Megaplatypus mutatus is causing serious economic damage in part of its native range and in a limited outbreak area of southern Italy. It is predicted to establish in the Mediterranean basin but its potential to establish in temperate climates, including the UK, is much more limited. Poplar and several orchard trees attacked in Italy are widely grown in the UK. There is a low risk of economic damage should M. mutatus establish here. 

This rapid assessment shows: 

Risk of entry is very unlikely to unlikely with host plants for planting (Populus or fruit trees – Prunus, Malus, Pyrus, Corylus, Juglans), with round wood (Populus) and in wood packaging materials; and very unlikely with sawn wood and by natural spread. Movement of large host trees into the UK from Italy remains a concern. 

Risk of establishment is unlikely to moderately likely outdoors and very unlikely under protection. This is based on climatic modelling of the region at risk in Europe and comparison with the summer temperatures in Italy and at the southern limit to its distribution in Argentina. 

Uncertainty concerns the extent to which M. mutatus can extend its generation time under sub-optimal temperatures. There is also uncertainty over the rate of spread of M. mutatus, measured by direct observation of adult behaviour compared to monitoring of presence / absence in the outbreak area. 

Economic impact is assessed as small with the highest risk being to fruit trees and Populus grown commercially and for amenity.

 Endangered area is assumed to be confined to orchards and urban areas of southern England with the highest summer temperatures. 

Risk management Tree boring beetles are difficult to eradicate because they spend most of their life cycle in the host. Exclusion would be the most effective way of managing risk and infested hosts would need to be destroyed in the event of an outbreak. Large host trees from Italy pose the highest risk of entry. 

Uncertainty The climatic suitability of the UK is the principal uncertainty. The reliability of the climatic modelling undertaken by EPPO is affected by uncertainties concerning: (i) the minimum threshold of development, (ii) the number of degree days required to complete development, (iii) the ability of the species to take more than one year to complete its life cycle if the summer is not sufficiently hot and (iv) the southern limit to its distribution in Argentina.