SWL supports new pesticide-free trials

SWL supports new pesticide-free trials

Scottish Woodlands Ltd is involved in a pioneering new trial of pesticide-free products designed to protect young trees against the scourge of weevils.

The large pine weevil (Hylobius abietis) is a major forest pest in the UK and can destroy nearly all the young seedlings in a replanted woodland.

To limit the spread of chemicals into the wider environment, insecticide is usually applied directly to individual young trees - but Scottish Woodlands Ltd (SWL) sees a future in which insecticides are no longer required.


Working with Scandinavian partner Bjorn-Thorsen, SWL is testing a new product called Connisafe at Barrhill Forest, near Kirkcudbright.

Euan Wilkie, SWL’s Forest Manager at Barrhill said, “If anywhere can test a weevil control method to its limits, it’s Barrhill - so we are confident of giving Connisafe a stiff test!”

The trial follows on from the promising testing of Bjorn-Thorsen’s Conniflex product last year.

Stuart Wilkie, SWL’s Environment and Certification Manager, said: “We have trialled many physical barrier methods in the past including nets, sleeves, and wax coatings but such methods have only protected 40-60% of trees.”

“Last year’s Conniflex trial gave us hope that where populations were low enough, good levels of protection could be achieved - but not at higher populations typically experienced in the West.”

“We were determined to try again and with the support of the owner, a randomised trial of 2500 plants was set out in early April.”

Connisafe is a mineral blend that encloses the plant using a water-based binder and has no insecticidal properties. The idea is that the pine weevil does not have the strength to bite off the coating to get to the trunk. At the same time, the coating is flexible so as not to impede the growth of the plant and is non-toxic. Normally it would be applied mechanically in the nursery but for the number of trees required for these trials, it was done manually in the forest.


Stuart Wilkie added: “We are looking forward to monitoring the trials over the summer to see how Connisafe performs against the high weevil numbers we normally experience at Barrhill.”

Scottish Woodlands Ltd is at the forefront of the industry’s drive to reduce pesticide use in forestry, especially for weevil control. It is a major supporter of HIRP (Hylobius: The Industry Research Programme) and Jemma McLachlan (Assistant Environment Forester) is currently the group secretary.

Jemma and Euan Wilkie will attend the New IPM Symposium 2024, at Swansea University, later this year, an event focused on emerging opportunities in crop protection and environmentally friendly control of pests.