Phymatodes testaceus (commonly known as the tanbark borer, or the violet tanbark beetle)[1] is a transpalearctic polymorphic species of beetle in the subfamily Cerambycinae in the longhorn beetle family.

[2] The P. testaceus imago is typically 6–16 mm in length.

[3] Distribution of these beetle extends from the European Atlantic coastline to the Southern Ural Mountains, from southern Sweden and Norway to North Africa and Syria.

[3] Larvae develop in and under the bark of various deciduous tree species, causing damage.

The beetle's life cycle lasts one year in central and southern parts, and two years in northern climes.