Phylloxera phyllkoxera vitifolia, a native of North America, is a notorious pest of grapevines, forming galls on roots and leaves, which damage the plant. European vines are markedly susceptible and many French vineyards suffered from the arrival of the pest in Europe in the late 19th Century, when nearly 2 million hectares of vineyards were destroyed. In 1993 infestation became apparent in Californian vineyards, threatening a loss of 20,000 hectares by the end of the 20th century. Phylloxera is  very resistant to treatment, as there are no natural enemies and it is difficult to treat with pesticide because of its depth in the soil. Phylloxera insects (hemipterancs) may be destroyed by spraying with carbon disulphide or petroleum

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