Ms Geraldine O'Sullivan:

Yes. I will start off with the great spruce bark beetle, which is the one of concern in the pest-free area that has been demarcated and where it has moved. That came into the UK in 1982. It started in England and it has been moving steadily and rapidly. There have been bark beetles in spruce forests for years, but what is happening with the longer periods of warmer weather, the drought and the stresses trees are under is that instead of producing once over the year, there are cycles and they could be producing three times, which has caused a rapid explosion in the beetle population. There is no cold spell when it dies so that population has increased and it is moving steadily throughout Europe and the UK.

The European beetle is not in Greece, Ireland or Portugal. There are mechanisms, but it causes the most significant dieback on spruce trees, in particular those that are stressed. It can take a number of years of sustained attack and then the plantation or forest is gone.