EIGHT-TOOTHED SPRUCE BARK BEETLE (Ips typographus)
Live adult Ips typographus were trapped at a mill during routine monitoring in August 1997. The beetles may have originated from infested UK spruce and the Forestry Commission urgently needs to identify possible source forests. It is vital that staff should look for symptoms identified in the photographs below and report them immediately by telephone to either:
Alice Holt Lodge
Tel: 0300 067 5645
Plant Health Service
231 Corstorphine Road
Tel: 0300 067 5155
WHAT TO LOOK FOR IN THE FOREST
Adult females lay eggs along a linear gallery system from which larval galleries radiate, becoming wider as the larvae grow. This pattern shows in both the bark and in the surface of the wood, and is unique to Ips typographus. This symptom should be looked for on any dead trees, whether standing or fallen.
The beetle is often associated with windblown, damaged and recently felled trees where it builds up in numbers before moving on to attack adjacent live trees. Inspection of trees in this category should be a high priority.
Look also for individual or groups of dead trees. This arises when the beetles 'mass-attack' trees, overcoming the normal tree defences by a combination of large numbers of beetles and a blue stain fungus carried by the adults. This phase can lead to extensive tree mortality.
WHAT IS THE PLANT HEALTH SERVICE DOING?
As it is vital to identify any area of infestation quickly in order that eradication measures can be started and steps to prevent further spread put in place, we have agreed with the Plant Health Working Group a strategy which will continue throughout the summer months. The main elements of the strategy are:
- continued surveillance at the 100 or so forests known to have supplied the Mill with logs immediately before the first beetle was caught. Pheromone traps have been erected at them all;
- monitoring of spruce deliveries, using pheromone traps, erected at the 'top 20' spruce processing plants throughout Britain;
- an assessment is being carried out to determine whether our Sitka spruce forest is at risk. All the information about outbreaks in Europe point to Norway spruce as the main host;
- our port pheromone trapping programme, which backs up our regular inspections of wood on the docksides. has been reviewed and traps placed more strategically, where appropriate;
- we will continue to maintain awareness of the risk throughout the forestry industry.
In collaboration with Forest Research, a Contingency Plan has been drawn up to assist forest managers in dealing with this pest in the event it does become established here. The Plan has been distributed for comment to forest managers. The Plan is a Forestry Commission discussion document and contains information gathered from other published literature but not, at this stage, attributed to the original authors. The full version, when published, will be supported by appropriate literature references and acknowledgements.