Colorado potato beetles found on Lappeenranta potato fields

The Finnish Food Authority has confirmed Colorado potato beetle infestations on two potato farms in Lappeenranta, urging growers across the region to actively monitor their crops.

Damage is visible as large sections of potato plant leaves eaten away or entirely consumed. The beetles are about one centimetre long, with yellow and black stripes and a domed back; larvae are orange with black spots and plump.

This summer, the pest has been detected on eight potato farms in total, with earlier findings in Lahti, Kouvola, Savonlinna, Luumäki, Ruokolahti, and Joensuu. The species is not permanently established in Finland.

Eradication is difficult once larvae burrow into the soil to overwinter, the authority warns. The larvae pose a severe threat to potatoes by consuming large amounts of foliage. Any sightings or suspicions must be reported to the Food Authority, which will order control measures. Growers are advised not to attempt eradication themselves, as this complicates official efforts.

If the beetle were to establish itself permanently, it would create additional work and costs for potato cultivation, the authority states. The pest can spread via wind currents or arrive with plant shipments from abroad, so vigilance is advised beyond the known risk areas in Southeast Finland.