THREE Coillte forests near Lough Gill, Co Sligo, have been closed following the discovery for the first time in this State of the small banded pine weevil, an insect which can cause considerable damage to trees. The official name of the insect, which is only five to 10 millimetres in size, is pissodes castaneus.

The Department of Agriculture has started an intensive survey in co-operation with Coillte staff to "establish the extent of the insect's occurrence." Pending the outcome of the survey, the movement of logs from the forests in question has been prohibited.

Under Irish and EU legislation the movement of wood contaminated with this insect, both within Ireland and into Northern Ireland, is prohibited.

While the insect has never been found in this State before, it can be found in most other EU countries, including England. Ireland was the only EU state to be free from the pest, which put Irish timber into a high category classification.

Mr Pat Twoomey, of the Irish Timber Council, said last night. "From our point of view, it is a worrying factor. It can do a lot of damage to trees and we are the ones who process the trees. If it has got into the west it could spread to the rest of Ireland. It is a worry because our trees are classified as pest free."

The Minister for Agriculture, Food and Forestry, Mr Yates, said Irish forests were among the best managed in Europe, and there were now some 16,000 people employed directly and indirectly in Irish forestry.

"It is of vital national importance that this valuable native, resource should be protected against the introduction of dangerous forest pests and diseases."

The value of timber production is in the region of £90 million and added value is put at £170 million per year. Mr Gerard Cahalane, a specialist in forest protection at the Department of Forestry, said. "We are free of a whole range of pests which could impact on the industry." They were carrying out a nationwide survey to see the extent of the insect. He could not say how much damage the weevil could do.

There was a debate among experts on what damage the insect could cause and about its economic impact. The insect was in the UK and they had managed to live with it it was not considered to be a devastating insect, he added.

He said it was impossible to know how it got into the State. There was a total ban on the importation of coniferous wood with bark attached.

The insect was found in a cleared bit of the forest in the stumps of trees.