Ash Bark Beetle

This piece of dead ash wood looks as if it has been used as a dart board.

But no.  These are the holes where adult Ash Bark Beetles (Leperisinus varius) have emerged, probably last summer.

When the bark is removed you can see the typical pattern of galleries tunnelled by the beetle grubs as they fed on the nutritious substances just under the bark.

The female beetle lays eggs in a horizontal line and the larvae tunnel either upwards or downwards, avoiding each other.