturbance may induce ambulatory dispersal. These findings highlight the role of vegetation structure and its management in shaping Phytoseiidae distribution. Further research is however needed to clarify the mechanisms driving these patterns and the role of inter-row management in enhancing biological control.