Britain was invaded recently by voracious harlequin ladybirds – seems like they’re causing problems too for vintners in the US:
“When crushed or even just stressed, the insects release blood from their leg sockets. Several volatile compounds in that blood are highly aromatic, with distinctly vegetal scents, notes Iowa State University analytical chemist Lingshuang Cai. The barest whiff can bring to mind a mix of green bell peppers, roasted peanuts, raw potatoes, and musty earth. It may not sound too bad, she says, but “it’s actually quite noxious” and can definitely spoil a batch of wine. Indeed, her team notes, “entire harvests and some vineyards have failed because of multicolored Asian ladybug contamination.”
A well-meaning introduction for biological control turns out (yet again…) to be not such a good thing after all.
For info about the harlequin ladybird in the UK see ‘Harlequin Ladybird Survey’. I haven’t seen any in my patch of Lincolnshire, but it’s only a matter of time…