I see the theme has strayed from insect vulnerability to mechanical strength, but I'm sure these things are all related, and thanks for the ideas.

Of all these, reversing growth sense (as in a gunstock post) appeals to me; insects disoriented in not finding the wood structure layout as it would be in nature.

It lead me on to think about twist of fibres and vascular tissue. Has anyone noted whether torsion changes due to drying always exist in the same sense (cw or ccw), and if so, could this relate to the coriolis effect? Do trees (for a given species) growing nearer the equator twist more than those near the poles?