The Invasion of the Asian Ladybird
Harmonia axyridis is an Asian species of ladybird which was introduced into the USA in the 1960's in order to fight against greenfly. But wasn't until 1988 that it really acclimatized. It has been introduced into Europe more recently, at first in professional greenhouses , then for private use, in order to combat greenfly naturally. It was imported into France by the INRA (the agricultural research institute) in 1982. The idea was a good one in that it was intended to reduce the use of pesticides in the fight againt parasites. But why didn't we favour the local species ?
This ladybird, which comes from China, Korea and Japan, has adapted so well that it has since invaded whole regions, progressing from the north to the south. It was sold in Belgium at the end of the 1990's and it invaded Flanders in 4 years ! The invasion of France is under way. It is present in a large part of the country. It has recently been discovered in the Loire-Atlantic region, and it seen more and more in the Pays-de-la-Loire, in Burgundy, in Franche-Compté and in the Rhone-Alpes.
Although it is harmless to humans, it does great damage to local species like the 7-spotted ladybird (Adalia 7-punctata). The larva of the Asian species attacks the larva of local ladybirds when it has no food left, or whenever it gets the opportunity.
Asian ladybirds regroup in the autumn using a substance which they excrete, and they move about in groups, looking for a safe place to hibernate. They like to find refuge in houses.
Once again, in trying to interfere with Nature, man has created an irreversible imbalance. We now have no choice but to accept this new species and its invasive presence for the moment, while we wait for a new order to establish itself.