The distribution of grape phylloxera, Daktulosphaira vitifolii (Fitch), in central and north-eastern Victoria

Abstract

All known vineyards in the North Central and Geelonq Vine Disease Districts of Victoria were systematically surveyed for grape phylloxera, Daktulosphaira vztlfoliz (Fitch) (Hemiptera, Phylloxeridae). Forty-one of the 28 1 vineyards surveyed were found to be infested. The infested vineyards were located near Nagambie, Ardmona, Glenrowan, Milawa and Rutherglen. There were significant relationships ( ¿2 , Plt; 0.001) between the infestation of vineyards and the age of the grapevines, the source of planting material, and the use of rootstocks. There was no apparent relationship between phylloxera infestation and soil type. Comparison with a previous survey reported in 1902 indicates a reduction in the number (from 69 to 41), but an increase in the area (from 275 to 653 ha) of infested vineyards. Differences in the distribution of phylloxera were small. There was evidence of spread of phylloxera within districts already infested, but only the Glenrowan- Milawa district contained infestations not previously recorded. Some previously infested areas were found to be free of phylloxera, owing to changing land use. The survey provided a basis for redefining quarantine areas according to the current distribution of grape phylloxera.