Nature’s answer to deadly tree pest is paying off in the uplands of Wales

New natural methods of stopping Wales’ deadliest tree pest in its tracks are already beginning to pay off at field trials in the upland forests near Tregaron

Pine Weavil Hylobius abietis - the large pine weevil – is the single most important insect pest of plantation forestry in Europe and there are fears that climate change could increase populations.

But now researchers from the Aberystwyth-led IMPACT project have discovered that a cocktail of the pest’s natural enemies - microscopic nematode worms and fungi – are a potent weapon in fighting back against Hylobius.

“Hylobius can kill up to half the young trees after re-planting,” said Prof Hugh Evans, Head of Forest Research in Wales and co-ordinator of the project, which is part funded by the European Regional Development Fund (ERDF) through the Ireland Wales Programme (INTERREG 4A), with match funding from Forestry Commission Wales.

“Now latest results from trials at Cwm Berwyn suggest that a cocktail of entomopathogenic natural agents can be used to attack and kill the larvae, pupae and young adult Hylobius, reducing the pest population by at least 40 per cent,” he said.

The IMPACT researchers have drafted in reinforcements for the microscopic nematode worms that are already part of the armoury for Forestry Commission Wales in its battle against Hylobius.

“Building on the pioneering work of our project partners at Swansea University, led by Professor Tariq Butt in the College of Science, we are testing insect-killing fungi alongside the nematodes, at reduced concentrations compared to using them separately. Results are highly promising giving increased efficiency of natural control, further reducing the need for chemical protection of young trees,” said Professor Evans.

Forest Research in Wales is looking at improved pest control measures through IMPACT with partners from Swansea University and the National University of Ireland, Maynooth.

Top of the agenda for the Integrated Management of forest Pests Addressing Climate Trends (IMPACT) team is assessing just how changing climate will influence the damage caused by forest and woodland pests.

“As the climate becomes warmer and wetter, the conditions will improve for Hylobius, so it is important that we should have even more effective controls,” Prof Evans said.

The IMPACT scientists expect future weather extremes – drought, flooding, higher and lower temperatures – to put woodlands under increasing levels of stress.

Increased stress lowers the defences of trees, opening them up to attack from insect pests such as the pine weevil,  bark beetles, wood boring beetles and a wide range of root and leaf feeders, all of which affect tree growth, sometimes leading to tree death.

The key will be biological control integrated into novel monitoring regimes, concentrating especially on microbial control agents – fungi, bacteria, viruses and parasitic nematodes.

The IMPACT partnership already has a strong track record in use of these agents and expects to deliver improved technology to any land users whose trees are at risk from pest infestations.


This news item was generated by IMPACT