Coming from the tropics, the nightclub of the tomato devours more than a hundred useful plants in Switzerland. The butterfly is now spreading north. In the south of Germany, his vanguard already causes damage.
This pest gives a hard time to agriculture in Switzerland, which monitors the propagation of the tomato noctual, or Helicoverpa Armigerasince last year using 25 traps. In 2023, the caterpillar had already caused strong loss of performance in market gardening, going as far as total loss, explains the Federal Center for Agricultural Research Agroscope.
At the end of June, the traps contained more butterflies than the previous year, observed Cornelia Sauer, expert in vegetable cultivation at Agroscope. The first damage of the season appeared on tomatoes south of the Alps.
The insect is called night because it moves at night. The caterpillars are polyphagous and appreciate a multitude of useful plants, beans with peas, tomatoes, peppers or sweet corn, passing by salads or beets.
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Worse than the Japanese beetle
In Germany, the caterpillars are already wreaking havoc on chickpeas, told the German press agency DPA Olaf Zimmermann, pests expert at the Augustenberg Agricultural Center (LTZ) in Karlsruhe. Some have already been found to Hanover and Berlin.
“The nightclubs of the tomato are much more problematic in the great crops than the beetle of Japan,” he explains. “The latter eats leaves and fruits and goes mainly in the vine and the fruits. The noctual of the tomato goes on the other hand in surface crops, such as corn and vegetables on the spot.”
Even young caterpillars are not content to bite the leaves and deeply dig into the plants. According to Agroscope, they are even more voracious at the subsequent stages of the caterpillar. In addition to these damage, vegetables are soiled by droppings, which makes the harvest unusable.
“There is not yet wintering in Germany, but arrivals every year. The question is not whether [l’insecte] Go come and stay, but when, “adds Olaf Zimmermann.
Moving to the north
Butterflies can fly 1000 kilometers and cross the Alps. Cornelia Sauer considers that these tropical pests can spend the winter north of the Alps. At most, this would be possible in greenhouses.
According to specialists, climate change moves distribution areas to the north, as is the case for other pests. “We can assume that at one point, a population will adapt to our climatic conditions and that we may then have a first enclave in the south of the Land of Baden. In Hungary, they are already hibernating,” notes Olaf Zimmermann.
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There, they established themselves permanently as corn pests. In 2023, butterflies attacked lavender in the south of France, causing significant loss of performance.
In Switzerland, national monitoring has highlighted the arrivals of butterflies from southern, west and east. The butterfly moves north, according to Cornelia Sauer, and “he also reached the canton of Zurich”. The traps and controls in the field must make it possible to detect in time a presence in a region in order to save the crops by a targeted use of insecticides.
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