Heating the wood to 133 F throughout will kill the beetles, the larva, and the eggs. We need to do all three.
Heating to 100 F or so will not make the insects leave the wood as it takes time for the larva to make a hole to the surface and also to convert to a beetle...most of the time, the insect is in the wood making tunnels in a larva (worm) form and not as a beetle. So, the previous information about heating is totally incorrect for the wood inhabiting insects.
Because the larva are deep within the wood and professional treatments by exterminators are surface treatments basically, they are no effective for wood. The only chemical treatment for wood is fumigation with a dangerous gas (methyl bromide) which requires a special treating chamber or treating the entire home which is covered in a air-tight tent and takes three days at least, during which the occupants must stay away as the gas kills people too. Because the gas also destroys ozone, it is not environmentally friendly. The cost is very high indeed. One option for a stack of lumber is to take it to a port facility where they do have fumigation chambers, but the cost is very high.
The bottom line is to use reasonable steps to avoid getting the lyctid powderpost beetle in the first place , but if it still comes in (from contact with other infected lumber) then use heat. When using heat, the air is often 150 F or hotter so the wood gets heated to 133 F throughout.