Woodworm in window lintel

[pineapple]

Hello
Getting a bit of 'dust' falling down from two window lintels from what I had thought were old inactive infestations. Does this mean that every bit of wood in the house has to be treated or is it sufficient to treat only where you see activity?

 

[Burnerman]

The holes are where the creature has exited the timber, and bashing the lintel will always release some dust.
Treat where you see activity......it may only be the lintel that was infected, and was probably so when it was put in.
On occasion, you can see beetles on window sills, where they fly to the light.
What I have done in the past is to fill every exit hole I could find, and if more appear then things are obviously still live. Not so easy if you want to keep the lintel in its natural state!
Give the roof space and underfloor timbers a close inspection, and treat if in any doubt.
John