First of all, it is a bit sad that there is no direct translation for the beautiful German word of ‘Nuetzling’. It is the word for the opposite and/or antidote to pest. Of course the definition is always from a human perspective; as such, every animal or plant has its place and is more or less useful to something.
So much about the philosophical prelude to pests and useful creatures. That the border between the two is blurry at times is known. There are innumerous examples of useful creatures being transferred to new environments and becoming a nuisance. Take for example the case of cane toads in Australia, which were introduced as a biological pest control for sugar cane beetles. Sadly, they ate everything else and became a major pest.
The same thing seems to have happened in the case of the Asian Ladybug species Harmonia axyridis. Introduced as a biological pest control for aphids, things looked good at the beginning. These ladybirds ate far more aphids than the local species and people were happy that the usage of insecticides could be reduced.
Not much later, entomologists and biologists started to point out that the new species was displacing the local species of ladybirds. They are bigger, eat more and produce more offspring and have no natural enemies in Europe, as they do have a nasty taste and smell as defense mechanism. If things go bad, we might not see our local and much beloved red and black ladybirds in the future.
I think the last step in the transformation from helpful pest controller to pest has happened a few months back, when it was discovered that these ‘bitter tasting’ beetles have the potential to spoil wine in France. It seems that the beetles like to hide among the grapes and their bitter taste can affect the taste of the wine. 1.7 beetles in a kilogram of Riesling grapes are already said to be noticeable.
In addition to this, when winter approaches, these beetles emit a pheromone that leads to swarms of them trying to find cracks and crevices as a safe hibernation place and might come into your house. It can easily be a few thousands of them at the same time. As a preventive measure, also against other pests, it is suggested to seal all possible entry points.
Oh, and next time you have a glass of wine, make sure to enjoy, you don’t know how soon it will be a refreshing glass of a bitter digestive.
Visit Ben’s blog at www.beetlebreeding.ch