Asian ladybug causes strong damage to wine
Date : 3 June 2009
The Asian ladybug is an invasive insect that is known to cause wine to develop an unpleasant taste. It may be found in two areas of Western Europe: Switzerland and the French Champagne region. Researchers from the Agroscope of Changins-Wändeswil, in Switzerland have been studying its impact through tests that allow them to measure its impact according to the size of its population.
In this aim, they performed two tests, one using black pinot and another using chasselas. Both tests were performed with the aforementioned insect. The tests correctly simulated the problem of grape-harvesting operations in which these small and inoffensive insects which are difficult to detect end up entering the harvest bins. Similarly to oak particles which (positively) influence a wine’s quality, Asian ladybugs however cause the wine to develop an unpleasant taste, similar to that of rancid oil.
This puts in jeopardy the numerous years of efforts made to improve the quality of wine production.
According to these tests, five ladybugs per one kilogram of grape berries are enough to damage the whole wine production. The unpleasant taste develops as quickly as having 0.3 ladybugs per load of chasselas grapes and 0.2 per load of black pinot grapes.
The insect, which has fortunately been observed only sporadically in France, constitutes an important threat for the French vineyards and is therefore closely monitored.
La Vigne, April 2009
