Pine tree lappet moth {Dendrolimus pini) in Scotland: Discovery, timber movement controls and assessment of risk

摘要

The pine-tree lappet moth Dendrolimus pini L. is a pest of pine forests across Europe but until recently was not known to be established in Britain. In 2009, we confirmed a small breeding population in pine plantations near Inverness. Populations have remained low since and are currently much lower than cause economic damage in Europe. Restrictions on timber movements appear to have been effective at preventing spread, but there are early signs of short-distance range expansion. DNA analysis of moths revealed the Scottish population belonged to the southern of three European lineages, and showed markedly lower diversity than a population in central Europe. Climate analyses predict a risk that with warming summers in eastern Scotland it will become increasingly favourable for damaging outbreaks. However, the impact of Scotland's unpredictable seasons and the role of potential predators and parasites are not understood. The Forestry Commission consider D. pini to be a potentially serious threat to Scotland's ancient Caledonian pinewoods and commercial forestry plantations, whereas some others suggest it to be a harmless, previously unrecorded, native component of our fauna. Opinions may be divided, but in the face of uncertainty over its origin and damage potential, an on-going precautionary approach is prudent.