This very small (~3 mm / .12") betle which looks like it is glowing from within is another one of those which Stanislav Snäll showed me during the Stockholm Entomological Society excursion to the Nackareservatet nature reserve.
The scientific name is Bitoma crenata and I believe there are two vernacular English names in "saddle-backed bitoma" as well as "crenate cylindrical bark beetle".
These guys live under the bark of dead trees and can be found in large parts of Europe and North America and the photo was taken at 3.9:1 magnification