Pine sawyer

( Latin: Monochamus sutor )

This beetle is widely distributed in the conifer forests of northern Europe. The development normally takes one year. The eggs are laid in a depression which the female gnaws in the bark and the larva eats its way from there into the wood. Metamorphosis into the adult beetle takes place in the following spring in a special pupal chamber close to the surface of the tree, and the beetle gnaws its way out through an almost circular hole. This species is regarded as a very serious pest in Sweden, where it causes damage to softwoods before they reach sawmills.

The trees are infested while still growing and the larvae are unable to live for long in worked timber so there is no risk of the infection spreading indoors.