No observations of Colorado beetles

31.7.2008

<div>No observations of Colorado potato beetles so far have occurred in Finland. However, inspections of potato plantations will proceed until end of August. </div>

Currently is possible to find occurrences of Colorado beetle larvae, as eggs laid during the summer have had time by now to develop into large larvae that efficiently feed on leaves of potato plants.
Most observations in preceding years of Colorado beetles were done around mid-August.

Colorado beetles appear in colonies in potato fields where plant leaves have been consumed and leaves display brown heaps of excrements from larvae. Younger larvae carry a dark colour while as mature being chubby and orange. On the sides of the body appear two rows of black dots. These larvae eat and move constantly.

If a crop displays potato plants eaten to an extent having no leaves, the site may have habited larvae that now have burrowed into the ground to pass into the chrysalis stage. At this stage, the Colorado beetle is difficult to find. Small circular holes in the ground surface may be signs of pupated Colorado beetles.

Adult Colorado beetles are easier though to observe on potato leaves. During warm and sunny days they particularly migrate to the upper sections of the potato plants. An adult Colorado beetle is about one centimetre long. On its yellow back it has ten black longitudinal lines.

The Colorado beetle is a dangerous plant pest, the observations or suspicions of which are to be reported to an official plant protection organisation. Most important is that professional as well as household growers of potatoes actively take efforts to observe any occurrence of Colorado beetles.

The service number for the reporting of sightings is 040 801 4407 (between the hours of 9-20 pm).

More information on the Colorado beetle can be found on Evira’s Internet pages (in Finnish): www.evira.fi/koloradonkuoriainen

For additional information, please contact:
Deputy Director Raija Valtonen, Evira, tel. 020 77 25040
Senior Officer Salla Hannunen, Evira, tel. 020 77 25072


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