No observations of Colorado beetles in Finland so far
No Colorado beetles have been found in Finland this year. This beetle, which is regarded as the world’s most serious potato pest, was most recently found in Finland in 2007. However, the species is commonplace in the Baltic countries and in Russia, so the risk of it spreading to Finland is still high.
Warm weather conditions speed up the development of the Colorado beetle. At this time of the summer, leaves with holes or badly eaten leaves may be found among the potato plants. By examining such plants, one may find both adult beetles and larvae of different sizes. The larvae, in particular, first eat holes in the potato leaves and later eat the leaves completely, resulting in leafless plants in places.
An adult Colorado beetle is about one centimetre long. There are 10 black longitudinal stripes on the yellow back, and the pronotum is orange with black spots. The beetle’s 1.5-millimetre-long yellowy-orange eggs are found in tight groups on the underneath of the leaves.
A newly hatched larva is approximately 1–2 millimetres long and darkish in colour. The larvae grow rapidly, and their convex back soon turns orange to pinkish-red. The larva has a black head and two rows of black spots down the sides. A full-grown larva is slightly more than a centimetre long.
Evira asks all professional and small-scale potato farmers to monitor their potato crops. Any observations or suspicions of Colorado beetles must be reported immediately to Evira’s service number so as to verify the observations. The plant protection inspectors of Evira and the ELY Centres are responsible for the associated monitoring and control.
The service number for reporting observations is +358 (0)40 801 4407 (9am–8pm).
For further information and contact details, please see Evira’s Web site (in Finnish): www.evira.fi/koloradonkuoriainen.
Evira will release a new bulletin on Colorado beetles if they are observed in Finland.
For more information, please contact Raija Valtonen, Head of Section, Evira,
tel. +358 (0)40 560 2510.