Sorry - I don't know - although that definitely looks like some kind of boring or burrowing insect damage. It might help somebody else to identify the problem and suggest a solution if you could tell us your location (roughly), what type of tree it is and the general condition of the tree (does it look stressed etc)
I have a quince tree which is always shedding bark (no insect damage though) but the tree itself is absolutely fine except for fruit scab in wet summers.
Heaven is ... sitting in the garden with a G&T and a cat while watching the sun go down
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I have a quince tree which is always shedding bark (no insect damage though) but the tree itself is absolutely fine except for fruit scab in wet summers.
In the sticks near Peterborough