A ladybug love

Audio 02:42

By: Florent Guignard

Red with its black dots, the small beetle is one of the most popular insects. A great lover of aphids, the ladybug is the ally of gardeners.

Publicity

He has the eye to spot them. On the linden leaves in front of his house, in the wild grasses of his garden, ladybugs swarm. And that's pretty good, since Romain Nattier is an entomologist at the Muséum national d'Histoire naturelle in Paris, a specialist in the ladybug. "  Ah! There is one !  », He finds after a few seconds. A ladybird with seven points, red with three black points on each side of its shell, and a black point in the middle. One of the 6000 species listed in the world, one of the most widespread in France. There is also a foolproof trick to find a ladybug: spot aphids, his favorite meal.

Aphids, ladybugs, but also ants. It's a funny three-player game played by these families of insects. The ladybug feeds on aphids, and the ant, which feasts on the honeydew (sugar) produced by the aphid, will protect the latter by chasing the ladybug. "Ants tend to annoy the ladybird, to push it, to attack it," describes Romain Nattier. They do not go so far as to kill or eat it, but in any case they disturb it, and the ladybug is forced to go elsewhere, to find another place where there are aphids. "

The invasion of the Asian ladybug

The ladybug is so greedy that it always lays its larvae near aphids. From their birth, their meal is thus served to them on a sheet. "  Ah! Here is an Asian ladybug larva  , ”on a linden leaf. The Asian ladybug is increasingly present in European gardens. Red, orange or black, it is the same species, as there are red or brown in humans. Its development started in the 1980s, when it was introduced all over the planet to control aphid populations, because it is able to devour a large quantity, given its size. “  She was in laboratories, farms or greenhouses,  says Romain Nattier.  Unfortunately, it escaped, and spread everywhere. "

A study in Great Britain has shown that it was responsible for the decline of several native species of ladybugs. A threat that the researcher at the National Museum of Natural History puts into perspective. “  Yes, the Asian ladybug is invasive, since it comes from another geographical era, and that in the urbanized areas where it is found, it tends to push the native species out of their ecological niche.  The Asian ladybug can sometimes even be cannibalistic, eating larvae of other ladybug species. "  But in reality, the situation is mixed," continues Romain Nattier. Not all ladybugs are affected. Only those who share the same habitat, in these urbanized areas, where a certain ecological imbalance has already taken hold. "

"An iconic insect"

Aside from aphids, everyone loves the ladybug. An insect, it is said, is good luck. The legend dates back to the Middle Ages in France. A death row inmate owes him his survival. A ladybug constantly landed on the back of her neck when the executioner was about to slice her neck. A sign of God, in the eyes of the king, who pardoned the condemned, a little later cleared. The ladybug earned its nickname "  beast to God  ". And thanks to her diet, most often based on aphids, she has become an ally for gardeners. The City of Paris, before banning all pesticides in the town, had distributed ladybug larvae to individuals. Even if Romain Nattier nuances the ecological effectiveness of ladybugs against aphids, “  at least it allows people to reconnect with nature . "The garden ally is therefore popular, because of"  its shimmering colors, because it is easily recognizable, not too fast, it does not sting, it has an iconic side in nature! The Volkswagen Beetle, one of the best-selling cars in the world in the early 1970s, was named Beetle in France. And Walt Disney had made him the main character in a film called A love of Ladybug. We can not say it better.

" Captain Haddock called me a woodlouse. It's not very nice, is it ? "

Ah that, The woodlouse is not the ladybug. Not very beautiful, all gray, with its 14 legs under its shell. The only crustacean living on Earth is a lover of trash, dead leaves, dead wood and this is where it becomes interesting, like the ladybug, yes. The woodlouse does the housework, and then poops, to fertilize the soil. So we don't touch the woodlice!

Newsletter Receive all international news directly in your mailbox

Follow all international news by downloading the RFI application

• Biodiversity
• Flora
• Environment

On the same subject

It's in your nature

Urban nature, the largest vegetable patch in Paris

It's in your nature

The Limited Invasion of Collared Parakeets

It's in your nature

Maternal instinct in animals