Pests Almost all cantons must respond to corn rootworm infestation

In 23 cantons, at least partial measures to contain the corn rootworm will apply in the coming year. Among other things, farmers there will not be allowed to grow maize in two consecutive years. In the canton of Ticino, maize cultivation has been generally prohibited for some time.

This was announced by the Agroscope agricultural research center on Wednesday. This year, the pest has been monitored in 25 cantons and in the Principality of Liechtenstein. In addition, 209 pheromone traps were used. Beetles were ultimately caught in 72 traps.

For the 2025 season, 23 cantons are therefore applying at least partial measures relating to crop rotation in agriculture. To this end, the cantonal services are demarcating certain zones. For example, farmers in these areas are not allowed to grow maize for two consecutive years. In the canton of Ticino, the cultivation of maize has been completely banned since 2004 due to the influx of beetles from Italy.

Larvae eat the roots

The corn rootworm originally comes from North America. There it is the most important pest of maize. Most of the damage is caused by the larvae of the beetle, which feed on the corn roots. Adults feed on the so-called corn stover and the leaves. According to Agroscope, the problem is particularly bad in areas with monocultures of maize. The beetle can fly up to 70 kilometers.

The situation of the corn rootworm has been monitored annually in Switzerland since 2000.