But one thing can break even the most hardened of spirits of some growers, and that is the unforgiving attack of alien vine pestilences.Only a few, sometimes, can bear the sight of all their hard work, through the decades, disappear in one fell swoop...

Two such terrible visitations within less than a quarter of the century would almost certainly have put an end to the making of Madeira wines: the Mildew Epidemic (pre-oïdium) that occurred in 1852 and destroyed a massive 90 percent of all grapes in Madeira, and the vine pest (phylloxera vastatrix or pre-phylloxera) brought over from America in 1873. But had it not been for the courage, foresight and devotedness of some of the English merchants in Madeira, and more particularly Thomas Leacock and Charles Blandy, the wine industry may have fallen into deep and perhaps irrevocable apathy. Thomas Leacock was especially remembered for his continuous endeavour and success in introducing the more disease resilient and more prolific american vines.