found under a silver birch tree on the leucanthemum daisies, it has not moved for 24 hours even though it has rained almost all that time. Is it something which will attack the tree which is only 4 years old?
This is a long-horn beetle, I'm not 100% sure but I think it might be Rutpela maculata. The adults feed on flowers and its larva develop in the wood of trees which are decaying including Betula which fits with your description of it being near silver birch. The pattern on the wing cases can be very variable.
thank you for your fast response. Is it likely to be harmful to this young tree? there are dead trees nearby in a neighbours garden in which it may have hatched. I have kept it outside in a box overnight should I release it back into the garden?
Thanks for the confimation Episcophagus ,
I would release it as it won't kill the living tree, the larvae just develop in a tree that is already dead or decaying, I looked for some more information online and it has also been found on Ash, Cherry, Beech, Oak and Willow: