long and cold winters alone are not enough to curb the spread of the Colorado potato beetle (Leptinotarsa decemlineata), explains M.Sc. Saija Piiroinen’s doctoral dissertation.
The reason for this is the beetle’s remarkably good ability to acclimatise itself to the Finnish winter. Piiroinen defended her dissertation at the University of Jyväskylä on Saturday.
According to Piiroinen, the most effective way to control the Colorado potato beetle population is to use insecticides.
“The control measures are best left to plant protection authorities”, she points out.
In prevention of the spread of the Colorado potato beetle the best way is the early detection of the beetle combined with control measures.
That way the required measures will be much easier and cheaper than at a later stage.
“Apart from the use of insecticides, one can plant potatoes on the fields as a lure”, Piiroinen advices. This will help to locate those individuals that may have survived the pesticide treatment.
The Colorado potato beetle originates from Mexico, from where it has spread to the United States and Europe.
The northernmost Colorado potato beetle populations have been found in the Russian Republic of Karelia. The pest slipped into Finland through the southeast corner of the country.
Piiroinen looked into the factors and methods that control and limit the spreading of invasive populations into new territories. Piiroinen’s research falls under the category of ecology and evolutionary biology.
The Colorado potato beetle can unfortunately withstand insecticides remarkably well.
This ability depends on the temperature conditions experienced by the previous generation. Hence the prediction models for the spread of the beetle are difficult to devise.
As an adult the Colorado potato beetle survives over the winter months by digging itself into the ground.
Piiroinen’s study also established that there is less genetic variation within the European Colorado potato beetle populations compared with those in North America.
