Our Organisation Search
Quick Links
Toggle: Topics

PW-IPM Project

Towards integrated pest management for pine weevil in Ireland

Introduction - the pine weevil

Substantial tree plant mortality occurs regularly in Irish conifer reforestation sites. These losses are attributed mainly to damage caused by the large pine weevil (Hylobius abietis). It feeds on the bark of woody plants. 

Felling a coniferous crop produces a large increase in breeding material for pine weevil, whilst plant material suitable for adult feeding is reduced. Young trees used for restocking are liable to be heavily attacked by adult pine weevils feeding on the stem from the root collar upwards. Heavy damage can completely girdle stems and cause plant death.

It is estimated that on average 50% of the seedlings on untreated sites in Ireland and the UK are killed by pine weevil during the first few years. European estimates indicate that the pine weevil is the most important pest of reforestation sites in Europe.

This will increase the re-establishment costs substantially through the cost of insecticide application, replacing plants and additional weeding. A new collaborative DAFM-funded project between Maynooth University (lead institution), Teagasc and Coillte evaluates all possible management approaches of the pine weevil.  


Adult pine weevil
(Photo: F. Fedderwitz)

Pine weevil damage on a young Sitka spruce (blue oval).
A pine weevil is sitting further up the stem (yellow rectangle).
(Photo: F. Fedderwitz)

What is Integrated Pest Management?

Integrated Pest Management (IPM) means that pests are managed by a combination of cultural practices and chemical, physical and biological protection methods. When selecting an appropriate method many different factors need to be taken into account.

  • Silvicultural practices can, for example, be soil preparation or breeding of specific plant characteristics.
  • Chemical protection mostly refers to insecticides, which are also part of IPM. However they should only be used when no other possibilities would be successful.
  • Barriers or stem coats can prevent insects from physically feeding on seedlings.
  • Biological control uses natural enemies, such as nematodes, to reduce pest populations.

Project outline

The project aims to review current and potential management options to mitigate damage from the pine weevil in Irish reforestation based on literature searches and consultation with stakeholders.

Strengths and weaknesses of the main options will be identified and knowledge gaps and future research needs for Ireland pinpointed.

Furthermore, methods of forecasting times of onset and peak weevil emergence in Ireland will be refined.

Work Task 1: Evaluating management options for pine weevil

Contact: Louise McNamara (Teagasc)

  • Objective 1: Review of existing pine weevil management options
    Based on scientific literature and stakeholder experience, we will evaluate the advantages, disadvantages and suitability of existing pine weevil management options for Ireland.
  • Objective 2: Evaluate novel strategies
    Novel strategies, including new generation chemical pesticides, are evaluated in consultation with industry, researchers and regulatory authorities.
  • Objective 3: Identify need for research
    The above evaluations will point towards areas of pine weevil management with knowledge gabs that need to be filled with further research.

Work Task 2: Predicting time of weevil emergence

Contact: Christine Griffin (Maynooth University)

  • Objective: Refined prediction of weevil emergence will lead to better timing of insecticide application and an overall reduction of insecticide use.

Work Task 3: Dissemination

Contact: Louise McNamara (Teagasc)

  • Objective: Present findings to relevant stakeholders
    Different methods of dissemination will be used to reach all key groups of stakeholders (Irish foresters and forest contractors, forestry advisors, policy makers and the international research community).

Examples of dissemination will include:

  • Stakeholder consultations
  • Popular science articles
  • Scientific publications
  • Presentation at national and international conferences
  • Final report on IPM options for pine weevil in Ireland
  • Foresters Guide on management of pine weevil in Irish forestry

See also

Relevant publications


The project is funded by the Department of Agriculture, Food and the Marine under the 2017 Call for Research Proposals.