What to use to fill the small beetles holes after the external house wall is treated. Please tell me the product name and from where to buy.

As explained in our POWDERPOST BEETLE ARTICLE, exit holes represent locations where emerging adults have exited or left wood. Commonly these are the first "signs" people notice that anything is wrong in the first place. Following a thorough treatment with the right product, these holes shouldn't pose any problem in the future whether you choose to seal them up or leave them open. For many people, leaving them open is not an option; they just don't like the cosmetic look of small holes in their siding or wood floor and feel they must patch it up before applying a new stain, paint or finish.

More on filler for exit holes in siding