At a recent Barone Ricasoli winemaker’s dinner, Baron Fransesco Ricasoli talked about the fruit fly Drosophila suzukii had turned up in his vineyards this year, and made themselves noticed. This insect was discovered in Japan in the early parts of the twentieth century but have travelled the world fairly recently. The fly was discovered in the USA in 2008 and have also been found in Italy, France, Belgium and Spain. Fruit flies are not uncommon, but this one attacks healthy and ripe fruit.
In the vineyards of Ricasoli it attacked Sangiovese as the grapes were almost bursting with water after a wet season, an unusually wet season that is. Cabernet Sauvignon with its thicker skin was not affected. The female has a prominent ovipositor so it can cut into healthy fruit skins seemingly with more ease than other species, so they don’t need to wait for the berries to start rotting. This makes this fly a pest and they can spread very quickly. Each female can lay 300 eggs and there can be as much as 13 generations in one year. One upside is that the males seem to become sterile in excess temperatures of 30 degrees C, but the down side is that the insects can live for 300 days without fruit to feed on. The baron said the fruits got a stinky smell like vinegar once affected and that they got a strange look.
According to UCDavies, the fly is mostly attacking ripening raspberries, blackberries and strawberry crops, but has been observed occasionally attacking plums, apricots, plumcots, nectarines and figs. Now also grapes. There seems to be quite a few new insects to worry about for the wine lover these days, they are not new but they live places they haven't been before. Travelling wine killers.
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