Swiss producers face ladybird contamination
- Tuesday 21 August 2007
According to officials in the Vaud region of western Switzerland, two major Asian ladybird infestations were discovered earlier this month prompting fears for the region’s wine harvest.
If an Asian ladybird, lady bug or lady beetle, is present when the grapes are crushed, it can contaminate large quantities of wine. When crushed or scared, the insect secretes a yellow alkaloid that, although harmless to humans, produces a distinctive peanut, or ‘off’, smell in wines. According to some sources, tasters can detect Asian ladybird-infected wine containing two parts per trillion.
In 2001 several Canadian wineries had to destroy around one million litres of Asian ladybird-infected wine.
Two ladybird colonies were discovered near Nyon and Rolle, 25km north of Geneva, in sunflower and maize fields respectively. Although there is no sign of vineyard infestation, where the ladybirds take refuge in grape clusters, the Swiss federal authorities said contamination along the winemaking region of La Cote on the north shore of Lake Geneva ‘could not be excluded’.