Spruce seedlings (Picea abies) planted on clear felled sites in the forest may be harmed by pine weevils (Hylobius abietis) eating the bark of the young plants. If the feeding causes girdling, the seedling may die. This is a wide-spread problem in Europe, resulting in the practice of treating the seedlings with insecticides before they are planted. As insecticides may be harmful in the working environment in the forest nursery and for the people handling the plants, as well as for other insects than pine weevils, there is an increasing interest in replacing the chemical protection of the seedlings with other protection methods.
Unprotected spruce seedling planted in May 2017
About the project
In the MeritVoks project, young Norway spruce plants are planted in the forest with either Merit Forest (insecticide with imidacloprid) or Ekovax (a physical barrier containing wax) as protection against pine weevils. The plants are planted in 9 places in 9 of the counties of Norway. In three of them we also include Swedish plants with Conniflex (a physical barrier) as the protection method.
All fields also include unprotected plants, which will give an indication of the pressure of pine weevils on the spruce seedlings. The number and activity of pine weevils may differ between the study sites.
We compare the protection from the three methods, one insecticide and two mechanical methods.
The results are presented for stakeholders in Norwegian, primarily. A report about the findings after the first growing season in three sites (in Norwegian) and a presentation from a talk about the findings in all nine sites presented in December 2017 (in Norwegian) are available.
In an international meeting at Honne, 26th of April 2018, three presentations were given. They included information from research done on the wax as a physical barrier against pine weevil feeding by the University of Oslo and others since the year 1995. The talks are called "The road to an environmentally friendly wax protection of conifer seedlings", "Heat tolerance of spruce seedlings" and "Field trials".
The project is conducted with support from Skogtiltaksfondet, nine County Governors, Norwegian Forest Owners' Federation, the forest nursery Skogplanter Østnorge, and the wax producing company Norsk Wax.