Potential Economic Impact of Grapevine Phylloxera (Hemiptera: Phylloxeridae) on Western Australian Winegrapes

Abstract

Grapevine phylloxera Daktulosphaira vitifoliae Fitch (Hemiptera: Phylloxeridae) has been present in Australia for almost 150 years but has not spread to south-west Western Australia, in part due to the relative isolation of the region. Recent improvements in tourist access, with interstate flights now arriving at Busselton Margaret River Airport, raise concerns about potential phylloxera introductions via wine tourism. In this paper, we simulate the potential economic impact on the Western Australian winegrape industry following a hypothetical arrival event in the Margaret River wine region. We use soil texture maps to assess the suitability of winegrape-growing areas to phylloxera establishment and construct a model to predict the likely cost and revenue implications of replanting vines to resistant rootstock as they become infested. Our results suggest that if strict quarantine measures to limit spread are not implemented, a phylloxera incursion could affect 60%–70% of vines and cause cumulative losses of AUD150–290 million over a 50-year period. This is equivalent to a 3%–6% annual contraction of winegrape production.