Contents
Swiss premiere: Dark ladybirds are said to eat the aphids that attack cherry trees in spring.
It is black, has four red dots and is supposed to save Baselbieter cherries from aphids: the four-spot ladybird. Farmer Marcel Itin from Ormalingen (BL) imported this specifically from Italy, even though it is also native here.
Legend:
The four-spotted ladybird feels comfortable at lower temperatures and the larvae also eat aphids.
zvg
In Switzerland, the four-spotted ladybird prefers to live at the edges of forests where there are lots of flowers. So not with the cherry trees. In Italy, however, the beetles are bred. And: “This ladybug is not as much of a ‘goddamn’ as the pretty red ladybug with the black dots,” says Marcel Itin. That’s why he can already use it on the field.
Legend:
Organic farmer Marcel Itin checks whether his cherry trees are already infested with aphids.
zVg
The problem is that the aphids hatch at a daytime temperature of 10 to 12 degrees and are therefore currently spreading on the cherry trees. However, the lice’s native enemies only emerge when it is warmer. “The hoverfly, for example, comes much later. Even the eared brooder – our cavalry – isn’t on the move yet.”
The Italian ladybird is a game changer for us.
The black ladybird has another decisive advantage: “The larvae eat aphids, not just the adult beetles. This makes him a game changer for us.”
Legend:
There are now flower boxes between the cherry trees because the ladybirds like flowers and their nectar. The flowers also attract other beneficial insects such as the eared brooder or hoverflies.
SRF/laura baldini
Farmer Marcel Itin has now released 300 of these little black ladybirds onto his cherry trees. He doesn’t know yet whether it will work. But as an organic farmer, he can only combat the lice with soapy water and that is very time-consuming: “If a leaf is infected with lice, it curls up. So I would have to use a hand sprayer to spray every single leaf of my several hundred cherry trees with soapy water. I don’t have time for that.”
First attempt in Switzerland
The idea with the black ladybug comes from Franco Weibel. He is head of the fruit growing department at the Ebenrain Center for Agriculture, which is responsible for research and training on agricultural topics in the canton of Baselland. Franco Weibel learned of an experiment in Poland with the black ladybird and then organized the import from Italy to Switzerland.
Legend:
A box full of ladybugs: This is how the beneficial insects were delivered to Switzerland from Italy.
SRF/Laura Baldini
«I then called Marcel Itin and told him that I had a somewhat crazy idea. And he really went along with it,” says Franco Weibel. So far, no one in Switzerland has tried this. Then things had to happen quickly: the beetle had to get to the Basel area before the aphids multiplied too much.
Legend:
In mid-April the cherry trees in the Basel area are in full bloom. Whether they are infested with aphids will only become apparent in a few weeks.
SRF/Laura Baldini
Weibel admits that they are a little late this year. Next year he wants to order the ladybugs earlier. But now it’s time to watch the cherry trees and hope that the little black beetle kills the aphids.