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Phylloxera is reappearing in more and more European wine-growing regions, warn scientists in the journal SevenFifty. Particularly the leaf-eating populations are spreading worldwide. According to Austrian researcher Astrid Forneck, they have already been observed in several vineyards in Germany, Austria, and Northern Italy. However, China, Japan, the eastern USA, and parts of South America are also affected. Initially, it was assumed that the grapevines of the Vitis vinifera family were resistant to the leaf-eaters. Forneck explains: "When the leaf-eating insects cannot find leaves, they go directly to the roots, where they hibernate and reappear in the following season. Just by recognizing them in the vineyard, much could be achieved. But many winemakers cannot even identify them. Therefore, this pest is very difficult to control."
However, the root-infesting species is also spreading again. Since 2019, it has been causing problems in the US state of Washington. There, the vines were not grafted, as it was assumed that the sandy soils provide a sufficient barrier. In Australia, the protective zones had to be expanded despite strict quarantine regulations. Phylloxera was first discovered in Tenerife in 2025.
The reason for the spread could be, among other things, climate change, as higher temperatures promote the movement behavior of the insects. Plant material from nurseries and the increasing international movement of people, plants, and machines also contribute to this. However, according to research findings, the reduced use of pesticides could unintentionally lead to higher survival rates of the grapevine pests. At the same time, according to Australian researchers, new phylloxera strains are constantly developing, against which even proven American rootstocks may lose their protection.
(al; Image: Wikimedia Commons)
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