An analysis of the risk to the countries of the European Union from a possible introduction of Bursaphelenchus xylophilus and its vectors in the genus Monochamus is performed by assembling relevant biological, climatic and commercial information. The risks presented by different trade pathways are assessed and phytosanitary measures to reduce the risks are proposed. The conclusion of the PRA, based on EPPO PRA guideline no. 1, is that these pests present a serious risk to European coniferous forests.

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The importance of wood ants (Formica rufa) in determining the community structure (defined as the relative abundance of component species) and small-scale distribution of carabids was examined in a mature Scots pine stand in the New Forest, southern England. Carabids and wood ants were sampled by pitfall trapping throughout the forest stand from March to September 1998. The abundance of individual carabid species were modelled using vegetation type (grass or bracken), litter depth and wood ant density as independent explanatory variables. Models were fitted using a maximum-likelihood method (GLIM v.3.77; Baker 1985) with the assumption of a Poisson distribution, using a log-link function. Areas of high wood ant density were characterised by low abundance and species richness of carabids and high percentage dominance by the most commonly sampled species, Abax parallelepipedus. The extent and type of vegetation cover was found to influence the distribution and abundance of certain carabid species but only in areas where the density of wood ants was low. Large-bodied species occurred more frequently in bracken-dominated patches where the litter layer was deeper and the density of potential prey items was higher. Wood ant density was found to be the most important determinant of carabid species abundance in the study site.

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The searching behaviour of A.confusus females was investigated in an artificial arena. Females showed an increase in the frequency of turning movements following feeding and this concentrated search in a small area. As a result more prey were found in areas where prey distribution was clumped. If no prey was encountered within 5–8 min the search track straightened out. First and second instar nymphs searching on broad bean plants moved faster on the undersides of leaves which were the sites most likely to support aphid populations. A considerable proportion of available time was wasted in periods of inactivity. It was concluded that while plant topography strongly influences search pattern, the underlying trend demonstrated in these experiments was of advantage to predators searching for colonial prey.