Evaluation of Two Phylloxera Genotypes in Argentina on Six Vitis vinifera Cultivars and Three Rootstocks

Preference host is an important factor affecting population dynamics in plant-insect interactions. In this research, the two main phylloxera genotypes found in Argentina (gB and gD) were tested on Vitis vinifera cvs. Cabernet Sauvignon, Malbec, Pedro Giménez, Chardonnay, Cereza, Criolla Grande, and rootstocks 1103 Paulsen, 101-14 Mgt, and SO4 using an excised root assay. Statistical analysis showed that survivorship was affected by the interaction of Cultivar and Time, while hatching was influenced by the interaction of Cultivar and Phylloxera genotype. Cultivar also influenced maximum number of adults, developmental time, as well as gross and net reproductive rates. Phylloxera genotype gB developed faster than gD, however, no other significant differences were found between both genotypes. Principal component analysis showed that Pedro Giménez and Criolla Grande grouped closely with high values of reproduction-related variables, suggesting they are the most preferable hosts, followed by Cabernet Sauvignon; while Cereza, Malbec, and Chardonnay were less suitable. None of the rootstocks allowed the establishment of phylloxera colonies. This study will help improve the biological understanding of phylloxera in Argentina and help develop tools for its management.