Monitoring of Colorado Potato Beetles is beginning


<div>The cool weather of the early summer might possibly slow down the development of overwintered Colorado potato beetles. Last year’s weather in the areas close to Finland was not very favourable to the development of the beetle either, so there would not seem to be a great risk of invasion at this point in time.</div>

The closest permanent populations of Colorado potato beetles are found in Russia, north and south of Lake Ladoga. Occasional overwintered beetles can be found in Finland, mainly in the vicinity of the eastern border. The Colorado potato 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.

It is difficult to find single beetles, but there can be findings of several dozen adult beetles in a colony that has overwintered. The adult beetles and larvae first eat holes in the potato leaves, and later they eat the leaves completely. In this case the area has to be examined carefully for findings of adult Colorado potato beetles or egg masses. The Colorado potato beetles only eat potatoes or other solanaceae. In the home garden there are many other common insects eating the leaves of plants.

An adult Colorado potato 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 Colorado potato 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 potato 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.

Contact information for the reporting of any sightings and additional information about the Colorado potato beetle may be found on Evira's Internet pages (in Finnish):

The service number for the reporting of any sightings is +358 40 801 4407 (between the hours of 9-20).

For additional information, please contact:
Senior Officer Atro Virtanen, tel. +358 20 77 25047
Senior Officer Salla Hannunen, tel. +358 20 77 25072





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