Monitoring of Colorado Beetles is beginning
The closest permanent populations of Colorado beetles are found south and east of Lake Ladoga in Russia. The Colorado beetles that burrowed into the ground as adults come out of hibernation when the temperature of the soil exceeds 15 degrees. This usually happens at the end of June and beginning of July.
The Colorado beetle does not occur permanently in Finland. Colorado beetles occur commonly in the Baltic countries and in Russia, so especially the air flows and thunderstorm fronts from the east and south-east add to the risk of them drifting to Finland. In addition to the air flows, the beetles can be carried along with the car and train traffic from the east. The risk of the Colorado beetle spreading is highest in South Karelia, North Karelia and South Savo, but with thunderstorms the beetles can also be carried to other parts of Finland. The plant protection inspectors of Evira and the TE-centres are starting the inspections in mid-July.
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 semolina sized yellow eggs are in tight groups on the underneath of the leaves. The larvae are orange in colour and on both sides there are black spots in two rows. There are no larvae during the early summer.
The adult beetles and larvae first eat holes in the potato leaves, and later they eat the leaves completely, and they are then easy to detect. In the home garden there are many other common insects eating the leaves of plants. The Colorado beetles only eat potatoes or other solanaceae.
The Colorado beetle is one of the world’s worst potato pests. Its destructive power is based on the large quantity of beetles and their fast reproduction. In Finland the Colorado beetle is classified as a harmful organism and so far it has been possible to stop it from spreading. The plant protection authorities, that is to say Evira and the plant protection inspectors of the TE-centres are responsible for the monitoring and control.
The service number for the reporting of sightings is 040 801 4407 (between the hours of 9-20).
If there is no specific need for it, Evira will issue the next Colorado beetle communication on 16.7.2009.
For more information, please contact:
Inspector Esko Viikari, tel. +358 2077 25151
Senior Officer Olli Elfving, tel. +358 2077 25150