Carnivorous plant eats asian hornets

Scientists working to discover pheromone that attracts bee-killing insects

As honey production has hit its lowest level ever in France, a Nantes botanist has discovered a plant that eats the honeybee’s most dangerous predator, the asian hornet or frelon asiatique, a pest which now extends across 70% of the country.

Christian Besson, of the Pays-de-la-Loire capital’s Jardin des Plantes, discovered that a variety of carnivorous pitcher plant, the Sarracenia, trapped, killed and digested asian hornets and flies but did not affect other hornets, bees or wasps.

He said each of the long vaselike plants could deal with up to 50 asian hornets, which would not really affect the hundreds of thousands of asian hornets but researchers were trying to isolate the pheromone scent that attracted the frelons to develop a more effective chemical trap.

His discovery comes as Farming Minister Stéphane Le Foll said he was ready to declare the frelon a Category 1 pest, that must be destroyed, but was awaiting final tests on what was hoped to be an effective trap.

Typical traps – an upturned plastic bottle with sugar solution – have been shown to be inefficient as a Bordeaux study found only 1% of the insects trapped were asian hornets. It was also feared they killed the weakest hornets, encouraging the survival of the strongest.

The hornets now cover 70% of France since arriving in Lot-et- Garonne in Chinese pottery in 2004 and, along with pesticides, are blamed for honey production falling to just 10,000 tonnes in 2014 from 32,000 in 1995.

They hover outside hives and grab bees in mid-air to eat.

One beekeeper in Pau, André Lavignotte, has come up with his own way of stopping hornets entering his hives: he fitted a large mesh grill over the entrance, big enough to let bees out but too small for hornets.