Grape phylloxera (Viteus vitifoliae (Fitch)) infestation on American vine leaves in a nursery at San Pietro a Grado (Pisa) during the years 1982–1983

The Authors illustrate grape phylloxera infestation, from May to October in the years 1982 and 1983, on Kober 5BB vine rootstock leaves in a nursery at San Piero a Grado (Pisa). They examine in detail and discuss the results obtained, taking into account the increase in the average number of galls per leaf, the percentage composition of the population present during the various periods, the egg-laying females, the eggs and newly-hatched larvae inside the mother galls.