Great Spruce Bark Beetle

The Great spruce bark beetle, native to northern mainland Eurasia, was first discovered in the UK in 1982 in Shropshire, England. 

It's unknown how the Great spruce bark beetle arrived in the UK, but its range across Eurasia has been increasing over the past 100 years. Today, it is well established in England and Wales as well as southern and central Scotland. Great spruce bark beetle is a pest of spruce trees, spruce are not native in the UK but are widely grown for timber, in particular, Sitka and Norway spruce. 

The adult female tunnels into the bark to lay its eggs. The hatched larvae then cause damage by feeding on the inner living bark layers. They can create large breeding galleries, which prevent the tree from transporting water and nutrients, weakening the tree and, in cases of a large infestation, killing the host. 

A characteristic symptom of this pest are resin tubes which are produced when the beetle tunnels into the bark to lay eggs. Profuse resinosis, granulated resin below the entry hole, and dieback of foliage may also be seen. Older infestations often show signs of woodpecker activity or isolated dead trees. 

For more information about Great spruce bark beetle, see the resources below.