There are mounting fears in the northwest that an infestation of beetles could devastate heather cover on hills and bogs.

Difficulties with heather cover in upland areas and bogs have been reported in north Leitrim, with the problems suspected to have been caused by the heather beetle.

The heather beetle - or lochmaea suturalis - is a native herbivorous insect. The adults and larvae feed on heather plants at a level that is usually not noticed.

However, there can be outbreaks - the cause of which is not understood - where millions of beetle grubs can decimate hundreds of hectares of heather.

Natural response

Experts believe these outbreaks may be a natural response of the beetle when factors such as favourable habitat conditions, reduced predator populations and suitable weather coincide to facilitate an explosion in larvae numbers.

Worryingly, there are no control measures that can be implemented to counter a serious heather beetle infestation.

A spokesman for the National Parks and Wildlife Service declined to comment until the source of the problem in Leitrim had been definitively identified.

Farmers fear that the beetle has the potential to devastate large areas of heather, but biologists maintained that any serious damage would be localised.

However, the Heather Trust in Britain claimed that the heather beetle has been instrumental in driving the change from heather to grass-dominated moorland in some areas in the UK.