Draft for consultation by 4th March 2025

This PRA was initiated to investigate risk after a German NPPO PRA rated the phytosanitary risk of this pest as high for all EU member states. Melittomma sericeum is not listed in the EU plant health legislation and is not recommended for regulation as a quarantine pest by EPPO, nor is it on the EPPO Alert List. 

The primary pathway of entry identified is timber which is rated as moderately likely with medium confidence, due to the known association of this beetle with the heart- and sapwood of trees and the high volume of trade of sawn hardwood from the USA. The pathway of wood packaging material was rated as unlikely with medium confidence. While both wood pathways experience high trade, they are subject to phytosanitary measures that would limit pest association. The remaining pathways of plants for planting and cut branches were both rated as very unlikely with high confidence, as trade in these commodities from North America is either prohibited or very low volume. 

Outdoor establishment is assessed as unlikely due to the difference between the pest’s native climate and the UK climate, and the limited presence of known hosts in the PRA area. However, confidence level is low due to a lack of data regarding host suitability and lifecycle requirements. Spread is rated as slow for both natural spread and via trade, with low confidence as there is limited data on spread capability and presence of pest in trade. 

If damage to UK tree species is similar to American chestnut, timber being produced would be degraded and cause significant commercial losses. However, this is doubtful as current impacts are limited to dead/decaying white oak logs and damage to UK hosts is thought to be unlikely. Economic impact is rated as small with low confidence, due to limited data on suitability of hosts. Similarly, environmental and social impacts are rated as small with medium confidence, as limited damage has been reported in the beetle’s current range. 

There is no suggested endangered area as M. sericeum is not expected to cause an unacceptable level of damage where it could establish. 

Whilst the pest is not present in the PRA area, continued exclusion is preferrable, due to the uncertainty over the susceptibility of tree species in the UK. Current import regulations for plants for planting, timber and wood packaging material are considered sufficient to limit the likelihood of introduction. 

If M. sericeum did enter the PRA area, measures for control would be similar to that of other wood-boring beetles, such as felling and removal of infested trees, and surveillance for adults. Other methods may include limiting fires and other causes of wounds/lesions that may be used as oviposition sites.