Glue and sand eradicate the pine weevil

The pine weevil will have big problems in Sweden next year.

“One third of the plants in the risk areas can be effectively protected next year,” says

Malin Persson of the Swedish company BCC, which developed the equipment used to treat the seedlings.

The method is called Conniflex and the rights are owned by Sweden’s biggest forest owner, Sveaskog. Last year, their subsidiary Svenska Skogsplantor began supplying containerised spruce seedlings protected with this method.

“By the autumn there will be four machine lines in Sweden with a capacity to treat forty-five to fifty million plants,” Malin says. “We reckon that between a hundred and a hundred and fifty million plants are located in areas at risk of bark beetle attack.”

A Conniflex treatment is completely free from poisonous chemicals. It is a mechanical form of protection that prevents the beetles from gnawing on the plants.

The first stage involves spreading glue on two-thirds of the stem. The stem is then gently sandblasted so that the sand sticks to the glue. When the glue dries, the plant has a type of ‘armour’ that stretches as the plant grows and disappears by itself after a couple of years, when the pine weevil can no longer do much damage.

The advantages are that forest owners no longer have to give their plants a second treatment out in the forest, which is often necessary when using insecticides. Nor are forest owners very happy at having to handle plants treated with poison, no least because planting them out is often a family task together with the children.

“We’ve had a huge response here at the fair,” Malin says. “Many people have come and told us how well it worked for them last season, and even more have said they were disappointed not to be able to get our treated plants for this season.”

Availability should be much better by next season. Svenska Skogsplantor is now starting up its third treatment line and another big Swedish forest owner, Bergvik Skog, will start to treat its spruce seedlings with Conniflex in the autumn.

“Availability for Conniflex-treated plants will be better next season,” says Malin Persson of BCC, which has now installed four treatment lines in Sweden.
The seedlings are protected with an ‘armour’ of glue and sand.