A vine louse which devastated the vineyards of Europe in the late 18th Century. The cause of the disease was initially uncertain, but eventually the Phylloxera vastatrix louse was identified on the roots of the affected vines. It was imported from North America, where the indigenous American Vitis labrusca vines are resistant to the effects of the louse. The solution: graft the European Vitis vinifera vines onto American rootstock.